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Alcacer-Almansa, Julia, Ahmad, Amin, Braeckmans, Kevin, Blanco-Cabra, Nuria, Sanchez, Samuel, Torrents, Eduard, Fraire, Juan C, (2026). Photothermally Induced Vapor Nanobubbles Enable Disruption and Antibiotic-Improved Responsiveness in Uropathogenic Biofilms AAPS PHARMSCITECH 27, 299
Treating bacterial biofilms remains a major clinical challenge, particularly in uropathogenic infections where the dense extracellular matrix impedes antibiotic access and protects tolerant bacterial populations. In this work, we explored a nanomaterial-based strategy to improve antibiotic responsiveness by combining iron oxide nanoparticles (IONPs) with pulsed laser irradiation to induce vapor nanobubble (VNB)-mediated disruption of a mature flow-grown uropathogenic E. coli CFT073 biofilm. We tested three nanoparticle sizes (70 nm, 130 nm, and 500 nm) and identified IONP500 as the most effective formulation for generating VNBs upon irradiation with 532 nm nanosecond laser pulses, with a VNB threshold of 0.56 J/cm2 per pulse. In the mature biofilm model, the combined IONP500 + ciprofloxacin + laser treatment significantly enhanced antibiotic activity compared with ciprofloxacin alone, increasing dead biomass from approximately 16% to 23%, corresponding to a 39-45% relative increase, as quantified by COMSTAT analysis and one-way ANOVA with Tukey's post-hoc test. The combined treatment also reduced total biofilm biomass and increased biofilm porosity by 55.8% compared with ciprofloxacin alone, supporting a mechanism based on VNB-mediated matrix disruption and improved antibiotic access. Overall, these results support the use of photothermally active, biocompatible IONPs as a promising complementary strategy to enhance the efficacy of conventional antibiotics against persistent biofilm-associated infections.
JTD Keywords: Cells, Ciprofloxacin potentiation, Iron oxide nanoparticles, Laser, Nanoparticles, Photoporation, Photothermal biofilm disruption, Prostate, Resistance, Transurethral resection, Uropathogenic biofilms, Vapor nanobubbles, Vaporization
Prado-Morales, Carles, Waaijman, Taco, Macias-Tarrio, Ines, Huck-Iriart, Cristian, Russo, Tiziana, Galvez-Savoca, Joel, Rodriguez-Emmenegger, Cesar, Koning, Jasper J, Sanchez, Samuel, (2026). Enhancing Human Skin Penetration with Biodegradable Enzymatic Nanomotors ACS Nano 20, 23013-23033
The skin is the body's primary biological barrier, largely due to the highly organized structure of the stratum corneum (SC). Although essential for protection, this barrier function limits the efficacy of transdermal drug delivery, as most topically applied compounds fail to reach deeper skin layers at therapeutically relevant concentrations. Existing approaches often rely on physical disruption of the barrier, which can cause undesirable side effects. Moreover, many prior studies have been conducted in murine models, which do not accurately recapitulate human skin physiology, hindering the translation to humans. Here, we present an alternative approach using enzymatically powered nanomotors tested in a human reconstructed skin model. We developed organic nanomotors composed of poly(lactic-co-glycolic acid) functionalized with urease, and we proved their biocompatibility and degradability. Our results show that nanomotors penetrate the skin with 15.7% efficacy, 2.5 times more than passive nanoparticle controls. This enhanced penetration is attributed to their active motion and their ability to induce alterations in the lipid organization of the SC, an effect confirmed by synchrotron radiation small-angle X-ray scattering and electron microscopy. These findings highlight the potential of enzymatic nanomotors as a nondisruptive and effective platform for future transdermal delivery in human skin, combining advantages of both chemical enhancers and nanoparticles.
JTD Keywords: Barrier function, Biological barrier, Burden, Disease, Human skin model, Insights, Molecular-organization, Nanobots, Nanomedicine, Nanomotors, Nanoparticles, Permeation enhancers, Plga, Skin, Skin penetration, Spectroscopy, Transdermal delivery
Sortino, Rosalba, Gonzalez-Diez, Aleix, Milla-Navarro, Santiago, Martinez-Tambella, Joaquin, Paleo-Garcia, Victor, Calatayud, Eric, de Saralegui, Paula, Opar, Ekin, Claparols, Alvar, Quintanilla, Josecarlo A, Martinez-Soler, Xavier, Riefolo, Fabio, Matera, Carlo, Hernando, Jordi, Gomila, Alexandre M J, Perez-Batlle, Gerard, Pereira, Carles, Camarero, Nuria, Serra, Carme, Gomez-Santacana, Xavier, Llebaria, Amadeu, Rovira, Xavier, de la Villa, Pedro, Gorostiza, Pau, (2026). Restoration of SaccadicEye Movements and VisuallyGuided Behavior in Ambient White Light with Photoswitchable SmallMolecules JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 148, 31701-31715
Blinding diseases due to the degeneration of photoreceptors (PhRs), such as geographic atrophy (GA) secondary to dry age-related macular degeneration and retinitis pigmentosa (RP), leave the rest of the retinal circuitry largely intact, albeit unable to respond to light. Gene therapy has been able to revert PhR degeneration, but it can be applied only to a rare mutation affecting a small subset of RP patients. Alternatively, implanted electronic retinal prostheses aim at a larger population by electrically stimulating surviving neurons. However, the treatment is invasive and costly and provides limited resolution. Photopharmacology can develop photoswitchable small molecules to restore vision impairment by conferring light sensitivity to ion channels that are widely expressed in the remaining inner retinal neurons, and a first-in-human clinical trial is ongoing. Here, we have developed novel photoswitchable small-molecule ligands of metabotropic glutamate 6 (mGlu6) receptors, which are located exclusively at the dendrites of ON bipolar cells (postsynaptic to PhRs) and can leverage a privileged position to mimic physiological signals in the remnant retinal circuit. These photoswitchable ligands (prosthe6) thus act as "molecular prostheses" that can restore the light input to the retina via upstream-targeted control of the circuit after PhR degeneration. Prosthe6 compounds are allosteric, drug-like, water-soluble, and display outstanding in vitro properties including full efficacy, nanomolar potency, fast deactivation in ambient white light, and fast reactivation in the dark. In vivo experiments show that they readily recover the saccadic eye movements of blinded zebrafish larvae and restore the innate light-avoidance behavior in the mouse models of blindness (GA and RP). These effects are mediated by mGlu6 receptors in vivo. In addition, at least two compounds (prosthe6-12 and -15) can restore sight by topical administration and display promising safety properties to become potential drug candidates for sight restoration in patients with degenerative blinding diseases.
JTD Keywords: Allosteric modulators, Bipolar cells, Blind mice, Ectopic expression, Gene-therapy, Human rod, Protein-coupled receptors, Restores visual responses, Retinal degeneration, Zebrafish models
Costa, AD, Stonkute, L, Trujillo, S, Oliva, MAG, Burton, F, Dalby, MJ, Dobre, O, Smith, G, Salmeron-Sanchez, M, (2026). Mechanical and Electrical Phenotype of hiPSC-Cardiomyocytes on Fibronectin-Based Hydrogels Advanced Healthcare Materials 15, e01595
A major challenge in cardiac research is the limited translatability of drug screening and toxicity assays due to the use of in vitro models that poorly mimic the native cardiac environment. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) offer a promising route forward, but conventional 2D culture on rigid substrates hinders their functional maturation and predictive accuracy. This study addresses this problem by investigating the effect of hybrid fibronectin-based hydrogels with tunable stiffness on the mechanical and electrical properties of hiPSC-CMs. We engineered hydrogels with stiffness mimicking the lowest range of neonatal heart tissue stiffness (2-4 kPa) and compared hiPSC-CM behavior on these substrates to that on standard fibronectin-coated glass. Our results demonstrate that hydrogel culture promotes more uniform and stable cardiomyocyte contractions, as evidenced by increased single peak percentages and altered contraction duration. Electrophysiological analysis revealed that hydrogel stiffness influences action potential duration and signal amplitude. Furthermore, hiPSC-CMs on hydrogels exhibited enhanced cell-matrix and cell-cell adhesion, indicating improved structural and functional connectivity. Drug testing with known cardioactive compounds, including isoproterenol and nifedipine, revealed distinct differences in drug responses between hydrogel and glass cultures, suggesting that hydrogels provide a more physiologically relevant platform for assessing drug effects. This work highlights the potential of engineered hydrogel substrates to enhance the functional maturity and predictive accuracy of hiPSC-CMs for cardiac research and drug development.
JTD Keywords: Action potentials, Beat, Cell adhesion, Cell differentiation, Cells, Cells, cultured, Contraction, Fibronectins, Guinea-pig, Humans, Hydrogels, Induced pluripotent stem cells, Ipsc-cardiomyocytes, Ipsc‐cardiomyocytes, Isoproterenol, Maturation, Mechanical properties, Myocytes, cardiac, Nifedipine, Phenotype, Platform, Sensitive dye di-4-anepps
Kasuba, Krishna Chaitanya, Flaschner, Gotthold, Jain, Akanksha, Krieg, Michael, Sharma, Upnishad, Gensbittel, Valentin, Nava, Michele M, Camacho Rufino, Miguel, Treutlein, Barbara, Liberali, Prisca, Trepat, Xavier, Julicher, Frank, Piel, Matthieu, Iber, Dagmar, Lutolf, Matthias P, Roska, Botond, Vassalli, Massimo, Muller, Daniel J, (2026). Advancing mechanobiology from single molecules to complex cellular systems Nature Nanotechnology 21, 761-771
Cells operate as networks of proteins, membranes, condensates and compartments, each sensing and displaying distinct intracellular mechanical properties. However, cells also sense, adapt and respond to manifold mechanical properties of the environment, including adhesion, tension, stiffness, shear, viscoelasticity, plasticity, pressure and confinement. By gauging these properties at various timescales and across nano to macro length scales, cellular systems alter their collective responses. The field of mechanobiology aims to elucidate how cellular systems such as tissues, organoids or organs perceive, respond to and influence mechanical cues, and how these impact physiological processes including homeostasis, growth, division, differentiation, movement, development, adaptation and apoptosis. This Perspective highlights challenges within mechanobiology that must be systematically tackled to advance exploration and deepen our understanding of the mechanical attributes of intricate multicellular organisms. Such understanding necessitates the engineering of multicellular models as reference systems, the development of new tools to rigorously quantify and manipulate mechanical properties from the nanoscale to macroscale and theoretical frameworks to decode mechanobiological complexities. Ultimately, addressing these challenges will improve the analysis, monitoring and prediction of mechanobiological processes across molecular, multicellular and organismal scales, thus advancing mechanodiagnostics and mechanomedicine.
JTD Keywords: Force microscopy, Migration, Stem-cell, Tension, Yap
Lele, Mukta, Manchare, Ajit, Parit, Swapnali, Gholap, Amol D, Jadhav, Krishna, Hatvate, Navnath, Paudel, Keshav Raj, Rojekar, Satish, (2026). Unveiling the Power of Deuterium in Drug Discovery: A Comprehensive Overview MedComm 7, e70799
Deuterium, the heavy isotope of hydrogen, has unfolded as a cornerstone in modern drug discovery due to its potential to influence metabolic stability and pharmacokinetic behavior. The deuterium kinetic isotope effect (KIE), which strengthens carbon-deuterium bonds, make it possible to improve therapeutic efficacy while maintaining pharmacological activity. Although some deuterated drugs, notably donafenib and deutetrabenazine, have demonstrated clinically significant efficacy, their limited use is an effect of ongoing challenges with metabolic switching and species-specific variation, as well as inadequate mechanistic understanding. This review presents a systematic discussion of the recent innovations in site-selective deuteration, the principles that underpin the KIE process, and the effects of deuterium substitution on drug metabolism, toxicity, and blood-brain barrier penetration. It illustrates novel implications in oncology, rare diseases, and central nervous system disorders, as well as the integration of deuterated chemistry with modalities such as proteolysis-targeting chimaeras, peptides, and nucleic acid therapeutics. Furthermore, the review's discussion includes the current challenges, synthesis, analytical limits, and regulatory considerations that influence further development. Overall, the review offers a strategic roadmap for utilizing deuterium-enabled molecular engineering to accelerate the development of next-generation precision medicine, guiding rational design, innovation toward safer, longer-lasting, and more effective treatments.
JTD Keywords: Deucravacitinib, Deuterated drugs, Deuteration, Deuterium, Deutetrabenazine, Double-blind, Drug metabolism, Internal standard, Isotope, Labeled compounds, Mass-spectrometry, Medicinal chemistry, Metabolism, Pharmacokinetic properties, Site
Jacques, Cecile, Perrin, Louisiane, Ackermann, Joseph, Bell, Samuel, Zajac, Olivier, Lapierre, Ambre, Anger, Lucas, Hallopeau, Clement, Perez-Gonzalez, Carlos, Balasubramaniam, Lakshmi, Trepat, Xavier, Ladoux, Benoit, Maitra, Ananyo, Voituriez, Raphael, Vignjevic, Danijela Matic, (2026). Fibronectin matrix remodelling modulates the active nematic dynamics of cancer-associated fibroblasts NATURE MATERIALS 25, 1446-1457
Cancer-associated fibroblasts are major architects of the tumour stroma, where their aligned, elongated morphology forms a capsule that mechanically restrains tumour expansion. However, it is unclear how this supracellular organization emerges and persists. Here we show that fibroblasts generate a fibronectin matrix that progressively acquires the same nematic order as the cell layer, and that this matrix in turn feeds back to immobilize both cells and topological defects. Using long-term live imaging, traction force microscopy, matrix microfabrication and hydrodynamic modelling, we find that this reciprocal coupling induces an ageing process in which cellular flows and defect motion slow dramatically and ultimately freeze. Despite this arrest, the monolayer remains active, with defects concentrating contractile forces that may represent mechanical weak points. Disrupting fibronectin production fluidizes the capsule, reactivates defect dynamics and compromises its barrier-like function. These findings reveal a self-organizing mechanism by which fibroblasts and their matrix co-evolve to create a mechanically stable, yet active, stromal architecture with direct implications for tumour dissemination.
JTD Keywords: Cell-migration, Stress, Topological defects
Lodoso-Torrecilla, Irene, Moreno, Daniel, Ciucci, Gael, Mateu-Sanz, Miguel, Yoon, Ji-Young, Jimenez-Pique, Emilio, Franch, Jordi, Manzanares, Maria-Cristina, Konka, Joanna, Espanol, Montserrat, Ginebra, Maria-Pau, (2026). Strontium and gallium doping enhances in vivo bone regeneration in biomimetic hydroxyapatite 3D-printed scaffolds MATERIALS TODAY BIO 38, 103131
Doping of calcium phosphates (CaPs) with bioinorganic ions is a widely used strategy to enhance their biological performance in bone regeneration. However, conventional methods for ionic incorporation in CaP scaffolds often require high-temperature treatments or involve multiple complex steps. Here, we present two simple strategies to dope 3D-printed CaP scaffolds via incorporation of ions into the apatitic phase during the hydrolysis of alpha-tricalcium phosphate (alpha-TCP) to calcium deficient hydroxyapatite (CDHA). In the first strategy, ions were incorporated directly into the printing ink, whereas in the second, undoped robocasted scaffolds were immersed in ionic solutions, allowing ion incorporation into precipitated CDHA during phase transformation. We investigated several ions, including strontium (Sr2+), magnesium (Mg2+), silicon (SiO44- ) and gallium (Ga3+). Sr2+ and Ga3+ were successfully incorporated into the scaffolds, either by direct ink doping (Sr2+) or by soaking in ionic solutions (Sr2+ and Ga3+). Direct incorporation of Sr2+ in the ink resulted in a higher ion loading and release, enhancing bone formation and bone quality, as evidenced by increased mineral-to-matrix ratio and Young's modulus, as well as osteoinductive properties relative to non-doped scaffolds. Furthermore, we demonstrated for the first time the osteoinductive capacity of Ga3+ in an ectopic in vivo model.
JTD Keywords: 3d printing, Apatite, Biomimetic hydroxyapatite, Bone regeneration, Calcium phosphates, Calcium-phosphate cement, Differentiation, Ion doping, Magnesium-deficiency, Microporosity, Nanocrystals, Osteoinduction, Scaffold, Silicon, Substituted hydroxyapatite, Vitro
Cancilla, Francesco, Palumbo, Fabio Salvatore, Fiorica, Calogero, Pitarresi, Giovanna, Perez-Madrigal, Maria M, Aleman, Carlos, Resina, Leonor, (2026). Multiresponsive Glutathione-Functionalized Waterborne Polyurethane/PEDOT System for Electrically and Redox-Controlled Delivery of an Anticancer Peptide ACS Applied Polymer Materials 8, 8479-8494
Prostate cancer remains one of the leading causes of cancer-related mortality. Although there were advances in cancer therapy, there is a need for advanced drug delivery strategies to improve the spatiotemporal control of therapeutic action. Here, we developed conductive, redox-responsive hybrid sponges based on glutathione-extended waterborne polyurethane (WPU-GSSG) and the electroactive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) for dual-stimuli-triggered release of anticancer peptide in locoregional tumor therapy. WPU/PEDOT porous scaffolds presented lightweight and mechanically resilient structures with homogeneous loading of the pentapeptide Cys-Arg-N-methyl-Glu-Lys-Ala (CR(NMe)EKA). PEDOT incorporation significantly enhanced the electrochemical properties of the sponges, providing reversible redox activity, reduced impedance, and near-ideal capacitive behavior. The sponges supported cell adhesion and high cell viability within the three-dimensional architecture. In vitro release studies demonstrated that peptide delivery is regulated by a synergistic combination of redox and electrical stimuli. A mimetic tumor microenvironment accelerated peptide release relative to physiological conditions. Electrostimulation (+0.5 V chronoamperometry) further enhanced release kinetics, and the combined application of redox and electrical triggers enabled peptide release of up to similar to 94%, demonstrating tunable stimulus-responsive delivery. Functional assays on cancer cells supported the therapeutic potential of this platform. While WPU alone was fully cytocompatible and PEDOT-containing sponges exhibited moderate electrostimulation-dependent effects, CR(NMe)EKA-loaded conductive sponges induced a pronounced reduction in cancer cell viability under electrostimulation, decreasing survival to similar to 20%. Although further in vivo validation is required, these findings highlight the potential of multifunctional WPU/PEDOT sponges for localized, stimuli-responsive peptide delivery.
JTD Keywords: Cancer, Cell-line, Citrate transport, Design, Electrostimulation, Locoregional drugdelivery, Nanoparticle, Pedot, Ph, Polyurethane, Porosity, Prostate cancer, Redox, Scaffolds
Arca-Garcia, Carla, Godoy-Gallardo, Maria, Ginebra, Maria-Pau, (2026). Tailoring nanotopography and antibacterial properties of calcium phosphate bone grafts via fluoride incorporation Bioactive Materials 59, 205-223
Despite advances in bone graft design and surgical techniques, bacterial infection remains a major cause of graft failure, exacerbated by the global rise in antimicrobial resistance. This has intensified the pursuit of antibioticfree strategies to prevent bacterial colonization. Among these, antibacterial surface nanotopographies have emerged as promising tools, leveraging nanoscale geometries to physically disrupt bacteria upon contact. In this study, we engineered the surface of a calcium phosphate bone graft to confer antimicrobial functionality through a dual approach: the creation of high-aspect-ratio nanotopographies and ionic doping with fluoride. Through controlled hydrolysis of alpha-tricalcium phosphate by biomimetic and hydrothermal treatments, we generated calcium deficient hydroxyapatite nanoneedle structures whose morphology and biofunctionality were tuned via fluoride incorporation. XRD and Raman spectroscopy confirmed the formation of hydroxy-fluorapatite, with phase composition and surface morphology dependent on fluoride concentration and processing parameters. Fluoride doping significantly altered nanoneedle dimensions and spacing and enhanced bactericidal activity, particularly against P. aeruginosa, and to a lesser extent S. aureus. Notably, fluoride-doping alone showed no antibacterial effects; however, when combined with nanotopography, a synergistic increase in efficacy was observed. Importantly, the antimicrobial surfaces supported the proliferation and osteogenic differentiation of SaOS-2 cells. Co-culture assays modeling pre- and post-implantation infection scenarios demonstrated robust cell adhesion and markedly reduced bacterial colonization. In conclusion, our findings present a multifunctional, synthetic bone graft with both physical and chemical antibacterial properties, offering a promising strategy to mitigate infection risks while supporting osteointegration.
JTD Keywords: Antibacterial nanotopography, Bactericidal surfaces, Biomaterials, Bone regeneration, Calcium phosphate, Cements, Coatings, Cytokines, Fluoride, Hydroxyapatite, Infections, Magnesium, Pseudomonas-aeruginosa, Setting reaction
Akther, S, Lee, AB, Konno, A, Asiminas, A, Vittani, M, Mishima, T, Hirai, H, Meehan, CF, Duran, J, Guinovart, J, Ashida, H, Morita, T, Baba, O, Shigemoto, R, Nedergaard, M, Hirase, H, (2026). Distribution and functional significance of rodent cerebellar glycogen iScience 29, 115192
The mammalian brain stores glucose, the main circulating energy substrate, as glycogen. In rodents, the cer-ebellum contains relatively high glycogen levels, yet its cellular and subcellular distribution remains poorly defined. Using monoclonal antibodies against glycogen, we examined its distribution in the mouse cerebellar cortex. Glycogen was predominantly localized to Bergmann glia (BG) processes in the molecular layer and was also detected in Purkinje cells (PCs), the principal cerebellar neurons. To assess the functional signifi-cance of cerebellar glycogen, we analyzed behavior in mice lacking glycogen synthase 1 (Gys1) in BG or PCs using a floxed Gys1 line. Gys1 deficiency in either PCs or GFAP-positive cells reduced anxiety-like behavior, whereas combined deletion caused PC degeneration and ataxia. These findings reveal a critical role for glycogen metabolism in both astrocytes and neurons in cerebellar function.
JTD Keywords: Astrocytes, Expression, Glucose, Inflammation, Inhibition, Lactate, Metabolism, Purkinje-cells, Rat, Zebrin-ii
Nettleton, David F, Naveira-Souto, Iria, Rosell-Vives, Elisabet, Cruz-Conesa, Andres, Alsina, Roger Fabrega, Poch, Alexandra, (2026). Process Simulation of a Microfluidic Micromixer for Pharmaceutical Production of DNA-Lipid Nanoparticles Processes 14, 1203
Background/Objectives: The question addressed in the current work is to develop a simulation of a pharmaceutical process (DNA encapsulation within lipid nanoparticles using a microfluidic micromixer) which will be of utility to the end users (laboratory-scale formulation development). The simulation and the microfluidic approach also address sustainability issues, such as reducing the environmental impact of the process itself, and reducing the need for physical testing. The paper details the implementation and validation, taking into account key performance indicators and control parameters. Methods: The main method applied for simulation development is a novel multi-agent approach to incorporate stochastic probabilistic behavior, combined with theoretical definitions from the process experts and relevant literature, and data/results from laboratory-scale experiments with different parameter configurations. Results: The simulation was implemented as a representation of the real physical process, reproducing the relationships between process parameters (flow rates) and experimental key performance indicators (capsule diameter, poly dispersion index, encapsulation efficiency). The simulation results demonstrated a general agreement with the empirical results and provided useful predictive insights for the laboratory experiments. Conclusions: The simulation has potential as a support tool for laboratory experiments to reduce physical testing and indicate the most promising configurations on which to focus, with potential savings in time, resources and other costs.
JTD Keywords: Calibration, Encapsulation, Lipid nanoparticles, Microfluidics, Micromixer, Multi-agents, Optimization, Process simulation, Sustainability
López-Sampere, Y, Soler, PM, Roca-Pereira, S, Vinyals, A, Mato-Blanco, X, Vela-Martínez, M, Dakterzada, F, Romero, L, Santamaría, E, Fernández-Irigoyen, J, Ferrer, I, Povedano, M, Del Rio, JA, Santpere, G, Portero-Otín, M, Piñol-Ripoll, G, Andrés-Benito, P, (2026). NRF2 deficit prevents pathologic Tau seeding and spreading in an induced tauopathy mouse model Redox Biology 91, 104068
Background: Nuclear factor erythroid 2-related factor 2 (NRF2) regulates antioxidant defenses and protects against neurodegeneration, including Alzheimer's disease (AD). Its age-related decline disrupts redox balance and increases neuronal vulnerability, but the early hippocampal effects remain unclear. Here, we tested whether NRF2 loss affects tau seeding and spreading in a PHF-tau-inoculated mouse model, contributing to accelerated aging. Methodology: Three-month-old NRF2-knockout (Nfe2l2-/-) and wild-type (WT) mice received hippocampal inoculations of human AD-derived PHF-tau, and tau propagation was analyzed after three months. To elucidate the molecular underpinnings of the observed changes, we performed integrative phosphoproteotranscriptomic analyses of hippocampal tissue, supported by RT-qPCR and Western blot validation. Results: PHF-tau inoculation at 3 months of age in Nfe2l2-/- mice, surprisingly, exhibited markedly reduced tau seeding and spreading compared to WT after 3 months of incubation. Molecular characterization of the Nfe2l2-/- hippocampus was carried out to unravel the molecular changes associated with impaired tau propagation. Transcriptomic profiling revealed 745 deregulated genes in Nfe2l2-/- mice, characterized by upregulation of immune and metabolic pathways but downregulation of oxidative stress and redox-related genes. RT-qPCR confirmed diminished expression of antioxidant enzymes and anti-inflammatory receptors, alongside altered astrocytic markers. Proteomic analysis identified 157 dysregulated proteins associated with mitochondrial, synaptic, and inflammatory processes, while phosphoproteomics detected 824 altered phosphosites enriched in cytoskeletal and synaptic networks. Western blot showed increased GFAP-C-term, AQP4, 8-OHdG, and MDAL, with reduced GSTM2 expression. Notably, total and 4R-tau levels were decreased, while 3R-tau was elevated in Nfe2l2-/- mice. Conclusion: Our findings suggest that NRF2 loss induces a hippocampal state marked by impaired antioxidant defenses, astrocytic remodeling, and disrupted tau isoform balance. This environment, while metabolically altered, paradoxically hinders tau propagation, highlighting NRF2 as a key regulator of both redox and cellular maturity programs essential for tau spread and as a potential therapeutic target in tauopathies.
JTD Keywords: Aging, Alzheimer's disease, Brain, Disease progression, Expression, Fibrillary acidic protein, Inflammation, Mutations, Nrf2, Oxidative stress, Rat, Receptor, Tau, Transgenic mice
Fallica, Antonino N, Barbaraci, Carla, Ruiz-cantero, M Carmen, Scarlatti, Arianna, Coco, Alessandro, Giordano, Giorgia, La Mantia, Alfonsina, Prezzavento, Orazio, Di Stefano, Antonio, Cacciatore, Ivana, Siano, Giacomo, Cattaneo, Antonino, Pasquinucci, Lorella, Cobos, Enrique J, Di Primio, Cristina, Amata, Emanuele, Marrazzo, Agostino, (2026). Modulation of Tau Protein Neurotoxic Hallmarks by Novel σ1R Agonists/HDAC Inhibitor Dual-Acting Compounds ChemMedChem 21, e202500922
Neurodegenerative diseases, like Alzheimer's disease (AD), are characterized by the accumulation of tau aggregates, leading to neuronal dysfunction and cognitive decline. This study explores the development of dual-acting compounds combining sigma-1 receptor (sigma R-1) agonists and histone deacetylase inhibitors (HDACi) to target these pathological mechanisms. Compounds 2d and 3a demonstrated high affinity for sigma R-1 and significantly reduced tau aggregation and phosphorylation in vitro, notably at the AT8 epitope. These dual-acting compounds destabilized tau aggregates, increased tau solubility, and showed favorable pharmacokinetic properties, with compound 2d exhibiting enhanced chemical stability and longer half-life than 3a. In vivo, both compounds confirmed a sigma R-1 agonist profile by reversing the effect of the sigma R-1 antagonist BD-1063. This dual-action approach, acting on both HDAC and sigma R-1 pathways, holds significant potential for treating tauopathies. While further optimization and clinical evaluation are needed, these findings provide a strong foundation for the continued development of multimodal therapies for neurodegenerative diseases treatment.
JTD Keywords: Alzheimers, Amyloid-beta, Anavex2-73, Dual-acting compounds, Hdac inhibitors, Histone deacetylase, Ligands, Neurodegenerative diseases, Neuroprotection, Pathogenesis, Phenylbutyrate, Phenylbutyric acid, Phosphorylation, Sigma 1r agonists, Sigma receptors (sigma rs), Sigma(1) receptors, Tau protein, Valproic acid
Haro-Martínez, E, Muscolino, E, Moral, N, Duran, J, Fornaguera, C, (2026). Crossing the blood-brain barrier: nanoparticle-based strategies for neurodegenerative disease therapy Drug Delivery and Translational Research 16, 797-824
Neurodegenerative conditions, including Alzheimer's, Parkinson's, amyotrophic lateral sclerosis, and Huntington's disease, represent a critical medical challenge due to their increasing prevalence, severe consequences, and absence of curative treatments. Beyond the need for a deeper understanding of the fundamental mechanisms underlying neurodegeneration, the development of effective treatments is hindered by the blood-brain barrier, which poses a major obstacle to delivering therapeutic agents to the central nervous system. This review provides a comprehensive analysis of the current landscape of nanoparticle-based strategies to overcome the blood-brain barrier and enhance drug delivery for the treatment of neurodegenerative diseases. The nanocarriers reviewed in this work encompass a diverse array of nanoparticles, including polymeric nanoparticles (e.g. micelles and dendrimers), inorganic nanoparticles (e.g. superparamagentic iron oxide nanoparticles, mesoporous silica nanoparticles, gold nanoparticles, selenium and cerium oxide nanoparticles), lipid nanoparticles (e.g. liposomes, solid lipid nanoparticles, nanoemulsions), as well as quantum dots, protein nanoparticles, and hybrid nanocarriers. By examining recent advancements and highlighting future research directions, we aim to shed light on the promising role of nanomedicine in addressing the unmet therapeutic needs of these diseases.Graphical AbstractSchematic representation of the different types of nanoparticles used to tackle neurodegeneration.
JTD Keywords: Blood-brain barrier, Central nervous system deliver, Central-nervous-system, Drug-delivery, Gold nanoparticles, In-vitro, Messenger-rn, Nanocapsules promotes, Nanomedicines, Neurodegenerative diseases, Oxide nanoparticles, Polymeric nanoparticles, Receptors targeting, Solid lipid nanoparticles, Targeted delivery
Mateu-Sanz, M, Varela, P, del-Mazo-Barbara, L, Lodoso-Torrecilla, I, Jimenez-Pique, E, Franch, J, Alaminos, M, Ginebra, MP, (2026). Mechanically Tunable Bone Scaffolds: In Vivo Hardening of 3D-Printed Calcium Phosphate/Polycaprolactone Inks ADVANCED FUNCTIONAL MATERIALS 36, e09357
Calcium phosphate 3D printing has revolutionized customized bone grafting. However, its inherent fragility limits clinical applicability. In this work, this problem is overcome by designing a composite scaffold able to harden in vivo. An alpha-tricalcium phosphate/polycaprolactone scaffold is developed that is ductile and tough when freshly printed and undergoes a transformation to hydroxyapatite following implantation in the body, resulting in its hardening. The hardening reaction, that takes place under physiological conditions and its impact on the biological response and osteogenic capacity of the material are investigated, both in vitro and in vivo, by comparing the in vivo hardening scaffolds with 3D printed hydroxyapatite and hydroxyapatite/polycaprolactone counterparts. In vitro results confirm the bioactivity, osteogenicity, and immunomodulatory potential of the polycaprolactone-based scaffolds. MG-63 cells increase the expression of osteogenic markers, while a downregulation of proinflammatory cytokines is observed in RAW246.7 cells. In vivo evaluation in a rabbit model confirms progressive bone infiltration and maturation, while osteoclast-mediated scaffold degradation is observed, being gradually resorbed and replaced by newly formed bone. Overall, in vivo hardening alpha-tricalcium phosphate/polycaprolactone scaffolds achieve mechanical properties comparable to human trabecular bone while retaining the biocompatibility and osteogenic potential of biomimetic hydroxyapatite.
JTD Keywords: 3d printing, Biomaterials, Bone regeneration, Bone tissue engineering, Cells, Hydroxyapatite, Macrophages, Polarization, Regeneration, Size, Synthetic bone graft
Lerche, Martina, Mathieu, Mathilde, Hamidi, Hellyeh, Chastney, Megan, Jacquemet, Guillaume, Bruininks, Bart Marlon Herwig, Kaptan, Shreyas, Malerod, Lene, Pedersen, Nina Marie, Brech, Andreas, Matoba, Nobuyuki, Sato, Yuichiro, Vattulainen, Ilpo, Roca-Cusachs, Pere, Perez, Franck, Boncompain, Gaelle, Miserey, Stephanie, Ivaska, Johanna, (2026). Regulation of cell dynamics by rapid integrin transport through the biosynthetic pathway JOURNAL OF CELL BIOLOGY 225, e202508155
Constitutive integrin endocytosis and recycling control cell movement and morphology. In contrast, the role of newly synthesized integrins delivered via the biosynthetic pathway has been largely overlooked. We used the retention using selective hooks system to monitor the localization of new integrins exiting the endoplasmic reticulum in space and time. We discovered that new integrin delivery to the plasma membrane is polarized and enhances cell protrusion and focal adhesion growth in an extracellular matrix-ligand-dependent manner. Motor-clutch modeling explained the increased adhesion as higher integrin availability driving recruitment of additional receptors. Unexpectedly, live-cell imaging revealed a small subset of fast-emerging integrin vesicles rapidly transported to the cell surface to facilitate localized spreading. This unconventional secretion depended on cell adhesion and correlated with increased surface levels of immature, high-mannose glycosylated integrin, indicating bypass of the canonical Golgi-dependent secretory pathway. Thus, spatial plasma membrane-targeting of new integrins rapidly alters adhesion receptor availability, providing cells with added plasticity to respond to their environment.
JTD Keywords: Adhesion dynamics, Alpha-5-beta-1 integrin, Endocytosis, Essential roles, Migration, Molecular-dynamics, Talin, Trafficking, Transmission, Unconventional secretion
Ghanavati, S, Opar, E, Gobbo, VA, Matera, C, Riefolo, F, Castagna, R, Colombelli, J, Draganski, A, Baggott, J, Lastusaari, M, Gorostiza, P, Petit, L, Massera, J, (2026). Novel 3D-Printed Biophotonic Scaffold Displaying Luminescence under Near-Infrared Light for Photopharmacological Activation and Biological Signaling Compound Release Advanced Healthcare Materials 15, e02163
Despite significant efforts in developing novel biomaterials to regenerate tissue, only a few of them have successfully reached clinical use. It has become clear that the next generation of biomaterials must be multifunctional. Smart biomaterials can respond to environmental or external stimuli, interact in a spatial-temporal manner, and trigger specific tissue/organism responses. In this study, the fabrication of novel 3D-printed and bioresorbable scaffolds, with embedded crystals that can convert near-infrared (NIR) light into visible light, is presented. It is demonstrated that these biophotonic scaffolds are not only bioactive and bioresorbable, but can also be promising as a platform for the controlled release or activation of photoactivated drugs locally and on demand, under illumination. The scaffolds are analyzed based on their up-conversion spectroscopic properties and their chemical stability in simulated body fluid. Furthermore, it is demonstrated that the up-conversion properties of the scaffolds are sufficient to release the signaling molecule nitric oxide (NO) and to photoisomerize the muscarinic ligand Phthalimide-Azo-Iperoxo (PAI), in a controlled manner, upon NIR light stimulus. Finally, to assess their biocompatibility for potential implantation, a preliminary study is conducted with human adipose stem cells cultured in contact with scaffolds. Live/dead assays, morphological analysis, CyQUANT analysis, and ion release measurements confirm that, despite some release of the upconverter crystals, the biophotonic materia and its dissolution by-products, are biocompatible. These findings highlight the potential of these bioresorbable biophotonic scaffolds for localized drug release in response to NIR light stimuli.
JTD Keywords: 45s, 45s5, Bioactive glass scaffolds, Borate, Bulk, Drug targeting, Implants, Luminescence, Nitric oxide, Optopharmacology, Photopharmacology, Phototherapeutic window, Silicate, System, Upconversio, Upconversion
Garcia-de-Albeniz, N, Müller, DW, Mücklich, F, Ginebra, MP, Jiménez-Piqué, E, Mas-Moruno, C, (2026). Multiscale hierarchical surface structuring of zirconia using femtosecond laser and chemical etching: implications for cell response and antibacterial performance MATERIALS TODAY BIO 36, 102648
This study investigates a novel strategy combining ultrashort pulsed-direct laser interference patterning (USPDLIP) and chemical etching to create hierarchically micro- and nanorough topographies on zirconia with improved cell-instructive and antibacterial properties. Linear (L3) and grid (G3) micropatterns of 3 mu m periodicity were fabricated via USP-DLIP, and subsequently treated with hydrofluoric acid to introduce an additional homogeneous nanotopography across the patterns. The individual and combined effects of micropatterning and etching on biological responses were evaluated using human mesenchymal stem cells (hMSCs) and two bacterial strains (Pseudomonas aeruginosa and Staphylococcus aureus) in mono- and co-culture settings. Micropatterns primarily guided cell morphology, alignment, and migration, while the introduced nanotopography enhanced focal adhesion formation and modulated cell-surface interactions. Antibacterial effects were found to be topography- and species-specific: micropatterns restricted P. aeruginosa colonization through a bacterial confinement mechanism, whereas etching-induced nanotopography effectively reduced S. aureus adhesion by limiting contact points. In co-culture assays, hMSC survival depended on a complex interplay between cell spreading and bacterial retention, dictated by surface features. Notably, chemical etching improved the antibacterial potential of the patterns against S. aureus, but it did not result in a synergistic improvement on cellular responses. Indeed, among all tested surfaces, the non-etched linear pattern (L3) consistently exhibited the most favorable outcomes -enhancing hMSC adhesion, migration, and osteogenic differentiation and mineralization, while reducing bacterial colonization and supporting cell survival under infection-like co-culture conditions.
JTD Keywords: Antibacterial, Bacterial adhesion, Biofilm formation, Chemical etching, Dental implants, Differentiation, Energy, Growth, Laser patterning, Migration, Nanotopography, Osseointegration, Osteointegration, Titanium, Topography, Zirconia
Barmin, RA, Moosavifar, M, Rama, E, Blöck, J, Rix, A, Petrovskii, VS, Gumerov, RA, Köhler, J, Pohl, M, Bastard, C, Rütten, S, Charlton, L, Khiêm, VN, Domenici, F, Lisson, T, Savina, E, Zhang, R, Baier, J, Koletnik, S, Koutsos, V, Itskov, M, Paradossi, G, Schmitz, G, Vermonden, T, De Laporte, L, Göstl, R, Herrmann, A, Potemkin, II, Kiessling, F, Lammers, T, Pallares, RM, (2026). Microbubble Shell Stiffness Engineering Enhances Ultrasound Imaging, Drug Delivery, and Sonoporation ADVANCED MATERIALS 38, e07655
Microbubbles (MB) are widely used as contrast agents for ultrasound (US) imaging and US-enhanced drug delivery. While the majority of studies utilize commercial MB formulations, increasing experimental evidence indicates that distinct MB features critically determine their diagnostic and therapeutic performance. Here, it is shown that shell stiffness engineering of poly(alkyl cyanoacrylate) (PACA) MB, via introducing monomers with varying alkyl chain lengths and glass transition temperatures, preserves a narrow size distribution approximate to 2-3 mu m, while enhancing MB drug loading, in vitro sonoporation capability, and in vitro and in vivo acoustic responses. All-atom molecular dynamics simulations and spectroscopic experiments demonstrate that MB shell engineering increases drug diffusion rates in the shell, maximizing the loading capacity of the formulations. Atomic force microscopy demonstrates that the stiffness of the MB shell can be tailored by more than ten-fold, boosting sonoporation and imaging performance. Altogether, the work provides new insights into the control of polymeric MB structure and performance via dedicated shell engineering, promoting applications in US imaging and therapy.
JTD Keywords: Alkyl cyanoacrylate, Blood-brain-barrier, Br55, Cavitation, Cyanoacrylate microbubbles, Drug delivery, Dynamics, Focused ultrasound, Microbubbles, Polymeric microbubbles, Sonoporation, Term, Therapy, Ultrasound
Zimkowska, Karolina, Riu-Villanueva, Marc, del Rio, Jose A, (2026). Neuromechanobiology: Bridging Mechanobiology and Neuroscience Through Evidence and Open Questions Cells 15, 178
Neuromechanobiology has emerged as a multidisciplinary field at the interface of neuroscience and mechanobiology, aiming to elucidate how mechanical forces influence the development, organization, and function of the nervous system. This review offers a comprehensive overview of the historical evolution of the discipline, its molecular and biophysical foundations, and the experimental strategies employed to investigate it. Recent advances have revealed the pivotal roles of substrate stiffness, mechanical signaling, and force transduction in neural stem proliferation, axon guidance, synapse formation, and neural circuit maturation. All these effects originate at the molecular level and extend to the mesoscopic scale. Disrupted mechanotransduction has been increasingly implicated in neurodevelopmental disorders and neurodegenerative diseases, underscoring its clinical relevance. Key unresolved questions and future directions are also highlighted, with emphasis on the need for integrative approaches to decipher the complex interplay between mechanical forces and neural function.
JTD Keywords: Axon guidance, Brain development, Central-nervous-system, Contact inhibition, Force transmission, Hippo pathway, Human brain-development, Mechanical forces, Mechanical-properties, Mechanotransduction, Neural migration and regional specification, Neuromechanobiology, Patterned neural-tube, Pluripotent stem-cells, Signaling pathway, Synaptic activity, Tau mislocalization
Fernández-Simón, E, Tejedera-Villafranca, A, Fernández-Garabay, X, Clark, J, Monceau, A, Villalobos, E, Cox, D, Azcón, JR, Fernández-Costa, JM, Manera, JD, (2026). Investigating the role of EGFR signalling in muscle dystrophies: implications for Duchenne muscular dystrophy Cell Death & Disease 17, 18
The degeneration of the muscle in muscle dystrophies involves complex interactions among the different cell types. Here, we have used datasets from single-nuclei RNA sequencing (snRNAseq) of Duchenne Muscular Dystrophy (DMD) muscle samples to study the dysregulation of molecular pathways compared to healthy control muscle. We have observed that the epidermal growth factor (EGF) signaling is upregulated in DMD by an increase of the ligands EGF and EGF containing fibulin extracellular matrix protein 1 (EFEMP1). This study explores the role of EGF and EFEMP1 in FAPs and myoblasts in vitro. We provide evidence that EFEMP1 is secreted by FAPs in DMD and is mainly involved with increased myotube size but without enhancing muscle strength. Conversely, EGF enhances fibrotic differentiation in FAPs and promote smaller, proliferative myotubes in myoblasts, aligning with a fibrotic and dysfunctional muscle phenotype in DMD. The cellular differences from both ligands can be explained by the interactions with the receptor type, with EGF activating both EGFR and ErbB2, while EFEMP1 selectively maintained ErbB4 in an inactive state but promoting EGFR-ErbB2 and ErbB2-ErbB4 heterodimerization, potentially enhancing EGF signaling. Consequently, this study examinates the alteration of the EGF signalling in DMD and provides new molecular interactions in muscle that can be useful for targeted therapies of muscle degeneration.
JTD Keywords: Deposits, Efemp1, Migration, Regeneration, Satellite cells
del Río, EP, Esplugues-Lopez, A, Heyvaert, Y, Jergitsch, M, Colombi, S, Ahmadi, M, Martinez, H, Ginebra, MP, Alemán, C, Mateos-Timoneda, MA, García-Torres, J, (2026). Integrating electrical conductivity capability into 3D printed alginate-gelatin hydrogels as skin tissue constructs for temperature sensing COLLOIDS AND SURFACES B-BIOINTERFACES 257, 115206
The development of electrically conductive hydrogels has emerged as a critical advancement in soft electronics, enabling multifunctional devices for biomedical applications. This work introduces biocompatible and conductive three-dimensional (3D) printed hydrogels based on alginate-gelatin matrices, modified with gold nanoparticles (AuNPs) and MXene nanosheets (Ti3C2Tx), as electronic-engineered skin hybrid platforms for temperature sensing. The hydrogels demonstrate tunable conductivity, reaching values of 0.44 S/m for AuNPmodified and 1.04 S/m for MXene-modified samples. Structural analysis confirmed the preservation of a porous architecture, while rheological studies highlighted their mechanical integrity. Both modifications imparted temperature sensitivity, with an approximately 20 % increase in current response between 30 degrees C and 40 degrees C and sensitivities in the range from - 1.54-2.00 %degrees C- 1. These hydrogels also exhibit excellent cytocompatibility, making them ideal candidates for engineered skin scaffolds. The combination of temperature sensing and biocompatibility advances the potential use of conductive hydrogels in real-time physiological monitoring and infection detection, marking a significant contribution to the field of bioelectronics.
JTD Keywords: 3d hydrogels, Alginate-gelatin, Au nps, In-vitro, Mxene nanosheets, Nanoparticles, Scaffolds, Soft, Temperature sensor
Bota, Patricia M, Picon-Pages, Pol, Fanlo-Ucar, Hugo, Almabhouh, Saja, Bagudanch, Oriol, Zeylan, Melisa E, Senyuz, Simge, Gohl, Patrick, Molina-Fernandez, Ruben, Fernandez-Fuentes, Narcis, Barbu, Eduard, Vicente, Raul, Nattel, Stanley, Ois, Angel, Puig-Pijoan, Albert, Garcia-Ojalvo, Jordi, Keskin, Ozlem, Gursoy, Attila, Munoz, Francisco J, Oliva, Baldomero, (2026). Oxidative stress-driven transcriptomic remodeling in human astrocytes reveals network signatures associated with neurodegenerative and cardiovascular processes Computational and Structural Biotechnology Journal 31, 263-275
Astrocytes are central to brain homeostasis, supporting neuronal metabolism, synaptic activity, and the blood-brain barrier. With aging, these glial cells undergo molecular and functional changes that weaken support functions and promote neuroinflammation, contributing to neurodegeneration. Yet the systems-level mechanisms by which astrocytes respond to aging-related stressors remain poorly defined in human models. Because aging also heightens risk for cardiovascular disease, cognitive impairment, type 2 diabetes, and systemic inflammation, clarifying shared astrocytic pathways is critical for understanding brain-body crosstalk. Using an in vitro human astrocyte model exposed to sublethal oxidative stress (10 mu M H2O2) as a proxy for age-related cellular stress, we profiled transcriptomic changes and identified differentially expressed genes across antioxidant defenses, proteostasis, transcriptional regulation, vesicular trafficking, and inflammatory signaling. We then performed network-prioritization analyses on a curated human protein-protein interactome: one seeded with the astrocyte oxidative stress responsive genes and six with phenotype-associated gene sets (Alzheimer's disease, cardiovascular disease, cognitive impairment, type 2 diabetes, oxidative stress, and inflammation). Intersecting the top 5 % scoring genes from each run yielded a 127-gene core shared across all seven, enriched for proteostasis, DNA repair, mitochondrial regulation, and telomere and nuclear envelope maintenance. Structure-guided analyses highlighted vulnerable interfaces, including lamin A/C-lamin B1, alpha-actinin-filamins, 14-3-3 dimers, and aminoacyl-tRNA synthetase assemblies, where pathogenic variants are predicted to destabilize or aberrantly stabilize protein interactions. Structure-based interface predictions also highlight potential interactions between amyloid precursor protein (APP) and valosin-containing protein (VCP), and between p53 and 14-3-3 zeta, poten-tially linking proteostasis and stress signaling. Together, these analyses identify a conserved astrocyte-centered network signature that may relate neurodegenerative and cardiovascular processes, and prioritize structurally testable candidates for biomarker and intervention hypothesis testing.
JTD Keywords: 14-3-3-zeta, Aging-associated proteomic remodeling, Astrocytic vulnerability networks, Crosstalk, Disease, Dysfunction, Insights, Interactome, Interfaces, Mutations, Network-based gene-disease prioritization, Neurodegeneration-cardiovascular disease, Oxidative stress-responsive astrocyte pathways, Phosphorylation, Prediction, Proteostasis and mitochondrial dysfunction, Receptor, Structurally vulnerable proteinprotein, Structure-guided variant impact prediction, Telomere and nuclear envelope integrity, Update
Razavi, Seyed Ali, Fargas, Gemma, Serrano, Isabel, Laguna-Bercero, Miguel Angel, Vilella, Tania, Llanes, Luis, Rodriguez, Daniel, Ginebra, Maria-Pau, Llorca, Jordi, Morales, Miguel, (2025). Direct recycling of 3D-printed Co-YDZ catalysts for ethanol steam reforming Journal of Environmental Chemical Engineering 13, 120246
Additive manufacturing enhances the catalyst performance via hierarchical design. To address environmental and resource concerns, this work aims to fabricate directly recycled 3D-printed monoliths using Direct-Ink Writing (DIW) from 100 % recovered cobalt-zirconia powders. Virgin cobalt-zirconia monoliths were firstly fabricated by DIW of 3.0-7.0 wt% Co-enriched hydrogel-based ceramic inks, followed by calcination at 600 degrees C in a single thermal treatment. After testing the catalytic performance of monoliths in ethanol steam reforming, 3Dprinted cobalt-zirconia monoliths were fragmented and subjected to subsequent milling and sieving steps to recover composite cobalt-zirconia powders with the appropriate properties for reuse in DIW. The recovered powders, inks and monoliths were microstructurally, rheologically and catalytically characterized, and then compared to catalysts constituted by virgin materials. The rheology properties of inks for the recycled and virgin monoliths presented an appropriate printability. Furthermore, the catalytic performance of recycled monoliths was close to that exhibited by virgin catalysts. This study demonstrates the feasibility of directly recycling fully 3D-printed catalysts, potentially reducing the environmental impact with a circular production model to enhance sustainability in the catalyst industry.
JTD Keywords: Additive manufacturing, Catalyst ethanol steam reforming, Cobalt catalysts, Direct-ink writing, Efficient, Heterogeneous catalyst, Hydrogen production, Ionically conductive supports, Monoliths, Nanoparticles, Oxidation, Performance, Recycled ceramics, Regeneration, Solid oxide fuel, Zirconia
Mirza, W, De Corato, M, Pensalfini, M, Vilanova, G, Torres-Sánchez, A, Arroyo, M, (2025). Theory of active self-organization of dense nematic structures in the actin cytoskeleton eLife 13, RP93097
The actin cytoskeleton is remarkably adaptable and multifunctional. It often organizes into nematic bundles such as contractile rings or stress fibers. However, how a uniform and isotropic actin gel self-organizes into dense nematic bundles is not fully understood. Here, using an active gel model accounting for nematic order and density variations, we identify an active patterning mechanism leading to localized dense nematic structures. Linear stability analysis and nonlinear finite element simulations establish the conditions for nematic bundle self-assembly and how active gel parameters control the architecture, orientation, connectivity, and dynamics of self-organized patterns. Finally, we substantiate with discrete network simulations the main requirements for nematic bundle formation according to our theory, namely increased active tension perpendicular to the nematic direction and generalized active forces conjugate to nematic order. Our work portrays actin gels as reconfigurable active materials with a spontaneous tendency to develop patterns of dense nematic bundles.
JTD Keywords: Actin cytoskeleton, Alpha-actinin, Architecture, Cells, Contraction, Cooperate, Cortex, Drives, Mechanics, Myosin-ii, Nematic bundles, Self-organization, Stress fibers
Fischer, Nicholas G, De Jong, David A, Evans, Michael D, Aparicio, Conrado, (2025). Polarity of hemidesmosome instructive light-curable biosealants guides nascent extracellular matrix for favorable epithelial interactions MATERIALS TODAY BIO 35, 102513
Percutaneous medical devices - such as prosthetic limbs, dental implants, and subgingival dental restorations commonly fail due to their susceptibility to infection, posing serious morbidity and mortality and a significant economic burden. Current solutions for subgingival dental restoration failure - such as antimicrobial and degradation-resistant materials - remain largely experimental and have yet to achieve widespread clinical translation. Thus, as a next-generation strategy for improving subgingival restoration longevity, we draw inspiration from the tooth, a long-lasting percutaneous organ with robust soft tissue attachment enabled by cellmatrix adhesive hemidesmosomes (HDs). Promoting HD formation around subgingival restorations - mimicking the natural attachment seen in teeth - may extend dental restoration lifespan by fostering a stable mucosal barrier that blocks bacterial access. A family of scalable biologics-free HD instructive light-curable biosealants (HILBs) was engineered for point-of-care coating for subgingival restorations to trigger and guide beneficial pericellular extracellular matrix structural changes at the HILB surface. Material-based strategies for medical device integration with the human body have traditionally focused on controlling surface properties to provoke desired cellular and tissue responses at the bio/non-bio interface. However, this approach overlooks the evolving pericellular matrix that quickly enrobes cells and overrides engineered surface cues. The control of cell-secreted nascent matrix through HILB surface polarity markedly upregulated HD formation. This bioinstruction is dependent on nascent glycoprotein laminin332 secretion and recognized by HD integrins, which demonstrates the potential of biomaterial surface design to guide secreted pericellular matrix with implications for facilitating tissue repair and enhancing subgingival restoration outcomes.
JTD Keywords: Binding, Bioinspiration, Bioinstructive polar surface, Cells, Expression, Hemidesmosomes, Human keratinocytes, Ionomer, Keratinocytes adhesion, Laminin-5 gamma-2 chain, Light-curable biomaterial, Metalloproteinases, Proteins, Self-etch adhesives, Surface-energy
Garrido-Charles, A, Bosch, M, Lee, H, Rovira, X, Pittolo, S, Llobet, A, Wong, HHW, Trapero, A, Matera, C, Papotto, C, Serra, C, Llebaria, A, Soriano, E, Sanchez-Vives, MV, Holt, CE, Gorostiza, P, (2025). Photoswitching endogenous glutamate receptors in neural ensembles and single synapses in vivo Brain Stimulation 18, 1779-1793
Purpose: To interrogate animal physiology in vivo, there is a lack of non-genetic methods to control the activity of endogenous proteins with pharmacological and spatiotemporal precision. To address this need, we recently developed targeted covalent photoswitchable (TCP) compounds that enable the remote control of endogenous glutamate receptors (GluRs) using light. Methods: We combine the photopharmacological effector TCP9 with neuronal activity sensors to demonstrate all-optical reversible control of endogenous GluRs across multiple spatiotemporal scales in rat brain tissue ex vivo and in Xenopus tadpole brains in vivo. Findings: TCP9 allows photoactivation of neuronal ensembles, individual neurons, and single synapses in ex vivo tissue and in intact brain in vivo, which is challenging using optogenetics and neurotransmitter uncaging. TCP9 covalently targets AMPA and kainate receptors, maintaining their functionality and photoswitchability for extended periods (>8 h) after a single compound application. This allows tracking endogenous receptor physiology during synaptic plasticity events such as the reduction of functional AMPA receptors during long-term depression in hippocampal neurons. Conclusion: TCP9 is a unique non-invasive tool for durable labeling, reversible photoswitching, and functional tracking of native receptors in brain tissue without genetic manipulation.
JTD Keywords: 2-photon, Ampa receptors, Ampar, Azobenzene, Caged glutamate, Calcium imaging, Covalent drug, Dendritic spines, Hippocampus, Kainate, Long-term depression, Optical control, Optopharmacology, Photopharmacology, Photoswitch, Plasticity, Proteins, Pulse-chase, Rat, Subunit, Surface expression, Synaptic ampa, Xenopus, Zero hunger
Sanchez-Rubio, Alvaro, Hope, Lauren, Barcelona-Estaje, Eva, Jayawarna, Vineetha, Williams, Jonathan, Salmeron-Sanchez, Manuel, (2025). Gelatin vs GelMA in alginate-based bioinks as a platform for versatile 3D bioprintable in vitro systems BIOMATERIALS ADVANCES 177, 214408
3D in vitro model systems, such as hydrogels, have garnered popularity due to their ability to more accurately recapitulate in vivo environments compared to 2D cell culture systems. However, methods which involve casting hydrogels by hand may be time consuming, have poor reproducibility, and reduced capacity to generate complex structures. Hence, 3D bioprinting has emerged as a useful tool for the high throughput production of in vitro tissue models such as hydrogels and complex constructs. Here, we demonstrate the mechanical properties, printability, and ability to support single cells and spheroids in culture for two highly characterised composite bioinks: Alginate/Gelatin (AlgGel), which is ionically crosslinked, and Alginate/Gelatin Methacrylate (GelMA) (AlgGelMA), whereby the GelMA is crosslinked by illumination with UV light. In this study, we engineered gels that exhibit a wide range of stiffnesses, which vary due to the concentration of crosslinking polymer present. AlgGel hydrogels were softer (1.5-4.5 kPa), and stiffness decreased with time in culture, however, AlgGelMA hydrogels were stiffer (6-40 kPa), and the stiffness increased with time. Microarchitectural studies using Scanning Electron Microscopy and Microcomputed Tomography (mu CT) revealed that hydrogels produced using both bioinks bore a highly porous structure, further simulating in vivo conditions. To assess the ability of both bioink families to support cell culture, the Acute Myeloid Leukaemia cell line THP-1 and human Mesenchymal Stem Cells (hMSCs) as single cells and spheroids were bioprinted in each bioink. Interestingly, THP-1 cells formed larger clusters when cultured within AlgGel bioinks compared to AlgGelMA. Additionally, hMSCs appeared to be unable to migrate through the AlgGel matrix, as single hMSCs displayed rounded morphologies and hMSC spheroid shape was not disrupted after seven days. Contrastingly, hMSCs and spheroids cultured within AlgGelMA hydrogels were able to invade the gel matrix and migrate. Together, these data demonstrate that both AlgGel and AlgGelMA bioinks show promise for use as the basis of 3D bioprinted in vitro tissue models.
JTD Keywords: Alginate, Bioprinting, Culture, Endothelial cell, Gelma, Hydrogels, Matrix, Mode, Morphology, Porosity, Spheroids, Stem cells, Stem-cells, Substrate stiffness, Tissues
Castillo-Escario, Yolanda, Albu, Sergiu, Kumru, Hatice, Jane, Raimon, (2025). Evaluation of Sleep Apnea in Stroke Patients Using a Portable Smartphone-Based System IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING 33, 4546-4557
Sleep apnea is common but often underdiagnosed after stroke, hindering rehabilitation and functional recovery. Access to sleep studies remains limited for stroke patients, partly due to the inconvenience of current diagnostic tools. The widespread availability and built-in sensors of smartphones make them powerful solutions for mobile health applications, including sleep monitoring. This study aims to detect and evaluate sleep apnea in post-stroke patients using a smartphone and extract multimodal digital biomarkers to characterize their sleep patterns. For that, overnight sleep tests were conducted on 30 subacute stroke patients and 30 age- and sex-matched control subjects, using a smartphone-based system that recorded audio, accelerometer, and oximetry data. Signals were analyzed with custom-made algorithms to compute respiratory, oxygenation, and sleep position indices. Results showed that the apnea-hypopnea index (AHI) was significantly higher in the stroke than the control group (28 +/- 19 vs 14 +/- 11, p = 0.006). Moderate-to-severe sleep apnea (AHI >= 15) was present in 67% of stroke patients and 40% of control subjects. Stroke patients spent more time mouth breathing (22% vs 12%, p
JTD Keywords: Association, Biomedical signal processing, Entropy, Heart-rate, Ischemic-stroke, Mhealth, Monitoring, Obesity, Oximetry, Positions, Prediction, Prevalence, Sleep apnea, Smartphone, Stroke, Supine sleep, Wearables
Celles, Cicero Andrade Sigiliao, Aparicio, Conrado, Barao, Valentim Adelino Ricardo, Dini, Caroline, (2025). Magnesium-Doped Coatings as a Suitable Approach to Improve Osseointegration of Titanium-Based Implants: A Systematic Review and Meta-Analyses of Animal Studies JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS 113, e35681
This review evaluates the effect of magnesium (Mg)-doped coatings on the osseointegration of titanium (Ti)-based implants. The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the PRISMA 2020 Statement were followed, with registration in PROSPERO (CRD42024572571). The PICOS strategy was based on population: dental implants; intervention: Mg coatings; control: surfaces without Mg; outcomes: bone-implant contact (BIC), bone area (BA), implant stability coefficient (ISQ), and removal torque (RTQ); and study Design: in vivo studies. The SYRCLE tool was used to assess the risk of bias of animal studies. Meta-analyses were performed, using a random-effect model and 95% confidence interval. Twenty-three records were included, and 21 were enrolled in the meta-analyses. The most commonly used Mg doping method was microarc oxidation. The Mg-doped coatings, significantly favored pooled BIC values in animals [-6.09 (-8.35, -3.82), I-2: 50%, p < 0.00001], especially up to 3, 4, 6, and 8 weeks compared to surfaces without Mg. Interestingly, Mg-doped coatings favored BA up to 6 weeks [-8.20 (-14.31, -2.09), I-2: 0%, p = 0.008], and RTQ up to 3 [-8.44 (-12.33, -4.56), I-2: 63%, p < 0.0001]. Conversely, it did not influence ISQ [-0.24 (-2.05, 1.58), I-2: 88%, p = 0.80]. Mg-doped coatings significantly enhanced osseointegration in dental implants by improving BIC, BA, and RTQ, while showing no impact on ISQ. Supported by studies across various animal species, these results confirm that such coatings represent an effective and safe approach for promoting bone integration.
JTD Keywords: Alloys, Bone, Bone-implant interface, Dental implant, Dental implants, Expression, Incorporated oxidized implants, Ion-implantation, Magnesium, Mg, Osseointegration, Resonance frequency measurements, Strength, Surface-chemistry
Alonso-Valdesueiro, Javier, Fernandez, Luis, Gutierrez-Galvez, Agustin, Marco, Santiago, (2025). CSRR Chemical Sensing in Uncontrolled Environments by PLS Regression IEEE SENSORS JOURNAL 25, 37664-37673
Complementary split ring resonators (CSRRs) have been extensively studied as planar sensors in the last two decades. However, their practical use remains limited to controlled environments and classification problems. Their performance relies on high-end vector network analyzers (VNAs), highly repeatable laboratory conditions, and special sample holders or microfluidic circuits hinders its regular use in chemistry laboratories as an analytical tool. Temperature drifts and humidity variations during measuring, uncertainties in the electromagnetic properties of the sample containers, and careless sample handling introduce significant uncertainties in measurements, leading to unreliable results. Therefore, the prediction of target compounds concentration in samples has been out of the research focus up to now. Machine learning (ML) algorithms can help to mitigate these uncertainties and open the applicability of CSRR sensors to quantification problems, where it is necessary to determine the amount of a substance in a liquid (or solid) sample. This work presents a novel approach that tackles this issue, combining a CSRR sensor with well-stabilized ML algorithms that enhance its quantification performance. For illustration purposes, a low-cost, benchtop CSRR-based system is proposed to predict ethanol concentration in water solutions. Ethanol samples from 10% to 96% concentration were prepared in commercial vials, generating 450 randomized measurements. Principal component analysis (PCA) was employed for data exploration, while a partial least squares (PLS) regression model, tuned with leave-one-group-out cross validation (LOGO-CV), was trained for ethanol concentration prediction. No feature extraction technique or noise reduction strategy was applied. Although this straightforward workflow is well known in the chemical sensing field, it has not been applied to data acquired with CSRR sensors. The trained model achieved a root mean square error in prediction (RMSEP) of 3.7% . Compared with 23.4% RMSEP when using univariate calibration at optimized frequencies, it presents a prediction performance reduced by a factor of 6. No evidence of underfitting or overfitting was observed during the test of the trained model. The low RMSEP achieved by the presented setup demonstrates the potential of CSRR-based sensors when combined with ML techniques for concentration prediction working in realistic, uncontrolled conditions. This pushes forward the applicability of CSRR sensors in the chemical analysis field, which might lead to benchtop, low-cost, and reliable analysis devices for many laboratories.
JTD Keywords: Chemical analysis, Chemical sensors, Complementary, Complementary split ring resonator (csrr) sensors, Concentration prediction, Design, Electronic mail, Ethanol, Feature extraction, Filters, Machine learning (ml), Metamaterials, Principal component analysis, Resonators, Rf sensors, Sensor phenomena and characterization, Sensors, Split-ring resonators, Temperature measurement, Transmission, Transmission line measurements, Uncertainty, Variable selection
Reis, David Q P, Calvario, Joana, Chibeles, Ines, Kumar, Mohit, Pina, Ana S, (2025). Optimizing (Bio) Catalysis with Liquid-Liquid Phase Separation Systems ChemSystemsChem 7, e00089
Membraneless organelles, also known as biomolecular condensates, lack a surrounding membrane and are formed through liquid-liquid phase separation (LLPS). This process enhances reaction efficiency by compartmentalizing and concentrating reactants. Coacervates, a class of condensates, provide promising synthetic alternatives for improving enzymatic reactions. This review examines how LLPS enhances reaction efficiency in both natural and artificial systems, explores the design principles of coacervate-based artificial organelles employed in (bio)catalysis, and discusses challenges and future directions for leveraging LLPS in catalysis.
JTD Keywords: Acid, Activation, Catalysis, Coacervates, Compartmentalization, Droplets, In-vitro, Liquid-liquid phase separation, Membraneless organelles, Microdroplets, Nitric-oxide, Origins, Rna catalysis, Signaling molecules, Transition
Saad, A, Pillai, S, Tran, SD, Tamimi, F, Aparicio, C, Cerruti, M, (2025). Controlling collagen I orientation on polyetheretherketone implants to improve epithelial sealing ACS Biomaterials Science & Engineering 11, 5895-5906
Transcutaneous devices such as dental implants frequently fail due to infections at their interfaces with epithelial tissues. These infections are facilitated by the lack of integration between the devices and the surrounding soft tissues. This study aims to improve epithelial integration through surface modification of a transcutaneous implant material (polyetheretherketone (PEEK)). The modification involved covalent bonding of collagen via two distinct methods: (1) nonselective binding through any primary amines present on collagen using carbodiimide-based coupling and (2) site-specific binding to the free amine on the N-terminus of collagen molecules. The second approach preserves active sites responsible for interacting with integrins, crucial for epithelial cell adhesion, located near the C terminus. Both conjugation methods resulted in similar amounts of immobilized collagen; yet, surfaces with 2-PCA-based collagen conjugation exhibited 4 times more free amines. This indicates that fewer amines were used for conjugation in these samples, confirming that 2-PCA selectively binds collagen only through the N-terminus amines. Collagen-conjugated surfaces significantly enhanced HaCaT epithelial cell viability and adhesion compared to unmodified PEEK. Furthermore, 2-PCA-based conjugation resulted in a 2-fold increase in beta 4 subunit gene expression of integrin alpha 6 beta 4 (a key epithelial cell adhesion marker), higher integrin beta 4 immunofluorescence (IF) intensity, and over a 30% improvement in cell retention following mechanical detachment, compared to nonselective conjugation. These findings suggest that selective collagen conjugation on PEEK surfaces increases the accessibility of collagen domains responsible for binding with integrin receptors, which in turn improves epithelial cell attachment, offering a promising strategy for reducing infections and enhancing the longevity of transcutaneous devices.
JTD Keywords: Cell-adhesion, Conjugation, Domains, Fibroblasts, Fibronectin, Integrin, Matrix, Protein, Selective protein conjugation, Soft tissue integration, Strategies, Titanium surfaces, Transcutaneous implants
Grolleman, Janine, Bouten, Carlijn V C, Conte, Vito, Sahlgren, Cecilia M, (2025). An integrated 2D framework for quantifying cellular mechanics reveals the impact of juxtacrine Notch signalling on directed collective migration of endothelial cells BMC BIOLOGY 23, 291
BackgroundCollective migration is the coordinated movement of a group of cells-a fundamental process in health and disease. Many models have been developed to study the molecular and physical mechanisms of collective migration. However, the aim of this study is to engineer a flexible in vitro framework that allows for mechanobiological quantification of the separate and combined contributions of individual cell mechanics to the directed migration of a collective. We utilised this framework to understand the role of juxtacrine Notch signalling during collective endothelial migration-an essential process during the formation of new blood vessels (known as angiogenesis).ResultsThis framework enables users to perform high spatiotemporal analysis of migrative behaviour, cell-matrix traction forces, and intercellular forces in different microenvironments. With this framework, we show that Notch inhibited collectives adopt a distinct regime of directed collective migration. Whereas the directionality of migration, traction forces and intercellular forces are not affected by Notch inhibition, we observed spatiotemporal differences in migration speed, traction force magnitude and normal and shear stresses within Notch-inhibited collectives.ConclusionsThe in vitro framework is a powerful approach for dissecting the mechanisms of collective migration. With this framework, we show that a potential link exists between the juxtacrine signalling of Notch and an increased mechanical cohesiveness among collective cells.
JTD Keywords: Angiogenesis, Cell-cell dynamics, Cell-matrix dynamics, Collective endothelial migration, Dynamics, Forces, In vitro framework, Juxtacrine notch signalling, Migration kinematics, Morphogenesis, Organization
Gunstheimer, Hans, Flaschner, Gotthold, Adams, Jonathan D, Holscher, Hendrik, Hoogenboom, Bart W, (2025). High-Speed Quantitative Nanomechanical Mapping by Photothermal Off-Resonance Atomic Force Microscopy Small 21, e07640
Atomic force microscopy (AFM) is widely used to measure surface topography of solid, soft, and living matter at the nanoscale. Moreover, by mapping forces as a function of distance to the surface, AFM can provide a wealth of information beyond topography, with nanomechanical properties as a prime example. Here, a method based on photothermal off-resonance tapping (PORT) is presented to increase the speed of such force spectroscopy measurements by at least an order of magnitude, thereby enabling high-throughput, quantitative nanomechanical mapping of a wide range of materials. Specifically, photothermal actuation is used to modulate the position of the AFM probe at frequencies that far exceed those possible with traditional actuation by piezo-driven z scanners. Understanding and accounting for the microscale thermal and mechanical behavior of the AFM probe, the study determines the resulting probe position at sufficient accuracy to allow rapid and quantitative nanomechanical examination of polymeric and metallic materials.
JTD Keywords: Atomic force microscopy, Calibration, Dynamics, Force spectroscopy, Liqui, Liquid, Nanomechanical characterization, Off-resonance tapping, Photothermal excitatio, Photothermal excitation, Surface, Thermal noise
Parrilla-Gomez, Francisco Jose, Castellvi-Font, Andrea, Boutonnet, Victor, Parrilla-Gomez, Andres, Terreros, Marta Antolin, Somoza, Cristina Mestre, Bravo, Marina Blanes, de la Rubia, Paola Pratsobrerroca, Martin-Lopez, Eva, Marco, Santiago, Festa, Olimpia, Brochard, Laurent J, Goligher, Ewan C, Enviz, Joan Ramon Masclans, (2025). Association of Breathing Effort With Survival in Patients With Acute Respiratory Distress Syndrome CRITICAL CARE MEDICINE 53, e1982-e1994
OBJECTIVES: Invasive mechanical ventilation (IMV) is crucial for acute respiratory distress syndrome (ARDS) management, but mortality remains high. While spontaneous breathing is key to weaning, excessive respiratory effort may injure the lung and diaphragm. Most existing data on respiratory effort during IMV are based on brief periods of observation, potentially underestimating the burden of inappropriate efforts. This study aims to characterize the evolution of respiratory effort over time in ARDS patients and its relation to survival. We hypothesized that nonsurvivors would spend a greater proportion of time in the high-effort range during the active breathing phase compared with survivors. DESIGN, SETTING, AND PATIENTS: In this prospective cohort study, we continuously recorded airway pressure, flow, esophageal, and gastric pressures in ARDS patients on mechanical ventilation during 7 days after the onset of spontaneous breathing. We analyzed physiologic respiratory effort variables, focusing on the proportion of time spent within defined effort ranges, and compared these data between ICU survivors and nonsurvivors. Statistical analysis was conducted using variance weighted methods to account for variability in the number of respiratory cycles analyzed per patient. This study is registered at ClinicalTrials.gov under identifier NCT06490523. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 1,485,405 respiratory cycles were analyzed from 26 ARDS patients (19 survivors, seven nonsurvivors). Nonsurvivors spent significantly more time in high effort (12% vs. 3%; p = 0.006). In contrast, survivors spent more time in the moderate-effort range (50% vs. 5%; p < 0.001). The time spend with high dynamic transpulmonary driving pressure (> 25 cm H2O) was also significantly different between groups (32% survivors vs. 74% nonsurvivors; p = 0.001). CONCLUSIONS: Patients who die of ARDS are more likely to be exposed to high respiratory effort for prolonged periods of time compared with survivors.
JTD Keywords: Acute respiratory distress syndrome, Adult patients, Epidemiology, Esophageal, Esophageal pressure, Evolution, Lung injury, Mechanical ventilation, Mortality, Pressure support ventilation, Pulmonary, Respiratory effort, Transpulmonary pressure
Fagotto-Clavijo, Roberto, Lodoso-Torrecilla, Irene, Diez-Escudero, Anna, Ginebra, Maria-Pau, (2025). Strategic advances in Vat Photopolymerization for 3D printing of calcium phosphate-based bone scaffolds: A review Bioactive Materials 52, 719-752
3D-printing has emerged as a leading technology for fabricating personalized scaffolds for bone regeneration. Among the 3D-printing technologies, vat photopolymerization (VP) stands out for its high precision and versatility. It enables the creation of complex, patient-specific scaffolds with advanced pore architectures that enhance mechanical stability and promote cell growth, key factors for effective bone regeneration. This review provides an overview of the advances made in vat photopolymerization printing of calcium phosphates, covering both the fabrication of full ceramic bodies and polymer-calcium phosphate composites. The review examines key aspects of the fabrication process, including slurry composition, architectural design, and printing accuracy, highlighting their impact on the mechanical and biological performance of 3D-printed scaffolds. The need to tailor porosity, pore size, and geometric design to achieve both mechanical integrity and biological functionality is emphasized by a review of data published in the recent literature. This review demonstrates that advanced geometries like Triply Periodic Minimal Surfaces and nature-inspired designs, achievable with exceptional precision by this technology, enhance mechanical and osteogenic performance. In summary, VP's versatility, driven by the diversity of material options, consolidation methods, and precision opens new horizons for scaffold-based bone regeneration.
JTD Keywords: 3d printing, Additive manufacturing, Bioceramic scaffolds, Bone regeneratio, Ceramic scaffolds, Composite scaffolds, Fabrication, Ha scaffolds, Hydroxyapatite, Hydroxyapatite scaffolds, Mechanical-properties, Regeneratio, Scaffold, Stereolithography, Titanium surfaces, Vat polymerization
Arboleda, Alejandro, Franco, Manuel, Naranjo, Francisco, Giraldo, Beatriz Fabiola, (2025). Electromyographic Diaphragm and Electrocardiographic Signal Analysis for Weaning Outcome Classification in Mechanically Ventilated Patients SENSORS 25, 6000
Early prediction of weaning outcomes in mechanically ventilated patients has significant potential to influence the duration of treatment as well as associated morbidity and mortality. This study aimed to investigate the utility of signal analysis using electromyographic diaphragm (EMG) and electrocardiography (ECG) signals to classify the success or failure of weaning in mechanically ventilated patients. Electromyographic signals of 40 subjects were recorded using 5-channel surface electrodes placed around the diaphragm muscle, along with an ECG recording through a 3-lead Holter system during extubation. EMG and ECG signals were recorded from mechanically ventilated patients undergoing weaning trials. Linear and nonlinear signal analysis techniques were used to assess the interaction between diaphragm muscle activity and cardiac activity. Supervised machine learning algorithms were then used to classify the weaning outcomes. The study revealed clear differences in diaphragmatic and cardiac patterns between patients who succeeded and failed in the weaning trials. Successful weaning was characterised by a higher ECG-derived respiration amplitude, whereas failed weaning was characterised by an elevated EMG amplitude. Furthermore, successful weaning exhibited greater oscillations in diaphragmatic muscle activity. Spectral analysis and parameter extraction identified 320 parameters, of which 43 were significant predictors of weaning outcomes. Using seven of these parameters, the Naive Bayes classifier demonstrated high accuracy in classifying weaning outcomes. Surface electromyographic and electrocardiographic signal analyses can predict weaning outcomes in mechanically ventilated patients. This approach could facilitate the early identification of patients at risk of weaning failure, allowing for improved clinical management.
JTD Keywords: Cardiorespiratory characterisation, Classification, Coherence, Diaphragm, Ecg, Electromyography, Emg, Heart-rate-variability, Mechanical ventilation, Naive bayes classifier, Predictor, Signal analysis, Surface electromyography, Time-series analysis, Time-varying spectral analysis, Weaning outcome
Silva, Joao Pedro dos S, Mireski, Mariana, Mallor-Solis, Irene, Borges, Maria Helena Rossy, Piazza, Rodolfo Debone, Marques, Rodrigo Fernando Costa, Cruz, Nilson, Rangel, Elidiane C, Fortulan, Carlos A, da Silva, Jose H D, Geringer, Jean, Aparicio, Conrado, Barao, Valentim A R, (2025). Amino Silane High Positive Charge Layers: A Stable and Durable Alternative Based on Electrostatic Interactions for Titanium Applications, Combining Antimicrobial and Biological Properties ACS Applied Bio Materials 8, 8655-8672
Cationic coatings on titanium surfaces are a promising approach for dental and biomedical implants due to their low-cost antimicrobial effect and no need for antibiotics. These coatings are applied on hydroxylated (-OH) surfaces using silanes, such as 3-aminopropyltriethoxysilane (APTES). However, it is unclear whether the concentration of this organofunctional compound affects surface charge or potential toxicity. This study investigated how different concentrations of APTES in cationic coatings on titanium samples influence electrostatic behavior and interactions with bacteria and mesenchymal stem cells (MSCs). Titanium discs served as controls (Ti group) and were first treated by plasma electrolytic oxidation (PEO) to generate -OH groups (PEO group). Subsequently, APTES was applied at 83.8, 167.6, and 251.4 mM, forming PEO+APTES0.3, PEO+APTES0.6, and PEO+APTES0.9 groups, respectively. Surfaces were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), contact angle, Zeta potential, and profilometry. Microbiological assays assessed initial bacterial adhesion (1 h) and biofilm formation (24 h) using Staphylococcus aureus and Escherichia coli. Cell metabolism was assessed on days 1, 3, and 8, while cell viability was assessed on days 1 and 3 using mesenchymal stem cells. PEO-treated surfaces showed porous morphology, and silanization increased roughness and shifted surfaces toward hydrophobicity. Amines and surface charge changes were confirmed by XPS and Zeta potential. Increasing APTES concentration did not proportionally increase cation number. Crystalline hydroxyapatite oxides were identified following the electrochemical process. SEM, EDS, and FTIR confirmed treatment stability after 28 days of immersion, while tribological tests indicated improved performance for PEO-treated groups. Cationic coatings reduced bacterial adhesion by up to 65%, decreased biofilm Log10 values, and increased dead bacteria proportion. Biocompatibility was confirmed by metabolism and cell viability tests, with the group with lower APTES concentration showing the best performance on day 8, with an 80% higher cell metabolism than day 1. On the other hand, higher concentrations of APTES resulted in reduced cell metabolism. These findings indicate, for the first time, that APTES concentration does not affect electrostatic properties but that lower concentrations are required for cytocompatible cationic coatings.
JTD Keywords: Adhesion, Biofilms, Cationic coating, Cell proliferation, Coatings, Electrostatic interactions, Implant surfaces, In-vitro, Nanoparticles, Osteoblasts, Oxidation, Self-assembled monolayers, Thin-films, Titanium, Wettability
Lin, Jinwei, Guan, Qiaoxin, Feng, Jiangqi, Chen, Shuqin, Xu, Leilei, Guan, Jianguo, Sanchez, Samuel, (2025). Interactions Between Active Matters and Endogenous Fields ADVANCED MATERIALS 37, e03091
Active matter, encompassing both natural and artificial systems, utilizes environmental energy to sustain autonomous motion, exhibiting unique non-equilibrium behaviors. Artificial active matter (AAM), such as nano/micromotors, holds transformative potential in precision medicine by enhancing drug delivery and enabling targeted therapeutic interventions. Under the demand for increasing intelligence in AAM, controlling their non-equilibrium processes within complex in vivo environments presents significant challenges. Endogenous fields-biological fields generated within living systems-play a pivotal role in guiding natural active matter's (NAM) directional migration and collective transformations, offering a strategy for in vivo control of non-equilibrium systems. Research in NAMs-inspired AAMs spans biology, chemistry, materials science, engineering, and physics, yet communication barriers among disciplines often impede progress. This review seeks to bridge these gaps by summarizing the key characteristics of chemical and physical endogenous fields in biological contexts such as tumors, wounds, and inflammation. It explores how natural and artificial active matter sense, transmit, and execute responses to these fields, and discusses how insights from natural systems can inform the design of synthetic counterparts. Potential issues and prospects of this research direction are also discussed. It is hoped that this review fosters interdisciplinary collaborations and propels the development of intelligent active matter for biomedical applications.
JTD Keywords: Acoustic propulsion, Active matter, Cell-migration, Collective behavior, Endogenous fields, Exhaled breath condensate, Extracellular ph, Hydrogen-peroxide, In-vivo, Interstitial fluid pressure, Nanomotors, Shear-wave elastography, Stimuli-responsive polymers, Tumor microenvironment
Bernardo, Alejandro, Diaz-Valdivia, Natalia, Fernandez-Nogueira, Patricia, Alcaraz, Jordi, (2025). Stromagenesis and cancer-associated fibroblast heterogeneity in primary tumors and metastasis: focus in non-small cell lung cancer FEBS Open Bio 15, 1599-1617
Non-small cell lung cancer (NSCLC) is the most common lung cancer type and one of the deadliest neoplasias worldwide. NSCLC is histologically classified into adenocarcinoma, squamous cell carcinoma, and other less frequent subtypes. Both subtypes and other solid tumors are increasingly regarded as abnormal organs, highlighting the critical role of the desmoplastic tumor stroma rich in cancer-associated fibroblasts (CAFs) in driving tumor progression and therapeutic resistance. This tumor stroma resembles a chronic fibrotic wound and is largely formed by activated/myofibroblast-like alpha-SMA+ CAFs (myCAFs), which are strongly associated with immunosuppression and poor prognosis. Despite the dominance of the myCAF phenotype, we reported a decade ago phenotypic alterations in NSCLC with a strong dependence on the histologic subtype. Subsequent studies using functional assays, single-cell techniques, and in vivo models have refined these initial observations, enhancing our understanding of the biology of both normal fibroblasts/myofibroblasts and CAFs in NSCLC and other cancer types, including their origins, subclassification, and physiopathologic functions. Notably, increasing evidence supports that CAFs can exhibit tumor-restraining or tumor-promoting effects, and current therapeutic efforts aim to shift the balance towards tumor-restraining phenotypes. Here, we review major advances in our understanding of tumor stromagenesis and CAF heterogeneity in both primary tumors and metastasis, including emerging consensus, with a special focus on NSCLC and its frequent dissemination to the brain. We also highlight the critical role of smoking through epigenetic reprogramming of the TGF-beta/SMAD3 pathway. These advances are beginning to delineate how CAF heterogeneity depends on the stage and histologic subtype in NSCLC.
JTD Keywords: Accumulation, Activation, Cancer-associated fibroblasts, Carcinoma-associated-fibroblasts, Desmoplasia, Differentiation, Generation, Localization, Metastasis, Microenvironment, Myofibroblast, Myofibroblasts, Non-small cell lung cancer, Progression, Stroma, Stromagenesis
Carballo-Molina, Oscar A, Kolberg-Edelbrock, Alexandra N, Alvarez-Saavedra, Matias, Alvarez, Zaida, Fyrner, Timmy, Perez-Rosello, Tamara, Syrgiannis, Zois, Chin, Stacey M, Takata, Nozomu, Strong, Madison, Palmer, Liam C, James Surmeier, D, Stupp, Samuel I, (2025). Supramolecular nanostructure mimics GDNF trophic effects in vitro on human dopaminergic neurons npj Regenerative Medicine 10, 37
Peptide-based supramolecular nanostructures offer a versatile platform with substantial promise for clinical translation in regenerative medicine. These systems allow for the incorporation of biologically active sequences and can be engineered to modulate tissue-specific parameters such as stiffness, diffusivity, and biodegradability. We developed here a bioactive supramolecular nanostructure containing a peptide designed based on glial cell-derived neurotrophic factor. These nanostructures form scaffolds that mimic important trophic effects provided by this growth factor on iPSC-derived human dopaminergic neurons. Our in vitro data show that the nanostructures promote cell viability, confer neuroprotection against 6-hydroxydopamine toxicity, enhance neuronal morphology, facilitate electrophysiological maturation, and induce genes involved in neuronal survival. We also found that the scaffold promoted axonal extension in midbrain human organoids. These findings suggest that the supramolecular system could be useful to improve outcomes in cell-based therapies for Parkinson's disease, where progressive dopaminergic degeneration is a hallmark.
JTD Keywords: Cell-line, Mouse model, Neural transplantation, Neurite outgrowth, Neurotrophic factor, Parkinsons-disease, Rat model, Re, Receptor, Substantia-nigra
Chen, Shuqin, Fan, Donglei Emma, Fischer, Peer, Ghosh, Ambarish, Goepfrich, Kerstin, Golestanian, Ramin, Hess, Henry, Ma, Xing, Nelson, Bradley J, Padial, Tania Patino, Tang, Jinyao, Villa, Katherine, Wang, Wei, Zhang, Li, Sen, Ayusman, Sanchez, Samuel, (2025). A roadmap for next-generation nanomotors Nature Nanotechnology 20, 990-1000
Since their discovery in 2004, there has been remarkable progress in research on nanomotors, from the elucidation of different propulsion mechanisms to the study of their collective behaviour, culminating in investigations into their applications in biomedicine and environmental remediation. This Perspective reviews this evolution in nanomotor research and discusses the key challenges ahead, including the need for developing advanced characterization techniques, precise motion control, materials innovation, theory and modelling, and translationally feasible in vivo biomedical applications. These challenges highlight the current limitations of synthetic nanomotors and point to exciting future opportunities to revolutionize theranostics and create 'living' hybrid systems. We introduce the concept of 'systems materials' to encompass interacting functional materials across length scales from molecular to macro. Thus, this Perspective aims to inspire future generations of researchers to advance both fundamental understanding and practical breakthroughs, thereby engineering a paradigm shift in nanomotor research.
JTD Keywords: Autonomous movement, Catalytic nanomotors, Chemotactic behavior, Driven, Janus micromotors, Microrobots, Motion, Propulsion, Removal, Separatio
Borges-Fernandes, Barbara, Apriceno, Azzurra, Arango-Restrepo, Andres, Almadhi, Safa, Ghosh, Subhadip, Forth, Joe, Lopez-Alonso, Jorge Pedro, Ubarretxena-Belandia, Iban, Rubi, Jose Miguel, Ruiz-Perez, Lorena, Williams, Ian, Battaglia, Giuseppe, (2025). The minimal chemotactic cell Science Advances 11, eadx9364
The movement of cells and microorganisms in response to chemical gradients, chemotaxis, is fundamental to the evolution of myriad biological processes. In this work, we demonstrate that even the simplest cell-like structures are capable of chemotactic navigation. By encapsulating enzymes within lipid vesicles that incorporate a minimal number of membrane pores, we reveal that a solitary vesicle can actively propel itself toward an enzyme substrate gradient. Specifically, vesicles loaded with either glucose oxidase or urease and embedded with corresponding transmembrane proteins were tracked within a microfluidic device under a controlled substrate gradient. Our findings establish that a system comprising only an encapsulated enzyme and a single transmembrane pore is sufficient to initiate chemotaxis. This proof-of-concept model underscores the minimalistic yet powerful nature of cellular navigation mechanisms, providing a previously unknown perspective on the origins and evolution of chemotactic behavior in biological systems.
JTD Keywords: Alpha-hemolysin, Artificial cells, Colloid transport, Gradients, Migration, Model, Phospholipid-vesicles, Propulsion
Filippi, Miriam, Mock, Diana, Fuentes, Judith, Y Michelis, Mike, Balciunaite, Aiste, Paniagua, Pablo, Hopf, Raoul, Barteld, Adina, Eng, Selina, Badolato, Asia, Snedeker, Jess, Guix, Maria, Sanchez, Samuel, K Katzschmann, Robert, (2025). Multicellular muscle-tendon bioprinting of mechanically optimized musculoskeletal bioactuators with enhanced force transmission Science Advances 11, eadv2628
Biohybrid actuators leveraging living muscle tissue offer the potential to replicate natural motion for biomedical and robotic applications. However, challenges such as limited force output and inefficient force transfer at tissue interfaces persist. The myotendinous junction, a specialized interface connecting muscle to the tendon, plays a critical role in efficient force transmission for movement. Engineering muscle-tendon units in vitro is essential for replicating native musculoskeletal functions in biohybrid actuators. Here, we present a three-dimensionally bioprinted system integrating skeletal muscle tissue with tendon-mimicking anchors containing fibroblasts, forming a biomimetic interdigitated myotendinous junction. Using computational models, we optimized muscle geometries to enhance deformation and force generation. The engineered system improved mechanical stability, myofiber maturation, and force transmission, generating contractile forces of up to 350 micronewtons over a 3-month period. This work highlights how biomimetic designs and mechanical optimization can advance bioactuator technologies for applications in medicine and robotics.
JTD Keywords: Fabrication, Fibrinoge, Fibroblasts, Interleukin-6, Proliferation, Skeletal-muscle, Soft, Stiffness, Stimulation, Tissue
Arboleda A, Franco M, Valladares L, Naranjo F, Giraldo BF, (2025). Entropy analysis of diaphragmatic EMG signals as an indicator of extubation viability in mechanically ventilated patients. Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2025, 1-4
Surface electromyographic (sEMG) signals from the diaphragm has become a valuable tool for monitoring muscle activity during the weaning process from mechanical ventilation. However, EMG signals are inherently nonlinear and susceptible to noise contamination, which poses challenges for traditional signal processing methods. In this study, we propose the use of entropy metrics to evaluate the dynamic complexity and irregularity of surface electromyographic (EMG) signals of patients assisted with mechanical ventilation. Shannon entropy and spectral entropy were computed to analyze EMG signals from two surface diaphragm channels recorded in mechanically ventilated patients during extubation preparation. According to clinical criteria, the patients were classified into the successful group (GE) - 19 patients with successful extubation after 48 hours, and the failure group (GF) - 21 patients who required reconnection to the ventilator within 48 hours. sEMG signals were recorded using 5-channel surface electrodes placed around the diaphragm muscle. Shannon and spectral entropies were calculated using a 0.5-minute window with an overlap of 80%. The results presented a greater complexity of the EMG signal in the SG group. This group shows higher peaks in Shannon entropy and elevated spectral entropy values compared to the FG group. Channels 2 and 3 presented the largest statistically significant differences.Clinical Relevance- Analyzing diaphragm EMG signals using entropy metrics could improve patient outcomes by optimizing the timing of extubation. These metrics would serve as a key indicator of readiness for extubation, providing an objective basis for more informed clinical decision-making.
JTD Keywords: Aged, Airway extubation, Diaphragm, Electromyography, Entropy, Female, Humans, Male, Middle aged, Respiration, artificial, Signal processing, computer-assisted, Ventilator weaning
Garcia-de-Albeniz, N, Ginebra, MP, Jiménez-Piqué, E, Mas-Moruno, C, (2025). Chemical etching-induced nanoroughness enhances cell response and antibacterial activity on zirconia JOURNAL OF THE EUROPEAN CERAMIC SOCIETY 45, 117236
Surface topography at the nanoscale plays a crucial role in modulating the biological properties of dental implants. However, the understanding of how the nanoroughness of zirconia affects cell and bacteria responses remains unclear. In this study, chemical etching of 3Y-TZP was explored to develop a nanotopography capable of favoring eukaryotic cell behavior while simultaneously inhibiting bacterial adhesion. Three topographies of different roughness were created by varying the etching time with hydrofluoric acid (i.e., HF15, HF30, and HF60). The etched surfaces exhibited a nanorough topography with randomly distributed nanopits, and surface roughness increased at longer etching times. Mesenchymal stem cell adhesion, spreading, proliferation and mineralization were enhanced on the etched surfaces, compared to flat controls. The roughest surface (HF60) also inhibited S. aureus adhesion and caused significant damage to P. aeruginosa. This study highlights the potential of chemical etching to produce nanorough zirconia with improved biological outcomes.
JTD Keywords: Attachment, Bacteri, Bacterial adhesion, Biomaterials, Cell response, Chemical etching, Dental implants, Dental zirconia, Integration, Osseointegration, Osteogenic differentiation, Parameter, Roughness, Surface-topography, Titanium implants, Zirconia
Gavin, Rosalina, del Rio, Jose Antonio, (2025). Exploring the Biological Connection Between Tau and PrP© in Neuronal Cells: GSK3β as a Possible Key Player MOLECULAR NEUROBIOLOGY 62, 15284-15294
Cellular prion protein (PrPC) and tau are highly expressed in the brain and overlap at the cellular level in neurons. Both proteins contribute directly to neurodegeneration processes in a misfolding state, although in their natural conformation, they play important roles in neurogenesis that could have a common link according to the recent literature. In this sense, it is well known that the proteinase-K resistant PrPC isoform (PrPSc), the prion, is the causal agent of prionopathies. And misfolded tau, which is responsible for tauopathies, is considered "prion-like" because it displays similar behavior to prions in terms of self-aggregation and spreading properties. At the physiological level, PrPC potentiates neuronal differentiation while tau intervenes in axonal maturation and elongation. Likewise, recent studies from our laboratory reported that PrPC directly affects the alternative splicing of tau through inhibition of GSK3 beta while tau, in turn, can regulate PRNP transcription. In this review, we first describe the biology and physiological roles of PrPC and tau in the central nervous system (CNS). Second, in the effort to improve our understanding of a possible cooperation between them in various cellular circumstances, we also discuss the molecular convergence points between PrPC and tau in neurodegeneration and in natural neuronal physiology.
JTD Keywords: Alzheimers-disease, Amyloid-beta, Axonal-transport, Cellular prion protein, Creutzfeldt-jakob-disease, Developmental expression, Gene-expression, Neurodegeneration, Neurofibrillary tangles, Neurogènesi, Phosphorylatio, Straussler-scheinker disease, Tau
Arnau, Marc, Pielsticker, Lukas, Hetaba, Walid, Casanovas, Jordi, Turon, Pau, Aleman, Carlos, Sans, Jordi, (2025). The Synergistic Effect of Combining Electron Transfer and Photoactivation in Hydroxyapatite/ZrO2 Nanocomposites Promotes Efficient Nitrogen-to-Ammonia Fixation Reaction ACS Catalysis 15, 11150-11162
Catalytically active hydroxyapatite (ca-HAp) decorated with zirconia nanoparticles (ZrO2 NPs) is presented as a nanocomposite catalyst (ca-HAp/ZrO2) capable of performing highly efficient nitrogen to ammonia (N2-to-NH3) fixation reactions under mild conditions. Accordingly, reactions were carried out in a batch reactor operating at 120 degrees C, 6 bar of N2, and 20 mL of water, under UV irradiation (14 W) for 72 h. The yield of NH3 obtained was 1.592 +/- 0.146 mmolgc -1, which represents a N2 fixation efficiency of 6.4%. Near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) studies under in situ conditions (i.e., at elevated pressure and temperature and during UV irradiation) and density functional theory simulations (DFT) allowed us to elucidate the catalytic mechanism of the system. The ca-HAp/ZrO2 nanocomposites exhibit a strong synergy arising from the initial photoactivation of N2 by means of the pi-backdonation mechanism in ZrO2 (N2 is anchored by four Zr4+ atoms) followed by the dinitrogen spillover toward the Ca(I)2+ binding sites. Such sites, preferentially exposed in the (001) crystallographic planes of ca-HAp, show high activity due to the enhanced electron transfer properties of ca-HAp. These catalytic nanocomposites represent a viable alternative to the conventional catalysts used for N2-to-NH3 fixation reactions.
JTD Keywords: Amino-acids, Approximation, Catalyst, Electron enhancedproperties, Green catalysis, Hydroxyapatite, N-2 reduction, Permanently polarizedmaterial, Pi-back-donation, Polarized hydroxyapatite, Pressur, Temperature
Wang, Xinru, Guillem-Marti, Jordi, Kumar, Saurav, Lee, David S, Cabrerizo-Aguado, Daniel, Werther, Rachel, Alamo, Kevin Alexander Estrada, Zhao, Yan Ting, Nguyen, Adam, Kopyeva, Irina, Huang, Buwei, Li, Jing, Hao, Yuxin, Li, Xinting, Brizuela-Velasco, Aritza, Murray, Analisa, Gerben, Stacey, Roy, Anindya, DeForest, Cole A, Springer, Timothy, Ruohola-Baker, Hannele, Cooper, Jonathan A, Campbell, Melody G, Manero, Jose Maria, Ginebra, Maria-Pau, Baker, David, (2025). De Novo Design of Integrin α5β1 Modulating Proteins to Enhance Biomaterial Properties ADVANCED MATERIALS 37, 2500872
Integrin alpha 5 beta 1 is crucial for cell attachment and migration in development and tissue regeneration, and alpha 5 beta 1 binding proteins can have considerable utility in regenerative medicine and next-generation therapeutics. We use computational protein design to create de novo alpha 5 beta 1-specific modulating miniprotein binders, called NeoNectins, that bind to and stabilize the open state of alpha 5 beta 1. When immobilized onto titanium surfaces and throughout 3D hydrogels, the NeoNectins outperform native fibronectin (FN) and RGD peptides in enhancing cell attachment and spreading, and NeoNectin-grafted titanium implants outperformed FN- and RGD-grafted implants in animal models in promoting tissue integration and bone growth. NeoNectins should be broadly applicable for tissue engineering and biomedicine.
JTD Keywords: Activation, Alpha(5)beta(1), Biomaterial, Cell, De novo protein design, Differentiation, Fibronectin, Growth-factor-beta, Hydrogel, In-vivo, Integrin alpha 5 beta 1, Ligan, Microscopy, Migration, Regenerative medicine, Rgd, Titaniu
Borrallo-Lopez, L, Guzman, L, Romero, NG, Sampietro, A, Mallo-Abreu, A, Guardia-Escote, L, Teixidó, E, Flick, B, Fernàndez-Busquets, X, Muñoz-Torrero, D, Barenys, M, (2025). Combining the zebrafish embryo developmental toxicity assay (ZEDTA) with hemoglobin staining to accelerate the research of novel antimalarial drugs for pregnant women International Journal for Parasitology-Drugs and Drug Resistance 27, 100582
Background: Malaria during pregnancy implies a high risk for the mother and the developing child. However, the therapeutic options for pregnant women have historically been very limited, especially during the first trimester of pregnancy due to potential adverse effects on embryo-fetal development. Recently, there has been great controversy regarding these potential embryo-fetal adverse effects because the results of rodent studies were not in accordance with the clinical data available, and finally the WHO has changed the recommendations for pregnant women with uncomplicated P. falciparum malaria to treatment with artemether-lumefantrine during the first trimester. The discrepancy between pre-clinical and clinical studies has been attributed to speciesdifferences in the duration of the window of susceptibility of circulating primitive erythroblasts. Methods: Here we provide a tool based on an alternative method to animal experimentation that accelerates the research of novel drugs for pregnant women. We have adapted the zebrafish embryo developmental toxicity assay to include hemoglobin staining in the embryos and two time-points of lethality and dysmorphogenesis evaluation. These two time-points were selected to include one when the development is independent of and one when the development is dependent of erythrocytes function. The method was used to test four marketed antimalarial drugs and three new antimalarial drug candidates. Results: Our combination of tests can correctly predict the teratogenic and non-teratogenic effects of several antimalarial marketed drugs (artemisinin, quinine, chloroquine, and dihydroartemisinin + desbutyl-lumefantrine). Furthermore, we have tested three new drug candidates (GS-GUAN, DONE3TCl, and YAT2150) with novel mechanisms of action, and different from those of the marketed antimalarial drugs. Conclusions: We propose a decision tree combining the results of the two time-points of evaluation together with the information on significant erythrocyte depletion. The aim of this decision tree is to identify compounds with no or lower hazard on teratogenicity or erythrocyte depletion at an early phase of the drug development process.
JTD Keywords: Alternative methods to animal experimentation, Artesunate, Culture, Dihydroartemisinin, Drug discovery, Embryotoxicity test, In-vitro, Inhibitors, Mode, Nams, Paludism, Rat, Resistance, Safety, Teratogenesis, Toxicity testin
Oliver-Vila, I, Sesma-Herrero, E, Belda, F, Seriola, A, Ojosnegros, S, (2025). Robust differentiation and potent immunomodulation of human mesenchymal stromal cells cultured with a xeno-free GMP protein supplement CYTOTHERAPY 27, 552-561
Background/aims: Human mesenchymal stromal cells (hMSC) are multipotent adult cells commonly used in regenerative medicine as advanced therapy medicinal products. The expansion of these cells in xeno-free supplements is highly encouraged by regulatory agencies due to safety concerns. However, the number of supplements with robust performance and consistency for hMSC expansion are limited. Here, we evaluate a xeno-free human plasma-derived protein supplement (Plastem, Grifols) for the expansion and functional evaluation of hMSCs. Methods: hMSC from bone marrow, adipose tissue and umbilical cord were obtained from two suppliers and cultured in Dulbecco's modified Eagle's medium (DMEM/F-12) supplemented with fetal bovine serum 10% (FBS), human platelet lysate 5% (hPL) or Plastem 10%+ hPL0.5%. Cell proliferation was evaluated after culturing hMSC for 13 days with trypan blue exclusion. hMSC immunophenotype was assessed by flow cytometry of surface markers expression. Multipotentiality assay determined the ability of hMSC to differentiate into osteogenic, chondrogenic and adipogenic lineages after 21 days, by using specific staining. Immunomodulatory properties of hMSC were analyzed by measuring suppression of human peripheral blood mononuclear cell (PBMC) proliferation in co-culture with hMSC. Results: Plastem 10% + hPL 0.5% supported robust and sustained hMSC growth with a similar efficiency to the reference supplement FBS 10%. hMSC cultured with the xeno-free supplement presented a similar morphology comparable to FBS-supplemented cells and maintained typical expression of markers: positive (>95%) for CD90, CD73 and CD105; and negative (
JTD Keywords: Animal serum, Bone-marrow, Cell culture media, Cell therapy manufacturing, Expansion, Human mesenchymal stromal cells, Human platelet lysate, Immunomodulation, International-society, Multipotentiality, Proliferation, Serum-free media, Stem-cells, Substitut, Therapy, Xeno-fre
Gutierrez, PAH, Colombi, S, Casanovas, J, Resina, L, Sans, J, Engel, E, Enshaei, H, García-Torres, J, Pérez-Madrigal, MM, Alemán, C, (2025). Engineering Poly(lactic Acid)-Based Scaffolds for Abundant, Sustained, and Prolonged Lactate Release ACS Polymers Au 5, 247-260
Recent studies have revealed that cardiac tissue regeneration is promoted by administering an initial dose of exogenous lactate and locally maintaining an abundant concentration of this compound for a prolonged period (i.e., around 10-14 days) through sustained release. The aim of this study is to develop a scaffold based on poly(lactic acid) (PLA) for achieving a sustained daily release of lactate from the first day to the end of the recommended period. First, a five-layered electroresponsive scaffold has been engineered using three PLA layers (first, third, and fifth), each composed of electrospun microfibers (MFs), separated by spin coated lactate (second) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (fourth) intermediate layers. The hydrophobicity of the outer PLA layers (first and fifth) has been used to maintain the release of lactate from the intermediate second layer over 3 days, while the conducting fourth PEDOT:PSS layer has ensured a complete lactate release by electrostimulation. After that, in a second step, the same scaffold has been re-engineered to maintain the sustained release not only for a short period (3 days) but also for a prolonged period (>10 days). For this purpose, the PLA MFs of the intermediate third layer have been substituted by plasma-treated proteinase K-containing PLA MFs, obtained by electrospinning a PLA:enzyme mixture. The activity of the enzyme, which decomposes the ester bonds of PLA, combined with the effect of the plasma on the PLA structure, results in a prolonged sustained release that, in addition, can be modulated.
JTD Keywords: 4-ethylenedioxythiophene), Cardiac tissue regeneratio, Conducting polymer, Drug-release, Electroresponsivescaffolds, Electrospinning, Energy, Enzymatic degradation, Hydrogel, Nanofibers, Poly(3, Poly(lactic acid), Raman-spectroscopy
White, T, López-Márquez, A, Badosa, C, Jimenez-Mallebrera, C, Samitier, J, Giannotti, MI, Lagunas, A, (2025). Nanomechanics of cell-derived matrices as a functional read-out in collagen VI-related congenital muscular dystrophies Journal of the Royal Society Interface 22, 20240860
Changes in the mechanical properties of the extracellular matrix (ECM) are a hallmark of disease. Due to its relevance, several in vitro models have been developed for the ECM, including cell-derived matrices (CDMs). CDMs are decellularized natural ECMs assembled by cells that closely mimic the in vivo stromal fibre organization and molecular content. Here, we applied atomic force microscopy-force spectroscopy (AFM-FS) to evaluate the nanomechanical properties of CDMs obtained from patients diagnosed with collagen VI-related congenital muscular dystrophies (COL6-RDs). COL6-RDs are a set of neuromuscular conditions caused by pathogenic variants in any of the three major COL6 genes, which result in deficiency or dysfunction of the COL6 incorporated into the ECM of connective tissues. Current diagnosis includes the genetic confirmation of the disease and categorization of the phenotype based on maximum motor ability, as no direct correlation exists between genotype and phenotype of COL6-RDs. We describe differences in the elastic modulus (E) among CDMs from patients with different clinical phenotypes, as well as the restoration of E in CDMs obtained from genetically edited cells. Results anticipate the potential of the nanomechanical analysis of CDMs as a complementary clinical tool, providing phenotypic information about COL6-RDs and their response to gene therapies.
JTD Keywords: Atomic force microscopy-based force spectroscopy, Bethlem myopathy, Cell-derived matrices, Collagen vi-related congenital muscular dystrophies, Elastic modulus, Extracellular matrix, Extracellular-matrix, Fibroblasts, Gene editin, Microenvironment, Migration, Mode, Muscle, Position, Progenitors, Stiffness
Cazzaniga, Giulia, Mori, Matteo, Griego, Anna, Scarpa, Edoardo, Moschetti, Giorgia, Muzzioli, Stefano, Stelitano, Giovanni, Chiarelli, Laurent R, Cocorullo, Mario, Casali, Emanuele, Porta, Alessio, Zanoni, Giuseppe, Tresoldi, Andrea, Pini, Elena, Batalha, Iris L, Battaglia, Giuseppe, Tuccinardi, Tiziano, Rizzello, Loris, Villa, Stefania, Meneghetti, Fiorella, (2025). Nanoenabling MbtI Inhibitors for Next-Generation Tuberculosis Therapy JOURNAL OF MEDICINAL CHEMISTRY 68, 5312-5332
The urgent need for safer and innovative antitubercular agents remains a priority for the scientific community. In pursuit of this goal, we designed and evaluated novel 5-phenylfuran-2-carboxylic acid derivatives targeting Mycobacterium tuberculosis (Mtb) salicylate synthase (MbtI), a key enzyme, absent in humans, that plays a crucial role in Mtb virulence. Several potent MbtI inhibitors demonstrating significant antitubercular activity and a favorable safety profile were identified. Structure-guided optimization yielded 5-(3-cyano-5-isobutoxyphenyl)furan-2-carboxylic acid (1e), which exhibited strong MbtI inhibition (IC50 = 11.2 mu M) and a promising in vitro antitubercular activity (MIC99 = 32 mu M against M. bovis BCG). Esters of 1e were effectively loaded into poly(2-methacryloyloxyethyl phosphorylcholine)-poly(2-(diisopropylamino)ethyl methacrylate) (PMPC-PDPA) polymersomes (POs) and delivered to intracellular mycobacteria, resulting in reduced Mtb viability. This study provides a foundation for the use of POs in the development of future MbtI-targeted therapies for tuberculosis.
JTD Keywords: Chemistry, Discovery, Drug-delivery, Insigh, Polymersomes, Salicylate synthase mbti, Siderophore, Strategies, Target, Visualization
Teule-Trull, Marta, Altuna, Pablo, Arregui, Maria, Rodriguez-Ciurana, Xavier, Aparicio, Conrado, (2025). Antibacterial coatings for dental implants: A systematic review DENTAL MATERIALS 41, 229-247
Objectives: Despite the high survival rates of dental implants, peri-implantitis is a prevalent complication. Periimplantitis is related to biofilm that adheres to the surface of implants and causes peri-implant chronic inflammation and bone destruction. Different surface treatments have been proposed to prevent biofilm formation. The objective of this systematic review was analyzing different types of antimicrobial coatings and identifying the most effective one(s) to control bacterial colonization over extended periods of analysis. Data, sources and study selection: We performed a bibliographic search in Pubmed and Cochrane base of articles published after 2010 to answer, according to the PICO system, the following question: What is the most effective antibacterial surface coating for dental implants? Only papers including a minimum follow-up bacteria growth analysis for at least 48 h were selected. After selection, the studies were classified using the PRISMA system. A total of 40 studies were included. Conclusions: Three main categories of coatings were identified: Antibacterial peptides, synthetic antimicrobial molecules (polymers, antibiotics, ...), and metallic nanoparticles (silver). Antibacterial peptide coatings to modify dental implant surfaces have been the most studied and effective surface modification to control bacterial colonization over extended periods of incubation as they are highly potent, durable and biocompatible. However, more in vitro and pre-clinical studies are needed to assess their true potential as a technology for preventing periimplant infections.
JTD Keywords: Anti-infective coating, Antibiotics, Antimicrobial peptide coatings, Antimicrobial peptides, Antimicrobial polymers, Bacterial colonizatio, Biofilm formatio, Cationic peptides, Chimeric peptides, Dental implants, Human gingival fibroblasts, Metal nanoparticles, Osseointegrated oral implants, Peri-implantitis, Silver nanoparticles, Surface treatment, Sustained-release device, Titanium surfaces
Martinez, Xavier Llorens, Macarrilla, Leonardo Ruiz, Rey-Vinolas, Sergi, Mateos-Timoneda, Miguel A, Engel, Elisabeth, Guix, J M Mora, (2025). Study of bone-tendon interface healing in an animal model using a synthetic scaffold and PRP European Journal of Trauma and Emergency Surgery 51, 124
PurposeBiological matrices have been used to reinforce large rotator cuff tear repairs. However, rapid resorption and initial immune reactions presented challenges in clinical practice. This study evaluates whether a resorbable synthetic matrix (scaffold), used alone or with platelet-rich plasma (PRP), impacts repair processes at microscopic, ultrasound, and biomechanical levels in a rabbit model of induced tendon-bone interface injury.MethodsAn experimental study was performed on 24 rabbits. Two experimental groups (n = 12 each) and a control group (n = 24) were defined. In the first group (BioP), the internal gastrocnemius tendon was sectioned and repaired to bone using double-row sutures, reinforced with a PLC (poly-L-lactic-co-epsilon-caprolactone) and PLA (polylactic acid) scaffold. In the second group (BioP + PRP), autologous PRP was added to the repair. The control group received no scaffold or PRP. Euthanasia was performed at 8 weeks, followed by microscopic, ultrasound, and biomechanical evaluations.ResultsMicroscopically, a granulomatous reaction limited to the foreign body was observed in both scaffold groups. The healing process was not altered in any group, showing good biocompatibility of the scaffold. Echographically, a greater sagittal diameter was observed in the group without PRP compared to the other groups. Biomechanically, no significant differences in rupture zones were found across groups, but the scaffold-only group required a higher maximum applied force before rupture.ConclusionsAt 8 weeks, using a degradable synthetic PLC and PLA scaffold as support at the bone-tendon interface did not significantly alter the normal repair process, showed echographic and biomechanical benefits, and PRP did not show additional benefits in our experimental model.
JTD Keywords: Augmentation, Biology, Biomaterials, Cells, Efficacy, Ge, Matrix, Platelet-rich plasma, Regeneration, Rotator cuff repair, Shoulder, Surgical repair, Technologies, Tissue engineerin
Colombi, S, Mingot, J, Morgado, J, Pérez-Madrigal, MM, García-Torres, J, Armelin, E, Alemán, C, (2025). Stabilizing Semi-Interpenetrated Alginate/Pedot Hydrogels via Glyoxal-Mediated Covalent Crosslinks for Water Steam Generation ADVANCED SUSTAINABLE SYSTEMS 9, 2401005
The chemical and physical stability of bio-hydrogels are of utmost interest to avoid the premature degradation of the polymer and to favor cyclic material operations (i.e., material recovery and re-using). In this work, the stability of different alginate hydrogels semi-interpenetrated with poly(3,4-ethylenedioxythiophene):polystyrene sulfonate conducting polymer (Alg/PEDOT), which acts as a photothermal absorber is examined. More specifically, the behavior of Alg/PEDOT hydrogels ionically and covalently crosslinked with Ca2+ ions and glyoxal, respectively, has been compared when used as water purification platforms. The homogenous porosity and higher cycling capacity of the glyoxal-crosslinked gels provide superior performance for water-steam generation under sunlight irradiation than that of the ionically stabilized gel. Furthermore, increasing the glyoxal cross-linking reaction time prove to have little effect on the porosity and the efficiency of freshwater supply from an artificial seawater solution. Covalent cross-links provide thermal absorber (PEDOT:PSS) retention capacity in artificial seawater, which is critical to maintaining such efficiency with the increasing number of purification cycles. This research opens new frontiers to promote the use of alginate biopolymer in chemical engineering processes such as water desalination, directly addressing the United Nations Sustainable Development Goals for Clean Water & Life on Land.
JTD Keywords: 4-ethylenedioxythiophene, Alginate polysaccharide, Cell delivery, Glyoxal, Interpenetrating hydrogel network, Poly(3, Raman-spectroscopy, Sodium alginate, Tissu
Ciccone G, Azevedo Gonzalez-Oliva M, Versaevel M, Cantini M, Vassalli M, Salmeron-Sanchez M, Gabriele S, (2025). Epithelial Cell Mechanoresponse to Matrix Viscoelasticity and Confinement Within Micropatterned Viscoelastic Hydrogels Advanced Science 12, e2408635-e2408635
Extracellular matrix (ECM) viscoelasticity has emerged as a potent regulator of physiological and pathological processes, including cancer progression. Spatial confinement within the ECM is also known to influence cell behavior in these contexts. However, the interplay between matrix viscoelasticity and spatial confinement in driving epithelial cell mechanotransduction is not well understood, as it relies on experiments employing purely elastic hydrogels. This work presents an innovative approach to fabricate and micropattern viscoelastic polyacrylamide hydrogels with independently tuneable Young's modulus and stress relaxation, specifically designed to mimic the mechanical properties observed during breast tumor progression, transitioning from a soft dissipative tissue to a stiff elastic one. Using this platform, this work demonstrates that matrix viscoelasticity differentially modulates breast epithelial cell spreading, adhesion, YAP nuclear import and cell migration, depending on the initial stiffness of the matrix. Furthermore, by imposing spatial confinement through micropatterning, this work demonstrates that confinement alters cellular responses to viscoelasticity, including cell spreading, mechanotransduction and migration. These findings establish ECM viscoelasticity as a key regulator of epithelial cell mechanoresponse and highlight the critical role of spatial confinement in soft, dissipative ECMs, which was a previously unexplored aspect.
JTD Keywords: Cell adhesion, Cell movement, Confinement, Dynamics, Elastic modulus, Elasticity, Epithelial cells, Extracellular matrix, Extracellular-matrix, Force transmission, Humans, Hydrogels, Mechanics, Mechanotransduction, cellular, Micropatterning, Migration, Morphology, Motilit, Polyacrylamide hydrogels, Stiffness, Substrate, Viscoelasticit, Viscoelasticity, Viscosity
Martinez Garcia de la Torre, Raquel A, Vallverdu, Julia, Xu, Zhenqing, Arino, Silvia, Ferrer-Lorente, Raquel, Zanatto, Laura, Mercado-Gomez, Maria, Aguilar-Bravo, Beatriz, Ruiz-Blazquez, Paloma, Fernandez- Fernandez, Maria, Navarro-Gascon, Artur, Blasco-Roset, Albert, Sanchez-Fernandez-de-Landa, Paula, Pera, Joan, Romero-Moya, Damia, Ayuso Garcia, Paula, Sanchez, Celia Martinez, Vinas, Laura Sererols, Vila, Paula Cantallops, Giraldez, Carmen I Carcamo, Mcquillin, Andrew, Morgan, Marsha Y, Moya-Rull, Daniel, Montserrat, Nuria, Eberle, Delphine, Staels, Bart, Antoine, Benedicte, Azkargorta, Mikel, Lozano, Juan-Jose, Martinez-Chantar, Maria L, Giorgetti, Alessandra, Elortza, Felix, Planavila, Anna, Varela-Rey, Marta, Woodhoo, Ashwin, Zorzano, Antonio, Graupera, Isabel, Moles, Anna, Coll, Mar, Affo, Silvia, Sancho-Bru, Pau, (2025). Trajectory analysis of hepatic stellate cell differentiation reveals metabolic regulation of cell commitment and fibrosis Nature Communications 16, 1489
Defining the trajectory of cells during differentiation and disease is key for uncovering the mechanisms driving cell fate and identity. However, trajectories of human cells remain largely unexplored due to the challenges of studying them with human samples. In this study, we investigate the proteome trajectory of iPSCs differentiation to hepatic stellate cells (diHSCs) and identify RORA as a key transcription factor governing the metabolic reprogramming of HSCs necessary for diHSCs' commitment, identity, and activation. Using RORA deficient iPSCs and pharmacologic interventions, we show that RORA is required for early differentiation and prevents diHSCs activation by reducing the high energetic state of the cells. While RORA knockout mice have enhanced fibrosis, RORA agonists rescue multi-organ fibrosis in in vivo models. Notably, RORA expression correlates negatively with liver fibrosis and HSCs activation markers in patients with liver disease. This study reveals that RORA regulates cell metabolic plasticity, important for mesoderm differentiation, pericyte quiescence, and fibrosis, influencing cell commitment and disease.
JTD Keywords: Generation, Inhibition, Mic
Perucca, Alice, Llonin, Andrea Gomez, Benach, Oriol Mane, Hallopeau, Clement, Rivas, Elisa I, Linares, Jenniffer, Garrido, Marta, Sallent-Aragay, Anna, Golde, Tom, Colombelli, Julien, Dalaka, Eleni, Linacero, Judith, Cazorla, Marina, Galan, Teresa, Pastor Viel, Jordi, Badenas, Xavier, Recort-Bascuas, Alba, Comerma, Laura, Fernandez-Nogueira, Patricia, Rovira, Ana, Roca-Cusachs, Pere, Albanell, Joan, Trepat, Xavier, Calon, Alexandre, Labernadie, Anna, (2025). Micro Immune Response On-chip (MIRO) models the tumour-stroma interface for immunotherapy testing Nature Communications 16, 1279
Immunotherapies are beneficial for a considerable proportion of cancer patients, but ineffective in others. In vitro modelling of the complex interactions between cancer cells and their microenvironment could provide a path to understanding immune therapy sensitivity and resistance. Here we develop MIRO, a fully humanised in vitro platform to model the spatial organisation of the tumour/stroma interface and its interaction with immune cells. We find that stromal barriers are associated with immune exclusion and protect cancer cells from antibody-dependent cellular cytotoxicity, elicited by targeted therapy. We demonstrate that IL2-driven immunomodulation increases immune cell velocity and spreading to overcome stromal immunosuppression and restores anti-cancer response in refractory tumours. Collectively, our study underscores the translational value of MIRO as a powerful tool for exploring how the spatial organisation of the tumour microenvironment shapes the immune landscape and influences the responses to immunomodulating therapies.
JTD Keywords: Activation, Animals, Architecture, Breast-cancer, Cancer-associated fibroblasts, Cell line, tumor, Collagen, Female, Humans, Immunomodulation, Immunotherapy, Interleukin-2, Lab-on-a-chip devices, Mechanism, Mice, Microenvironment, Migration, Neoplasms, Stromal cells, T-cells, Therap, Tumor microenvironment
Grolleman, J, Pijnenburg, IMT, Bouten, CVC, Conte, V, Sahlgren, CM, (2025). 2.5D Model for Ex Vivo Mechanical Characterization of Sprouting Angiogenesis in Living Tissue Jove-Journal of Visualized Experiments , e67641
Sprouting angiogenesis is the formation of new blood vessels from pre-existing vasculature and is of great importance for physiological such as tissue growth and repair and pathological processes, including cancer and metastasis. The multistep process of sprouting angiogenesis is a molecularly and mechanically driven process. It consists of induction of cellular sprout by vascular endothelial growth factor, leader/ follower cell selection through Notch signaling, directed migration of endothelial cells, and vessel fusion and stabilization. A variety of sprouting angiogenesis models have been developed over the years to better understand the underlying mechanisms of cellular sprouting. Despite advancements in understanding the molecular drivers of sprouting angiogenesis, the role of mechanical cues and the mechanical driver of sprouting angiogenesis remains underexplored due to limitations in existing models. In this study, we designed a 2.5D ex vivo model that enables us to mechanically characterize cellular sprouting from a porcine carotid artery using traction force microscopy. The model identifies distinct force patterns within the sprout, where leader cells exert pulling forces and follower cells exert pushing forces on the matrix. The model's versatility allows for the manipulation of both chemical and mechanical cues, such as matrix stiffness, enhancing its relevance to various microenvironments. Here, we demonstrate that the onset of sprouting angiogenesis is stiffness-dependent. The presented 2.5D model for quantifying cellular traction forces in sprouting angiogenesis offers a simplified yet physiologically relevant method, enhancing our understanding of cellular responses to mechanical cues, which could advance tissue engineering and therapeutic strategies against tumor angiogenesis.
JTD Keywords: Cancer, Capillary morphogenesis, Cell, In-vitro, Microscopy, Migration, Traction
Ding, Haitao, Su, Liping, Xie, Zhendong, Castano, Aroa Duro, Li, Yunkun, Perez, Lorena Ruiz, Chen, Junyang, Luo, Kui, Tian, Xiaohe, Battaglia, Giuseppe, (2025). Morphological insights in oxidative sensitive nanocarrier pharmacokinetics, targeting, and photodynamic therapy Journal of Materials Chemistry B 13, 3852-3863
Nanoparticle (NP) morphology holds significant importance in nanomedicine, particularly concerning its implications for biological responses. This study investigates the impact of synthesizing polymers with varying degrees of methionine (MET) polymerization on three distinct drug delivery systems: spherical micelles, worm-like micelles, and vesicles, all loaded with the photosensitizer chlorin e6 (Ce6). We analyzed their distribution at both cellular and animal levels, revealing how NP morphology influences cellular uptake, subcellular localization, penetration of multicellular spheroids, blood half-life, and biodistributions across major organs. Employing a physiologically based pharmacokinetic (PBPK) model enabled us to simulate diverse distribution patterns and quantify the targeting efficiency of NPs toward tumors. Our investigation elucidates that spherical micelles exhibit lower accumulation levels within the reticuloendothelial system, potentially mitigating adverse side effects despite their higher glomerular filtration rate. This nuanced understanding underscores the complex interplay between NP morphology and biological responses, providing valuable insights into optimizing therapeutic efficacy while minimizing undesirable effects. We thus report the integration of experimental analyses with PBPK modeling to elucidate the topological characteristics of NP, thereby shedding light on their distribution patterns, therapeutic efficacy, and potential side effects.
JTD Keywords: Drug, Nanorod, Polymersomes, Strategies
Castrejón-Comas, V, Mataró, N, Resina, L, Zanuy, D, Nuñez-Aulina, Q, Sánchez-Morán, J, Enshaei, H, Arnau, M, Muñoz-Galán, H, Worch, JC, Dove, AP, Alemán, C, Pérez-Madrigal, MM, (2025). Electro-responsive hyaluronic acid-based click-hydrogels for wound healing CARBOHYDRATE POLYMERS 348, 122941
With the aim of healing challenging skin wounds, electro-responsive click-hydrogels made of hyaluronic acid (clickHA) crosslinked with a modified polyethylene glycol precursor (PEG) were prepared by semi- interpenetrating a conducting polymer, poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PEDOT-MeOH) by oxidative polymerization. The porosity and pore size of the mixed hydrogel, clickHA/PEDOT-MeOH, were both higher than those determined for the hydrogel without PEDOT-MeOH, while a honeycomb-like morphology with PEDOT-MeOH covering the pore walls was observed. Although such PEDOT-MeOH-induced changes did not influence the water absorption capacity of clickHA, they drastically affected the mechanical and electrochemical behavior. More specifically, the semi-interpenetration of PEDOT-MeOH into clickHA resulted in an increase of the Young's modulus, the compressive strength and, especially, the electrochemical activity. The biocompatibility and the potential for skin regeneration of clickHA/PEDOT-MeOH were preliminary assessed using viability and wound-healing assays with epithelial cells. Not only is the conducting hydrogel formulation biocompatible, but also promotes efficient cell migration by electrostimulation using a small voltage (0.5 V) for a short time (15 min). Thus, in just 1 h the wound gap was repaired, and a homogeneous monolayer of migrated cells was formed.
JTD Keywords: 4-ethylenedioxythiophene, Car, Click hydrogel, Conducting polymer, Hyaluronic acid, Poly(3, Proliferation, Rational design, Scaffold, Skin, Wound dressing
Acevedo, HG, Arizmendi, CJ, Giraldo, BF, (2025). Analysis of Respiratory Flow Signals Using Poincare Plot Descriptors for Machine Learning-Based Prediction of Ventilator Weaning Success IEEE Access 13, 170523-170534
Acute respiratory distress syndrome (ARDS) is a severe pulmonary condition that often requires mechanical ventilation (MV) to ensure adequate gas exchange and minimize ventilator-induced lung injury. This study compares statistical descriptors derived from respiratory time series with nonlinear variability metrics obtained from Poincar & eacute; plots to predict the outcomes of the weaning process in mechanically ventilated patients. The database, which includes respiratory flow recordings from 243 patients who underwent a standardized 30-minute spontaneous breathing test (SBT), was used to validate the classification models. Patients were categorized into three clinical outcome groups: successful weaning (n = 132), failed weaning (n = 88), and reintubation within 48 hours after completion of the trial (n = 23). Features were selected using nonparametric statistical tests and correlation analysis, eliminating redundancy and retaining discriminative variables. Two machine learning (ML) classifiers, random forest and feedforward neural network, were designed to identify patients belonging to each of the three clinical outcome groups. Model performance was assessed using stratified hold-out cross-validation repeated over 150 iterations, with hyperparameters optimized using Bayesian methods. The random forest classifier using Poincar & eacute; descriptors achieved a mean accuracy of 90.4% and higher F1-scores across all groups, including those who required reintubation. These findings suggest that Poincar & eacute;-based variability metrics, in combination with ensemble learning, may enhance the accurate prediction of MV weaning outcomes in ARDS patients.
JTD Keywords: Heart-rate-variability, Mechanical ventilation,weaning,acute respiratory distress syndrome,poincar & eacute, Plot, Plot,mechanical ventilation,weaning,acute respiratory distress syndrome,poincar & eacute, Successful extubation
Ruperti, F, Dzieciatkowska, M, Pankey, MS, Asensio, CS, Anselmetti, D, Fernàndez-Busquets, X, Nichols, SA, (2024). Proteomic analysis of the sponge Aggregation Factor implicates an ancient toolkit for allorecognition and adhesion in animals PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 121, e2409125121
The discovery that sponges (Porifera) can fully regenerate from aggregates of dissociated cells launched them as one of the earliest experimental models to study the evolution of cell adhesion and allorecognition in animals. This process depends on an extracellular glycoprotein complex called the Aggregation Factor (AF), which is composed of proteins thought to be unique to sponges. We used quantitative proteomics to identify additional AF components and interacting proteins in the classical model, Clathria prolifera, and compared them to proteins involved in cell interactions in Bilateria. Our results confirm MAFp3/p4 proteins as the primary components of the AF but implicate related proteins with calx-beta and wreath domains as additional components. Using AlphaFold, we unveiled close structural similarities of AF components to protein domains in other animals, previously masked by the mutational decay of sequence similarity. The wreath domain, believed to be unique to the AF, was predicted to contain a central beta- sandwich of the same organization as the vWFD domain (also found in extracellular, gel- forming glycoproteins in other animals). Additionally, many copurified proteins share a conserved C- terminus, containing divergent immunoglobulin (Ig) and Fn3 domains predicted to serve as an AF-interaction interface. One of these proteins, MAF- associated protein 1, resembles Ig superfamily cell adhesion molecules and we hypothesize that it may function to link the AF to the surface of cells. Our results highlight the existence of an ancient toolkit of conserved protein domains regulating cell-cell and cell-extracellular matrix protein interactions in all animals, and likely reflect a common origin of cell adhesion and allorecognition.
JTD Keywords: Adhesion, Allorecognitio, Binding, Calcium, Carbohydrate-carbohydrate interactions, Cell-cell adhesion, Evolution, Marine sponge, Microciona-prolifera, Molecule, Porifera, Protein, Proteomics, Recepto, Recognition
Elshof, J, Oppersma, E, Wisse, JJ, Bladder, G, Meijer, PM, Torres, A, Wijkstra, PJ, Duiverman, ML, (2024). Deventilation Syndrome in Patients with Chronic Obstructive Pulmonary Disease Using Nocturnal Noninvasive Ventilation: What Are the Underlying Mechanisms? RESPIRATION 10, 723-732
Introduction: Patients with chronic obstructive pulmonary disease (COPD) commonly experience severe dyspnea after discontinuation of nocturnal noninvasive ventilation (NIV), known as deventilation syndrome (DVS), which negatively affects quality of life. Despite various hypotheses, the precise mechanisms of DVS remain unknown. Methods: An observational pilot study was performed monitoring 16 stable COPD patients before, during, and after an afternoon nap on NIV. Seven patients experienced DVS (Borg Dyspnea Scale >= 5), while nine served as controls (Borg Dyspnea Scale
JTD Keywords: Asynchrony, Chronic obstructive pulmonary disease, Copd patients, Deventilation syndrom, Dyspnea, End-expiratory pressure, Exercise, Hyperinflation, Noninvasive ventilation, Patter
Mastrantuono, E, Ghibaudi, M, Matias, D, Battaglia, G, (2024). The multifaceted therapeutical role of low-density lipoprotein receptor family in high-grade glioma Molecular Oncology 18, 2966-2976
The diverse roles of the low-density lipoprotein receptor family (LDLR) have been associated with many processes critical to maintaining central nervous system (CNS) health and contributing to neurological diseases or cancer. In this review, we provide a comprehensive understanding of the LDLR's involvement in common brain tumors, specifically high-grade gliomas, emphasizing the receptors' critical role in the pathophysiology and progression of these tumors due to LDLR's high expression. We delve into LDLR's role in regulating cellular uptake and transport through the brain barrier. Additionally, we highlight LDLR's role in activating several signaling pathways related to tumor proliferation, migration, and invasion, engaging readers with an in-depth understanding of the molecular mechanisms at play. By synthesizing current research findings, this review underscores the significance of LDLR during tumorigenesis and explores its potential as a therapeutic target for high-grade gliomas. The collective insights presented here contribute to a deeper appreciation of LDLR's multifaceted roles and implications for physiological and pathological states, opening new avenues for tumor treatment. The role of LDLR family receptors in mediating the transport of LDL across the blood-brain barrier (BBB), facilitating processes such as survival, proliferation, and invasion in high-grade gliomas. Nanoparticles targeting LDLR can be used for drug delivery, potentially inducing cell death and reducing tumor proliferation and survival in high-grade glioma cells. image
JTD Keywords: Animals, Blood-brain-barrier, Brain neoplasms, Cancer, Delivery, Doxorubicin, Expression, Glioblastomas, Glioma, Humans, Low-density lipoprotein receptors, Low‐density lipoprotein receptors, Migratio, Nanoparticles, Neoplasm grading, Proliferation, Receptors, ldl, Signal transduction, Targeted therapie, Targeted therapies, Targeting therapy, Tumor microenvironment
Alvira, M, Mondini, A, Puleo, GL, Tahirbegi, IB, Beccai, L, Sadeghi, A, Mazzolai, B, Mir, M, Samitier, J, (2024). Biomimetic Plant-Root-Inspired Robotic Sensor System Biosensors-Basel 14, 565
There are many examples in nature in which the ability to detect is combined with decision-making, such as the basic survival instinct of plants and animals to search for food. We can technically translate this innate function via the use of robotics with integrated sensors and artificial intelligence. However, the integration of sensing capabilities into robotics has traditionally been neglected due to the significant associated technical challenges. Inspired by plant-root chemotropism, we present a miniaturized electrochemical array integrated into a robotic tip, embedding a customized micro-potentiometer. The system contains solid-state sensors fitted to the tip of the robotic root to three-dimensionally monitor potassium and pH changes in a moist, soil-like environment, providing an integrated electronic readout. The sensors measure a range of parameters compatible with realistic soil conditions. The sensors' response can trigger the movement of the robotic root with a control algorithm inspired by the behavior of the plant root that determines the optimal path toward root growth, simulating the decision-making process of a plant. This nature-inspired technology may lead, in the future, to the realization of robotic devices with the potential for monitoring and exploring the soil autonomously.
JTD Keywords: Artificial intelligenc, Biomimetic, Chemical sensor, Ion-selective electrode (ise), Nitrate, Ph, Plant roots, Potassiu, Potassium, Robotics, Soil detection, Tropism
Murugan, D, Tintelott, M, Narayanan, MS, Vu, XT, Kurkina, T, Rodriguez-Emmenegger, C, Schwaneberg, U, Dostalek, J, Ingebrandt, S, Pachauri, V, (2024). Recent Advances in Grating Coupled Surface Plasmon Resonance Technology Advanced Optical Materials 12, 2401862
Surface plasmon resonance (SPR) is a key technique in developing sensor platforms for clinical diagnostics, drug discovery, food quality, and environmental monitoring applications. While prism-coupled (Kretschmann) SPR remains a "gold-standard" for laboratory work-flows due to easier fabrication, handling and high through put, other configurations such as grating-coupled SPR (GC-SPR) and wave-guide mode SPR are yet to fulfil their technology potential. This work evaluates the technical aspects influencing the performance of GC-SPR and reviews recent progress in the fabrication of such platforms. In principle, the GC-SPR involves the illumination of the plasmonic metal film with periodic gratings to excite the surface plasmons (SP) via diffraction-based phase matching. The real performance of the GC-SPR is, however, heavily influenced by the topography of the grating structures produced via top-down lithography techniques. This review discusses latest in approaches to achieve consistent plasmonic gratings with uniform features and periodicity over a large scale and explores the choice of plasmon-active and substrate material for enhanced performance. The review also provides insights into the different GC-SPR measurement configurations and highlights on opportunities with their potential applications as biosensors with translational capabilities. A review on recent progress in the realization of grating-coupled and wave-guide mode surface plasmon resonance (SPR) platforms which have seen very limited progress toward diagnostics applications in comparison to Kretchmann configured SPR. Sophisticated topography manipulation during large-area nanofabrication, integration of emerging nanomaterials, and machine learning-based data analytics are expected to overcome concurrent challenges toward clinical adoption of grating-coupled SPR in coming years. image
JTD Keywords: Aluminum, Biosensor, Chemical sensor, Compact, Fabrication methods, Gc-spr, Gold, Lase, Lithography, Nanogratings, Performance, Plasmonics, Sensitivity enhancement, Sp, Spr sensor
Fontana-Escartín, A, Bertran, O, Alemán, C, (2024). Materials engineering in electrochemical biosensors: A review of cost-effective approaches to efficient biodetection Materials Today Communications 41, 111030
Electrochemical sensors are sophisticated devices capable of detecting a wide range of chemical compounds with exceptional sensitivity and efficiency. Their importance is particularly pronounced in biomedical applications, where the rapid and accurate detection of biomolecules such as dopamine (DA), glucose (G), and nicotinamide adenine dinucleotide (NADH) is crucial for early diagnosis and disease management. These biomarkers are key in monitoring and managing conditions like diabetes, Parkinson and Alzheimer diseases, and bacterial infections. This review provides a comprehensive overview of electrochemical biosensors, detailing the methodologies commonly used by researchers and the latest technological advancements that enable more efficient device development. In this regard, the focus is on the impact and trends of various materials utilized in the fabrication of electrochemical biosensors, including conducting polymers, ceramics, and carbon-based materials. By examining the state of the art, we explore how these materials contribute to enhanced performance and reliability. Furthermore, while the development of highly selective and sensitive nanocomposites has been a primary focus in the field, this review also highlights efforts toward creating cost-effective biosensors with rapid prototyping capabilities. Such innovations aim to maintain high efficacy in electrochemical detection while making advanced diagnostics more accessible. In conclusion, this study aims to inform researchers and professionals about the evolving materials landscape in electrochemical biosensing, offering insights into the future directions of this critical technology.
JTD Keywords: Biomolecules, Biosensor, Dopamine, Electroactive materials, Electrochemical sensors, Electrode, Glucose biosensor, Nanoparticles, Nanosheets, Oxidas, Sensor, Temperature, Transition-metal carbides, Uric-acid
Johansson, L, Raymond, Y, Labay, C, Mateu-Sanz, M, Ginebra, MP, (2024). Enhancing the mechanical performance of 3D-printed self-hardening calcium phosphate bone scaffolds: PLGA-based strategies CERAMICS INTERNATIONAL 50, 46300-46317
Over the last decade, 3D-printed porous calcium phosphates have emerged in the market for customized bone reconstruction. However, despite their excellent biological properties, the inherent brittleness is an obstacle that limits their clinical applications, as the scaffolds must withstand the surgical procedures and the mechanical stresses once implanted. Low-temperature self-hardening calcium phosphate inks offer unique possibilities to be reinforced with polymers, as they do not require high-temperature treatments. This study compares two routes for incorporating poly (lactic-co-glycolic acid) (PLGA) into 3D-printed calcium phosphate scaffolds: i) the use of a PLGA solution as a binder in an alpha-tricalcium phosphate self-hardening ink; ii) the infiltration of a PLGA solution into previously hardened 3D-printed calcium-deficient hydroxyapatite scaffolds. The influence of the added PLGA on the physical-chemical properties, mechanical performance and in vitro biological properties is assessed using a commercially available biomimetic calcium phosphate scaffold as a control. The addition of PLGA increases the plastic deformation capacity and the strength, both in compression and bending, and significantly improves the work of fracture of the scaffolds, up to an 8-fold in compression when PLGA is incorporated as a binder in the ink. Moreover, screwability tests demonstrate the enhanced fixability of the composite scaffolds in a knife-edge ridge indication with challenging fixation in the jaw. Importantly, the improvement of the mechanical properties by the addition of PLGA does not impair the good cytocompatibility of the material. Regarding the two routes studied, the PLGA incorporation in the ink is the best option in terms of overall improvement of the mechanical performance and osteogenic cell response.
JTD Keywords: Alkaline-phosphatase, B. composites, C. mechanical properties, Composite scaffold, D. apatite, Differentiation, E. biomedical application, In-vivo, Join, Regeneration
Niro, F, Fernandes, S, Cassani, M, Apostolico, M, de la Cruz, J, Pereira-Sousa, D, Pagliari, S, Vinarsky, V, Zdrahal, Z, Potesil, D, Pustka, V, Pompilio, G, Sommariva, E, Rovina, D, Maione, AS, Bersanini, L, Becker, M, Rasponi, M, Forte, G, (2024). Fibrotic extracellular matrix impacts cardiomyocyte phenotype and function in an iPSC-derived isogenic model of cardiac fibrosis Translational Research 273, 58-77
Cardiac fibrosis occurs following insults to the myocardium and is characterized by the abnormal accumulation of non-compliant extracellular matrix (ECM), which compromises cardiomyocyte contractile activity and eventually leads to heart failure. This phenomenon is driven by the activation of cardiac fibroblasts (cFbs) to myofibroblasts and results in changes in ECM biochemical, structural and mechanical properties. The lack of predictive in vitro models of heart fibrosis has so far hampered the search for innovative treatments, as most of the cellular-based in vitro reductionist models do not take into account the leading role of ECM cues in driving the progression of the pathology. Here, we devised a single-step decellularization protocol to obtain and thoroughly characterize the biochemical and micro-mechanical properties of the ECM secreted by activated cFbs differentiated from human induced pluripotent stem cells (iPSCs). We activated iPSC-derived cFbs to the myofibroblast phenotype by tuning basic fibroblast growth factor (bFGF) and transforming growth factor beta 1 (TGF-beta 1) signalling and confirmed that activated cells acquired key features of myofibroblast phenotype, like SMAD2/3 nuclear shuttling, the formation of aligned alpha-smooth muscle actin (alpha- SMA)-rich stress fibres and increased focal adhesions (FAs) assembly. Next, we used Mass Spectrometry, nanoindentation, scanning electron and confocal microscopy to unveil the characteristic composition and the visco-elastic properties of the abundant, collagen-rich ECM deposited by cardiac myofibroblasts in vitro. Finally, we demonstrated that the fibrotic ECM activates mechanosensitive pathways in iPSC-derived cardiomyocytes, impacting on their shape, sarcomere assembly, phenotype, and calcium handling properties. We thus propose human bio-inspired decellularized matrices as animal-free, isogenic cardiomyocyte culture substrates recapitulating key pathophysiological changes occurring at the cellular level during cardiac fibrosis.
JTD Keywords: Adhesio, Cardiac fibrosis modelling, Decellularized extracellular matrix, Differentiation, Expression, Fibroblast activation, Fibronectin, Heart, Induced pluripotent stem cells, Ipsc-derived-cardiac fibroblasts, Ipsc-derived-cardiomyocyte, Myocardial-infarction, Neonatal cardiomyocytes, Smooth muscle actin, Substrate stiffness
Montcusi, B, Madrid-Gambin, F, Marin, S, Mayol, X, Pascual, M, Cascante, M, Pozo, OJ, Pera, M, (2024). Circulating Metabolic Markers Identify Patients at Risk for Tumor Recurrence ANNALS OF SURGERY 280, 842-849
Objective:To investigate the spermidine pathway capability to predict patients at risk for tumor recurrence following colorectal cancer (CRC) surgery.Background:Recurrence rates after CRC surgery remain at about 20% despite an optimal technique and adjuvant therapy when necessary. Identification of risk biomarkers of recurrence is an unmet need. The spermidine pathway is indispensable for cell proliferation and differentiation, and is suggested to accelerate tumor spread.Methods:This was a prospective cohort study of patients undergoing CRC surgery from 2015 to 2018. Plasma samples were collected before surgery and on postoperative day 4, and the spermidine pathway was assessed through mass spectrometry. Oncological outcomes were registered.Results:A total of 146 patients were included and 24 (16.4%) developed tumor recurrence. Higher levels of preoperative spermidine pathway components (spermidine, spermine, spermidine synthase enzyme, and spermine/arginine balance) were positively associated with recurrence. Surgery promoted a decrease in these pathway elements. The greater the decline was, the lower the risk of recurrence. Preoperative spermidine over the cut-off of 0.198 mu M displayed a 4.69-fold higher risk of recurrence. The spermine synthase enzyme behaved in the opposite direction.Conclusions:The spermidine pathway is associated with tumor recurrence following CRC surgery and, after confirmation in larger cohorts, could be translated as a risk biomarker of recurrence into clinical practice.
JTD Keywords: Adjuvant chemotherapy, Colon-cancer, Colorectal cancer, Energ, Metabolomics, Polyamine levels, Postoperative intraabdominal infection, Spermidine pathway, Stage, Tumor recurrenc
Ximenes-Carballo, Celia, Rey-Vinolas, Sergi, Blanco-Fernandez, Barbara, Perez-Amodio, Soledad, Engel, Elisabeth, Castano, Oscar, (2024). Combining three-dimensionality and CaP glass-PLA composites: Towards an efficient vascularization in bone tissue healing BIOMATERIALS ADVANCES 164, 213985
Bone regeneration often fails due to implants/grafts lacking vascular supply, causing necrotic tissue and poor integration. Microsurgical techniques are used to overcome this issue, allowing the graft to anastomose. These techniques have limitations, including severe patient morbidity and current research focuses on stimulating angiogenesis in situ using growth factors, presenting limitations, such as a lack of control and increased costs. Non-biological stimuli are necessary to promote angiogenesis for successful bone constructs. Recent studies have reported that bioactive glass dissolution products, such as calcium-releasing nanoparticles, stimulate hMSCs to promote angiogenesis and new vasculature. Moreover, the effect of 3D microporosity has also been reported to be important for vascularisation in vivo. . Therefore, we used room-temperature extrusion 3D printing with polylactic acid (PLA) and calcium phosphate (CaP) based glass scaffolds, focusing on geometry and solvent displacement for scaffold recovery. Combining both methods enabled reproducible control of 3D structure, porosity, and surface topography. Scaffolds maintained calcium ion release at physiological levels and supported human mesenchymal stem cell proliferation. Scaffolds stimulated the secretion of vascular endothelial growth factor (VEGF) after 3 days of culture. Subcutaneous implantation in vivo indicated good scaffold integration and blood vessel infiltration as early as one week after. PLA-CaP scaffolds showed increased vessel maturation 4 weeks after implantation without vascular regression. Results show PLA/CaP-based glass scaffolds, made via controlled 3D printing, support angiogenesis and vessel maturation, promising improved vascularization for bone regeneration.
JTD Keywords: 3d-printed porosity, Angiogenic growth-factors, Bioceramic scaffolds, Bone angiogenesis, Calcium phosphat, Calcium-phosphate, Cells, Composite, Extracellular calcium, Functional-role, In-vitro, Inorganic trace-elements, Matri, Polylactic acid, Regeneration
Lodoso-Torrecilla, I, Konka, J, Kreuzer, M, Jimenez-Pique, E, Espanol, M, Ginebra, MP, (2024). Quality assessment of regenerated bone in intraosseous and intramuscular scaffolds by spectroscopy and nanoindentation BIOMATERIALS ADVANCES 164, 213982
The efficiency of synthetic bone grafts can be evaluated either in osseous sites, to analyze osteoconduction or ectopically, in intramuscular or subcutaneous sites, to assess osteoinduction. Bone regeneration is usually evaluated in terms of the presence and quantity of newly formed bone, but little information is normally provided on the quality of this bone. Here, we propose a novel approach to evaluate bone quality by the combined use of spectroscopy techniques and nanoindentation. Calcium phosphate scaffolds with different architectures, either foamed or 3D-printed, that were implanted in osseous or intramuscular defects in Beagle dogs for 6 or 12 weeks were analyzed. ATR-FTIR and Raman spectroscopy were performed, and mineral-to-matrix ratio, crystallinity, and mineral and collagen maturity were calculated and mapped for the newly regenerated bone and the mature cortical bone from the same specimen. For all the parameters studied, the newly-formed bone showed lower values than the mature host bone. Hardness and elastic modulus were determined by nanoindentation and, in line with what was observed by spectroscopy, lower values were observed in the regenerated bone than in the cortical bone. While, as expected, all techniques pointed to an increase in the maturity of the newly-formed bone between 6 and 12 weeks, the bone found in the intramuscular samples after 12 weeks presented lower mineralization than the intraosseous counterparts. Moreover, scaffold architecture also played a role in bone maturity, with the foamed scaffolds showing higher mineralization and crystallinity than the 3D-printed scaffolds after 12 weeks.
JTD Keywords: Atr-ftir, Bone regeneration, Calcium-phosphate, Ectopic implantation, Implant interface, In-vivo, Indentation, Mechanical-properties, Micromechanical properties, Nanoindentation, Orthotropic implantation, Raman spectroscop, Raman-spectroscopy, Strengt, Substitutes
Barcelona-Estaje, E, Oliva, MAG, Cunniffe, F, Rodrigo-Navarro, A, Genever, P, Dalby, MJ, Roca-Cusachs, P, Cantini, M, Salmeron-Sanchez, M, (2024). N-cadherin crosstalk with integrin weakens the molecular clutch in response to surface viscosity Nature Communications 15, 8824
Mesenchymal stem cells (MSCs) interact with their surroundings via integrins, which link to the actin cytoskeleton and translate physical cues into biochemical signals through mechanotransduction. N-cadherins enable cell-cell communication and are also linked to the cytoskeleton. This crosstalk between integrins and cadherins modulates MSC mechanotransduction and fate. Here we show the role of this crosstalk in the mechanosensing of viscosity using supported lipid bilayers as substrates of varying viscosity. We functionalize these lipid bilayers with adhesion peptides for integrins (RGD) and N-cadherins (HAVDI), to demonstrate that integrins and cadherins compete for the actin cytoskeleton, leading to an altered MSC mechanosensing response. This response is characterised by a weaker integrin adhesion to the environment when cadherin ligation occurs. We model this competition via a modified molecular clutch model, which drives the integrin/cadherin crosstalk in response to surface viscosity, ultimately controlling MSC lineage commitment. The crosstalk between cell-cell and cell-matrix adhesions regulates stem cell fate. Here, the authors reveal a critical role for matrix viscosity in controlling this crosstalk, which they explain via a modified molecular clutch model.
JTD Keywords: Actin cytoskeleton, Adhesion, Animals, Arginyl-glycyl-aspartic acid, Cadherins, Cell adhesion, Cell communication, Fibronectin, Force transmission, Humans, Hydrogel, Integrins, Lipid bilayers, Matrix, Mechanotransduction, Mechanotransduction, cellular, Mesenchymal stem cells, Mobility, Oligopeptides, Osteogenic differentiation, Substrate stiffness, Vinculin, Viscosity
Fanlo-Ucar, H, Picón-Pagès, P, Herrera-Fernández, V, ILL-Raga, G, Muñoz, FJ, (2024). The Dual Role of Amyloid Beta-Peptide in Oxidative Stress and Inflammation: Unveiling Their Connections in Alzheimer's Disease Etiopathology Antioxidants 13, 1208
Alzheimer's disease (AD) is a progressive neurodegenerative disease, and it is currently the seventh leading cause of death worldwide. It is characterized by the extracellular aggregation of the amyloid beta-peptide (A beta) into oligomers and fibrils that cause synaptotoxicity and neuronal death. A beta exhibits a dual role in promoting oxidative stress and inflammation. This review aims to unravel the intricate connection between these processes and their contribution to AD progression. The review delves into oxidative stress in AD, focusing on the involvement of metals, mitochondrial dysfunction, and biomolecule oxidation. The distinct yet overlapping concept of nitro-oxidative stress is also discussed, detailing the roles of nitric oxide, mitochondrial perturbations, and their cumulative impact on A beta production and neurotoxicity. Inflammation is examined through astroglia and microglia function, elucidating their response to A beta and their contribution to oxidative stress within the AD brain. The blood-brain barrier and oligodendrocytes are also considered in the context of AD pathophysiology. We also review current diagnostic methodologies and emerging therapeutic strategies aimed at mitigating oxidative stress and inflammation, thereby offering potential treatments for halting or slowing AD progression. This comprehensive synthesis underscores the pivotal role of A beta in bridging oxidative stress and inflammation, advancing our understanding of AD and informing future research and treatment paradigms.
JTD Keywords: A-beta, Alzheimer's disease, Amyloid beta-peptide, Bace, Blood-brain-barrier, Central-nervous-system, Genome-wide association, Mitochondrial dysfunctio, Mouse model, Neurodegeneration, Nitric-oxide, Nitro-oxidative stress, Precursor protein, Reactive oxygen, Receptor-related protein-1
Cicconofri, G, Blanco, P, Vilanova, G, Sáez, P, Arroyo, M, (2024). Active interfacial degradation/deposition of an elastic matrix by a fluid inclusion: Theory and pattern formation JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS 191, 105773
During collective invasion in 3D, cohesive cellular tissues migrate within a fibrous extracellular matrix (ECM). This process requires significant remodeling of the ECM by cells, notably proteolysis at the cell-ECM interface by specialized molecules. Motivated by this problem, we develop a theoretical framework to study the dynamics of a fluid inclusion (modeling the cellular tissue) embedded in an elastic matrix (the ECM), which undergoes surface degradation/deposition. To account for the active nature of this process, we develop a continuum theory based on irreversible thermodynamics, leading to a kinetic relation for the degradation front that locally resembles the force-velocity relation of a molecular motor. We further study the effect of mechanotransduction on the stability of the cell-ECM interface, finding a variety of self- organized dynamical patterns of collective invasion. Our work identifies ECM proteolysis as an active process possibly driving the self-organization of cellular tissues.
JTD Keywords: Accretion, Accretion and erosion, Active matter, Cell-migration, Collective invasion, Growth, Insight, Irreversible thermodynamics, Mechanics, Model, Morphogenesis, Moving non-material interfaces, Pattern formatio, Proteolysis, Surface, Surface growth
Deng, LL, Olea, AR, Ortiz-Perez, A, Sun, BB, Wang, JH, Pujals, S, Palmans, ARA, Albertazzi, L, (2024). Imaging Diffusion and Stability of Single-Chain Polymeric Nanoparticles in a Multi-Gel Tumor-on-a-Chip Microfluidic Device Small Methods 8, e2301072
The performance of single-chain polymeric nanoparticles (SCPNs) in biomedical applications highly depends on their conformational stability in cellular environments. Until now, such stability studies are limited to 2D cell culture models, which do not recapitulate the 3D tumor microenvironment well. Here, a microfluidic tumor-on-a-chip model is introduced that recreates the tumor milieu and allows in-depth insights into the diffusion, cellular uptake, and stability of SCPNs. The chip contains Matrigel/collagen-hyaluronic acid as extracellular matrix (ECM) models and is seeded with cancer cell MCF7 spheroids. With this 3D platform, it is assessed how the polymer's microstructure affects the SCPN's behavior when crossing the ECM, and evaluates SCPN internalization in 3D cancer cells. A library of SCPNs varying in microstructure is prepared. All SCPNs show efficient ECM penetration but their cellular uptake/stability behavior depends on the microstructure. Glucose-based nanoparticles display the highest spheroid uptake, followed by charged nanoparticles. Charged nanoparticles possess an open conformation while nanoparticles stabilized by internal hydrogen bonding retain a folded structure inside the tumor spheroids. The 3D microfluidic tumor-on-a-chip platform is an efficient tool to elucidate the interplay between polymer microstructure and SCPN's stability, a key factor for the rational design of nanoparticles for targeted biological applications.© 2024 The Authors. Small Methods published by Wiley-VCH GmbH.
JTD Keywords: 3d cancer cell uptake, Cancer cells, Cell culture, Cell uptake, Cellular uptake, Diseases, Ecm penetration, Extracellular matrices, Extracellular matrix penetration, Functional polymers, Hydrogen bonds, Medical applications, Microfluidics, Microstructure, Nanoparticles, Polymeric nanoparticles, Scpns, Single chains, Single-chain polymeric nanoparticle, Stability, Tumor-on-a-chip, Tumors
Garcia-de-Albeniz, N, Hodásová, L, Buxadera-Palomero, J, Jiménez-Piqué, E, Ginebra, MP, Llanes, L, Alemán, C, Armelin, E, Mas-Moruno, C, Fargas, G, (2024). Peptidic biofunctionalization of infiltrated zirconia scaffolds produced by direct ink writing CERAMICS INTERNATIONAL 50, 36993-37001
Porous zirconia scaffolds manufactured using polymer-infiltrated ceramic network (PICN) and additive manufacturing technologies are emerging as promising alternatives to traditional ceramic materials in dental restorations. However, incomplete osseointegration and bacterial infections still represent challenges for the long-term performance of this new composite material. To address this, the present study aims to investigate the effect of peptide biofunctionalization on the biological performance of infiltrated zirconia scaffold surfaces. The samples used in the work consisted of a 3D-printed zirconia scaffold infiltrated with a dimethacrylate copolymer. Surface biofunctionalization was achieved using a synthetic platform containing the cell-adhesive sequence RGD and the antibacteria LF1-11 peptide (RGD-LF). The attachment of the molecule was characterized through fluorescence confocal laser scanning microscopy and X-ray photoelectron spectroscopy. The biological performance of the samples was evaluated in terms of human mesenchymal stem cell adhesion and early attachment of S. aureus. The physicochemical characterization verified the successful anchoring of the biomolecule to the surface, leading to a peptide density of 288 pmol/cm2. 2 . The biological assays confirmed the potential of RGD-LF to improve cell adhesion and spreading. In this sense, the average cell area increased fourfold in the biofunctionalized surface. Regarding bacterial adhesion, it was demonstrated that RGD-LF significantly inhibited it, reducing early adhesion by half compared to the untreated surface. Overall, this study provides valuable insights into the biofunctionalization of polymer-infiltrated 3D scaffolds for the development of cell-instructive and antibacterial surfaces tailored for dental applications.
JTD Keywords: Antibacteria, Biocompatibility, Cell adhesion, Composite, Dental ceramics, Direct ink writing, Fabrication, Infiltrated zirconia scaffolds, Mechanical-properties, Peptide biofunctionalization, Picn material, Strength, Surface, Topograph, Wear behavior
Hinnekens, C, Harizaj, A, Berdecka, D, Aernout, I, Shariati, M, Peeters, S, Lion, E, De Smedt, SC, Vandekerckhove, B, Braeckmans, K, Fraire, JC, (2024). Photoporation of NK-92MI cells with biodegradable polydopamine nanosensitizers as a promising strategy for the generation of engineered NK cell therapies Applied Materials Today 40, 102402
Chimeric antigen receptor (CAR)-T cells have made significant advancements in the field of adoptive immune cell therapies and the treatment of hematological malignancies. However, there are several drawbacks associated with the production and administration of these therapies. As a result, there has been interest in using natural killer (NK) cells to develop allogeneic CAR-NK cell therapies instead. While viral transduction is powerful for engineering T cells, NK cells have shown limited efficacy and high toxicity with this method. Therefore, efforts are being made to optimize non-viral transfection technologies for engineering NK cells. One such emerging technology is photoporation, which has demonstrated high efficiency and versatility for transfecting different immune cells. In this study, we evaluated the potential of nanoparticle-sensitized photoporation for genetic engineering of NK cells. Our findings show that both FD500 and eGFP mRNA can be successfully delivered into NK-92MI cells with high efficiency and low toxicity. When compared to state-of-the-art electroporation, photoporation proved to be more efficient, gentle, and capable of preserving the phenotype of NK-92MI cells. Overall, our work highlights the promising prospects of photoporation for NK cell engineering.
JTD Keywords: Cancer immunotherapie, Car, Cell engineering, Deliver, Messenger-rna, Nanoparticles, Natural killer cells, Natural-killer-cells, Photoporation, Polydopamine nanoparticles, T-cells
Gómez, SG, Ginebra, MP, Gil, FJ, Barraquer, RI, Manero, JM, (2024). Antibacterial and cytocompatible silver coating for titanium Boston Keratoprosthesis Frontiers in Bioengineering and Biotechnology 12, 1421706
The Boston Keratoprosthesis (BKPro) serves as a medical solution for restoring vision in complex cases of corneal blindness. Comprising a front plate made of polymethylmethacrylate (PMMA) and a back plate of titanium (Ti), this device utilizes the beneficial biomaterial properties of Ti. While BKPro demonstrates promising retention rates, infection emerges as a significant concern that impacts its long-term efficacy. However, limited research exists on enhancement of BKPros through intrinsic infection-preventing mechanisms. In this regard, metal ions, especially the well-known Ag+ ions, are a promising alternative to obtain implants with innate antibacterial properties. However, little information is available about the effects of Ag in corneal tissue, especially within human corneal keratocytes (HCKs). In this work, an electrodeposition treatment using a constant pulse is proposed to attach Ag complexes onto rough Ti surfaces, thus providing antibacterial properties without inducing cytotoxicity. Complete physicochemical characterization and ion release studies were carried out with both control and Ag-treated samples. The possible cytotoxic effects in the short and long term were evaluated in vitro with HCKs. Moreover, the antibacterial properties of the silver-treated surfaces were tested against the gram-negative bacterial strain Pseudomonas aeruginosa and the gram-positive strain Staphylococcus epidermidis, that are common contributors to infections in BKPros. Physicochemical characterization confirmed the presence of silver, predominantly in oxide form, with low release of Ag+ ions. Ag-treated surfaces demonstrated no cytotoxicity and promoted long-term proliferation of HCKs. Furthermore, the silver-treated surfaces exhibited a potent antibacterial effect, causing a reduction in bacterial adhesion and evident damage to the bacterial cell walls of P. aeruginosa and S. epidermidis. The low release of Ag+ ions suggested reactive oxygen species (ROS)-mediated oxidative stress imbalance as the bactericidal mechanism of the silver deposits. In conclusion, the proposed electrodeposition technique confers antibacterial protection to the Ti backplate of BKPro, mitigating implant-threatening infections while ensuring non-cytotoxicity within the corneal tissue.
JTD Keywords: Antibacterial properties, Biofilm, Boston keratoprosthesis (bkpro), Corneal blindness, Cytotoxicicity, Cytotoxicit, Electrodeposition, I keratoprosthesis, Infection, Infectious endophthalmitis, Ion, Long-term outcomes, Nanoparticles, Silver depositio, Surface, Titanium (ti)
Camerin, L, Maleeva, G, Gomila, AMJ, Suárez-Pereira, I, Matera, C, Prischich, D, Opar, E, Riefolo, F, Berrocoso, E, Gorostiza, P, (2024). Photoswitchable Carbamazepine Analogs for Non-Invasive Neuroinhibition In Vivo ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 63, e202403636
A problem of systemic pharmacotherapy is off-target activity, which causes adverse effects. Outstanding examples include neuroinhibitory medications like antiseizure drugs, which are used against epilepsy and neuropathic pain but cause systemic side effects. There is a need of drugs that inhibit nerve signals locally and on-demand without affecting other regions of the body. Photopharmacology aims to address this problem with light-activated drugs and localized illumination in the target organ. Here, we have developed photoswitchable derivatives of the widely prescribed antiseizure drug carbamazepine. For that purpose, we expanded our method of ortho azologization of tricyclic drugs to meta/para and to N-bridged diazocine. Our results validate the concept of ortho cryptoazologs (uniquely exemplified by Carbazopine-1) and bring to light Carbadiazocine (8), which can be photoswitched between 400-590 nm light (using violet LEDs and halogen lamps) and shows good drug-likeness and predicted safety. Both compounds display photoswitchable activity in vitro and in translucent zebrafish larvae. Carbadiazocine (8) also offers in vivo analgesic efficacy (mechanical and thermal stimuli) in a rat model of neuropathic pain and a simple and compelling treatment demonstration with non-invasive illumination.
JTD Keywords: Antiepileptic drugs, Anxiet, Azobenzene, Diazocine, Epileps, Ion channels, Neuromodulation, Optical control, Pain, Photopharmacology, Rat, Receptors, Release, Spatiotemporal control, Tricyclic drugs, Zebrafish
Vercruysse, E, Brückner, DB, Gómez-González, M, Remson, A, Luciano, M, Kalukula, Y, Rossetti, L, Trepat, X, Hannezo, E, Gabriele, S, (2024). Geometry-driven migration efficiency of autonomous epithelial cell clusters Nature Physics 20, 1492-1500
The directed migration of epithelial cell collectives through coordinated movements plays a crucial role in various physiological processes and is increasingly understood at the level of large confluent monolayers. However, numerous processes rely on the migration of small groups of polarized epithelial clusters in complex environments, and their responses to external geometries remain poorly understood. To address this, we cultivate primary epithelial keratocyte tissues on adhesive microstripes to create autonomous epithelial clusters with well-defined geometries. We show that their migration efficiency is strongly influenced by the contact geometry and the orientation of cell-cell contacts with respect to the direction of migration. A combination of velocity and polarity alignment with contact regulation of locomotion in an active matter model captures quantitatively the experimental data. Furthermore, we predict that this combination of rules enables efficient navigation in complex geometries, which we confirm experimentally. Altogether, our findings provide a conceptual framework for extracting the interaction rules of active systems from their interaction with physical boundaries, as well as design principles for collective navigation in complex microenvironments. The collective migration of cell clusters is modulated by substrate geometry through a combination of velocity and polarity alignment.
JTD Keywords: Collective migration, Complex, Forces, Mode
González, H, Arizmendi, CJ, Giraldo, BF, (2024). Development of a Deep Learning Model for the Prediction of Ventilator Weaning International Journal Of Online And Biomedical Engineering 20, 161-178
The issue of failed weaning is a critical concern in the intensive care unit (ICU) setting. This scenario occurs when a patient experiences difficulty maintaining spontaneous breathing and ensuring a patent airway within the first 48 hours after the withdrawal of mechanical ventilation. Approximately 20% of ICU patients experience this phenomenon, which has severe repercussions on their health. It also has a substantial impact on clinical evolution and mortality, which can increase by 25% to 50%. To address this issue, we propose a medical support system that uses a convolutional neural network (CNN) to assess a patient's suitability for disconnection from a mechanical ventilator after a spontaneous breathing test (SBT). During SBT, respiratory flow and electrocardiographic activity were recorded and after processed using time-frequency analysis (TFA) techniques. Two CNN architectures were evaluated in this study: one based on ResNet50, with parameters tuned using a Bayesian optimization algorithm, and another CNN designed from scratch, with its structure also adapted using a Bayesian optimization algorithm. The WEANDB database was used to train and evaluate both models. The results showed remarkable performance, with an average accuracy 98 +/- 1.8% when using CNN from scratch. This model has significant implications for the ICU because it provides a reliable tool to enhance patient care by assisting clinicians in making timely and accurate decisions regarding weaning. This can potentially reduce the adverse outcomes associated with failed weaning events.
JTD Keywords: Bayesian optimization algorithm (boa, Continuous wavelet transform (cwt), Convolutional, Extubation, Failur, Intensive-care-unit, Neural network (cnn) from scratch, Respiratory-distress-syndrome, Time-frequency analysis (tfa), Weaning
Colombi, S, Sáez, I, Borras, N, Estrany, F, Pérez-Madrigal, MM, García-Torres, J, Morgado, J, Alemán, C, (2024). Glyoxal crosslinking of electro-responsive alginate-based hydrogels: Effects on the properties CARBOHYDRATE POLYMERS 337, 122170
To improve the features of alginate-based hydrogels in physiological conditions, Ca2+-crosslinked 2 +-crosslinked semi interpenetrated hydrogels formed by poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid and alginate (PEDOT/Alg) were subjected to a treatment with glyoxal to form a dual ionic/covalent network. The covalent network density was systematically varied by considering different glyoxalization times (tG). t G ). The content of Ca2+ was significantly higher for the untreated hydrogel than for the glyoxalized ones, while the properties of the hydrogels were found to largely depend on t G . The porosity and swelling capacity decreased with increasing while the stiffness and electrical conductance retention capacity increased with t G . The potentiodynamic response of the hydrogels notably depended on the amount of conformational restraints introduced by the glyoxal, which is a very short crosslinker. Thus, the re-accommodation of the polymer chains during the cyclic potential scans became more difficult with increasing number of covalent crosslinks. This information was used to improve the performance of untreated PEDOT/Alg as electrochemical sensor of hydrogen peroxide by simply applying a tG G of 5 min. Overall, the control of the properties of glyoxalized hydrogels through tG G is very advantageous and can be used as an on-demand strategy to improve the performance of such materials depending on the application.
JTD Keywords: 4-ethylenedioxythiophene), Acid, Behavior, Cell, Conducting hydrogels, Dual networ, Electrochemical biosensor, Fabrication, Gel, Linke, Microspheres, Peroxidase, Poly(3, Polyvinyl-alcohol, Semi-interpenetrated hydrogel
Longarzo, ML, Vázquez, RF, Bellini, MJ, Zamora, RA, Redondo-Morata, L, Giannotti, MI, Oliveira, ON Jr, Fanani, ML, Maté, SM, (2024). Understanding the effects of omega-3 fatty acid supplementation on the physical properties of brain lipid membranes iScience 27, 110362
A deficiency in omega-3 fatty acids ( to 3 FAs) in the brain has been correlated with cognitive impairment, learning deficiencies, and behavioral changes. In this study, we provided to 3 FAs as a supplement to spontaneously hypertensive rats (SHR+ to 3). Our focus was on examining the impact of dietary supplementation on the physicochemical properties of the brain-cell membranes. Significant increases in to 3 levels in the cerebral cortex of SHR+ to 3 were observed, leading to alterations in brain lipid membranes molecular packing, elasticity, and lipid miscibility, resulting in an augmented phase disparity. Results from synthetic lipid mixtures confirmed the disordering effect introduced by to 3 lipids, showing its consequences on the hydration levels of the monolayers and the organization of the membrane domains. These findings suggest that dietary to 3 FAs influence the organization of brain membranes, providing insight into a potential mechanism for the broad effects of dietary fat on brain health and disease.
JTD Keywords: Behavio, Bilayers, Docosahexaenoic acid, Metabolism, Molecular packing, Phosphatidylcholine, Phosphatidylethanolamine, Polyunsaturated fatty-acids, Raft, Spectroscopy, Sphingomyelin
Parra, A, Denkova, D, Burgos-Artizzu, XP, Aroca, E, Casals, M, Godeau, A, Ares, M, Ferrer-Vaquer, A, Massafret, O, Oliver-Vila, I, Mestres, E, Acacio, M, Costa-Borges, N, Rebollo, E, Chiang, HJ, Fraser, SE, Cutrale, F, Seriola, A, Ojosnegros, S, (2024). METAPHOR: Metabolic evaluation through phasor-based hyperspectral imaging and organelle recognition for mouse blastocysts and oocytes PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 121, e2315043121
Only 30% of embryos from in vitro fertilized oocytes successfully implant and develop to term, leading to repeated transfer cycles. To reduce time-to-pregnancy and stress for patients, there is a need for a diagnostic tool to better select embryos and oocytes based on their physiology. The current standard employs brightfield imaging, which provides limited physiological information. Here, we introduce METAPHOR: Metabolic Evaluation through Phasor-based Hyperspectral Imaging and Organelle Recognition. This non-invasive, label-free imaging method combines two-photon illumination and AI to deliver the metabolic profile of embryos and oocytes based on intrinsic autofluorescence signals. We used it to classify i) mouse blastocysts cultured under standard conditions or with depletion of selected metabolites (glucose, pyruvate, lactate); and ii) oocytes from young and old mouse females, or in vitro-aged oocytes. The imaging process was safe for blastocysts and oocytes. The METAPHOR classification of control vs. metabolites-depleted embryos reached an area under the ROC curve (AUC) of 93.7%, compared to 51% achieved for human grading using brightfield imaging. The binary classification of young vs. old/in vitro-aged oocytes and their blastulation prediction using METAPHOR reached an AUC of 96.2% and 82.2%, respectively. Finally, organelle recognition and segmentation based on the flavin adenine dinucleotide signal revealed that quantification of mitochondria size and distribution can be used as a biomarker to classify oocytes and embryos. The performance and safety of the method highlight the accuracy of noninvasive metabolic imaging as a complementary approach to evaluate oocytes and embryos based on their physiology.
JTD Keywords: Ai, Consumption, Culture, Embryo development, Fluorescence, Hyperspectral imagin, Implantation, In vitro fertilization, Infertility, Label-free imaging, Microscopy, Morphokinetics, Oxygen concentrations, Selectio, Time-lapse
Vera, D, García-Díaz, M, Torras, N, Castillo, O, Illa, X, Villa, R, Alvarez, M, Martinez, E, (2024). A 3D bioprinted hydrogel gut-on-chip with integrated electrodes for transepithelial electrical resistance (TEER) measurements Biofabrication 16, 035008
Conventional gut-on-chip (GOC) models typically represent the epithelial layer of the gut tissue, neglecting other important components such as the stromal compartment and the extracellular matrix (ECM) that play crucial roles in maintaining intestinal barrier integrity and function. These models often employ hard, flat porous membranes for cell culture, thus failing to recapitulate the soft environment and complex 3D architecture of the intestinal mucosa. Alternatively, hydrogels have been recently introduced in GOCs as ECM analogs to support the co-culture of intestinal cells in in vivo-like configurations, and thus opening new opportunities in the organ-on-chip field. In this work, we present an innovative GOC device that includes a 3D bioprinted hydrogel channel replicating the intestinal villi architecture containing both the epithelial and stromal compartments of the gut mucosa. The bioprinted hydrogels successfully support both the encapsulation of fibroblasts and their co-culture with intestinal epithelial cells under physiological flow conditions. Moreover, we successfully integrated electrodes into the microfluidic system to monitor the barrier formation in real time via transepithelial electrical resistance measurements.
JTD Keywords: A-chip, Bioprinted, Caco-2, Cells, Culture, Gut-on-a-chip, Hydrogels, Impedance spectroscopy, Integrated electrodes, Intestinal barrier, Intestinal mucos, Model
Krukiewicz, K, Contessotto, P, Nedjari, S, Martino, MM, Redenski, I, Gabet, Y, Speranza, G, O'Brien, T, Altankov, G, Awaja, F, (2024). Clinical potential of plasma-functionalized graphene oxide ultrathin sheets for bone and blood vessel regeneration: Insights from cellular and animal models BIOMATERIALS ADVANCES 161, 213867
Graphene and graphene oxide (GO), due to their unique chemical and physical properties, possess biochemical characteristics that can trigger intercellular signals promoting tissue regeneration. Clinical applications of thin GO-derived sheets have inspired the development of various tissue regeneration and repair approaches. In this study, we demonstrate that ultrathin sheets of plasma-functionalized and reduced GO, with the oxygen content ranging from 3.2 % to 22 % and the nitrogen content from 0 % to 8.3 %, retain their essential mechanical and molecular integrity, and exhibit robust potential for regenerating bone tissue and blood vessels across multiple cellular and animal models. Initially, we observed the growth of blood vessels and bone tissue in vitro using these functionalized GO sheets on human adipose-derived mesenchymal stem cells and umbilical vein endothelial cells. Remarkably, our study indicates a 2.5-fold increase in mineralization and two-fold increase in tubule formation even in media lacking osteogenic and angiogenic supplements. Subsequently, we observed the initiation, conduction, and formation of bone and blood vessels in a rat tibial osteotomy model, evident from a marked 4-fold increase in the volume of low radio-opacity bone tissue and a significant elevation in connectivity density, all without the use of stem cells or growth factors. Finally, we validated these findings in a mouse critical-size calvarial defect model (33 % higher healing rate) and a rat skin lesion model (up to 2.5-fold increase in the number of blood vessels, and 35 % increase in blood vessels diameter). This study elucidates the proosteogenic and pro-angiogenic properties of both pristine and plasma-treated GO ultrathin films. These properties suggest their significant potential for clinical applications, and as valuable biomaterials for investigating fundamental aspects of bone and blood vessel regeneration.
JTD Keywords: Adhesion, Angiogenesis, Biocompatibilit, Bone regeneratio, Coatings, Fibronectin, Graphene oxide, Growth, Mesenchymal stem-cells, Osteoblast, Osteogenic differentiation, Plasma treatment, Protein, Tissue regeneration
Morales, J, Almazán, DB, Catthoor, F, Groenendaal, W, Jané, R, (2024). Validation of a novel wearable device to estimate heart rate variability and cardiorespiratory indexes 2024 IEEE INTERNATIONAL SYMPOSIUM ON MEDICAL MEASUREMENTS AND APPLICATIONS, MEMEA 2024
Heart rate variability and cardiorespiratory coupling parameters show great potential in offering insights for the assessment and follow-up of patients with different conditions and diseases. The continual acquisition of these parameters would facilitate the ongoing evaluation of patients dealing with various health issues. In this work, we demonstrate the usability of a novel wearable device, the Digipredict Physiopatch, for estimating heart rate variability parameters in the frequency domain and a measure of cardiorespiratory coupling continuously. Signals recorded with the wearable and a Biopac benchtop system were utilized to calculate these parameters. We evaluate differences in the results obtained from the signals of the two devices. The results reveal three distinct aspects. Firstly, the values obtained with the Digipredict Physiopatch are, in general, not significantly different from the ones estimated with the Biopac system. Secondly, we illustrate that it is possible to estimate the cardiorespiratory index using the respiratory signals from the wearable, acquired through bioimpedance. This result validates the use of bioimpedance recorded with Digipredict Physiopatch as an alternative method for acquiring respiratory signals in wearable devices. Thirdly, the cardiorespiratory parameter evaluated in this work appears to be more robust to movement artifacts compared to the heart rate variability parameters due to the inclusion of respiratory information in the algorithms.
JTD Keywords: Cardiorespiratory coupling, Heart rate variabilit, Human, Respiratory sinus arrhythmia, Wearable devices
Palma-Florez, S, Lagunas, A, Mir, M, (2024). Neurovascular unit on a chip: the relevance and maturity as an advanced in vitro model Neural Regeneration Research 19, 1165-1166
[No abstract available]
JTD Keywords: Alpha synuclein, Animal cell, Article, Astrocyte, Brain blood flow, Capillary endothelial cell, Cardiovascular system, Cell interaction, Coculture, Degenerative disease, Differential expression analysis, Endothelium cell, Entactin, Extracellular matrix, Fibronectin, Gene expression, Human, Human cell, Huntington chorea, Hydroxyapatite, In vitro study, Induced pluripotent stem cell, Laminin, Macrophage, Maturity, Microglia, Nervous system, Nervous system inflammation, Neuroprotection, Neurotoxicity, Nonhuman, Parkinson disease, Pericyte, Perivascular space, Personalized medicine, Shear stress, Smooth muscle cell, Three dimensional printing
Dhawan, U, Williams, JA, Windmill, JFC, Childs, P, Gonzalez-Garcia, C, Dalby, MJ, Salmeron-Sanchez, M, (2024). Engineered Surfaces That Promote Capture of Latent Proteins to Facilitate Integrin-Mediated Mechanical Activation of Growth Factors ADVANCED MATERIALS 36, 2310789
Conventional osteogenic platforms utilize active growth factors to repair bone defects that are extensive in size, but they can adversely affect patient health. Here, an unconventional osteogenic platform is reported that functions by promoting capture of inactive osteogenic growth factor molecules to the site of cell growth for subsequent integrin-mediated activation, using a recombinant fragment of latent transforming growth factor beta-binding protein-1 (rLTBP1). It is shown that rLTBP1 binds to the growth-factor- and integrin-binding domains of fibronectin on poly(ethyl acrylate) surfaces, which immobilizes rLTBP1 and promotes the binding of latency associated peptide (LAP), within which inactive transforming growth factor beta 1 (TGF-beta 1) is bound. rLTBP1 facilitates the interaction of LAP with integrin beta 1 and the subsequent mechanically driven release of TGF-beta 1 to stimulate canonical TGF-beta 1 signaling, activating osteogenic marker expression in vitro and complete regeneration of a critical-sized bone defect in vivo. An osteogenic platform that functions by capturing inactive growth factor molecules is engineered to overcome conventional challenges associated with the use of active growth factors. The platform triggers capture of inactive transforming growth factor beta-1 for its subsequent integrin-mediated activation which activates osteogenic downstream signaling in vitro and fully repairs critical-sized bone defect in vivo. image
JTD Keywords: Animals, Bone, Bone defect, Bone regeneration, Cell proliferation, Cells, Chemical activation, Defects, Differentiation, Fibronectin, Fibronectins, Growth factor, Growth factors, Humans, Integrin beta1, Integrins, Latency associated peptides, Latent tgf-beta binding proteins, Ltbp1, Osteogenesis, Osteogenic, Protein binding, Recombinant proteins, Release, Repair, Signal transduction, Surface properties, Tgf-beta, Tgf-β1, Transforming growth factor beta1, Transforming growth factors
Hinnekens, C, Harizaj, A, Berdecka, D, De Smedt, SC, Vandekerckhove, B, Braeckmans, K, Fraire, J, (2024). PHOTOPORATION OF NK-92MI CELLS WITH BIODEGRADABLE POLYDOPAMINE NANOSENSITIZERS AS A PROMISING STRATEGY FOR THE GENERATION OF CAR-NK CELL THERAPIES CYTOTHERAPY 26, S170-S170
Ramon, J, Pinheiro, C, Vandendriessche, C, Lozano-Andrés, E, Arkesteijn, GJ, De Keersmaecker, H, Punj, D, Fraire, J, Geeurickx, E, Wauben, MH, Vandenbroucke, RE, Hendrix, A, Stremersch, S, De Smedt, SC, Raemdonck, K, Braeckmans, K, (2024). PRE-FORMATION LOADING OF EXTRACELLULAR VESICLES WITH EXOGENOUS MOLECULES BY PHOTOPORATION CYTOTHERAPY 26, S85-S86
Asensio-López, J, Làzaro-Díez, M, Hernández-Cruz, TM, Blanco-Cabra, N, Sorzabal-Bellido, I, Arroyo-Urea, EM, Buetas, E, González-Paredes, A, de Solórzano, CO, Burgui, S, Torrents, E, Monteserin, M, Garmendia, J, (2024). Multimodal evaluation of drug antibacterial activity reveals cinnamaldehyde analog anti-biofilm effects against Haemophilus influenzae BIOFILM 7, 100178
Biofilm formation by the pathobiont Haemophilus influenzae is associated with human nasopharynx colonization, otitis media in children, and chronic respiratory infections in adults suffering from chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD). beta-lactam and quinolone antibiotics are commonly used to treat these infections. However, considering the resistance of biofilm-resident bacteria to antibiotic -mediated killing, the use of antibiotics may be insufficient and require being replaced or complemented with novel strategies. Moreover, unlike the standard minimal inhibitory concentration assay used to assess antibacterial activity against planktonic cells, standardization of methods to evaluate anti-biofilm drug activity is limited. In this work, we detail a panel of protocols for systematic analysis of drug antimicrobial effect on bacterial biofilms, customized to evaluate drug effects against H. influenzae biofilms. Testing of two cinnamaldehyde analogs, (E)- trans-2-nonenal and (E)-3-decen-2-one, demonstrated their effectiveness in both H. influenzae inhibition of biofilm formation and eradication or preformed biofilms. Assay complementarity allowed quantifying the dynamics and extent of the inhibitory effects, also observed for ampicillin resistant clinical strains forming biofilms refractory to this antibiotic. Moreover, cinnamaldehyde analog encapsulation into poly(lactic-co-glycolic acid) (PLGA) polymeric nanoparticles allowed drug vehiculization while maintaining efficacy. Overall, we demonstrate the usefulness of cinnamaldehyde analogs against H. influenzae biofilms, present a test panel that can be easily adapted to a wide range of pathogens and drugs, and highlight the benefits of drug nanoencapsulation towards safe controlled release.
JTD Keywords: Anti-biofilm drugs, Antibodies, Biofilm, Cinnamaldehyde-analogs, Haemophilus influenzae, In-vitro, Maturation, Multimodal methods, Nanoformulation
Dai, JH, Fischer, NG, Rahimi, JR, Wang, HN, Hu, CM, Chen, WE, Lin, YF, Sang, T, Chew, HP, Kong, L, Aparicio, C, Ye, Z, Huang, SB, (2024). Interpenetrating nanofibrillar membrane of self-assembled collagen and antimicrobial peptides for enhanced bone regeneration INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES 267, 131480
Bone regeneration remains a major clinical challenge, especially when infection necessitates prolonged antibiotic treatment. This study presents a membrane composed of self-assembled and interpenetrating GL13K, an antimicrobial peptide (AMP) derived from a salivary protein, in a collagen membrane for antimicrobial activity and enhanced bone regeneration. Commercially available collagen membranes were immersed in GL13K solution, and self-assembly was initiated by raising the solution pH to synthesize the multifunctional membrane called COL-GL. COL-GL was composed of interpenetrating large collagen fibers and short GL13K nanofibrils, which increased hydrophobicity, reduced biodegradation from collagenase, and stiffened the matrix compared to control collagen membranes. Incorporation of GL13K led to antimicrobial and anti-fouling activity against early oral surface colonizer Streptococcus gordonii while not affecting fibroblast cytocompatibility or pre-osteoblast osteogenic differentiation. GL13K in solution also reduced macrophage inflammatory cytokine expression and increased pro-healing cytokine expression. Bone formation in a rat calvarial model was accelerated at eight weeks with COL-GL compared to the gold-standard collagen membrane based on microcomputed tomography and histology. Interpenetration of GL13K within collagen sidesteps challenges with antimicrobial coatings on bone regeneration scaffolds while increasing bone regeneration. This strength makes COL-GL a promising approach to reduce post-surgical infections and aid bone regeneration in dental and orthopedic applications. Statement of significance: The COL-GL membrane, incorporating the antimicrobial peptide GL13K within a collagen membrane, signifies a noteworthy breakthrough in bone regeneration strategies for dental and orthopedic applications. By integrating self-assembled GL13K nanofibers into the membrane, this study successfully addresses the challenges associated with antimicrobial coatings, exhibiting improved antimicrobial and antifouling activity while preserving compatibility with fibroblasts and pre-osteoblasts. The accelerated bone formation observed in a rat calvarial model emphasizes the potential of this innovative approach to minimize postsurgical infections and enhance bone regeneration outcomes. As a promising alternative for future therapeutic interventions, this material tackles the clinical challenges of extended antibiotic treatments and antibiotic resistance in bone regeneration scenarios.
JTD Keywords: Antibacterial, Antimicrobial, Antimicrobial peptide, Bone regeneration, Coatings, Collagen, Gl13k, Growth-factor delivery, Infection, Release, Scaffolds, Self -assembly, Strategies, Titanium
Ortega, J Alberto, Soares de Aguiar, Gisele P, Chandravanshi, Palash, Levy, Natacha, Engel, Elisabeth, Alvarez, Zaida, (2024). Exploring the properties and potential of the neural extracellular matrix for next-generation regenerative therapies Wiley Interdisciplinary Reviews-Nanomedicine and Nanobiotechnology 16, e1962
The extracellular matrix (ECM) is a dynamic and complex network of proteins and molecules that surrounds cells and tissues in the nervous system and orchestrates a myriad of biological functions. This review carefully examines the diverse interactions between cells and the ECM, as well as the transformative chemical and physical changes that the ECM undergoes during neural development, aging, and disease. These transformations play a pivotal role in shaping tissue morphogenesis and neural activity, thereby influencing the functionality of the central nervous system (CNS). In our comprehensive review, we describe the diverse behaviors of the CNS ECM in different physiological and pathological scenarios and explore the unique properties that make ECM-based strategies attractive for CNS repair and regeneration. Addressing the challenges of scalability, variability, and integration with host tissues, we review how advanced natural, synthetic, and combinatorial matrix approaches enhance biocompatibility, mechanical properties, and functional recovery. Overall, this review highlights the potential of decellularized ECM as a powerful tool for CNS modeling and regenerative purposes and sets the stage for future research in this exciting field. This article is categorized under: Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Implantable Materials and Surgical Technologies > Nanomaterials and Implants
JTD Keywords: Amyotrophic-lateral-sclerosis, Biologic scaffold, Central nervous system, Central-nervous-system, Chondroitin sulfate proteoglycans, Decellularization, Extracellular matrix, Motor-neurons, Neural disorders, Neural regeneratio, Perineuronal nets, Self-healing hydrogel, Spinal-cord-injury, Stem-cell, Vascular basement-membrane
Salgado, Blanca, Izquierdo, Beatriz, Zapata, Alba, Sastre, Isabel, Kristen, Henrike, Terreros, Julia, Mejias, Victor, Bullido, Maria J, Aldudo, Jesus, (2024). Cholesterol Modulation Attenuates the AD-like Phenotype Induced by Herpes Simplex Virus Type 1 Infection Biomolecules 14, 603
Cholesterol, a crucial component of cell membranes, influences various biological processes, including membrane trafficking, signal transduction, and host-pathogen interactions. Disruptions in cholesterol homeostasis have been linked to congenital and acquired conditions, including neurodegenerative disorders such as Alzheimer's disease (AD). Previous research from our group has demonstrated that herpes simplex virus type I (HSV-1) induces an AD-like phenotype in several cell models of infection. This study explores the interplay between cholesterol and HSV-1-induced neurodegeneration. The impact of cholesterol was determined by modulating its levels with methyl-beta-cyclodextrin (M beta CD) using the neuroblastoma cell lines SK-N-MC and N2a. We have found that HSV-1 infection triggers the intracellular accumulation of cholesterol in structures resembling endolysosomal/autophagic compartments, a process reversible upon M beta CD treatment. Moreover, M beta CD exhibits inhibitory effects at various stages of HSV-1 infection, underscoring the importance of cellular cholesterol levels, not only in the viral entry process but also in subsequent post-entry stages. M beta CD also alleviated several features of AD-like neurodegeneration induced by viral infection, including lysosomal impairment and intracellular accumulation of amyloid-beta peptide (A beta) and phosphorylated tau. In conclusion, these findings highlight the connection between cholesterol, neurodegeneration, and HSV-1 infection, providing valuable insights into the underlying mechanisms of AD.
JTD Keywords: Alzheimer's disease, Arterial cells, Beta-amyloid, Cholesterol, Hsv-1, Hyperphosphorylated ta, Infection, Lysosomal alterations, Methyl-beta-cyclodextrin, Neuroblastoma cells, Neurodegeneration, Syste
Brewer, MK, Torres, P, Ayala, V, Portero-Otin, M, Pamplona, R, Andrés-Benito, P, Ferrer, I, Guinovart, JJ, Duran, J, (2024). Glycogen accumulation modulates life span in a mouse model of amyotrophic lateral sclerosis JOURNAL OF NEUROCHEMISTRY 168, 744-759
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by the progressive loss of motor neurons in the spinal cord. Glial cells, including astrocytes and microglia, have been shown to contribute to neurodegeneration in ALS, and metabolic dysfunction plays an important role in the progression of the disease. Glycogen is a soluble polymer of glucose found at low levels in the central nervous system that plays an important role in memory formation, synaptic plasticity, and the prevention of seizures. However, its accumulation in astrocytes and/or neurons is associated with pathological conditions and aging. Importantly, glycogen accumulation has been reported in the spinal cord of human ALS patients and mouse models. In the present work, using the SOD1G93A mouse model of ALS, we show that glycogen accumulates in the spinal cord and brainstem during symptomatic and end stages of the disease and that the accumulated glycogen is associated with reactive astrocytes. To study the contribution of glycogen to ALS progression, we generated SOD1G93A mice with reduced glycogen synthesis (SOD1G93A GShet mice). SOD1G93A GShet mice had a significantly longer life span than SOD1G93A mice and showed lower levels of the astrocytic pro-inflammatory cytokine Cxcl10, suggesting that the accumulation of glycogen is associated with an inflammatory response. Supporting this, inducing an increase in glycogen synthesis reduced life span in SOD1G93A mice. Altogether, these results suggest that glycogen in reactive astrocytes contributes to neurotoxicity and disease progression in ALS.© 2023 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of International Society for Neurochemistry.
JTD Keywords: activation, astrocytes, brain, contributes, expression, glycogen, impairment, mice, motor neurons, neurodegeneration, reactive astrocytes, spinal cord, Amyotrophic lateral sclerosis, Astrocytes, Glycogen, Motor neurons, Motor-neuron degeneration, Neurodegeneration, Spinal cord
Arnau, M, Sans, J, Gallego, E, Peraales, JF, Turon, P, Alemán, C, (2024). Polarized hydroxyapatite, a ceramic nanocatalyst to convert automotive carbon emissions into ethanol Journal of Environmental Chemical Engineering 12, 112255
This paper is aimed to develop ultrananoporous polarized hydroxyapatite (HAp) catalyst and evaluate its per-formance in transforming CO2 into useable ethanol considering three different scenarios: 1) a batch reaction using a mixture of CO2 and CH4 as feeding gas; 2) a batch reaction using as reactant exhaust gases captured from the fumes of diesel vehicles; and 3) a continuous flow reaction using pure CO2 as feeding gas. Ultrananoporous HAp scaffolds were prepared using a four-step process: 1) as prepared HAp powder was mixed with 60% wt. of a commercial hydrogel at low-temperature; 2) the resulting paste was shaped at low temperature to reduce the adhesion between the metallic tools and the mixture, enhancing the homogeneity of the sample; 3) the shaped paste was calcined in air by applying 1000 oC during 2 h to eliminate the hydrogel; and 4) an external DC electric field of 3 kV/cm was imposed at 1000 oC during 1 h to the calcined scaffold. The resulting polarized scaffolds both ultrananoporosity and catalytic activation. Thus, the mass: volume ratio of the ultrananoporous catalyst was much lower than that of conventional HAp catalyst (718 vs 5093 g/L. Furthermore, the ethanol yield was much higher (up to a factor of x21.4) for the ultrananoporous catalyst than for the compact one, allowing us to conclude that ultrananoporous polarized HAp catalyst is a promising technology for transforming CO2 into valuable chemical products from highly polluted gases, especially those coming from road, sea and air transport.
JTD Keywords: A: ceramics, Air pollution, Automotives, Batch reactions, Calcination, Carbon, Carbon dioxide, Co2 fixation, Co2 reduction, Desig, Electric fields, Environmental process, Ethanol, Exhaust gases, Feeding gas, Fumes, Hydrogels, Hydroxyapatite, Lows-temperatures, Nano-catalyst, Nanocatalysts, Polarized catalys, Polarized catalyst, Scaffolds, Temperature, ]+ catalyst
Simo, C, Serra-Casablancas, M, Hortelao, AC, Di Carlo, V, Guallar-Garrido, S, Plaza-Garcia, S, Rabanal, RM, Ramos-Cabrer, P, Yaguee, B, Aguado, L, Bardia, L, Tosi, S, Gomez-Vallejo, V, Martin, A, Patino, T, Julian, E, Colombelli, J, Llop, J, Sanchez, S, (2024). Urease-powered nanobots for radionuclide bladder cancer therapy Nature Nanotechnology 19, 554-564
Bladder cancer treatment via intravesical drug administration achieves reasonable survival rates but suffers from low therapeutic efficacy. To address the latter, self-propelled nanoparticles or nanobots have been proposed, taking advantage of their enhanced diffusion and mixing capabilities in urine when compared with conventional drugs or passive nanoparticles. However, the translational capabilities of nanobots in treating bladder cancer are underexplored. Here, we tested radiolabelled mesoporous silica-based urease-powered nanobots in an orthotopic mouse model of bladder cancer. In vivo and ex vivo results demonstrated enhanced nanobot accumulation at the tumour site, with an eightfold increase revealed by positron emission tomography in vivo. Label-free optical contrast based on polarization-dependent scattered light-sheet microscopy of cleared bladders confirmed tumour penetration by nanobots ex vivo. Treating tumour-bearing mice with intravesically administered radio-iodinated nanobots for radionuclide therapy resulted in a tumour size reduction of about 90%, positioning nanobots as efficient delivery nanosystems for bladder cancer therapy.© 2024. The Author(s).
JTD Keywords: cell, drug-delivery, nanomotors, tissue, Bladder cancers, Cancer therapy, Diseases, Drug administration, Drug delivery, Enhanced diffusion, Enhanced mixing, Ex-vivo, In-vivo, Mammals, Nanobots, Nanoparticles, Nanosystems, Oncology, Positron emission tomography, Radioisotopes, Silica, Survival rate, Therapeutic efficacy, Tumor penetration, Tumors
Tanwar, S, Millan-Solsona, R, Ruiz-Molina, S, Mas-Torrent, M, Kyndiah, A, Gomila, G, (2024). Nanoscale Operando Characterization of Electrolyte-Gated Organic Field-Effect Transistors Reveals Charge Transport Bottlenecks ADVANCED MATERIALS 36, 2309767
Charge transport in electrolyte-gated organic field-effect transistors (EGOFETs) is governed by the microstructural property of the semiconducting thin film that is in direct contact with the electrolyte. Therefore, a comprehensive nanoscale operando characterization of the active channel is crucial to pinpoint various charge transport bottlenecks for rational and targeted optimization of the devices. Here, the local electrical properties of EGOFETs are systematically probed by in-liquid scanning dielectric microscopy (in-liquid SDM) and a direct picture of their functional mechanism at the nanoscale is provided across all operational regimes, starting from subthreshold, linear to saturation, until the onset of pinch-off. To this end, a robust interpretation framework of in-liquid SDM is introduced that enables quantitative local electric potential mapping directly from raw experimental data without requiring calibration or numerical simulations. Based on this development, a straightforward nanoscale assessment of various charge transport bottlenecks is performed, like contact access resistances, inter- and intradomain charge transport, microstructural inhomogeneities, and conduction anisotropy, which have been inaccessible earlier. Present results contribute to the fundamental understanding of charge transport in electrolyte-gated transistors and promote the development of direct structure-property-function relationships to guide future design rules. This study delves into the charge transport properties of electrolyte-gated organic field-effect transistors by employing in-liquid scanning dielectric microscopy. By introducing a novel interpretation framework, the research achieves quantitative mapping of the local electric potential, facilitating a detailed assessment of charge transport bottlenecks across all operational regimes. The findings can fosterthe formulation ofstructure-property-function relationships for device optimization.image
JTD Keywords: Conduction anisotropy, Conductivity maps, Electrolyte-gated organic field-effect transistors, Nanoscale, Operando, Operation regimes, Potential maps, Scanning dielectric microscopy
Ramirez-Alba, Maria Dolores, Molins-Martinez, Marta, Garcia-Torres, Jose, Romanini, Michela, Macovez, Roberto, Perez-Madrigal, Maria M, Aleman, Carlos, (2024). pH and electrically responsive hydrogels with adhesive property REACTIVE & FUNCTIONAL POLYMERS 196, 105841
Applications of sodium alginate (Alg) and polyacrylic acid (PAA) hydrogels in biomedicine are well-known. These are predefined by the strength and weakness of their properties, which in turn depend on the chemical structure and the architecture of their crosslinks. In this work, Alg biopolymer has been grafted to synthetic PAA that has been chemically crosslinked using N,N '-methylene-bisacrylamide (MBA) to produce a pH responsive hydrogel with adhesive property. The double crosslinking network, which combines MBA-mediated covalent crosslinks and ionic crosslinks in Alg domains, results in an elastic modulus that resembles that of highly anisotropic and viscoelastic human skin. After addressing the influence of the dual network onto the Alg-g-PAA hydrogel properties, a prospection of its potential as an adhesive has been made considering different surfaces (rubber, paper steel, porcine skin, etc). The bonding energy onto porcine skin, 32.6 +/- 4.6 J/m2, revealed that the Alg-g-PAA hydrogel can be proposed in the biomedical field as tissue adhesive for wound healing applications. Finally, the hydrogel has been semi-interpenetrated with poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PEDOT-MeOH) chains through a chemical oxidative polymerization process. The resulting hydrogel, Alg-g- PAA/PEDOT-MeOH, which is even more porous than Alg-g-PAA, in addition to being electro-responsive, maintains adhesive properties.
JTD Keywords: Adhesion properties, Adhesion properties,biomedical applications,bonding energy,dual network,conducting hydrogel, Adhesive properties, Adhesives, Biomedical applications, Biopolymers, Bonding energies, Bonding energy, Chemical bonds, Conducting hydrogels, Crosslinking, Dual network, Hydrogels, Medical applications, Methylenebisacrylamide, Poly(acrylic acid), Porcine skin, Property, Rational design,film, Sodium alginate
Montcusí, B, Madrid-Gambin, F, Pozo, OJ, Marco, S, Marin, S, Mayol, X, Pascual, M, Alonso, S, Salvans, S, Jiménez-Toscano, M, Cascante, M, Pera, M, (2024). Circulating metabolic markers after surgery identify patients at risk for severe postoperative complications: a prospective cohort study in colorectal cancer International Journal of Surgery 110, 1493-1501
Background: Early detection of postoperative complications after colorectal cancer (CRC) surgery is associated with improved outcomes. The aim was to investigate early metabolomics signatures capable to detect patients at risk for severe postoperative complications after CRC surgery. Materials and methods: Prospective cohort study of patients undergoing CRC surgery from 2015 to 2018. Plasma samples were collected before and after surgery, and analyzed by mass spectrometry obtaining 188 metabolites and 21 ratios. Postoperative complications were registered with Clavien-Dindo Classification and Comprehensive Complication Index. Results: One hundred forty-six patients were included. Surgery substantially modified metabolome and metabolic changes after surgery were quantitatively associated with the severity of postoperative complications. The strongest positive relationship with both Clavien-Dindo and Comprehensive Complication Index (beta=4.09 and 63.05, P<0.001) corresponded to kynurenine/tryptophan, against an inverse relationship with lysophosphatidylcholines (LPCs) and phosphatidylcholines (PCs). Patients with LPC18:2/PCa36:2 below the cut-off 0.084 mu M/mu M resulted in a sevenfold higher risk of major complications (OR=7.38, 95% CI: 2.82-21.25, P<0.001), while kynurenine/tryptophan above 0.067 mu M/mu M a ninefold (OR=9.35, 95% CI: 3.03-32.66, P<0.001). Hexadecanoylcarnitine below 0.093 mu M displayed a 12-fold higher risk of anastomotic leakage-related complications (OR=11.99, 95% CI: 2.62-80.79, P=0.004). Conclusion: Surgery-induced phospholipids and amino acid dysregulation is associated with the severity of postoperative complications after CRC surgery, including anastomotic leakage-related outcomes. The authors provide quantitative insight on metabolic markers, measuring vulnerability to postoperative morbidity that might help guide early decision-making and improve surgical outcomes.
JTD Keywords: Acids, Anastomotic leakage, Bypass, Clinical-practice guidelines, Colon, Colorectal cancer, Metabolomics, Postoperative complications, Predict, Sepsis, Trauma, Tryptophan degradation
Avalos-Padilla, Y, Fernandez-Busquets, X, (2024). Nanotherapeutics against malaria: A decade of advancements in experimental models Wiley Interdisciplinary Reviews-Nanomedicine and Nanobiotechnology 16, e1943
Malaria, caused by different species of protists of the genus Plasmodium, remains among the most common causes of death due to parasitic diseases worldwide, mainly for children aged under 5. One of the main obstacles to malaria eradication is the speed with which the pathogen evolves resistance to the drug schemes developed against it. For this reason, it remains urgent to find innovative therapeutic strategies offering sufficient specificity against the parasite to minimize resistance evolution and drug side effects. In this context, nanotechnology-based approaches are now being explored for their use as antimalarial drug delivery platforms due to the wide range of advantages and tuneable properties that they offer. However, major challenges remain to be addressed to provide a cost-efficient and targeted therapeutic strategy contributing to malaria eradication. The present work contains a systematic review of nanotechnology-based antimalarial drug delivery systems generated during the last 10 years. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease
JTD Keywords: Adjuvant system, Antimalarial activities, Antimalarial agent, Antimalarial drug, Antimalarial drugs, Antimalarials, Artemisinin resistance, Causes of death, Child, Controlled drug delivery, Diseases, Drug delivery system, Drug delivery systems, Drug interactions, Drug side-effects, Drug-delivery, Experimental modelling, Heparan-sulfate, Human, Humans, In-vitro, Malaria, Malaria vaccine, Mannosylated liposomes, Medical nanotechnology, Models, theoretical, Nanocarriers, Nanomedicine, Nanotechnology, Parasite-, Parasitics, Plasmodium, Plasmodium-falciparum malaria, Red-blood-cells, Targeted delivery, Targeted drug delivery, Theoretical model, Therapeutic strategy
Humbert, P, Kampleitner, C, De Lima, J, Brennan, MA, Lodoso-Torrecilla, I, Sadowska, JM, Blanchard, F, Canal, C, Ginebra, MP, Hoffmann, O, Layrolle, P, (2024). Phase composition of calcium phosphate materials affects bone formation by modulating osteoclastogenesis Acta Biomaterialia 176, 417-431
Human mesenchymal stromal cells (hMSCs) seeded on calcium phosphate (CaP) bioceramics are extensively explored in bone tissue engineering and have recently shown effective clinical outcomes. In previous pre-clinical studies, hMSCs-CaP-mediated bone formation was preceded by osteoclastogenesis at the implantation site. The current study evaluates to what extent phase composition of CaPs affects the osteoclast response and ultimately influence bone formation. To this end, four different CaP bioceramics were used, hydroxyapatite (HA), beta-tricalcium phosphate (beta-TCP) and two biphasic composites of HA/beta- TCP ratios of 60/40 and 20/80 respectively, for in vitro osteoclast differentiation and correlation with in vivo osteoclastogenesis and bone formation. All ceramics allowed osteoclast formation in vitro from mouse and human precursors, except for pure HA, which significantly impaired their maturation. Ectopic implantation alongside hMSCs in subcutis sites of nude mice revealed new bone formation at 8 weeks in all conditions with relative amounts for beta-TCP > biphasic CaPs > HA. Surprisingly, while hMSCs were essential for osteoinduction, their survival did not correlate with bone formation. By contrast, the degree of early osteoclastogenesis (2 weeks) seemed to define the extent of subsequent bone formation. Together, our findings suggest that the osteoclastic response could be used as a predictive marker in hMSC-CaPbased bone regeneration and strengthens the need to understand the underlying mechanisms for future biomaterial development. Statement of significance The combination of mesenchymal stromal cells (MSCs) and calcium phosphate (CaP) materials has demonstrated its safety and efficacy for bone regeneration in clinical trials, despite our insufficient understanding of the underlying biological mechanisms. Osteoclasts were previously suggested as key mediators between the early inflammatory phase following biomaterial implantation and the subsequent bone formation. Here we compared the affinity of osteoclasts for various CaP materials with different ratios of hydroxyapatite to beta-tricalcium phosphate. We found that osteoclast formation, both in vitro and at early stages in vivo, correlates with bone formation when the materials were implanted alongside MSCs in mice. Surprisingly, MSC survival did not correlate with bone formation, suggesting that the number or phenotype of osteoclasts formed was more important. (c) 2024 The Author(s). Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )
JTD Keywords: Acid phosphatase tartrate resistant isoenzyme, Animal, Animal cell, Animal experiment, Animal tissue, Animals, Article, Beta-tricalcium phosphate, Bioceramics, Biocompatible materials, Biomaterial, Bone, Bone development, Bone formation, Bone regeneration, Calcium phosphate, Calcium phosphate materials, Calcium phosphates, Cd14 antigen, Cell differentiation, Cell engineering, Cell maturation, Cell survival, Ceramics, Chemical composition, Controlled study, Correlation analysis, Correlation coefficient, Data correlation, Durapatite, Engraftment, Flowcharting, Human, Human cell, Human mesenchymal stromal cell, Human mesenchymal stromal cells, Humans, Hydroxyapatite, Hydroxyapatites, In vitro study, In vivo study, In-vitro, In-vivo, Mammals, Marrow stromal cells, Material composition, Material compositions, Mesenchymal stroma cell, Mesenchymal stromal cells, Mice, Mice, nude, Monocyte, Mouse, Nonhuman, Nude mouse, Ossification, Osteoclast, Osteoclastogenesis, Osteoclasts, Osteogenesis, Osteoinduction, Phase composition, Regeneration strategies, Resorption, Scaffolds, Stem-cells, Subcutaneous tissue, Tissue engineering, Transmission control protocol, Tri-calcium phosphates, Vimentin
Husser, Clara, Kwon, Hyesoo, Andersson, Klara, Appelberg, Sofia, Montserrat, Nuria, Mirazimi, Ali, Monteil, Vanessa M, Monteil, Vanessa M, (2024). P53-Independent G1-Cell Cycle Arrest Increases SARS-CoV-2 RNA Replication Microorganisms 12, 443
While having already killed more than 7 million of people worldwide in 4 years, SARS-CoV-2, the etiological agent of COVID-19, is still circulating and evolving. Understanding the pathogenesis of the virus is of capital importance. It was shown that in vitro and in vivo infection with SARS-CoV-2 can lead to cell cycle arrest but the effect of the cell cycle arrest on the virus infection and the associated mechanisms are still unclear. By stopping cells in the G1 phase as well as targeting several pathways involved using inhibitors and small interfering RNAs, we were able to determine that the cell cycle arrest in the late G1 is beneficial for SARS-CoV-2 replication. This cell cycle arrest is independent of p53 but is dependent on the CDC25A-CDK2/cyclin E pathway. These data give a new understanding in SARS-CoV-2 pathogenesis and highlight some possible targets for the development of novel therapeutic approaches.
JTD Keywords: Cell lung-cancer,exchanger nhe,g1 phase,proliferation,inhibitio, Covid-19,coronavirus,pathogenicity,replication,cdk2,cyclin e,cdc25a,treatment
Blanco-Cabra, Nuria, Alcacer-Almansa, Julia, Admella, Joana, Arevalo-Jaimes, Betsy Veronica, Torrents, Eduard, (2024). Nanomedicine against biofilm infections: A roadmap of challenges and limitations Wiley Interdisciplinary Reviews-Nanomedicine and Nanobiotechnology 16, e1944
Microbial biofilms are complex three-dimensional structures where sessile microbes are embedded in a polymeric extracellular matrix. Their resistance toward the host immune system as well as to a diverse range of antimicrobial treatments poses a serious health and development threat, being in the top 10 global public health threats declared by the World Health Organization. In an effort to combat biofilm-related microbial infections, several strategies have been developed to independently eliminate biofilms or to complement conventional antibiotic therapies. However, their limitations leave room for other treatment alternatives, where the application of nanotechnology to biofilm eradication has gained significant relevance in recent years. Their small size, penetration efficiency, and the design flexibility that they present makes them a promising alternative for biofilm infection treatment, although they also present set-backs. This review aims to describe the main possibilities and limitations of nanomedicine against biofilms, while covering the main aspects of biofilm formation and study, and the current therapies for biofilm treatment. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine.
JTD Keywords: Anti-bacterial agents, Anti-infective agents, Antiinfective agent, Antimicrobial, Antimicrobials, Antimicrobials,bacteria,biofilm,infectious diseases,microorganism, Bacteria, Biofilm, Biofilm infections, Biofilms, Complex three dimensional structures, Diseases, Diverse range, Drug-delivery systems,in-vitro,cellular toxicity,nanoparticles,penetration,model,biocompatibility,perspectives,hyperthermia,diagnosi, Extracellular matrices, Global public health, Health risks, Infectious disease, Infectious diseases, Medical nanotechnology, Microbial biofilm, Microorganisms, Nanomedicine, Polymer, Polymers, Regulatory issues, Roadmap
Hafa, L, Breideband, L, Posada, LR, Torras, N, Martinez, E, Stelzer, EHK, Pampaloni, F, (2024). Light Sheet-Based Laser Patterning Bioprinting Produces Long-Term Viable Full-Thickness Skin Constructs ADVANCED MATERIALS 36, e2306258
Tissue engineering holds great promise for biomedical research and healthcare, offering alternatives to animal models and enabling tissue regeneration and organ transplantation. Three-dimensional (3D) bioprinting stands out for its design flexibility and reproducibility. Here, we present an integrated fluorescent light sheet bioprinting and imaging system that combines high printing speed (0.66 mm3 /s) and resolution (9 μm) with light sheet-based imaging. This approach employs direct laser patterning and a static light sheet for confined voxel crosslinking in photocrosslinkable materials. The developed bioprinter enables real-time monitoring of hydrogel crosslinking using fluorescent recovery after photobleaching (FRAP) and brightfield imaging as well as in situ light sheet imaging of cells. Human fibroblasts encapsulated in a thiol-ene click chemistry-based hydrogel exhibited high viability (83% ± 4.34%) and functionality. Furthermore, full-thickness skin constructs displayed characteristics of both epidermal and dermal layers and remained viable for 41 days. The integrated approach demonstrates the capabilities of light sheet bioprinting, offering high speed, resolution, and real-time characterization. Future enhancements involving solid-state laser scanning devices such as acousto-optic deflectors and modulators will further enhance resolution and speed, opening new opportunities in light-based bioprinting and advancing tissue engineering. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.
JTD Keywords: cadherin, collagen, culture, differentiation, fluorescence microscopy, full-thickness skin model, hydrogels, light sheet bioprinter, light sheet fluorescence microscopy, proliferation, survival, tissue engineering, Animal, Animals, Biofabrication, Bioprinting, Cell culture, Crosslinking, Fluorescence, Fluorescence microscopy, Full-thickness skin model, Hair follicle, Human, Humans, Hydrogel, Hydrogels, Image resolution, Laser patterning, Light sheet, Light sheet bioprinter, Light sheet fluorescence microscopy, Molecular biology, Photobleaching, Printing, three-dimensional, Procedures, Reproducibility, Reproducibility of results, Skin model, Three dimensional printing, Tissue, Tissue engineering, Tissue regeneration, Tissue scaffolds, Tissues engineerings
Farré, R, Rodríguez-Lázaro, MA, Otero, J, Gavara, N, Sunyer, R, Farré, N, Gozal, D, Almendros, I, (2024). Low-cost, open-source device for simultaneously subjecting rodents to different circadian cycles of light, food, and temperature Frontiers in Physiology 15, 1356787
Exposure of experimental rodents to controlled cycles of light, food, and temperature is important when investigating alterations in circadian cycles that profoundly influence health and disease. However, applying such stimuli simultaneously is difficult in practice. We aimed to design, build, test, and open-source describe a simple device that subjects a conventional mouse cage to independent cycles of physiologically relevant environmental variables. The device is based on a box enclosing the rodent cage to modify the light, feeding, and temperature environments. The device provides temperature-controlled air conditioning (heating or cooling) by a Peltier module and includes programmable feeding and illumination. All functions are set by a user-friendly front panel for independent cycle programming. Bench testing with a model simulating the CO2 production of mice in the cage showed: a) suitable air renewal (by measuring actual ambient CO2), b) controlled realistic illumination at the mouse enclosure (measured by a photometer), c) stable temperature control, and d) correct cycling of light, feeding, and temperature. The cost of all the supplies (retail purchased by e-commerce) was <300 US$. Detailed technical information is open-source provided, allowing for any user to reliably reproduce or modify the device. This approach can considerably facilitate circadian research since using one of the described low-cost devices for any mouse group with a given light-food-temperature paradigm allows for all the experiments to be performed simultaneously, thereby requiring no changes in the light/temperature of a general-use laboratory. 1 Introduction
JTD Keywords: Animal experiment, Animal model, Animal research, Article, Circadian alteration, Circadian rhythm, Commercial phenomena, Controlled study, Cycling, Energy consumption, Energy-expenditure, Experimental model, Feeding, Food, Food availability, Illumination, Intermittent fasting, Light, Light cycle, Light dark cycle, Mouse, Nonhuman, Open source technology, Open-source hardware, Performance, Photography, Research, Rhythms, Rodent, Temperature, Temperature cycle
Sans, Jordi, Arnau, Marc, Bosque, Ricard, Turon, Pau, Aleman, Carlos, (2024). Synthesis of urea from CO2 and N2 fixation under mild conditions using polarized hydroxyapatite as a catalyst Sustainable Energy & Fuels 8, 1473-1482
Polarized hydroxyapatite (p-HAp) has been used as a catalyst for the synthesis of urea coupling N-2, CO2 and water under mild reaction conditions when compared to classical nitrogen fixation reactions, such as the Haber-Bosch process. The reaction of 3 bar of N-2 and 3 bar of CO2 under UV illumination at 120 degrees C (for 48 h) results in a urea yield of 1.5 +/- 0.1 mmol per gram of catalyst (g(c)) with a selectivity close to 80%, whereas the reaction is not successful without UV irradiation. However, the addition of small amounts of NO (314 ppm) produces 15.2 +/- 0.6 and 4.6 +/- 0.4 mmol g(c)(-1) with and without UV illumination, respectively, with the selectivity in both cases being close to 100%. As nitrogen fixation without UV irradiation using p-HAp as a catalyst is a challenge, studies with NO have been conducted varying the reaction conditions (time, pressure and temperature). The results suggest a mechanism based on the production of NH4+ through the oxidation of N-2.
JTD Keywords: Carbon dioxide, Carbon,dinitrogen,reduction,nitrogen,ammonia,dioxid, Catalyst selectivity, Condition, Haber-bosch process, Hydroxyapatite, Irradiation, Metabolism, Mild reaction conditions, Nitrogen fixation, Pressure and temperature, Reaction conditions, Time pressures, Time-temperature, Urea, Uv illuminations, Without uv irradiations, ]+ catalyst
Wagner, AM, Kostina, NY, Xiao, Q, Klein, ML, Percec, V, Rodriguez-Emmenegger, C, (2024). Glycan-Driven Formation of Raft-Like Domains with Hierarchical Periodic Nanoarrays on Dendrimersome Synthetic Cells BIOMACROMOLECULES 25, 366-378
The accurate spatial segregation into distinct phases within cell membranes coordinates vital biochemical processes and functionalities in living organisms. One of nature's strategies to localize reactivity is the formation of dynamic raft domains. Most raft models rely on liquid-ordered L-0 phases in a liquid-disordered L-d phase lacking correlation and remaining static, often necessitating external agents for phase separation. Here, we introduce a synthetic system of bicomponent glycodendrimersomes coassembled from Janus dendrimers and Janus glycodendrimers (JGDs), where lactose-lactose interactions exclusively drive lateral organization. This mechanism results in modulated phases across two length scales, yielding raft-like microdomains featuring nanoarrays at the nanoscale. By varying the density of lactose and molecular architecture of JGDs, the nanoarray type and size, shape, and spacing of the domains were controlled. Our findings offer insight into the potential primordial origins of rudimentary raft domains and highlight the crucial role of glycans within the glycocalyx.
JTD Keywords: Article, Artificial cells, Atomic force microscopy, Bicomponents, Bilayer, Bilayer membrane, Biochemical functionality, Biochemical process, Biological-membranes, Cell component, Cell membrane, Cellular parameters, Chemical interaction, Chemical structure, Chemistry, Cytology, Defined janus glycodendrimers, Dehydration, Dendrimer, Dendrimers, Dilution, Dimer, External agents, Fourier transform, Giant vesicles, Glycan, Glycans, Glycocalyx, Glycodendrimers, Janus dendrimer, Janus glycodendrimer, Lactose, Lateral organization, Lectin, Lipid rafts, Living organisms, Membrane damage, Membrane microdomain, Membrane microdomains, Membrane structure, Metabolism, Modulated phases, Molecule, Monomer, Nanoarrays, Oligosaccharide, Organization, Periodicity, Phase separation, Phase-separation, Phospholipids, Polysaccharide, Polysaccharides, Raft like domain, Relative humidity, Spatial segregation, Structure analysis, Sugars, Synthetic systems, Tetramer, Unclassified drug, Unilamellar vesicles, Water
Rae, CD, Baur, JA, Borges, K, Dienel, G, Díaz-García, CM, Douglass, SR, Drew, K, Duarte, JMN, Duran, J, Kann, O, Kristian, T, Lee-Liu, D, Lindquist, BE, Mcnay, EC, Robinson, MB, Rothman, DL, Rowlands, BD, Ryan, TA, Scafidi, J, Scafidi, S, Shuttleworth, CW, Swanson, RA, Uruk, G, Vardjan, N, Zorec, R, Mckenna, MC, (2024). Brain energy metabolism: A roadmap for future research JOURNAL OF NEUROCHEMISTRY 168, 910-954
Although we have learned much about how the brain fuels its functions over the last decades, there remains much still to discover in an organ that is so complex. This article lays out major gaps in our knowledge of interrelationships between brain metabolism and brain function, including biochemical, cellular, and subcellular aspects of functional metabolism and its imaging in adult brain, as well as during development, aging, and disease. The focus is on unknowns in metabolism of major brain substrates and associated transporters, the roles of insulin and of lipid droplets, the emerging role of metabolism in microglia, mysteries about the major brain cofactor and signaling molecule NAD+, as well as unsolved problems underlying brain metabolism in pathologies such as traumatic brain injury, epilepsy, and metabolic downregulation during hibernation. It describes our current level of understanding of these facets of brain energy metabolism as well as a roadmap for future research. This article details current knowledge and major unknowns in brain energy metabolism and lays out a roadmap for future research.image
JTD Keywords: Acetate, Acetyl-coa, Aerobic glycolysis, Atp-citrate lyase, Extracellular glutamate concentration, Fatty-acid transport, Glucose-metabolism, Glut4, In-vivo, Insulin, Lipid droplet accumulation, Nicotinamide adenine-dinucleotide, Noradrenaline, Obese zucker rats, Rat cerebral-cortex
Molina, BG, Arnau, M, Sánchez, M, Alemán, C, (2024). Controlled dopamine release from cellulose-based conducting hydrogel EUROPEAN POLYMER JOURNAL 202, 112635
Very recently, the controlled release of dopamine (DA), a neurotransmitter whose deficiency is associated with Parkinson's disease, has been postulated as a good alternative to the oral administration of levodopa (L-Dopa), a dopamine precursor, to combat the effects of said disease. However, this is still a very little explored field and there are very few carriers that are capable of releasing DA, a small and water-soluble molecule, in an efficient and controlled manner. In this work, we report a carrier based on a conductive hydrogel capable of loading DA and releasing it progressively and efficiently (100 % release) in a period of five days by applying small electrical stimuli (-0.4 V) daily for a short time (1 min). The hydrogel (CMC/PEDOT), which is electrically active, has been prepared from sodium carboxymethylcellulose and poly(3,4-ethylenedioxythiophene) microparticles, using citric acid as a cross-linking agent. Furthermore, the results have shown that when relatively hydrophobic small molecules, such as chloramphenicol, are loaded, the electrostimulated release is significantly less efficient, demonstrating the usefulness of CMC/PEDOT as a carrier for neurotransmitters.
JTD Keywords: Amines, Carboxymethyl cellulose, Carboxymethylcellulose, Conducting hydrogels, Conducting polymers, Controlled release, Crosslinking, Dopamine, Drug-delivery system, Electrostimulation, Hydrogels, Joining, Levodopa, Loading, Molecules, Neurophysiology, Neurotransmitter release, Neurotransmitters release, Oral administration, Parkinson's disease, Parkinsons-disease, Poly(3,4-ethylenedioxythiophene), Release, Sodium, Transport, Water-soluble molecule
Liu, M, Zhang, C, Gong, XM, Zhang, T, Lian, MM, Chew, EGY, Cardilla, A, Suzuki, K, Wang, HM, Yuan, Y, Li, Y, Naik, MY, Wang, YX, Zhou, BR, Soon, WZ, Aizawa, E, Li, P, Low, JH, Tandiono, M, Montagud, E, Moya-Rull, D, Esteban, CR, Luque, Y, Fang, ML, Khor, CC, Montserrat, N, Campistol, JM, Belmonte, JCI, Foo, JN, Xia, Y, (2024). Kidney organoid models reveal cilium-autophagy metabolic axis as a therapeutic target for PKD both in vitro and in vivo Cell Stem Cell 31, 52-70.e8
Human pluripotent stem cell -derived kidney organoids offer unprecedented opportunities for studying polycystic kidney disease (PKD), which still has no effective cure. Here, we developed both in vitro and in vivo organoid models of PKD that manifested tubular injury and aberrant upregulation of renin-angiotensin aldosterone system. Single -cell analysis revealed that a myriad of metabolic changes occurred during cystogenesis, including defective autophagy. Experimental activation of autophagy via ATG5 overexpression or primary cilia ablation significantly inhibited cystogenesis in PKD kidney organoids. Employing the organoid xenograft model of PKD, which spontaneously developed tubular cysts, we demonstrate that minoxidil, a potent autophagy activator and an FDA -approved drug, effectively attenuated cyst formation in vivo. This in vivo organoid model of PKD will enhance our capability to discover novel disease mechanisms and validate candidate drugs for clinical translation.
JTD Keywords: Adenylate kinase, Adult, Animal cell, Animal experiment, Animal model, Animal tissue, Article, Autophagosome, Autophagy, Autophagy (cellular), Autosomal-dominant, Calcium homeostasis, Cilia, Cilium, Cohort analysis, Controlled study, Cyclic amp, Disease, Dominant polycystic kidney, Enzyme linked immunosorbent assay, Epithelium, Exon, Expression, Female, Food and drug administration, Framework, Generation, Growth, Hepatitis a virus cellular receptor 1, Human, Human cell, Humans, Immunohistochemistry, In vitro study, In vivo study, Kidney, Kidney organoid, Kidney polycystic disease, Male, Minoxidil, Mouse, Mutations, Nonhuman, Organoid, Organoids, Platelet derived growth factor beta receptor, Pluripotent stem-cells, Polycystic kidney diseases, Protein kinase lkb1, Renin, Sequestosome 1, Single cell analysis, Single cell rna seq, Small nuclear rna, Tunel assay, Upregulation, Western blotting, Whole exome sequencing
Jonkman, AH, Warnaar, RSP, Baccinelli, W, Carbon, NM, D'Cruz, RF, Doorduin, J, van Doorn, JLM, Elshof, J, Estrada-Petrocelli, L, Grasshoff, J, Heunks, LMA, Koopman, AA, Langer, D, Moore, CM, Silveira, JMN, Petersen, E, Poddighe, D, Ramsay, M, Rodrigues, A, Roesthuis, LH, Rossel, A, Torres, A, Duiverman, ML, Oppersma, E, (2024). Analysis and applications of respiratory surface EMG: report of a round table meeting CRITICAL CARE 28, 2
Surface electromyography (sEMG) can be used to measure the electrical activity of the respiratory muscles. The possible applications of sEMG span from patients suffering from acute respiratory failure to patients receiving chronic home mechanical ventilation, to evaluate muscle function, titrate ventilatory support and guide treatment. However, sEMG is mainly used as a monitoring tool for research and its use in clinical practice is still limited-in part due to a lack of standardization and transparent reporting. During this round table meeting, recommendations on data acquisition, processing, interpretation, and potential clinical applications of respiratory sEMG were discussed. This paper informs the clinical researcher interested in respiratory muscle monitoring about the current state of the art on sEMG, knowledge gaps and potential future applications for patients with respiratory failure.
JTD Keywords: Acute respiratory failure, Artificial ventilation, Asthmatic-children, Breathing muscle, Clinical monitoring, Clinical practice, Clinical research, Consensus development, Data interpretation, Disease exacerbation, Drive, Electrode positioning, Electrode removal, Electromyography, Force, Home care, Human, Human diaphragm, Humans, Information processing, Inspiratory muscle training, Inspiratory muscles, Intensive care unit, Knowledge gap, Long term care, Mechanical ventilation, Medical procedures, Muscle contraction, Muscle fatigue, Muscle function, Muscle training, Muscle, skeletal, Muscle-activity, Noninvasive ventilation, Patient monitoring, Patient-ventilator asynchrony, Physiology, Prognosis, Quality of life, Reporting and data system, Respiratory failure, Respiratory muscles, Review, Severe exacerbations, Signal processing, Skeletal muscle, Standardization, Surface electromyography, Time factor
Garcia-de-Albeniz, N, Ginebra, MP, Jimenez-Piqué, E, Roa, JJ, Mas-Moruno, C, (2024). Influence of nanosecond laser surface patterning on dental 3Y-TZP: Effects on the topography, hydrothermal degradation and cell response DENTAL MATERIALS 40, 139-150
Laser surface micropatterning of dental-grade zirconia (3Y-TZP) was explored with the objective of providing defined linear patterns capable of guiding bone-cell response.A nanosecond (ns-) laser was employed to fabricate microgrooves on the surface of 3Y-TZP discs, yielding three different groove periodicities (i.e., 30, 50 and 100 µm). The resulting topography and surface damage were characterized by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). X-Ray diffraction (XRD) and Raman spectroscopy techniques were employed to assess the hydrothermal degradation resistance of the modified topographies. Preliminary biological studies were conducted to evaluate adhesion (6 h) of human mesenchymal stem cells (hMSC) to the patterns in terms of cell number and morphology. Finally, Staphylococcus aureus adhesion (4 h) to the microgrooves was investigated.The surface analysis showed grooves of approximately 1.8 µm height that exhibited surface damage in the form of pile-up at the edge of the microgrooves, microcracks and cavities. Accelerated aging tests revealed a slight decrease of the hydrothermal degradation resistance after laser patterning, and the Raman mapping showed the presence of monoclinic phase heterogeneously distributed along the patterned surfaces. An increase of the hMSC area was identified on all the microgrooved surfaces, although only the 50 µm periodicity, which is closer to the cell size, significantly favored cell elongation and alignment along the grooves. A decrease in Staphylococcus aureus adhesion was observed on the investigated micropatterns.The study suggests that linear microgrooves of 50 µm periodicity may help in promoting hMSC adhesion and alignment, while reducing bacterial cell attachment.Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.
JTD Keywords: abutment material, alumina toughened zirconia, antibacterial, bacterial adhesion, biofilm growth, cell adhesion, dental implants, hydrothermal degradation, implant surfaces, in-vitro, laser patterning, osseointegration, osteogenic differentiation, part 1, surface topography, y-tzp ceramics, Antibacterial, Antibacterials, Bacteria, Bone, Cell adhesion, Cell culture, Cells adhesion, Ceramics, Chemistry, Degradation resistance, Dental implants, Dental material, Dental materials, Dental prostheses, Human, Human mesenchymal stem cells, Humans, Hydrothermal degradation, Laser patterning, Laser surface, Lasers, Low-temperature degradation, Materials testing, Microscopy, electron, scanning, Nanosecond lasers, Osseointegration, Piles, Scanning electron microscopy, Staphylococcus aureus, Stem cells, Surface analysis, Surface damages, Surface properties, Surface property, Surface topography, Topography, Yttrium, Zirconia, Zirconium
Barbosa, F, Garrudo, FFF, Alberte, PS, Resina, L, Carvalho, MS, Jain, A, Marques, AC, Estrany, F, Rawson, FJ, Aléman, C, Ferreira, FC, Silva, JC, (2023). Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 24, 2242242
Osteoporotic-related fractures are among the leading causes of chronic disease morbidity in Europe and in the US. While a significant percentage of fractures can be repaired naturally, in delayed-union and non-union fractures surgical intervention is necessary for proper bone regeneration. Given the current lack of optimized clinical techniques to adequately address this issue, bone tissue engineering (BTE) strategies focusing on the development of scaffolds for temporarily replacing damaged bone and supporting its regeneration process have been gaining interest. The piezoelectric properties of bone, which have an important role in tissue homeostasis and regeneration, have been frequently neglected in the design of BTE scaffolds. Therefore, in this study, we developed novel hydroxyapatite (HAp)-filled osteoinductive and piezoelectric poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-TrFE) nanofibers via electrospinning capable of replicating the tissue's fibrous extracellular matrix (ECM) composition and native piezoelectric properties. The developed PVDF-TrFE/HAp nanofibers had biomimetic collagen fibril-like diameters, as well as enhanced piezoelectric and surface properties, which translated into a better capacity to assist the mineralization process and cell proliferation. The biological cues provided by the HAp nanoparticles enhanced the osteogenic differentiation of seeded human mesenchymal stem/stromal cells (MSCs) as observed by the increased ALP activity, cell-secreted calcium deposition and osteogenic gene expression levels observed for the HAp-containing fibers. Overall, our findings describe the potential of combining PVDF-TrFE and HAp for developing electroactive and osteoinductive nanofibers capable of supporting bone tissue regeneration.© 2023 The Author(s). Published by National Institute for Materials Science in partnership with Taylor & Francis Group.
JTD Keywords: composites, electrospinning, hydroxyapatite, piezoelectricity, promote, pvdf, pvdf-trfe, removal, scaffolds, temperature, Bone tissue engineering, Electrospinning, Electrospun polycaprolactone, Hydroxyapatite, Piezoelectricity, Pvdf-trfe
Porro, GM, Lorandi, I, Liu, XY, Kataoka, K, Battaglia, G, Gonzalez-Carter, D, (2023). Identifying molecular tags selectively retained on the surface of brain endothelial cells to generate artificial targets for therapy delivery Fluids and Barriers of the CNS 20, 88
Current strategies to identify ligands for brain delivery select candidates based on preferential binding to cell-membrane components (CMC) on brain endothelial cells (EC). However, such strategies generate ligands with inherent brain specificity limitations, as the CMC (e.g., the transferrin receptor TfR1) are also significantly expressed on peripheral EC. Therefore, novel strategies are required to identify molecules allowing increased specificity of therapy brain delivery. Here, we demonstrate that, while individual CMC are shared between brain EC and peripheral EC, their endocytic internalization rate is markedly different. Such differential endocytic rate may be harnessed to identify molecular tags for brain targeting based on their selective retention on the surface of brain EC, thereby generating 'artificial' targets specifically on the brain vasculature. By quantifying the retention of labelled proteins on the cell membrane, we measured the general endocytic rate of primary brain EC to be less than half that of primary peripheral (liver and lung) EC. In addition, through bio-panning of phage-displayed peptide libraries, we unbiasedly probed the endocytic rate of individual CMC of liver, lung and brain endothelial cells. We identified phage-displayed peptides which bind to CMC common to all three endothelia phenotypes, but which are preferentially endocytosed into peripheral EC, resulting in selective retention on the surface of brain EC. Furthermore, we demonstrate that the synthesized free-form peptides are capable of generating artificial cell-surface targets for the intracellular delivery of model proteins into brain EC with increasing specificity over time. The developed identification paradigm, therefore, demonstrates that the lower endocytic rate of individual CMC on brain EC can be harnessed to identify peptides capable of generating 'artificial' targets for the selective delivery of proteins into the brain vasculature. In addition, our approach identifies brain-targeting peptides which would have been overlooked by conventional identification strategies, thereby increasing the repertoire of candidates to achieve specific therapy brain delivery.© 2023. The Author(s).
JTD Keywords: brain endothelium, endocytic rates, ligand identification, nanoparticles, phage-display, Barrier, Brain, Brain endothelium, Brain targeting, Endocytic rates, Endothelial cells, Endothelium, Ligand identification, Peptides, Phage-display
Eills, J, Picazo-Frutos, R, Bondar, O, Cavallari, E, Carrera, C, Barker, SJ, Utz, M, Herrero-Gómez, A, Marco-Rius, I, Tayler, MCD, Aime, S, Reineri, F, Budker, D, Blanchard, JW, (2023). Enzymatic Reactions Observed with Zero- and Low-Field Nuclear Magnetic Resonance ANALYTICAL CHEMISTRY 95, 17997-18005
We demonstrate that enzyme-catalyzed reactions can be observed in zero- and low-field NMR experiments by combining recent advances in parahydrogen-based hyperpolarization methods with state-of-the-art magnetometry. Specifically, we investigated two model biological processes: the conversion of fumarate into malate, which is used in vivo as a marker of cell necrosis, and the conversion of pyruvate into lactate, which is the most widely studied metabolic process in hyperpolarization-enhanced imaging. In addition to this, we constructed a microfluidic zero-field NMR setup to perform experiments on microliter-scale samples of [1-C-13]-fumarate in a lab-on-a-chip device. Zero- to ultralow-field (ZULF) NMR has two key advantages over high-field NMR: the signals can pass through conductive materials (e.g., metals), and line broadening from sample heterogeneity is negligible. To date, the use of ZULF NMR for process monitoring has been limited to studying hydrogenation reactions. In this work, we demonstrate this emerging analytical technique for more general reaction monitoring and compare zero- vs low-field detection.
JTD Keywords: Fumarates, Hydrogenation, Magnetic resonance imaging, Magnetic resonance spectroscopy, Nmr j-spectroscopy, Pyruvic acid
Englert, J, Witzdam, L, Söder, D, Garay-Sarmiento, M, Joseph, A, Wagner, AM, Rodriguez-Emmenegger, C, (2023). Synthetic Evolution of a Supramolecular Harpooning Mechanism to Immobilize Vesicles at Antifouling Interfaces MACROMOLECULAR CHEMISTRY AND PHYSICS 224, 2300306
The immobilization of vesicles has been conceptualized as a method to functionalize biointerfaces. However, the preservation of their integrity post immobilization remains a considerable challenge. Interfacial interactions can cause vesicle rupture upon close surface contact and non-specific protein adsorption impairing surface functions. To date, immobilization of vesicles has relied solely on either entrapment or prior modification of vesicles, both of which require laborious preparation and limit their applications. This work develops a bioinspired strategy to pin vesicles without prior modification while preserving their intact shape. This work introduces antifouling diblock copolymers and ultrathin surface-attached hydrogels containing a brush-like interface consisting of a bottle brush copolymer of N-(2-hydroxypropyl) methacrylamide (HPMA) and N-(3-methacrylamidopropyl)-N,N-dimethyldodecan-1-aminiumiodide (C12+). The presence of positive charges generates an attractive force that pulls vesicles toward the surface. At the surface, the amphiphilic properties of the combs facilitate their insertion into the membrane, mimicking the harpooning mechanism observed in antimicrobial peptides. Importantly, the antifouling poly(HPMA) backdrop serves to safeguard the vesicles by preventing deformation and breakage. Using a combination of thermodynamic analysis, surface plasmon resonance, and confocal laser scanning microscopy, this work demonstrates the efficiency of this biomimetic system to capture vesicles while maintaining an antifouling interface necessary for bioapplications. This work presents a novel supramolecular approach that combines three key elements: long-range attraction, vesicle pinning, and short-range repulsion to attract and harpoon vesicles, while protecting them at the surface. This work envisions these coatings as universal and biocompatible platforms that can be used not only to study vesicle interactions, but also as tools for biomedical applications.image
JTD Keywords: Antifouling coatings, Coatings, Delivery, Extracellular vesicles, Fabrication, Hydrogel, Janus dendrimers, Lipid vesicles, Liposomes, Membrane insertion, Polymer brushes, Proteins, Surface-energy components, Ultrathin surface-attached hydrogels, Vesicle pinning
Nauryzgaliyeva, Z, Corredera, IG, Garreta, E, Montserrat, N, (2023). Harnessing mechanobiology for kidney organoid research Frontiers in Cell and Developmental Biology 11, 1273923
Recently, organoids have emerged as revolutionizing tools with the unprecedented potential to recreate organ-specific microanatomy in vitro. Upon their derivation from human pluripotent stem cells (hPSCs), organoids reveal the blueprints of human organogenesis, further allowing the faithful recapitulation of their physiology. Nevertheless, along with the evolution of this field, advanced research exposed the organoids' shortcomings, particularly regarding poor reproducibility rates and overall immatureness. To resolve these challenges, many studies have started to underscore the relevance of mechanical cues as a relevant source to induce and externally control hPSCs differentiation. Indeed, established organoid generation protocols from hPSCs have mainly relyed on the biochemical induction of fundamental signalling pathways present during kidney formation in mammals, whereas mechanical cues have largely been unexplored. This review aims to discuss the pertinence of (bio) physical cues within hPSCs-derived organoid cultures, while deciphering their effect on morphogenesis. Moreover, we will explore state-of-the-art mechanobiology techniques as revolutionizing means for understanding the underlying role of mechanical forces in biological processes in organoid model systems.
JTD Keywords: development, hpscs, mechanobiology, nephrogenesis, Activated ion-channel, Development, Extracellular-matrix viscoelasticity, Forces, Hpscs, Ips cells, Mechanical regulation, Mechanobiology, Nephrogenesis, Nephron progenitors, Organoids, Pluripotent stem-cells, Self-renewal, Substrate mechanics, Tissue
Pereira, I, Lopez-Martinez, MJ, Samitier, J, (2023). Advances in current in vitro models on neurodegenerative diseases Frontiers in Bioengineering and Biotechnology 11, 1260397
Many neurodegenerative diseases are identified but their causes and cure are far from being well-known. The problem resides in the complexity of the neural tissue and its location which hinders its easy evaluation. Although necessary in the drug discovery process, in vivo animal models need to be reduced and show relevant differences with the human tissues that guide scientists to inquire about other possible options which lead to in vitro models being explored. From organoids to organ-on-a-chips, 3D models are considered the cutting-edge technology in cell culture. Cell choice is a big parameter to take into consideration when planning an in vitro model and cells capable of mimicking both healthy and diseased tissue, such as induced pluripotent stem cells (iPSC), are recognized as good candidates. Hence, we present a critical review of the latest models used to study neurodegenerative disease, how these models have evolved introducing microfluidics platforms, 3D cell cultures, and the use of induced pluripotent cells to better mimic the neural tissue environment in pathological conditions.
JTD Keywords: 3d in vitro models, bioprinting, ipsc cell culture, microfluidic device, 3d in vitro models, Bioprinting, Blood-brain-barrier, Cerebral organoids, Culture model, Endothelial-cells, Expression profile, Extracellular-matrix, Ipsc cell culture, Microfluidic device, Neurodegenerative diseases, On-a-chip, Pluripotent stem-cells, Shear-stress, Substrate stiffness
Gómez, SG, Guillem-Marti, J, Martín-Gómez, H, Mas-Moruno, C, Ginebra, MP, Gil, FJ, Barraquer, RI, Manero, JM, (2023). Titanium Boston keratoprosthesis with corneal cell adhesive and bactericidal dual coating BIOMATERIALS ADVANCES 154, 213654
The Boston keratoprosthesis (BKPro) is a medical device used to restore vision in complicated cases of corneal blindness. This device is composed by a front plate of polymethylmethacrylate (PMMA) and a backplate usually made of titanium (Ti). Ti is an excellent biomaterial with numerous applications, although there are not many studies that address its interaction with ocular cells. In this regard, despite the good retention rates of the BKPro, two main complications compromise patients' vision and the viability of the prosthesis: imperfect adhesion of the corneal tissue to the upside of the backplate and infections. Thus, in this work, two topographies (smooth and rough) were generated on Ti samples and tested with or without functionalization with a dual peptide platform. This molecule consists of a branched structure that links two peptide moieties to address the main complications associated with BKPro: the well-known RGD peptide in its cyclic version (cRGD) as cell pro-adherent motif and the first 11 residues of lactoferrin (LF1-11) as antibacterial motif. Samples were physicochemically characterized, and their biological response was evaluated in vitro with human corneal keratocytes (HCKs) and against the gram-negative bacterial strain Pseudomonas aeruginosa. The physicochemical characterization allowed to verify the functionalization in a qualitative and quantitative manner. A higher amount of peptide was anchored to the rough surfaces. The studies performed using HCKs showed increased long-term proliferation on the functionalized samples. Gene expression was affected by topography and peptide functionalization. Roughness promoted α-smooth muscle actin (α-SMA) overexpression, and the coating notably increased the expression of extracellular matrix components (ECM). Such changes may favour the development of unwanted fibrosis, and thus, corneal haze. In contrast, the combination of the coating with a rough topography decreased the expression of α-SMA and ECM components, which would be desirable for the long-term success of the prosthesis. Regarding the antibacterial activity, the functionalized smooth and rough surfaces promoted the death of bacteria, as well as a perturbation in their wall definition and cellular morphology. Bacterial killing values were 58 % for smooth functionalised and 68 % for rough functionalised samples. In summary, this study suggests that the use of the dual peptide platform with cRGD and LF1-11 could be a good strategy to improve the in vitro and in vivo performance of the rough topography used in the commercial BKPro.Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.
JTD Keywords: binding, corneal blindness, differentiation, dual coating, iii collagen, in-vitro, infectious endophthalmitis, keratocyte, myofibroblast, peptide platform, proliferation, surface-roughness, titanium implant, Boston keratoprostheses, Corneal blindness, Dual coating, Gram-negative bacteria, Peptide platform, Titanium implant
Kechagia, Z, Sáez, P, Gómez-González, M, Canales, B, Viswanadha, S, Zamarbide, M, Andreu, I, Koorman, T, Beedle, AEM, Elosegui-Artola, A, Derksen, PWB, Trepat, X, Arroyo, M, Roca-Cusachs, P, (2023). The laminin-keratin link shields the nucleus from mechanical deformation and signalling NATURE MATERIALS 22, 1409-1420
The mechanical properties of the extracellular matrix dictate tissue behaviour. In epithelial tissues, laminin is a very abundant extracellular matrix component and a key supporting element. Here we show that laminin hinders the mechanoresponses of breast epithelial cells by shielding the nucleus from mechanical deformation. Coating substrates with laminin-111-unlike fibronectin or collagen I-impairs cell response to substrate rigidity and YAP nuclear localization. Blocking the laminin-specific integrin β4 increases nuclear YAP ratios in a rigidity-dependent manner without affecting the cell forces or focal adhesions. By combining mechanical perturbations and mathematical modelling, we show that β4 integrins establish a mechanical linkage between the substrate and keratin cytoskeleton, which stiffens the network and shields the nucleus from actomyosin-mediated mechanical deformation. In turn, this affects the nuclear YAP mechanoresponses, chromatin methylation and cell invasion in three dimensions. Our results demonstrate a mechanism by which tissues can regulate their sensitivity to mechanical signals.© 2023. The Author(s).
JTD Keywords: actin, cell migration, filaments, force transmission, localization, membrane, motility, proteins, yap, Cell adhesion, Cytoskeleton, Extracellular matrix, Fibronectins, Integrin alpha-6-beta-4, Integrins, Keratins, Laminin
Barbazan, J, Pérez-González, C, Gómez-González, M, Dedenon, M, Richon, S, Latorre, E, Serra, M, Mariani, P, Descroix, S, Sens, P, Trepat, X, Vignjevic, DM, (2023). Cancer-associated fibroblasts actively compress cancer cells and modulate mechanotransduction Nature Communications 14, 6966
During tumor progression, cancer-associated fibroblasts (CAFs) accumulate in tumors and produce an excessive extracellular matrix (ECM), forming a capsule that enwraps cancer cells. This capsule acts as a barrier that restricts tumor growth leading to the buildup of intratumoral pressure. Combining genetic and physical manipulations in vivo with microfabrication and force measurements in vitro, we found that the CAFs capsule is not a passive barrier but instead actively compresses cancer cells using actomyosin contractility. Abrogation of CAFs contractility in vivo leads to the dissipation of compressive forces and impairment of capsule formation. By mapping CAF force patterns in 3D, we show that compression is a CAF-intrinsic property independent of cancer cell growth. Supracellular coordination of CAFs is achieved through fibronectin cables that serve as scaffolds allowing force transmission. Cancer cells mechanosense CAF compression, resulting in an altered localization of the transcriptional regulator YAP and a decrease in proliferation. Our study unveils that the contractile capsule actively compresses cancer cells, modulates their mechanical signaling, and reorganizes tumor morphology.© 2023. The Author(s).
JTD Keywords: force, migration, yap, Cancer-associated fibroblasts, Cell line, tumor, Fibroblasts, Mechanotransduction, cellular, Neoplasms, Tumor, Tumor microenvironment
Resina, L, Alemán, C, Ferreira, FC, Esteves, T, (2023). Protein-imprinted polymers: How far have "plastic antibodies" come? BIOTECHNOLOGY ADVANCES 68, 108220
Antibodies are highly selective and sensitive, making them the gold standard for recognition affinity tools. However, their production cost is high and their downstream processing is time-consuming. Molecularly imprinted polymers (MIPs) are tailor-made by incorporating specific molecular recognition sites in their structure, thus translating into receptor-like activity mode of action. The interest in molecular imprinting technology, applied to biomacromolecules, has increased in the past decade. MIPs, produced using biomolecules as templates, commonly referred to as "plastic antibodies" or "artificial receptors", have been considered as suitable cheaper and easy to produce alternatives to antibodies. Research on MIPs, designed to recognize proteins or peptides is particularly important, with potential contributions towards biomedical applications, namely biosensors and targeted drug delivery systems. This mini review will cover recent advances on (bio)molecular imprinting technology, where proteins or peptides are targeted or mimicked for sensing and therapeutic applications. Polymerization methods are reviewed elsewhere, being out of the scope of this review. Template selection and immobilization approaches, monomers and applications will be discussed, highlighting possible drawbacks and gaps in research.Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.
JTD Keywords: artificial antibodies, assay, biomimetics, biomolecules, biosensors, delivery, diagnostics, drug delivery, electrochemical detection, nanoparticles, receptors, science-and-technology, selective recognition, selective targeting, separation, templates, Artificial antibodies, Biomimetics, Biomolecules, Biosensors, Diagnostics, Drug delivery, Molecularly imprinted polymers, Nanoparticles, Selective targeting, Solid-phase synthesis
Hinnekens, C, De Smedt, SC, Fraire, JC, Braeckmans, K, (2023). Non-viral engineering of NK cells BIOTECHNOLOGY ADVANCES 68, 108212
The last decade has witnessed great progress in the field of adoptive cell therapies, with the authorization of Kymriah (tisagenlecleucel) in 2017 by the Food and Drug Administration (FDA) as a crucial stepstone. Since then, five more CAR-T therapies have been approved for the treatment of hematological malignancies. While this is a great step forward to treating several types of blood cancers, CAR-T cell therapies are still associated with severe side-effects such as Graft-versus-Host Disease (GvHD), cytokine release syndrome (CRS) and neurotoxicity. Because of this, there has been continued interest in Natural Killer cells which avoid these side-effects while offering the possibility to generate allogeneic cell therapies. Similar to T-cells, NK cells can be genetically modified to improve their therapeutic efficacy in a variety of ways. In contrast to T cells, viral transduction of NK cells remains inefficient and induces cytotoxic effects. Viral vectors also require a lengthy and expensive product development process and are accompanied by certain risks such as insertional mutagenesis. Therefore, non-viral transfection technologies are avidly being developed aimed at addressing these shortcomings of viral vectors. In this review we will present an overview of the potential of NK cells in cancer immunotherapies and the non-viral transfection technologies that have been explored to engineer them.Copyright © 2023 Elsevier Inc. All rights reserved.
JTD Keywords: adoptive cell therapy, cancer immunotherapy, immunotherapy, messenger-rna delivery, nanoparticle, nk cells, non -viral engineering, sonoporation, t-cell, transfection, ultrasound, Adoptive cell therapy, Cancer immunotherapy, Cell engineering, Natural-killer-cells, Nk cells, Non-viral engineering
Grolleman, J, van Engeland, NCA, Raza, M, Azimi, S, Conte, V, Sahlgren, CM, Bouten, CVC, (2023). Environmental stiffness restores mechanical homeostasis in vimentin-depleted cells Scientific Reports 13, 18374
Recent experimental evidence indicates a role for the intermediate filament vimentin in regulating cellular mechanical homeostasis, but its precise contribution remains to be discovered. Mechanical homeostasis requires a balanced bi-directional interplay between the cell's microenvironment and the cellular morphological and mechanical state-this balance being regulated via processes of mechanotransduction and mechanoresponse, commonly referred to as mechanoreciprocity. Here, we systematically analyze vimentin-expressing and vimentin-depleted cells in a swatch of in vitro cellular microenvironments varying in stiffness and/or ECM density. We find that vimentin-expressing cells maintain mechanical homeostasis by adapting cellular morphology and mechanics to micromechanical changes in the microenvironment. However, vimentin-depleted cells lose this mechanoresponse ability on short timescales, only to reacquire it on longer time scales. Indeed, we find that the morphology and mechanics of vimentin-depleted cell in stiffened microenvironmental conditions can get restored to the homeostatic levels of vimentin-expressing cells. Additionally, we observed vimentin-depleted cells increasing collagen matrix synthesis and its crosslinking, a phenomenon which is known to increase matrix stiffness, and which we now hypothesize to be a cellular compensation mechanism for the loss of vimentin. Taken together, our findings provide further insight in the regulating role of intermediate filament vimentin in mediating mechanoreciprocity and mechanical homeostasis.© 2023. The Author(s).
JTD Keywords: contributes, dynamics, focal adhesions, forces, mechanotransduction, migration, motility, organization, tissue, Intermediate-filaments
Smith, CS, Alvarez, Z, Qiu, RM, Sasselli, IR, Clemons, T, Ortega, JA, Vilela-Picos, M, Wellman, H, Kiskinis, E, Stupp, SI, (2023). Enhanced Neuron Growth and Electrical Activity by a Supramolecular Netrin-1 Mimetic Nanofiber ACS Nano 17, 19887-19902
Neurotrophic factors are essential not only for guiding the organization of the developing nervous system but also for supporting the survival and growth of neurons after traumatic injury. In the central nervous system (CNS), inhibitory factors and the formation of a glial scar after injury hinder the functional recovery of neurons, requiring exogenous therapies to promote regeneration. Netrin-1, a neurotrophic factor, can initiate axon guidance, outgrowth, and branching, as well as synaptogenesis, through activation of deleted in colorectal cancer (DCC) receptors. We report here the development of a nanofiber-shaped supramolecular mimetic of netrin-1 with monomers that incorporate a cyclic peptide sequence as the bioactive component. The mimetic structure was found to activate the DCC receptor in primary cortical neurons using low molar ratios of the bioactive comonomer. The supramolecular nanofibers enhanced neurite outgrowth and upregulated maturation as well as pre- and postsynaptic markers over time, resulting in differences in electrical activity similar to neurons treated with the recombinant netrin-1 protein. The results suggest the possibility of using the supramolecular structure as a therapeutic to promote regenerative bioactivity in CNS injuries.
JTD Keywords: axon growth, axon guidance, cell-migration, colorectal-cancer, dcc, dopaminergic-neurons, force-field, functional recovery, netrin-1, neurite outgrowth, neuronal maturation, neurotrophic factor, neurotrophicfactor mimetic, synapsis, Axon growth, Axons, Cells, cultured, Central nervous system, Coarse-grained model, Nanofibers, Netrin-1, Neurogenesis, Neuronal maturation, Neurons, Neurotrophic factor mimetic, Peptide amphiphile, Synapsis
Perich, MP, Palma-Florez, S, Solé, C, Goberna-Ferrón, S, Samitier, J, Gómez-Romero, P, Mir, M, Lagunas, A, (2023). Polyoxometalate-Decorated Gold Nanoparticles Inhibit β-Amyloid Aggregation and Cross the Blood-Brain Barrier in a µphysiological Model Nanomaterials 13, 2697
Alzheimer's disease is characterized by a combination of several neuropathological hallmarks, such as extracellular aggregates of beta amyloid (Aβ). Numerous alternatives have been studied for inhibiting Aβ aggregation but, at this time, there are no effective treatments available. Here, we developed the tri-component nanohybrid system AuNPs@POM@PEG based on gold nanoparticles (AuNPs) covered with polyoxometalates (POMs) and polyethylene glycol (PEG). In this work, AuNPs@POM@PEG demonstrated the inhibition of the formation of amyloid fibrils, showing a 75% decrease in Aβ aggregation in vitro. As it is a potential candidate for the treatment of Alzheimer's disease, we evaluated the cytotoxicity of AuNPs@POM@PEG and its ability to cross the blood-brain barrier (BBB). We achieved a stable nanosystem that is non-cytotoxic below 2.5 nM to human neurovascular cells. The brain permeability of AuNPs@POM@PEG was analyzed in an in vitro microphysiological model of the BBB (BBB-on-a-chip), containing 3D human neurovascular cell co-cultures and microfluidics. The results show that AuNPs@POM@PEG was able to cross the brain endothelial barrier in the chip and demonstrated that POM does not affect the barrier integrity, giving the green light to further studies into this system as a nanotherapeutic.
JTD Keywords: beta-amyloid, blood-brain barrier organ-on-a-chip, cellular uptake, citrate, cytotoxicity, electrocatalytic reduction, gold nanoparticles, hypothesis, nanorods, polyoxometalates, size, stability, surface, Alzheimers-disease, Blood–brain barrier organ-on-a-chip, Gold nanoparticles, Nanovehicle, Polyoxometalates, Β-amyloid
García-Torres, J, Lázaro, C, Sylla, D, Lanzalaco, S, Ginebra, MP, Alemán, C, (2023). Combining 2D organic and 1D inorganic nanoblocks to develop free-standing hybrid nanomembranes for conformable biosensors Journal of Nanostructure in Chemistry 13, 507-517
We report a simple approach to fabricate free-standing perforated 2D nanomembranes hosting well-ordered 1D metallic nanostructures to obtain hybrid materials with nanostructured surfaces for flexible electronics. Nanomembranes are formed by alternatively depositing perforated poly(lactic acid) (PLA) and poly(3,4-ethylenedioxythiophene) layers. Copper metallic nanowires (NWs) were incorporated into the nanoperforations of the top PLA layer by electrodeposition and further coated with silver via a transmetallation reaction. The combination of 2D polymeric nanomembranes and aligned 1D metallic NWs allows merging the flexibility and conformability of the ultrathin soft polymeric nanomembranes with the good electrical properties of metals for biointegrated electronic devices. Thus, we were able to tailor the nanomembrane surface chemistry as it was corroborated by SEM, EDX, XPS, CV, EIS and contact angle. The obtained hybrid nanomembranes were flexible and conformable showing sensing capacity towards H2O2 with good linear concentration range (0.35–10 mM), sensitivity (120 µA cm?2 mM?1) and limit of detection (7 ?m). Moreover, the membranes showed good stability, reproducibility and selectivity towards H2O2.
JTD Keywords: biointegrated sensors, designs, electronics, fabrication, free-standing films, h2o2, metallic nanowires, nanoparticles, nanowires, sensor, skin, Hydrogen-peroxide, Perforated nanomembranes
Torras, N, Zabalo, J, Abril, E, Carré, A, García-Díaz, M, Martínez, E, (2023). A bioprinted 3D gut model with crypt-villus structures to mimic the intestinal epithelial-stromal microenvironment BIOMATERIALS ADVANCES 153, 213534
The intestine is a complex tissue with a characteristic three-dimensional (3D) crypt-villus architecture, which plays a key role in the intestinal function. This function is also regulated by the intestinal stroma that actively supports the intestinal epithelium, maintaining the homeostasis of the tissue. Efforts to account for the 3D complex structure of the intestinal tissue have been focused mainly in mimicking the epithelial barrier, while solutions to include the stromal compartment are scarce and unpractical to be used in routine experiments. Here we demonstrate that by employing an optimized bioink formulation and the suitable printing parameters it is possible to produce fibroblast-laden crypt-villus structures by means of digital light projection stereolithography (DLP-SLA). This process provides excellent cell viability, accurate spatial resolution, and high printing throughput, resulting in a robust biofabrication approach that yields functional gut mucosa tissues compatible with conventional testing techniques.Copyright © 2023 Elsevier B.V. All rights reserved.
JTD Keywords: 3d microstructure, barrier, cells, epithelial-stromal interactions, gelma-pegda soft hydrogels, growth, hydrogel, intestinal mucosa model, methacrylamide, microfabrication, proliferation, scaffold, stereolithography, 3d bioprinting, 3d microstructure, Epithelial-stromal interactions, Fibroblasts, Gelma-pegda soft hydrogels, Intestinal mucosa model
Farré, R, Navajas, D, (2023). Ventilation Mechanics SEMINARS IN RESPIRATORY AND CRITICAL CARE MEDICINE 44, 511-525
A fundamental task of the respiratory system is to operate as a mechanical gas pump ensuring that fresh air gets in close contact with the blood circulating through the lung capillaries to achieve O2 and CO2 exchange. To ventilate the lungs, the respiratory muscles provide the pressure required to overcome the viscoelastic mechanical load of the respiratory system. From a mechanical viewpoint, the most relevant respiratory system properties are the resistance of the airways (R aw), and the compliance of the lung tissue (C L) and chest wall (C CW). Both airflow and lung volume changes in spontaneous breathing and mechanical ventilation are determined by applying the fundamental mechanical laws to the relationships between the pressures inside the respiratory system (at the airway opening, alveolar, pleural, and muscular) and R aw, C L, and C CW. These relationships also are the basis of the different methods available to measure respiratory mechanics during spontaneous and artificial ventilation. Whereas a simple mechanical model (R aw, C L, and C CW) describes the basic understanding of ventilation mechanics, more complex concepts (nonlinearity, inhomogeneous ventilation, or viscoelasticity) should be employed to better describe and measure ventilation mechanics in patients.Thieme. All rights reserved.
JTD Keywords: airway-resistance, alveolar, compliance, dilution, elastance, flow, inhomogeneous ventilation, input impedance, lung-volume, mechanical ventilation, monitoring, pendelluft, pleural pressure, respiratory-distress-syndrome, viscoelasticity, Chest-wall mechanics, Resistance
Valenti, S, Arioli, M, Jamett, A, Tamarit, JL, Puiggalí, J, Macovez, R, (2023). Amorphous solid dispersions of curcumin in a poly(ester amide): Antiplasticizing effect on the glass transition and macromolecular relaxation dynamics, and controlled release INTERNATIONAL JOURNAL OF PHARMACEUTICS 644, 123333
In order to exploit the pharmacological potential of natural bioactive molecules with low water solubility, such as curcumin, it is necessary to develop formulations, such as amorphous polymer dispersions, which allow a constant release rate and at the same time avoid possible toxicity effects of the crystalline form of the molecule under scrutiny. In this study, polymer dispersions of curcumin were obtained in PADAS, a biodegradable semicrystalline copolymer based on 1,12-dodecanediol, sebacic acid and alanine. The dispersions were fully characterized by means of differential scanning calorimetry and broadband dielectric spectroscopy, and the drug release profile was measured in a simulated body fluid. Amorphous homogeneous binary dispersions were obtained for curcumin mass fraction between 30 and 50%. Curcumin has significantly higher glass transition temperature Tg (≈ 347 K) than the polymer matrix (≈274-277 K depending on the molecular weight), and dispersions displayed Tg's intermediate between those of the pure amorphous components, implying that curcumin acts as an effective antiplasticizer for PADAS. Dielectric spectroscopy was employed to assess the relaxation dynamics of the binary dispersion with 30 wt% curcumin, as well as that of each (amorphous) component separately. The binary dispersion was characterized by a single structural relaxation, a single Johari-Goldstein process, and two local intramolecular processes, one for each component. Interestingly, the latter processes scaled with the Tg of the sample, indicating that they are viscosity-sensitive. In addition, both the pristine polymer and the dispersion exhibited an interfacial Maxwell-Wagner relaxation, likely due to spatial heterogeneities associated with phase disproportionation in this polymer. The release of curcumin from the dispersion in a simulated body fluid followed a Fickian diffusion profile, and 51% of the initial curcumin content was released in 48 h.Copyright © 2023. Published by Elsevier B.V.
JTD Keywords: antioxidant, bioavailability, dielectric spectroscopy, domain havriliak-negami, glass transition temperature, kinetic stability, molecular mobility, nm pores, phase-behavior, physical stability, release kinetics, temperature, thermodynamic quantities, time, Amorphous formulations, Dielectric spectroscopy, Glass transition temperature, Kinetic stability, Kohlrausch-williams-watts, Molecular mobility, Release kinetics
Colombi, S, Macor, LP, Ortiz-Membrado, L, Pérez-Amodio, S, Jiménez-Piqué, E, Engel, E, Pérez-Madrigal, MM, García-Torres, J, Alemán, C, (2023). Enzymatic Degradation of Polylactic Acid Fibers Supported on a Hydrogel for Sustained Release of Lactate ACS Applied Bio Materials 6, 3889-3901
The incorporation of exogenous lactate into cardiac tissues is a regenerative strategy that is rapidly gaining attention. In this work, two polymeric platforms were designed to achieve a sustained release of lactate, combining immediate and prolonged release profiles. Both platforms contained electrospun poly(lactic acid) (PLA) fibers and an alginate (Alg) hydrogel. In the first platform, named L/K(x)/Alg-PLA, lactate and proteinase K (x mg of enzyme per 1 g of PLA) were directly loaded into the Alg hydrogel, into which PLA fibers were assembled. In the second platform, L/Alg-K(x)/PLA, fibers were produced by electrospinning a proteinase K:PLA solution and, subsequently, assembled within the lactate-loaded hydrogel. After characterizing the chemical, morphological, and mechanical properties of the systems, as well as their cytotoxicity, the release profiles of the two platforms were determined considering different amounts of proteinase K (x = 5.2, 26, and 52 mg of proteinase K per 1 g of PLA), which is known to exhibit a broad cleavage activity. The profiles obtained using L/Alg-K(x)/PLA platforms with x = 26 and 52 were the closest to the criteria that must be met for cardiac tissue regeneration. Finally, the amount of lactate directly loaded in the Alg hydrogel for immediate release and the amount of protein in the electrospinning solution were adapted to achieve a constant lactate release of around 6 mM per day over 1 or 2 weeks. In the optimized bioplatform, in which 6 mM lactate was loaded in the hydrogel, the amount of fibers was increased by a factor of x3, the amount of enzyme was adjusted to 40 mg per 1 g of PLA, and a daily lactate release of 5.9 +/- 2.7 mM over a period of 11 days was achieved. Accordingly, the engineered device fully satisfied the characteristics and requirements for heart tissue regeneration.
JTD Keywords: biodegradable fibers, cardiac tissue regeneration, cell, drug-release, elastic-modulus, electrospinning, heart, nanoindentation, plasma treatment, proteinase, scaffold, stiffness, Alginate, Alginates, Biodegradable fibers, Cardiac tissue, Cardiac tissue regeneration, Cell, Delayed-action preparations, Drug-release, Elastic-modulus, Electrospinning, Endopeptidase k, Heart, Hydrogels, Lactic acid, Nanoindentation, Plasma treatment, Poly(lactide), Polyesters, Proteinase, Regeneration, Scaffold, Skeletal-muscle, Stiffness
Gholami, S, Rezvani, A, Vatanpour, V, Khoshravesh, SH, Llorens, J, Engel, E, Castano, O, Cortina, JL, (2023). Chlorine resistance property improvement of polyamide reverse osmosis membranes through cross-linking degree increment SCIENCE OF THE TOTAL ENVIRONMENT 889, 164283
Highly permeable polyamide reverse osmosis (RO) membranes are desirable for reducing the energy burden and ensuring future water resources in arid and semiarid regions. One notable drawback of thin film composite (TFC) polyamide RO/NF membranes is the polyamide's sensitivity to degradation by free chlorine, the most used biocide in water purification trains. This investigation demonstrated a significant increase in the crosslinking-degree parameter by the m-phenylenediamine (MPD) chemical structure extending in the thin film nanocomposite (TFN) membrane without adding extra MPD monomers to enhance the chlorine resistance and performance. Membrane modification was carried out according to monomer ratio changes and Nanoparticle embedding into the PA layer approaches. A new class of TFN-RO membranes incorporating novel aromatic amine functionalized (AAF)-MWCNTs embedded into the polyamide (PA) layer was introduced. A purposeful strategy was carried out to use cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) as an intermediate functional group in the AAF-MWCNTs. Thus, amidic nitrogen, connected to benzene rings and carbonyl groups, assembles a structure similar to the standard PA, consisting of MPD and trimesoyl chloride. The resulting AAF-MWCNTs were mixed in the aqueous phase during the interfacial polymerization to increase the susceptible positions to chlorine attack and improve the crosslinking degree in the PA network. The characterization and performance results of the membrane demonstrated an increase in ion selectivity and water flux, impressive stability of salt rejection after chlorine exposure, and improved antifouling performance. This purposeful modification resulted in overthrowing two tradeoffs; i) high crosslink density-water flux and ii) salt rejection-permeability. The modified membrane demonstrated ameliorative chlorine resistance relative to the pristine one, with twice the increase in crosslinking degree, more than four times the enhancement of the oxidation resistance, negligible reduction in the salt rejection (0.83 %), and only 5 L/m2.h flux loss following a rigorous static chlorine exposure of 500 ppm.h under acidic conditions. The excellent performance of new chlorine resistant TNF RO membranes fabricated via AAF-MWCNTs together with the facile membrane manufacturing process offered the possibility of postulating them in the desalination field, which could eventually help the current freshwater supply challenge.Copyright © 2023 Elsevier B.V. All rights reserved.
JTD Keywords: behavior, carbon nanotubes, desalination, interfacial polymerization, naclo resistance, nanocomposite, nanofiltration membrane, performance, polymerization, ro membranemodification, substrate, water, Antifouling, Desalination, Interfacial polymerization, Naclo resistance, Ro membrane modification, Thin-film composite
del Moral, M, Loeck, M, Muntimadugu, E, Vives, G, Pham, V, Pfeifer, P, Battaglia, G, Muro, S, Andrianov, AK, (2023). Role of the Lactide:Glycolide Ratio in PLGA Nanoparticle Stability and Release under Lysosomal Conditions for Enzyme Replacement Therapy of Lysosomal Storage Disorders Journal of Functional Biomaterials 14, 440
Prior studies demonstrated that encapsulation in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) enhanced the delivery of enzymes used for replacement therapy (ERT) of lysosomal storage disorders (LSDs). This study examined how the copolymer lactide:glycolide ratio impacts encapsulation, physicochemical characteristics, stability, and release under lysosomal conditions. Hyaluronidase, deficient in mucopolysaccharidosis IX, was encapsulated in NPs synthesized using 50:50, 60:40, or 75:25 lactide:glycolide copolymers. All NPs had diameters compatible with cellular transport (≤168 nm) and polydispersity indexes (≤0.16) and ζ-potentials (≤-35 mV) compatible with colloidal stability. Yet, their encapsulation efficiency varied, with 75:25 NPs and 60:40 NPs having the lowest and highest EE, respectively (15% vs. 28%). Under lysosomal conditions, the 50:50 copolymer degraded fastest (41% in 1 week), as expected, and the presence of a targeting antibody coat did not alter this result. Additionally, 60:40 NPs destabilized fastest (<1 week) because of their smaller diameter, and 75:25 NPs did not destabilize in 4 weeks. All formulations presented burst release under lysosomal conditions (56-78% of the original load within 30 min), with 50:50 and 60:40 NPs releasing an additional small fraction after week 1. This provided 4 weeks of sustained catalytic activity, sufficient to fully degrade a substrate. Altogether, the 60:40 NP formulation is preferred given its higher EE, and 50:50 NPs represent a valid alternative, while the highest stability of 75:25 NPs may impair lysosomes. These results can guide future studies aiming to translate PLGA NP-based ERT for this and other LSDs.
JTD Keywords: biodegradation, copolymer ratio, degradation, drug-delivery, emulsification, enzyme release, enzyme replacement therapy, hyaluronidase, mechanisms, microspheres, nanoparticle stability, poly(lactide-co-glycolide) nanoparticles, size, sphingomyelinase, transport, Central-nervous-system, Copolymer ratio, Enzyme release, Enzyme replacement therapy, Hyaluronidase, Lysosomal storage disorder, Nanoparticle stability, Poly(lactide-co-glycolide) nanoparticles
Sauer, F, Grosser, S, Shahryari, M, Hayn, A, Guo, J, Braun, J, Briest, S, Wolf, B, Aktas, B, Horn, LC, Sack, I, Käs, JA, (2023). Changes in Tissue Fluidity Predict Tumor Aggressiveness In Vivo Advanced Science 10, e2303523
Cancer progression is caused by genetic changes and associated with various alterations in cell properties, which also affect a tumor's mechanical state. While an increased stiffness has been well known for long for solid tumors, it has limited prognostic power. It is hypothesized that cancer progression is accompanied by tissue fluidization, where portions of the tissue can change position across different length scales. Supported by tabletop magnetic resonance elastography (MRE) on stroma mimicking collagen gels and microscopic analysis of live cells inside patient derived tumor explants, an overview is provided of how cancer associated mechanisms, including cellular unjamming, proliferation, microenvironment composition, and remodeling can alter a tissue's fluidity and stiffness. In vivo, state-of-the-art multifrequency MRE can distinguish tumors from their surrounding host tissue by their rheological fingerprints. Most importantly, a meta-analysis on the currently available clinical studies is conducted and universal trends are identified. The results and conclusions are condensed into a gedankenexperiment about how a tumor can grow and eventually metastasize into its environment from a physics perspective to deduce corresponding mechanical properties. Based on stiffness, fluidity, spatial heterogeneity, and texture of the tumor front a roadmap for a prognosis of a tumor's aggressiveness and metastatic potential is presented.© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.
JTD Keywords: brain, cancer, cells, collective migration, elastic energy, elastography, in vivo magnetic resonance elastography, invasion, medical imaging, solid stress, tissue fluidity, tumor mechanics, viscoelastic properties, Cancer, Collagen, Extracellular-matrix, Humans, In vivo magnetic resonance elastography, Medical imaging, Neoplasms, Prognosis, Tissue fluidity, Tumor mechanics, Tumor microenvironment
Fulgheri, F, Aroffu, M, Ramírez, M, Román-Alamo, L, Peris, JE, Usach, I, Nacher, A, Manconi, M, Fernàndez-Busquets, X, Manca, ML, (2023). Curcumin or quercetin loaded nutriosomes as oral adjuvants for malaria infections INTERNATIONAL JOURNAL OF PHARMACEUTICS 643, 123195
Artemisinin, curcumin or quercetin, alone or in combination, were loaded in nutriosomes, special phospholipid vesicles enriched with Nutriose FM06®, a soluble dextrin with prebiotic activity, that makes these vesicles suitable for oral delivery. The resulting nutriosomes were sized between 93 and 146 nm, homogeneously dispersed, and had slightly negative zeta potential (around -8 mV). To improve their shelf life and storability over time, vesicle dispersions were freeze-dried and stored at 25 °C. Results confirmed that their main physico-chemical characteristics remained unchanged over a period of 12 months. Additionally, their size and polydispersity index did not undergo any significant variation after dilution with solutions at different pHs (1.2 and 7.0) and high ionic strength, mimicking the harsh conditions of the stomach and intestine. An in vitro study disclosed the delayed release of curcumin and quercetin from nutriosomes (∼53% at 48 h) while artemisinin was quickly released (∼100% at 48 h). Cytotoxicity assays using human colon adenocarcinoma cells (Caco-2) and human umbilical vein endothelial cells (HUVECs) proved the high biocompatibility of the prepared formulations. Finally, in vitro antimalarial activity tests, assessed against the 3D7 strain of Plasmodium falciparum, confirmed the effectiveness of nutriosomes in the delivery of curcumin and quercetin, which can be used as adjuvants in the antimalaria treatment. The efficacy of artemisinin was also confirmed but not improved. Overall results proved the possible use of these formulations as an accompanying treatment of malaria infections.Copyright © 2023. Published by Elsevier B.V.
JTD Keywords: artemisinin, delivery, flavonol, formulations, liposomes, malaria infections, nanomedicine, nutriose (r) fm06, oral administration, plasmodium falciparum, In-vitro, Liposomes, Malaria infections, Nanomedicine, Nutriose® fm06, Oral administration, Plasmodium falciparum
Fontana-Escartín, A, Lanzalaco, S, Bertran, O, Aradilla, D, Alemán, C, (2023). Aqueous alginate/MXene inks for 3D printable biomedical devices COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 671, 131632
Electrochemically responsive hydrogel networks have been obtained usin g printable inks made of a biopolymer, alginate (Alg), and an inorganic 2D material , MXene (titaniu m carbide, Ti3C2Tx) nanosheets. While MXene offers an electrically conductive pathway for electron transfer and Alg provides an interconnected framework for ion diffusion, the printed nanocomposite results, after gelation, in an extended active interface for redox reactions, being an ideal framework to design and construct flexible devices for biomedical applications. In this work, after characterization, we demonstrate that hydrogels obtained by cross-linking printed Alg /MXene inks exhibit great potential for bioelectronics. More specifically, we prove that flexible Alg/MXene hydrogels act as self-supported electroactive electrodes for the electrochemical detection of bioanalytes, such as dopamine, with a performance similar to that achieved using more sophisticated electrodes, as for example those containing conducting poly-mers and electrocatalytic gold nanoparticles. In addition, Alg/MXene hydrogels have been successfully used to regulate the release of a previously loaded broad spectrum antibiotic (chloramphenicol) by electrical stimulation.
JTD Keywords: 3d-printing, Biomedical application s, Composites, Conducting polymers, Drug release, Electroresponsive hydrogels, Fabrication, Hydrogels, Platform, Sensors, Strategy, Surface, Thin-film, Titanium carbide
Gregori-Pla, C, Zirak, P, Cotta, G, Bramon, P, Blanco, I, Serra, I, Mola, A, Fortuna, A, Solà-Soler, J, Giraldo, BFG, Durduran, T, Mayos, M, (2023). How does obstructive sleep apnea alter cerebral hemodynamics? SLEEP 46, zsad122
We aimed to characterize the cerebral hemodynamic response to obstructive sleep apnea/hypopnea events, and evaluate their association to polysomnographic parameters. The characterization of the cerebral hemodynamics in obstructive sleep apnea (OSA) may add complementary information to further the understanding of the severity of the syndrome beyond the conventional polysomnography.Severe OSA patients were studied during night sleep while monitored by polysomnography. Transcranial, bed-side diffuse correlation spectroscopy (DCS) and frequency-domain near-infrared diffuse correlation spectroscopy (NIRS-DOS) were used to follow microvascular cerebral hemodynamics in the frontal lobes of the cerebral cortex. Changes in cerebral blood flow (CBF), total hemoglobin concentration (THC), and cerebral blood oxygen saturation (StO2) were analyzed.We considered 3283 obstructive apnea/hypopnea events from sixteen OSA patients (Age (median, interquartile range) 57 (52-64.5); females 25%; AHI (apnea-hypopnea index) 84.4 (76.1-93.7)). A biphasic response (maximum/minimum followed by a minimum/maximum) was observed for each cerebral hemodynamic variable (CBF, THC, StO2), heart rate and peripheral arterial oxygen saturation (SpO2). Changes of the StO2 followed the dynamics of the SpO2, and were out of phase from the THC and CBF. Longer events were associated with larger CBF changes, faster responses and slower recoveries. Moreover, the extrema of the response to obstructive hypopneas were lower compared to apneas (p < .001).Obstructive apneas/hypopneas cause profound, periodic changes in cerebral hemodynamics, including periods of hyper- and hypo-perfusion and intermittent cerebral hypoxia. The duration of the events is a strong determinant of the cerebral hemodynamic response, which is more pronounced in apnea than hypopnea events.© The Author(s) 2023. Published by Oxford University Press on behalf of Sleep Research Society.
JTD Keywords: cerebral hemodynamics, desaturation, diffuse correlation spectroscopy, duration, hypopnea, hypoxemia, near-infrared spectroscopy, optical pathlength, oxygenation, severity, sleep disorder, spectroscopy, tissue, Adult, Airway obstruction, Apnea hypopnea index, Arterial oxygen saturation, Article, Blood oxygen tension, Blood-flow, Brain blood flow, Brain cortex, Cerebral hemodynamics, Controlled study, Diffuse correlation spectroscopy, Disease severity, Female, Frequency, Frontal lobe, Heart rate, Hemodynamics, Hemoglobin, Hemoglobin determination, Human, Humans, Major clinical study, Male, Near infrared spectroscopy, Near-infrared spectroscopy, Obstructive sleep apnea, Oxygen, Periodicity, Polysomnography, Sleep apnea syndromes, Sleep apnea, obstructive, Sleep disorder, Spectroscopy, near-infrared
Rodriguez, J, Schulz, S, Voss, A, Herrera, S, Benito, S, Giraldo, BF, (2023). Baroreflex activity through the analysis of the cardio-respiratory variability influence over blood pressure in cardiomyopathy patients Frontiers in Physiology 14, 1184293
A large portion of the elderly population are affected by cardiovascular diseases. Early prognosis of cardiomyopathies remains a challenge. The aim of this study was to classify cardiomyopathy patients by their etiology based on significant indexes extracted from the characterization of the baroreflex mechanism in function of the influence of the cardio-respiratory activity over the blood pressure. Forty-one cardiomyopathy patients (CMP) classified as ischemic (ICM-24 patients) and dilated (DCM-17 patients) were considered. In addition, thirty-nine control (CON) subjects were used as reference. The beat-to-beat (BBI) time series, from the electrocardiographic (ECG) signal, the systolic (SBP), and diastolic (DBP) time series, from the blood pressure signal (BP), and the respiratory time (TT), from the respiratory flow (RF) signal, were extracted. The three-dimensional representation of the cardiorespiratory and vascular activities was characterized geometrically, by fitting a polygon that contains 95% of data, and by statistical descriptive indices. DCM patients presented specific patterns in the respiratory response to decreasing blood pressure activity. ICM patients presented more stable cardiorespiratory activity in comparison with DCM patients. In general, CMP shown limited ability to regulate changes in blood pressure. In addition, patients also shown a limited ability of their cardiac and respiratory systems response to regulate incremental changes of the vascular variability and a lower heart rate variability. The best classifiers were used to build support vector machine models. The optimal model to classify ICM versus DCM patients achieved 92.7% accuracy, 94.1% sensitivity, and 91.7% specificity. When comparing CMP patients and CON subjects, the best model achieved 86.2% accuracy, 82.9% sensitivity, and 89.7% specificity. When comparing ICM patients and CON subjects, the best model achieved 88.9% accuracy, 87.5% sensitivity, and 89.7% specificity. When comparing DCM patients and CON subjects, the best model achieved 87.5% accuracy, 76.5% sensitivity, and 92.3% specificity. In conclusion, this study introduced a new method for the classification of patients by their etiology based on new indices from the analysis of the baroreflex mechanism.Copyright © 2023 Rodriguez, Schulz, Voss, Herrera, Benito and Giraldo.
JTD Keywords: abnormalities, blood pressure variability, cardio-respiratory variability, dilated cardiomyopathy, disease, heart-failure secondary, ischemic cardiomyopathy, ischemic-dilated cardiomyopathy, morphology-relative change, Baroreflex activity, Blood pressure variability, Cardio-respiratory variability, Cheyne-stokes respiration, Ischemic-dilated cardiomyopathy, Morphology-relative change
Blasi, D, Gonzalez-Pato, N, Rodriguez, XR, Diez-Zabala, I, Srinivasan, SY, Camarero, N, Esquivias, O, Roldán, M, Guasch, J, Laromaine, A, Gorostiza, P, Veciana, J, Ratera, I, (2023). Ratiometric Nanothermometer Based on a Radical Excimer for In Vivo Sensing Small 19, 2207806
Ratiometric fluorescent nanothermometers with near-infrared emission play an important role in in vivo sensing since they can be used as intracellular thermal sensing probes with high spatial resolution and high sensitivity, to investigate cellular functions of interest in diagnosis and therapy, where current approaches are not effective. Herein, the temperature-dependent fluorescence of organic nanoparticles is designed, synthesized, and studied based on the dual emission, generated by monomer and excimer species, of the tris(2,4,6-trichlorophenyl)methyl radical (TTM) doping organic nanoparticles (TTMd-ONPs), made of optically neutral tris(2,4,6-trichlorophenyl)methane (TTM-αH), acting as a matrix. The excimer emission intensity of TTMd-ONPs decreases with increasing temperatures whereas the monomer emission is almost independent and can be used as an internal reference. TTMd-ONPs show a great temperature sensitivity (3.4% K-1 at 328 K) and a wide temperature response at ambient conditions with excellent reversibility and high colloidal stability. In addition, TTMd-ONPs are not cytotoxic and their ratiometric outputs are unaffected by changes in the environment. Individual TTMd-ONPs are able to sense temperature changes at the nano-microscale. In vivo thermometry experiments in Caenorhabditis elegans (C. elegans) worms show that TTMd-ONPs can locally monitor internal body temperature changes with spatio-temporal resolution and high sensitivity, offering multiple applications in the biological nanothermometry field.© 2023 The Authors. Small published by Wiley-VCH GmbH.
JTD Keywords: dual emission, elegans, excimer emission, fluorescence, in vivo sensing, luminescence, nanoparticles, organic radical nanoparticles, ratiometric nanothermometers, sensors, thermometry, trityl radicals, Caenorhabditis elegans, Excimer emission, In vivo sensing, Intracellular ph, Luminescence, Organic radical nanoparticles, Ratiometric nanothermometers, Trityl radicals
Heras-Parets, A, Ginebra, MP, Manero, JM, Guillem-Marti, J, (2023). Guiding Fibroblast Activation Using an RGD‐Mutated Heparin Binding II Fragment of Fibronectin for Gingival Titanium Integration Advanced Healthcare Materials 12, e2203307
The formation of a biological seal around the neck of titanium (Ti) implants is critical for ensuring integration at the gingival site and for preventing bacterial colonization that may lead to periimplantitis. This process is guided by activated fibroblasts, named myofibroblasts, which secrete extracellular matrix (ECM) proteins and ECM-degrading enzymes resolving the wound. However, in some cases, Ti is not able to attract and activate fibroblasts to a sufficient extent, which may compromise the success of the implant. Fibronectin (FN) is an ECM component found in wounds that is able to guide soft tissue healing through the adhesion of cells and attraction of growth factors (GFs). However, clinical use of FN functionalized Ti implants is problematic because FN is difficult to obtain, and is sensitive to degradation. Herein, functionalizing Ti with a modified recombinant heparin binding II (HBII) domain of FN, mutated to include an Arg-Gly-Asp (RGD) sequence for promoting both fibroblast adhesion and GF attraction, is aimed at. The HBII-RGD domain is able to stimulate fibroblast adhesion, spreading, proliferation, migration, and activation to a greater extent than the native HBII, reaching values closer to those of full-length FN suggesting that it might induce the formation of a biological sealing.© 2023 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.
JTD Keywords: alpha-4-beta-1, beta, cell-binding, collagen, extracellular-matrix, fibroblast activation, fibronectin, growth factors, integrins, metalloproteinases, myofibroblasts, proliferation, soft-tissue integration, titanium, Biological-activities, Fibroblast activation, Titanium
Almadhi, S, Forth, J, Rodriguez-Arco, L, Duro-Castano, A, Williams, I, Ruiz-Pérez, L, Battaglia, G, (2023). Bottom-Up Preparation of Phase-Separated Polymersomes MACROMOLECULAR BIOSCIENCE 23, 2300068
A bottom-up approach to fabricating monodisperse, two-component polymersomes that possess phase-separated ("patchy") chemical topology is presented. This approach is compared with already-existing top-down preparation methods for patchy polymer vesicles, such as film rehydration. These findings demonstrate a bottom-up, solvent-switch self-assembly approach that produces a high yield of nanoparticles of the target size, morphology, and surface topology for drug delivery applications, in this case patchy polymersomes of a diameter of ≈50 nm. In addition, an image processing algorithm to automatically calculate polymersome size distributions from transmission electron microscope images based on a series of pre-processing steps, image segmentation, and round object identification is presented.© 2023 Wiley-VCH GmbH.
JTD Keywords: assemblies, copolymers, evolution, membranes, micelles, ph, phase separation, polymersomes, rafts, self-assembly, size, vesicles, Cell biology, Drug delivery, Drug delivery systems, Microscopy, Nanoparticles, Phase separation, Polymers, Polymersomes, Self-assembly, Solvents, Vesicles
Eills, J, Picazo-Frutos, R, Burueva, DB, Kovtunova, LM, Azagra, M, Marco-Rius, I, Budker, D, Koptyug, IV, (2023). Combined homogeneous and heterogeneous hydrogenation to yield catalyst-free solutions of parahydrogen-hyperpolarized [1-13C]succinate CHEMICAL COMMUNICATIONS 59, 9509-9512
We show that catalyst-free aqueous solutions of hyperpolarized [1-13C]succinate can be produced using parahydrogen-induced polarization (PHIP) and a combination of homogeneous and heterogeneous catalytic hydrogenation reactions. We generate hyperpolarized [1-13C]fumarate via PHIP using para-enriched hydrogen gas with a homogeneous ruthenium catalyst, and subsequently remove the toxic catalyst and reaction side products via a purification procedure. Following this, we perform a second hydrogenation reaction using normal hydrogen gas to convert the fumarate into succinate using a solid Pd/Al2O3 catalyst. This inexpensive polarization protocol has a turnover time of a few minutes, and represents a major advance for in vivo applications of [1-13C]succinate as a hyperpolarized contrast agent.
JTD Keywords: acid, c-13, conversion, fumarate, in-vivo, metabolism, order, Induced polarization
Noguchi, H, Walani, N, Arroyo, M, (2023). Estimation of anisotropic bending rigidities and spontaneous curvatures of crescent curvature-inducing proteins from tethered-vesicle experimental data Soft Matter 19, 5300-5310
The Bin/amphiphysin/Rvs (BAR) superfamily proteins have a crescent binding domain and bend biomembranes along the domain axis. However, their anisotropic bending rigidities and spontaneous curvatures have not been experimentally determined. Here, we estimated these values from the bound protein densities on tethered vesicles using a mean-field theory of anisotropic bending energy and orientation-dependent excluded volume. The dependence curves of the protein density on the membrane curvature are fitted to the experimental data for the I-BAR and N-BAR domains reported by C. Prevost et al. Nat. Commun., 2015, 6, 8529 and F.-C. Tsai et al. Soft Matter, 2021, 17, 4254-4265, respectively. For the I-BAR domain, all three density curves of different chemical potentials exhibit excellent fits with a single parameter set of anisotropic bending energy. When the classical isotropic bending energy is used instead, one of the curves can be fitted well, but the others exhibit large deviations. In contrast, for the N-BAR domain, two curves are not well fitted simultaneously the anisotropic model, although it is significantly improved compared to the isotropic model. This deviation likely suggests a cluster formation of the N-BAR domains.
JTD Keywords: Membrane-mediated interactions,elastic properties,bar,shape,mechanisms,inclusions,generation,polymers,driven,bod
Colom-Cadena, M, Davies, C, Sirisi, S, Lee, JE, Simzer, EM, Tzioras, M, Querol-Vilaseca, M, Sánchez-Aced, E, Chang, YY, Holt, K, McGeachan, RI, Rose, J, Tulloch, J, Wilkins, L, Smith, C, Andrian, T, Belbin, O, Pujals, S, Horrocks, MH, Lleó, A, Spires-Jones, TL, (2023). Synaptic oligomeric tau in Alzheimer's disease - A potential culprit in the spread of tau pathology through the brain NEURON 111, 2170-+
In Alzheimer's disease, fibrillar tau pathology accumulates and spreads through the brain and synapses are lost. Evidence from mouse models indicates that tau spreads trans-synaptically from pre- to postsynapses and that oligomeric tau is synaptotoxic, but data on synaptic tau in human brain are scarce. Here we used sub-diffraction-limit microscopy to study synaptic tau accumulation in postmortem temporal and occipital cortices of human Alzheimer's and control donors. Oligomeric tau is present in pre- and postsynaptic terminals, even in areas without abundant fibrillar tau deposition. Furthermore, there is a higher proportion of oligomeric tau compared with phosphorylated or misfolded tau found at synaptic terminals. These data suggest that accumulation of oligomeric tau in synapses is an early event in pathogenesis and that tau pathology may progress through the brain via trans-synaptic spread in human disease. Thus, specifically reducing oligomeric tau at synapses may be a promising therapeutic strategy for Alzheimer's disease.Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.
JTD Keywords: accumulation, alpha-synuclein, array tomography, cognitive impairment, dendritic spines, mouse model, neurodegeneration, neurons, synapses, Alzheimer, Amyloid-beta, Synapse, Tau
Alcàcer-Almansa, J, Arévalo-Jaimes, BV, Blanco-Cabra, N, Torrents, E, (2023). Methods for studying biofilms: Microfluidics and translation in the clinical context Methods in Microbiology 53, 195-233
Nong, J, Glassman, PM, Myerson, JW, Zuluaga-Ramirez, V, Rodriguez-Garcia, A, Mukalel, A, Omo-Lamai, S, Walsh, LR, Zamora, ME, Gong, XJ, Wang, ZC, Bhamidipati, K, Kiseleva, RY, Villa, CH, Greineder, CF, Kasner, SE, Weissman, D, Mitchell, MJ, Muro, S, Persidsky, Y, Brenner, JS, Muzykantov, VR, Marcos-Contreras, OA, (2023). Targeted Nanocarriers Co-Opting Pulmonary Intravascular Leukocytes for Drug Delivery to the Injured Brain ACS Nano 17, 13121-13136
Ex vivo-loaded white blood cells (WBC) can transfer cargo to pathological foci in the central nervous system (CNS). Here we tested affinity ligand driven in vivo loading of WBC in order to bypass the need for ex vivo WBC manipulation. We used a mouse model of acute brain inflammation caused by local injection of tumor necrosis factor alpha (TNF-α). We intravenously injected nanoparticles targeted to intercellular adhesion molecule 1 (anti-ICAM/NP). We found that (A) at 2 h, >20% of anti-ICAM/NP were localized to the lungs; (B) of the anti-ICAM/NP in the lungs >90% were associated with leukocytes; (C) at 6 and 22 h, anti-ICAM/NP pulmonary uptake decreased; (D) anti-ICAM/NP uptake in brain increased up to 5-fold in this time interval, concomitantly with migration of WBCs into the injured brain. Intravital microscopy confirmed transport of anti-ICAM/NP beyond the blood-brain barrier and flow cytometry demonstrated complete association of NP with WBC in the brain (98%). Dexamethasone-loaded anti-ICAM/liposomes abrogated brain edema in this model and promoted anti-inflammatory M2 polarization of macrophages in the brain. In vivo targeted loading of WBC in the intravascular pool may provide advantages of coopting WBC predisposed to natural rapid mobilization from the lungs to the brain, connected directly via conduit vessels.
JTD Keywords: drug delivery, icam-1, inflammation, lung injury, messenger-rna, migration, model, nanoparticles, neutrophils, pharmacokinetics, t-cells, white bloodcells, Adhesion molecules, Brain, Drug delivery, Inflammation, Nanoparticles, Pharmacokinetics, White blood cells
Fowler, DM, Adams, DJ, Gloyn, AL, Hahn, WC, Marks, DS, Muffley, LA, Neal, JT, Roth, FP, Rubin, AF, Starita, LM, Hurles, ME, Ahituv, N, Bahcal, OG, Baldridge, D, Berg, JS, Berger, AH, Bianchi, AH, Bolognesi, B, Boutros, M, Brenner, S, Brush, MH, Bryant, V, Bult, CJ, Bulyk, M, Call, M, Carter, H, Claussnitzer, M, Chen, F, Cline, MS, Cuperus, JT, Dawood, M, De Jong, HN, Dias, M, Dunn, M, Engreitz, J, Farh, K, Febbo, PG, Fields, S, Findlay, GM, Firth, H, Fraser, JS, Frazer, J, Frontini, M, Romero, IG, Glazer, AM, Guler, M, Hartmann-Petersen, R, Houlston, R, Huang, KL, Hutter, CM, Jagannathan, S, James, RG, Kampmann, M, Karchin, R, Kinney, JB, Komor, AC, Kosuri, S, Lehner, B, Lindorff-Larsen, K, Lombard, Z, MacArthur, DG, Martin, M, McDermott, U, McNulty, SM, Ba, ANN, O'Donnell-Luria, A, O'Roak, BJ, Parikh, VN, Parts, L, Pazin, MJ, Pesaran, T, Petrovski, S, Queitsch, C, Root, DE, Shendure, J, Spurdle, AB, Taylor, KL, Turnbull, C, Villen, J, Vissers, LELM, Wagner, AH, Wakefield, MJ, Weile, J, Xiao, J, (2023). An Atlas of Variant Effects to understand the genome at nucleotide resolution GENOME BIOLOGY 24, 147
Sequencing has revealed hundreds of millions of human genetic variants, and continued efforts will only add to this variant avalanche. Insufficient information exists to interpret the effects of most variants, limiting opportunities for precision medicine and comprehension of genome function. A solution lies in experimental assessment of the functional effect of variants, which can reveal their biological and clinical impact. However, variant effect assays have generally been undertaken reactively for individual variants only after and, in most cases long after, their first observation. Now, multiplexed assays of variant effect can characterise massive numbers of variants simultaneously, yielding variant effect maps that reveal the function of every possible single nucleotide change in a gene or regulatory element. Generating maps for every protein encoding gene and regulatory element in the human genome would create an 'Atlas' of variant effect maps and transform our understanding of genetics and usher in a new era of nucleotide-resolution functional knowledge of the genome. An Atlas would reveal the fundamental biology of the human genome, inform human evolution, empower the development and use of therapeutics and maximize the utility of genomics for diagnosing and treating disease. The Atlas of Variant Effects Alliance is an international collaborative group comprising hundreds of researchers, technologists and clinicians dedicated to realising an Atlas of Variant Effects to help deliver on the promise of genomics.
JTD Keywords: functional genomics, genome interpretation, global alliance, multiplexed assay of variant effect, saturation mutagenesis, Functional genomics, Genome interpretation, Global alliance, Multiplexed assay of variant effect, Saturation mutagenesis, Variant effect
Raptopoulos, M, Fischer, NG, Aparicio, C, (2023). Implant surface physicochemistry affects keratinocyte hemidesmosome formation JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A 111, 1021-1030
Previous studies have shown hydrophilic/hydrophobic implant surfaces stimulate/hinder osseointegration. An analogous concept was applied here using common biological functional groups on a model surface to promote oral keratinocytes (OKs) proliferation and hemidesmosomes (HD) to extend implant lifespans through increased soft tissue attachment. However, it is unclear what physicochemistry stimulates HDs. Thus, common biological functional groups (NH2 , OH, and CH3 ) were functionalized on glass using silanization. Non-functionalized plasma-cleaned glass and H silanization were controls. Surface modifications were confirmed with X-ray photoelectron spectroscopy and water contact angle. The amount of bovine serum albumin (BSA) and fibrinogen, and BSA thickness, were assessed to understand how adsorbed protein properties were influenced by physicochemistry and may influence HDs. OKs proliferation was measured, and HDs were quantified with immunofluorescence for collagen XVII and integrin β4. Plasma-cleaned surfaces were the most hydrophilic group overall, while CH3 was the most hydrophobic and OH was the most hydrophilic among functionalized groups. Modification with the OH chemical group showed the highest OKs proliferation and HD expression. The OKs response on OH surfaces appeared to not correlate to the amount or thickness of adsorbed model proteins. These results reveal relevant surface physicochemical features to favor HDs and improve implant soft tissue attachment.© 2023 The Authors. Journal of Biomedical Materials Research Part A published by Wiley Periodicals LLC.
JTD Keywords: attachment, chemistry, collagen, differentiation, epithelial-cells, hemidesmosome, implant, in-vitro, integrin, keratinocyte, mechanism, organosilane, physicochemistry, protein adsorption, Attachment, Cell-adhesion, Physicochemistry
Schierwagen, R, Gu, WY, Brieger, A, Brüne, B, Ciesek, S, Dikic, I, Dimmeler, S, Geisslinger, G, Greten, FR, Hermann, E, Hildt, E, Kempf, VAJ, Klein, S, Koch, I, Mühl, H, Müller, V, Peiffer, KH, Kestner, RI, Piiper, A, Rohde, G, Scholich, K, Schulz, MH, Storf, H, Toptan, T, Vasa-Nicotera, M, Vehreschild, MJGT, Weigert, A, Wild, PJ, Zeuzem, S, Engelmann, C, Schaefer, L, Welsch, C, Trebicka, J, (2023). Pathogenetic mechanisms and therapeutic approaches of acute-to-chronic liver failure AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY 325, C129-C140
Liver cirrhosis is the end stage of all chronic liver diseases and contributes significantly to overall mortality of 2% globally. The age-standardized mortality from liver cirrhosis in Europe is between 10 and 20% and can be explained by not only the development of liver cancer but also the acute deterioration in the patient's overall condition. The development of complications including accumulation of fluid in the abdomen (ascites), bleeding in the gastrointestinal tract (variceal bleeding), bacterial infections, or a decrease in brain function (hepatic encephalopathy) define an acute decompensation that requires therapy and often leads to acute-on-chronic liver failure (ACLF) by different precipitating events. However, due to its complexity and organ-spanning nature, the pathogenesis of ACLF is poorly understood, and the common underlying mechanisms leading to the development of organ dysfunction or failure in ACLF are still elusive. Apart from general intensive care interventions, there are no specific therapy options for ACLF. Liver transplantation is often not possible in these patients due to contraindications and a lack of prioritization. In this review, we describe the framework of the ACLF-I project consortium funded by the Hessian Ministry of Higher Education, Research and the Arts (HMWK) based on existing findings and will provide answers to these open questions.
JTD Keywords: 12/15-lipoxygenase, combination, inflammation, interleukin-22, metabolism, mortality, organ failure, portal-hypertension, receptor, regeneration, systemic inflammation, systems medicine, translational hepatology, Decompensated cirrhosis, Organ failure, Systemic inflammation, Systems medicine, Translational hepatology
Rey-Viñolas, S, Valls-Lacalle, L, Pérez-Amodio, S, Castaño, O, Mateos-Timoneda, MA, Engel, E, (2023). Biodegradable and bioactive personalized implant for guided bone regeneration (94238135204) Tissue Engineering Part A 29, 177-178
Ferre-Torres, J, Noguera-Monteagudo, A, Lopez-Canosa, A, Romero-Arias, JR, Barrio, R, Castaño, O, Hernandez-Machado, A, (2023). Modelling of chemotactic sprouting endothelial cells through an extracellular matrix Frontiers in Bioengineering and Biotechnology 11, 1145550
Sprouting angiogenesis is a core biological process critical to vascular development. Its accurate simulation, relevant to multiple facets of human health, is of broad, interdisciplinary appeal. This study presents an in-silico model replicating a microfluidic assay where endothelial cells sprout into a biomimetic extracellular matrix, specifically, a large-pore, low-concentration fibrin-based porous hydrogel, influenced by chemotactic factors. We introduce a novel approach by incorporating the extracellular matrix and chemotactic factor effects into a unified term using a single parameter, primarily focusing on modelling sprouting dynamics and morphology. This continuous model naturally describes chemotactic-induced sprouting with no need for additional rules. In addition, we extended our base model to account for matrix sensing and degradation, crucial aspects of angiogenesis. We validate our model via a hybrid in-silico experimental method, comparing the model predictions with experimental results derived from the microfluidic setup. Our results underscore the intricate relationship between the extracellular matrix structure and angiogenic sprouting, proposing a promising method for predicting the influence of the extracellular matrix on angiogenesis.Copyright © 2023 Ferre-Torres, Noguera-Monteagudo, Lopez-Canosa, Romero-Arias, Barrio, Castaño and Hernandez-Machado.
JTD Keywords: angiogenesis, biomimmetic, chemotaxis, endothelial cells, filopodia, growth, in silico model, mathematical models, mechanisms, metalloproteinase, migration, morphogenesis, phase field, pore-size, simulation, Angiogenesis, Biomimmetic, Chemotaxis, Endothelial cells, Extracellular matrix, In silico model, Mathematical models, Phase field, Tip cells
Chausse, V, Casanova-Batlle, E, Canal, C, Ginebra, MP, Ciurana, J, Pegueroles, M, (2023). Solvent-cast direct-writing and electrospinning as a dual fabrication strategy for drug-eluting polymeric bioresorbable stents Additive Manufacturing 71, 103568
JTD Keywords: alignment, bioresorbable stents, cells, design, electrospinning, everolimus, impact, in-vitro, poly(l-lactic-co-e-caprolactone), proliferation, release, sirolimus, Scaffold topography, Solvent-cast direct-writing
Oliver-Cervelló, L, Martin-Gómez, H, Gonzalez-Garcia, C, Salmeron-Sanchez, M, Ginebra, MP, Mas-Moruno, C, (2023). Protease-degradable hydrogels with multifunctional biomimetic peptides for bone tissue engineering Frontiers in Bioengineering and Biotechnology 11, 1192436
Mimicking bone extracellular matrix (ECM) is paramount to develop novel biomaterials for bone tissue engineering. In this regard, the combination of integrin-binding ligands together with osteogenic peptides represents a powerful approach to recapitulate the healing microenvironment of bone. In the present work, we designed polyethylene glycol (PEG)-based hydrogels functionalized with cell instructive multifunctional biomimetic peptides (either with cyclic RGD-DWIVA or cyclic RGD-cyclic DWIVA) and cross-linked with matrix metalloproteinases (MMPs)-degradable sequences to enable dynamic enzymatic biodegradation and cell spreading and differentiation. The analysis of the intrinsic properties of the hydrogel revealed relevant mechanical properties, porosity, swelling and degradability to engineer hydrogels for bone tissue engineering. Moreover, the engineered hydrogels were able to promote human mesenchymal stem cells (MSCs) spreading and significantly improve their osteogenic differentiation. Thus, these novel hydrogels could be a promising candidate for applications in bone tissue engineering, such as acellular systems to be implanted and regenerate bone or in stem cells therapy.Copyright © 2023 Oliver-Cervelló, Martin-Gómez, Gonzalez-Garcia, Salmeron-Sanchez, Ginebra and Mas-Moruno.
JTD Keywords: biomaterials, cross-linking, dwiva, functionalization, hydrogel, integrin, kinetics, marrow stromal cells, matrices, multifunctionality, myogenic differentiation, osteogenic differentiation, regeneration, stem-cells, Biomimetic peptides, Dwiva, Functionalization, Hydrogel, Multifunctionality, Osteogenic differentiation, Poly(ethylene glycol) hydrogels
Macor, LP, Colombi, S, Tamarit, JL, Engel, E, Pérez-Madrigal, MM, García-Torres, J, Alemán, C, (2023). Immediate-sustained lactate release using alginate hydrogel assembled to proteinase K/polymer electrospun fibers INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES 238, 124117
This work proposes a microfibers-hydrogel assembled composite as delivery vehicle able to combine into a single system both burst and prolonged release of lactate. The prolonged release of lactate has been achieved by electrospinning a mixture of polylactic acid and proteinase K (26.0 mg of proteinase K and 0.99 g of PLA dissolved in 6 mL of 2:1 chloroform:acetone in the optimal case), which is a protease that catalyzes the degradation of polylactic acid into lactate. The degradation of microfibers into lactate reflects that proteinase K preserves its enzymatic activity even after the electrospinning process because of the mild operational conditions used. Besides, burst release is obtained from the lactate-loaded alginate hydrogel. The successful assembly between the lactate-loaded hydrogel and the polylactic acid/proteinase K fibers has been favored by applying a low-pressure (0.3 mbar at 300 W) oxygen plasma treatment, which transforms hydrophobic fibers into hydrophilic while the enzymatic activity is still maintained. The composite displays both fast (< 24 h) and sustained (> 10 days) lactate release, and allows the modulation of the release by adjusting either the amount of loaded lactate or the amount of active enzyme.Copyright © 2023. Published by Elsevier B.V.
JTD Keywords: biodegradable fibers, proteases, regeneration, repair, Alginate, Alginates, Biodegradable fibers, Endopeptidase k, Hydrogels, Lactic acid, Myocardial-infarction, Polymers, Proteases
Oerther, C, Marco-Rius, I, (2023). Chapter 14: Fast Multi-dimensional NMR for In Vivo Spectroscopy New Developments in NMR 27, 415-440
Andrés-Benito, P, Iñigo-Marco, I, Brullas, M, Carmona, M, del Rio, JA, Fernández-Irigoyen, J, Santamaría, E, Povedano, M, Ferrer, I, (2023). Proteostatic modulation in brain aging without associated Alzheimer's disease-and age-related neuropathological changes Aging-US 15, 3295-3330
(Phospho)proteomics of old-aged subjects without cognitive or behavioral symptoms, and without AD-neuropathological changes and lacking any other neurodegenerative alteration will increase understanding about the physiological state of human brain aging without associate neurological deficits and neuropathological lesions.(Phospho)proteomics using conventional label-free- and SWATH-MS (Sequential window acquisition of all theoretical fragment ion spectra mass spectrometry) has been assessed in the frontal cortex (FC) of individuals without NFTs, senile plaques (SPs) and age-related co-morbidities classified by age (years) in four groups; group 1 (young, 30-44); group 2 (middle-aged: MA, 45-52); group 3 (early-elderly, 64-70); and group 4 (late-elderly, 75-85).Protein levels and deregulated protein phosphorylation linked to similar biological terms/functions, but involving different individual proteins, are found in FC with age. The modified expression occurs in cytoskeleton proteins, membranes, synapses, vesicles, myelin, membrane transport and ion channels, DNA and RNA metabolism, ubiquitin-proteasome-system (UPS), kinases and phosphatases, fatty acid metabolism, and mitochondria. Dysregulated phosphoproteins are associated with the cytoskeleton, including microfilaments, actin-binding proteins, intermediate filaments of neurons and glial cells, and microtubules; membrane proteins, synapses, and dense core vesicles; kinases and phosphatases; proteins linked to DNA and RNA; members of the UPS; GTPase regulation; inflammation; and lipid metabolism. Noteworthy, protein levels of large clusters of hierarchically-related protein expression levels are stable until 70. However, protein levels of components of cell membranes, vesicles and synapses, RNA modulation, and cellular structures (including tau and tubulin filaments) are markedly altered from the age of 75. Similarly, marked modifications occur in the larger phosphoprotein clusters involving cytoskeleton and neuronal structures, membrane stabilization, and kinase regulation in the late elderly.Present findings may increase understanding of human brain proteostasis modifications in the elderly in the subpopulation of individuals not having AD neuropathological change and any other neurodegenerative change in any telencephalon region.
JTD Keywords: (phospho)proteomics, cortex, cytoskeleton, hippocampus, kinases, membranes, mitochondria, mitochondrial-function, pathological process, phosphoproteome analysis, phosphorylation, proteome, quantitative proteomics, synapsis, tau-protein, therapeutic target, (phospho)proteomics, Aged, Alzheimer disease, Brain, Brain aging, Cytoskeleton, Humans, Kinases, Membranes, Middle aged, Mitochondria, Nervous system diseases, Neurodegenerative diseases, Neurons, Phosphoric monoester hydrolases, Proteome, Synapsis, Tau proteins
Rodríguez-Contreras, A, Torres, D, Piñera-Avellaneda, D, Pérez-Palou, L, Ortiz-Hernández, M, Ginebra, MP, Calero, JA, Manero, JM, Rupérez, E, (2023). Dual-Action Effect of Gallium and Silver Providing Osseointegration and Antibacterial Properties to Calcium Titanate Coatings on Porous Titanium Implants INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 24, 8762
Previously, functional coatings on 3D-printed titanium implants were developed to improve their biointegration by separately incorporating Ga and Ag on the biomaterial surface. Now, a thermochemical treatment modification is proposed to study the effect of their simultaneous incorporation. Different concentrations of AgNO3 and Ga(NO3)3 are evaluated, and the obtained surfaces are completely characterized. Ion release, cytotoxicity, and bioactivity studies complement the characterization. The provided antibacterial effect of the surfaces is analyzed, and cell response is assessed by the study of SaOS-2 cell adhesion, proliferation, and differentiation. The Ti surface doping is confirmed by the formation of Ga-containing Ca titanates and nanoparticles of metallic Ag within the titanate coating. The surfaces generated with all combinations of AgNO3 and Ga(NO3)3 concentrations show bioactivity. The bacterial assay confirms a strong bactericidal impact achieved by the effect of both Ga and Ag present on the surface, especially for Pseudomonas aeruginosa, one of the main pathogens involved in orthopedic implant failures. SaOS-2 cells adhere and proliferate on the Ga/Ag-doped Ti surfaces, and the presence of gallium favors cell differentiation. The dual effect of both metallic agents doping the titanium surface provides bioactivity while protecting the biomaterial from the most frequent pathogens in implantology.
JTD Keywords: 3d-printing, agent, antibacterial activity, bioactive ti, biomaterials, coatings, competition, cu, gallium, glasses, ions, metal, porous structures, promote osseointegration, silver, titanium implants, In-vitro, Porous structures, Titanium implants
Andrés-Benito, P, Carmona, M, Pirla, MJ, Torrejón-Escribano, B, del Rio, J, Ferrer, I, (2023). Dysregulated Protein Phosphorylation as Main Contributor of Granulovacuolar Degeneration at the First Stages of Neurofibrillary Tangles Pathology NEUROSCIENCE 518, 119-140
The hippocampus of cases with neurofibrillary tangles (NFT) pathology classified as stages I–II, III–IV, and V–VI without comorbidities, and middle-aged (MA) individuals with no NFT pathology, were examined to learn about the composition of granulovacuolar degeneration (GVD). Our results confirm the presence of CK1-?, p38-P Thr180/Tyr182, SAPK/JNK-P Thr183/Thr185, GSK-3?/?-P Tyr279/Tyr216, and GSK-3? Ser9 in the cytoplasmic granules in a subset of neurons of the CA1 and CA2 subfields of the hippocampus. Also, we identify the presence of PKA ?/?-P Thr197, SRC-P Tyr416, PAK1-P Ser199/Ser204, CAMK2A-P Tyr197, and PKCG-P Thr655 in cytoplasmic granules in cases with NFT pathology, but not in MA cases. Our results also confirm the presence of ?-catenin-P Ser45/Thr41, IRE?-P Ser274, eIF2?-P Ser51, TDP-43-P Ser403-404 (but absent TDP-43), and ubiquitin in cytoplasmic granules. Other components of the cytoplasmic granules are MAP2-P Thr1620/1623, MAP1B-P Thr1265, ADD1-P Ser726, and ADD1/ADD1-P Ser726/Ser713, in addition to several tau species including 3Rtau, 4Rtau, and tau-P Ser262. The analysis of GVD at progressive stages of NFT pathology reveals the early appearance of phosphorylated kinases and proteins in cytoplasmic granules at stages I–II, before the appearance of pre-tangles and NFTs. Most of these granules are not surrounded by LAMP1-positive membranes. Markers of impaired ubiquitin-protesome system, abnormal reticulum stress response, and altered endocytic and autophagic pathways occur in a subpopulation of neurons containing cytoplasmic granules, and they appear later. These observations suggest early phosphorylation of kinases leading to their activation, and resulting in the abnormal phosphorylation of various substrates, including tau, as a main alteration at the first stages of GVD. © 2021 The Author(s)
JTD Keywords: alzheimer's disease, alzheimers association guidelines, alzheimer’s disease, brain aging, cyclin-dependent kinase-5, granulovacuolar degeneration, kinases, national institute, neuropathologic assessment, p38 kinase, progressive supranuclear palsy, protein phosphorylation, tau, tau pathology, up-regulation, upstream activator, Alzheimer disease, Alzheimer's disease, Alzheimer’s disease, Brain aging, Dna-binding proteins, Glycogen synthase kinase 3 beta, Glycogen-synthase kinase-3, Granulovacuolar degeneration, Hippocampus, Humans, Kinases, Middle aged, Nerve degeneration, Neurofibrillary tangles, Phosphorylation, Protein phosphorylation, Tau, Tau proteins, Ubiquitins
Pesce, M, Duda, GN, Forte, G, Girao, H, Raya, A, Roca-Cusachs, P, Sluijter, JPG, Tschöpe, C, Van Linthout, S, (2023). Cardiac fibroblasts and mechanosensation in heart development, health and disease Nature Reviews Cardiology 20, 309-324
The term 'mechanosensation' describes the capacity of cells to translate mechanical stimuli into the coordinated regulation of intracellular signals, cellular function, gene expression and epigenetic programming. This capacity is related not only to the sensitivity of the cells to tissue motion, but also to the decryption of tissue geometric arrangement and mechanical properties. The cardiac stroma, composed of fibroblasts, has been historically considered a mechanically passive component of the heart. However, the latest research suggests that the mechanical functions of these cells are an active and necessary component of the developmental biology programme of the heart that is involved in myocardial growth and homeostasis, and a crucial determinant of cardiac repair and disease. In this Review, we discuss the general concept of cell mechanosensation and force generation as potent regulators in heart development and pathology, and describe the integration of mechanical and biohumoral pathways predisposing the heart to fibrosis and failure. Next, we address the use of 3D culture systems to integrate tissue mechanics to mimic cardiac remodelling. Finally, we highlight the potential of mechanotherapeutic strategies, including pharmacological treatment and device-mediated left ventricular unloading, to reverse remodelling in the failing heart.© 2022. Springer Nature Limited.
JTD Keywords: cardiomyocyte proliferation, cross-linking, extracellular-matrix, focal adhesions, gene-expression, mechanical regulation, myocardial-infarction, substrate stiffness affects, t-cells, Ventricular assist device
Cominetti, O, Agarwal, S, Oller-Moreno, S, (2023). Editorial: Advances in methods and tools for multi-omics data analysis Frontiers in Molecular Biosciences 10, 1186822
JTD Keywords: deep generative models, eatris european infrastructure for translational medicine, integrative omics, machine learning, multi-omics, personalized medicine, Deep generative models, Eatris european infrastructure for translational medicine, Integrative omics, Machine learning, Multi-omics, Personalized medicine, Protein protein interaction (ppi) network
Garcia-Torres, J, Colombi, S, Mahamed, I, Sylla, D, Arnau, M, Sans, J, Ginebra, MP, Aleman, C, (2023). Nanocomposite Hydrogels with Temperature Response for Capacitive Energy Storage ACS Applied Energy Materials 6, 4487-4495
Juste-Lanas, Y, Díaz-Valdivia, N, Llorente, A, Ikemori, R, Bernardo, A, Arshakyan, M, Borau, C, Ramírez, J, Ruffinelli, JC, Nadal, E, Reguart, N, García-Aznar, JM, Alcaraz, J, (2023). 3D collagen migration patterns reveal a SMAD3-dependent and TGF-β1-independent mechanism of recruitment for tumour-associated fibroblasts in lung adenocarcinoma BRITISH JOURNAL OF CANCER 128, 967-981
The TGF-β1 transcription factor SMAD3 is epigenetically repressed in tumour-associated fibroblasts (TAFs) from lung squamous cell carcinoma (SCC) but not adenocarcinoma (ADC) patients, which elicits a compensatory increase in SMAD2 that renders SCC-TAFs less fibrotic. Here we examined the effects of altered SMAD2/3 in fibroblast migration and its impact on the desmoplastic stroma formation in lung cancer.We used a microfluidic device to examine descriptors of early protrusions and subsequent migration in 3D collagen gels upon knocking down SMAD2 or SMAD3 by shRNA in control fibroblasts and TAFs.High SMAD3 conditions as in shSMAD2 fibroblasts and ADC-TAFs exhibited a migratory advantage in terms of protrusions (fewer and longer) and migration (faster and more directional) selectively without TGF-β1 along with Erk1/2 hyperactivation. This enhanced migration was abrogated by TGF-β1 as well as low glucose medium and the MEK inhibitor Trametinib. In contrast, high SMAD2 fibroblasts were poorly responsive to TGF-β1, high glucose and Trametinib, exhibiting impaired migration in all conditions.The basal migration advantage of high SMAD3 fibroblasts provides a straightforward mechanism underlying the larger accumulation of TAFs previously reported in ADC compared to SCC. Moreover, our results encourage using MEK inhibitors in ADC-TAFs but not SCC-TAFs.© 2022. The Author(s).
JTD Keywords: cancer, cell, degradation, nintedanib, osteoblast migration, phenotype, progression, protrusion dynamics, smad3, Growth-factor-beta
Claudia, GM, Ivan, G, Laia, OM, Emilio, JP, Maria-Pau, G, Maurizio, V, Luis, CJ, Marta, P, (2023). Influence of ECAP process on mechanical, corrosion and bacterial properties of Zn-2Ag alloy for wound closure devices MATERIALS & DESIGN 228, 111817
Actual polymeric wound closure devices are not optimal for load-bearing applications due to the low mechanical properties and the risk of inflammation and bacterial infection mainly produced by multifil-ament and braided configurations. Biodegradable metallic Zn alloys are promising materials candidates; however, mechanical performance, corrosion behaviour, and biological response should be controlled in order to inhibit the risk of inflammation and bacterial infection. To this end, a Zn-2Ag (2 wt% Ag) alloy was processed by ECAP to evaluate the concurrent combined effect of grain refinement and Ag alloying on biodegradation and antibacterial activity. Two ECAP cycles were successfully applied to a Zn-2Ag alloy obtaining a homogeneous ultra-fine-grained structure in which nanoindentation maps suggested isotro-pic mechanical properties. Lower UTS and YS with higher elongation was reported after ECAP with similar corrosion rates as before processing. ECAP processed samples showed a homogeneous Ag+ release below the minimum inhibitory concentration for S. Aureus and no antibacterial effect was observed by diffusion. As expected, the presence of Ag in Zn-Ag alloys reduced bacterial attachment. Nevertheless, ECAP processed Zn-2Ag provided an excellent antibacterial activity after 3 h probably caused by the uniformly degraded and thus, non- stable, surface observed after bacterial adhesion.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
JTD Keywords: Behavior, Binary alloys, Biodegradable zinc-alloys, Biomaterials, Equal channel angular pressing, Grain-refinement, In-vitro degradation, Mg, Microstructure, Nanoindentation, Progress, Staphylococcus-aureus, Temperature superplasticity, Ultrafine-grained materials, Zinc alloys, Zn alloys
Romero, D, Jané, R, (2023). Dynamic Bayesian Model for Detecting Obstructive Respiratory Events by Using an Experimental Model SENSORS 23, 3371-3371
In this study, we propose a model-based tool for the detection of obstructive apnea episodes by using ECG features from a single lead channel. Several sequences of recurrent apnea were provoked in separate 15-min periods in anesthetized rats during an experimental model of obstructive sleep apnea (OSA). Morphology-based ECG markers and the beat-to-beat interval (RR) were assessed in each sequence. These markers were used to train dynamic Bayesian networks (DBN) with different orders and feature combinations to find a good tradeoff between network complexity and apnea-detection performance. By using a filtering approach, the resulting DBNs were used to infer the apnea probability signal for subsequent episodes in the same rat. These signals were then processed using by 15-s epochs to determine whether epochs were classified as apneic or nonapneic. Our results showed that fifth-order models provided suitable RMSE values, since higher order models become significantly more complex and present worse generalization. A global threshold of 0.2 gave the best overall performance for all combinations tested, with Acc = 81.3%, Se = 69.8% and Sp = 81.5%, using only two parameters including the RR and Ds (R-wave downslope) markers. We concluded that multivariate models using DBNs represent a powerful tool for detecting obstructive apnea episodes in short segments, which may also serve to estimate the number of total events in a given time period.
JTD Keywords: chronic respiratory diseases, obstructive sleep apnea, probabilistic models, Obstructive sleep apnea,probabilistic models,respiratory events,chronic respiratory disease, Respiratory events, Sleep-apnea syndrome,automated detection,oxygen-saturation,classification,recordings,signal
Comelles, J, Fernández-Majada, V, Acevedo, V, Rebollo-Calderon, B, Martínez, E, (2023). Soft topographical patterns trigger a stiffness-dependent cellular response to contact guidance MATERIALS TODAY BIO 19, 100593
Topographical patterns are a powerful tool to study directional migration. Grooved substrates have been extensively used as in vitro models of aligned extracellular matrix fibers because they induce cell elongation, alignment, and migration through a phenomenon known as contact guidance. This process, which involves the orientation of focal adhesions, F-actin, and microtubule cytoskeleton along the direction of the grooves, has been primarily studied on hard materials of non-physiological stiffness. But how it unfolds when the stiffness of the grooves varies within the physiological range is less known. Here we show that substrate stiffness modulates the cellular response to topographical contact guidance. We find that for fibroblasts, while focal adhesions and actin respond to topography independently of the stiffness, microtubules show a stiffness-dependent response that regulates contact guidance. On the other hand, both clusters and single breast carcinoma epithelial cells display stiffness-dependent contact guidance, leading to more directional and efficient migration when increasing substrate stiffness. These results suggest that both matrix stiffening and alignment of extracellular matrix fibers cooperate during directional cell migration, and that the outcome differs between cell types depending on how they organize their cytoskeletons.© 2023 The Authors.
JTD Keywords: actin, behavior, cell migration, contact guidance, cytoskeleton, fibroblasts, focal adhesions, matrix, microtubules, stiffness, stress fibers, topography, transduction, Contact guidance, Substrate stiffness, Topography
Schamberger, B, Ziege, R, Anselme, K, Ben Amar, M, Bykowski, M, Castro, APG, Cipitria, A, Coles, RA, Dimova, R, Eder, M, Ehrig, S, Escudero, LM, Evans, ME, Fernandes, PR, Fratzl, P, Geris, L, Gierlinger, N, Hannezo, E, Iglic, A, Kirkensgaard, JJK, Kollmannsberger, P, Kowalewska, L, Kurniawan, NA, Papantoniou, I, Pieuchot, L, Pires, THV, Renner, LD, Sageman-Furnas, AO, Schroder-Turk, GE, Sengupta, A, Sharma, VR, Tagua, A, Tomba, C, Trepat, X, Waters, SL, Yeo, EF, Roschger, A, Bidan, CM, Dunlop, JWC, (2023). Curvature in Biological Systems: Its Quantification, Emergence, and Implications across the Scales ADVANCED MATERIALS 35, 2206110
Surface curvature both emerges from, and influences the behavior of, living objects at length scales ranging from cell membranes to single cells to tissues and organs. The relevance of surface curvature in biology is supported by numerous experimental and theoretical investigations in recent years. In this review, first, a brief introduction to the key ideas of surface curvature in the context of biological systems is given and the challenges that arise when measuring surface curvature are discussed. Giving an overview of the emergence of curvature in biological systems, its significance at different length scales becomes apparent. On the other hand, summarizing current findings also shows that both single cells and entire cell sheets, tissues or organisms respond to curvature by modulating their shape and their migration behavior. Finally, the interplay between the distribution of morphogens or micro-organisms and the emergence of curvature across length scales is addressed with examples demonstrating these key mechanistic principles of morphogenesis. Overall, this review highlights that curved interfaces are not merely a passive by-product of the chemical, biological, and mechanical processes but that curvature acts also as a signal that co-determines these processes.© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.
JTD Keywords: biological systems, butterfly wing scales, cubic membranes, extracellular-matrix, geometry, mechanotransduction, membrane curvature, morphogenesis, neotissue growth, pattern-formation, soft materials, surface curvature, tissue-growth, Biological systems, Collective cell-migration, Surface curvature
Fontcuberta-PiSunyer, M, García-Alamán, A, Prades, É, Téllez, N, Alves-Figueiredo, H, Ramos-Rodríguez, M, Enrich, C, Fernandez-Ruiz, R, Cervantes, S, Clua, L, Ramón-Azcón, J, Broca, C, Wojtusciszyn, A, Montserrat, N, Pasquali, L, Novials, A, Servitja, JM, Vidal, J, Gomis, R, Gasa, R, (2023). Direct reprogramming of human fibroblasts into insulin-producing cells using transcription factors Communications Biology 6, 256
Direct lineage reprogramming of one somatic cell into another without transitioning through a progenitor stage has emerged as a strategy to generate clinically relevant cell types. One cell type of interest is the pancreatic insulin-producing β cell whose loss and/or dysfunction leads to diabetes. To date it has been possible to create β-like cells from related endodermal cell types by forcing the expression of developmental transcription factors, but not from more distant cell lineages like fibroblasts. In light of the therapeutic benefits of choosing an accessible cell type as the cell of origin, in this study we set out to analyze the feasibility of transforming human skin fibroblasts into β-like cells. We describe how the timed-introduction of five developmental transcription factors (Neurog3, Pdx1, MafA, Pax4, and Nkx2-2) promotes conversion of fibroblasts toward a β-cell fate. Reprogrammed cells exhibit β-cell features including β-cell gene expression and glucose-responsive intracellular calcium mobilization. Moreover, reprogrammed cells display glucose-induced insulin secretion in vitro and in vivo. This work provides proof-of-concept of the capacity to make insulin-producing cells from human fibroblasts via transcription factor-mediated direct reprogramming.© 2023. The Author(s).
JTD Keywords: adult, beta-cells, differentiation, direct conversion, genes, in-vivo, islets, maturation, pancreatic progenitors, Pluripotent stem-cells
Ye, Z, Qi, YP, Zhang, AQ, Karels, BJ, Aparicio, C, (2023). Biomimetic Mineralization of Fibrillar Collagen with Strontium-doped Hydroxyapatite ACS Macro Letters 12, 408-414
Fibrillar collagen structures mineralized with hydroxyapatite using the polymer-induced liquid precursor (PILP) process have been explored as synthetic models for studying biomineralization of human hard tissues and have also been applied in the fabrication of scaffolds for hard tissue regeneration. Strontium has important biological functions in bone and has been used as a therapeutic agent for treating diseases that result in bone defects, such as osteoporosis. Here, we developed a strategy to mineralize collagen with Sr-doped hydroxyapatite (HA) using the PILP process. Doping with Sr altered the crystal lattice of HA and inhibited the degree of mineralization in a concentration-dependent manner, but did not affect the unique formation of intrafibrillar minerals using the PILP. The Sr-doped HA nanocrystals were aligned in the [001] direction but did not recapitulate the parallel alignment of the c-axis of pure Ca HA in relation to the collagen fiber long axis. The mimicry of doping Sr in PILP-mineralized collagen can help understand the doping of Sr in natural hard tissues and during treatment. The fibrillary mineralized collagen with Sr-doped HA will be explored in future work as biomimetic and bioactive scaffolds for regeneration of bone and tooth dentin.
JTD Keywords: bone regeneration, osteoblast differentiation, osteoporosis, ranelate, risk, scaffolds, women, Intrafibrillar mineralization
Gierse, M, Nagel, L, Keim, M, Lucas, S, Speidel, T, Lobmeyer, T, Winter, G, Josten, F, Karaali, S, Fellermann, M, Scheuer, J, Müller, C, van Heijster, F, Skinner, J, Löffler, J, Parker, A, Handwerker, J, Marshall, A, Salhov, A, El-Kassem, B, Vassiliou, C, Blanchard, JW, Picazo-Frutos, R, Eills, J, Barth, H, Jelezko, F, Rasche, V, Schilling, F, Schwartz, I, Knecht, S, (2023). Parahydrogen-Polarized Fumarate for Preclinical in Vivo Metabolic Magnetic Resonance Imaging JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 145, 5960-5969
We present a versatile method for the preparation of hyperpolarized [1-13C]fumarate as a contrast agent for preclinical in vivo MRI, using parahydrogen-induced polarization (PHIP). To benchmark this process, we compared a prototype PHIP polarizer to a state-of-the-art dissolution dynamic nuclear polarization (d-DNP) system. We found comparable polarization, volume, and concentration levels of the prepared solutions, while the preparation effort is significantly lower for the PHIP process, which can provide a preclinical dose every 10 min, opposed to around 90 min for d-DNP systems. With our approach, a 100 mM [1-13C]-fumarate solution of volumes up to 3 mL with 13-20% 13C-hyperpolarization after purification can be produced. The purified solution has a physiological pH, while the catalyst, the reaction side products, and the precursor material concentrations are reduced to nontoxic levels, as confirmed in a panel of cytotoxicity studies. The in vivo usage of the hyperpolarized fumarate as a perfusion agent in healthy mice and the metabolic conversion of fumarate to malate in tumor-bearing mice developing regions with necrotic cell death is demonstrated. Furthermore, we present a one-step synthesis to produce the 13C-labeled precursor for the hydrogenation reaction with high yield, starting from 13CO2 as a cost-effective source for 13C-labeled compounds.
JTD Keywords: Animals, Contrast media, Fumarates, Hydrogenation, Magnetic resonance imaging, Magnetic resonance spectroscopy, Mice, Para-hydrogen
Resina, L, El Hauadi, K, Sans, J, Esteves, T, Ferreira, FC, Perez-Madrigal, MM, Aleman, C, (2023). Electroresponsive and pH-Sensitive Hydrogel as Carrier for Controlled Chloramphenicol Release BIOMACROMOLECULES 24, 1432-1444
Multiresponsive hydrogels, which are smart soft materials that respond to more than one external stimulus, have emerged as powerful tools for biomedical applications, such as drug delivery. Within this context and with the aim of eliminating the systematic administration of antibiotics, special attention is being paid to the development of systems for controlled delivery of antibiotic for topical treatment of bacterial infections. In this work, an electro-chemo responsive hydrogel able to release chloramphenicol (CAM), a broad spectrum antibiotic also used for anticancer therapy, is proposed. This has been prepared by grafting poly(acrylic acid) (PAA) to sodium alginate (Alg) and in situ encapsulation of poly(3,4-ethylenedioxythiophene) nanoparticles loaded with CAM (PEDOT/CAM NPs), which were obtained by emulsion polymerization. Although the response to electrical stimuli of PEDOT was the main control for the release of CAM from PEDOT/CAM NPs, the release by passive diffusion had a relatively important contribution. Conversely, the passive release of antibiotic from the whole engineered hydrogel system, Alg-g-PAA/PEDOT/CAM, was negligible, whereas significant release was achieved under electrostimulation in an acid environment. Bacterial tests and assays with cancer cells demonstrated that the biological activity of CAM remained after release by electrical stimulation. Notably, the successful dual-response of the developed hydrogel to electrical stimuli and pH changes evidence the great prospect of this smart material in the biomedical field, as a tool to fight against bacterial infections and to provide local cancer treatment.
JTD Keywords: drug-delivery, films, growth, nanoparticles, Anti-bacterial agents, Bacterial infections, Cancer stem-cells, Chloramphenicol, Humans, Hydrogels, Hydrogen-ion concentration
Guillem-Marti, J, Vidal, E, Girotti, A, Heras-Parets, A, Torres, D, Arias, FJ, Ginebra, MP, Rodriguez-Cabello, JC, Manero, JM, (2023). Functionalization of 3D-Printed Titanium Scaffolds with Elastin-like Recombinamers to Improve Cell Colonization and Osteoinduction Pharmaceutics 15, 872
The 3D printing of titanium (Ti) offers countless possibilities for the development of personalized implants with suitable mechanical properties for different medical applications. However, the poor bioactivity of Ti is still a challenge that needs to be addressed to promote scaffold osseointegration. The aim of the present study was to functionalize Ti scaffolds with genetically modified elastin-like recombinamers (ELRs), synthetic polymeric proteins containing the elastin epitopes responsible for their mechanical properties and for promoting mesenchymal stem cell (MSC) recruitment, proliferation, and differentiation to ultimately increase scaffold osseointegration. To this end, ELRs containing specific cell-adhesive (RGD) and/or osteoinductive (SNA15) moieties were covalently attached to Ti scaffolds. Cell adhesion, proliferation, and colonization were enhanced on those scaffolds functionalized with RGD-ELR, while differentiation was promoted on those with SNA15-ELR. The combination of both RGD and SNA15 into the same ELR stimulated cell adhesion, proliferation, and differentiation, although at lower levels than those for every single moiety. These results suggest that biofunctionalization with SNA15-ELRs could modulate the cellular response to improve the osseointegration of Ti implants. Further investigation on the amount and distribution of RGD and SNA15 moieties in ELRs could improve cell adhesion, proliferation, and differentiation compared to the present study.
JTD Keywords: 3d printing, adhesion, biofunctionalization, elastin-like recombinamers, functionalization, hydroxyapatite, osseointegration, polymers, purification, technology, titanium, 3d printing, Surfaces, Titanium
Blanco-Fernandez, G, Blanco-Fernandez, B, Fernandez-Ferreiro, A, Otero-Espinar, FJ, (2023). Lipidic lyotropic liquid crystals: Insights on biomedical applications ADVANCES IN COLLOID AND INTERFACE SCIENCE 313, 102867
Liquid crystals (LCs) possess unique physicochemical properties, translatable into a wide range of applications. To date, lipidic lyotropic LCs (LLCs) have been extensively explored in drug delivery and imaging owing to the capability to encapsulate and release payloads with different characteristics. The current landscape of lipidic LLCs in biomedical applications is provided in this review. Initially, the main properties, types, methods of fabrication and applications of LCs are showcased. Then, a comprehensive discussion of the main biomedical applications of lipidic LLCs accordingly to the application (drug and biomacromolecule delivery, tissue engi-neering and molecular imaging) and route of administration is examined. Further discussion of the main limi-tations and perspectives of lipidic LLCs in biomedical applications are also provided.Statement of significance: Liquid crystals (LCs) are those systems between a solid and liquid state that possess unique morphological and physicochemical properties, translatable into a wide range of biomedical applications. A short description of the properties of LCs, their types and manufacturing procedures is given to serve as a background to the topic. Then, the latest and most innovative research in the field of biomedicine is examined, specifically the areas of drug and biomacromolecule delivery, tissue engineering and molecular imaging. Finally, prospects of LCs in biomedicine are discussed to show future trends and perspectives that might be utilized. This article is an ampliation, improvement and actualization of our previous short forum article "Bringing lipidic lyotropic liquid crystal technology into biomedicine" published in TIPS.
JTD Keywords: drug delivery, glycerol monooleate, imaging, liquid crystals, Cancer, Drug delivery, Drug-delivery-systems, Glycerol monooleate, Imaging, In-situ, Liquid crystals, Nano-carriers, Nanoparticles, Phase-behavior, Stratum-corneum, Sustained-release, Tissue engineering, Vegetable-oil, Water
Pereira, I, Lopez-Martinez, MJ, Villasante, A, Introna, C, Tornero, D, Canals, JM, Samitier, J, (2023). Hyaluronic acid-based bioink improves the differentiation and network formation of neural progenitor cells Frontiers in Bioengineering and Biotechnology 11, 1110547
Introduction: Three-dimensional (3D) bioprinting is a promising technique for the development of neuronal in vitro models because it controls the deposition of materials and cells. Finding a biomaterial that supports neural differentiation in vitro while ensuring compatibility with the technique of 3D bioprinting of a self-standing construct is a challenge.Methods: In this study, gelatin methacryloyl (GelMA), methacrylated alginate (AlgMA), and hyaluronic acid (HA) were examined by exploiting their biocompatibility and tunable mechanical properties to resemble the extracellular matrix (ECM) and to create a suitable material for printing neural progenitor cells (NPCs), supporting their long-term differentiation. NPCs were printed and differentiated for up to 15 days, and cell viability and neuronal differentiation markers were assessed throughout the culture.Results and Discussion: This composite biomaterial presented the desired physical properties to mimic the ECM of the brain with high water intake, low stiffness, and slow degradation while allowing the printing of defined structures. The viability rates were maintained at approximately 80% at all time points. However, the levels of beta-III tubulin marker increased over time, demonstrating the compatibility of this biomaterial with neuronal cell culture and differentiation. Furthermore, these cells showed increased maturation with corresponding functional properties, which was also demonstrated by the formation of a neuronal network that was observed by recording spontaneous activity via Ca2+ imaging.
JTD Keywords: biomaterials, bioprinting, differentiation, in vitro models, neural progenitor cells, 2d, Biomaterials, Bioprinting, C17.2, Differentiation, Extracellular-matrix, Hydrogels, In vitro models, In-vitro, Neural progenitor cells, Neuronal models, Proliferation, Scaffolds, Stem-cells, Substrate stiffness
Duran, J, (2023). Role of Astrocytes in the Pathophysiology of Lafora Disease and Other Glycogen Storage Disorders Cells 12, 722
Lafora disease is a rare disorder caused by loss of function mutations in either the EPM2A or NHLRC1 gene. The initial symptoms of this condition are most commonly epileptic seizures, but the disease progresses rapidly with dementia, neuropsychiatric symptoms, and cognitive deterioration and has a fatal outcome within 5–10 years after onset. The hallmark of the disease is the accumulation of poorly branched glycogen in the form of aggregates known as Lafora bodies in the brain and other tissues. Several reports have demonstrated that the accumulation of this abnormal glycogen underlies all the pathologic traits of the disease. For decades, Lafora bodies were thought to accumulate exclusively in neurons. However, it was recently identified that most of these glycogen aggregates are present in astrocytes. Importantly, astrocytic Lafora bodies have been shown to contribute to pathology in Lafora disease. These results identify a primary role of astrocytes in the pathophysiology of Lafora disease and have important implications for other conditions in which glycogen abnormally accumulates in astrocytes, such as Adult Polyglucosan Body disease and the buildup of Corpora amylacea in aged brains.
JTD Keywords: abnormal glycogen, accumulation, aggregation, bodies, branching enzyme deficiency, corpora-amylacea, epilepsy, glycogen, lafora disease, mice, mouse model, neurodegeneration, neuroinflammation, progressive myoclonus epilepsy, ubiquitin ligase, Glycogen, Neuroinflammation, Polyglucosan body disease
Ortiz, C, Klein, S, Reul, WH, Magdaleno, F, Gröschl, S, Dietrich, P, Schierwagen, R, Uschner, FE, Torres, S, Hieber, C, Meier, C, Kraus, N, Tyc, O, Brol, M, Zeuzem, S, Welsch, C, Poglitsch, M, Hellerbrand, C, Alfonso-Prieto, M, Mira, F, Keller, UAD, Tetzner, A, Moore, A, Walther, T, Trebicka, J, (2023). Neprilysin-dependent neuropeptide Y cleavage in the liver promotes fibrosis by blocking NPY-receptor 1 Cell Reports 42, 112059
Development of liver fibrosis is paralleled by contraction of hepatic stellate cells (HSCs), the main profibrotic hepatic cells. Yet, little is known about the interplay of neprilysin (NEP) and its substrate neuropeptide Y (NPY), a potent enhancer of contraction, in liver fibrosis. We demonstrate that HSCs are the source of NEP. Importantly, NPY originates majorly from the splanchnic region and is cleaved by NEP in order to terminate contraction. Interestingly, NEP deficiency (Nep-/-) showed less fibrosis but portal hypertension upon liver injury in two different fibrosis models in mice. We demonstrate the incremental benefit of Nep-/- in addition to AT1R blocker (ARB) or ACE inhibitors for fibrosis and portal hypertension. Finally, oral administration of Entresto, a combination of ARB and NEP inhibitor, decreased hepatic fibrosis and portal pressure in mice. These results provide a mechanistic rationale for translation of NEP-AT1R-blockade in human liver fibrosis and portal hypertension.Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.
JTD Keywords: activation, cirrhosis, cirrhotic rats, cp: cell biology, expression, hepatic stellate cell, identification, inhibition, mechanisms, modulation, neprilysin, neuropeptide y, neuropeptide y receptor 1, portal hypertension, portal-hypertension, web server, Renin-angiotensin system
Venugopal, A, Ruiz-Perez, L, Swamynathan, K, Kulkarni, C, Calò, A, Kumar, M, (2023). Caught in Action: Visualizing Dynamic Nanostructures Within Supramolecular Systems Chemistry ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 62, e202208681
Supramolecular systems chemistry has been an area of active research to develop nanomaterials with life-like functions. Progress in systems chemistry relies on our ability to probe the nanostructure formation in solution. Often visualizing the dynamics of nanostructures which transform over time is a formidable challenge. This necessitates a paradigm shift from dry sample imaging towards solution-based techniques. We review the application of state-of-the-art techniques for real-time, in situ visualization of dynamic self-assembly processes. We present how solution-based techniques namely optical super-resolution microscopy, solution-state atomic force microscopy, liquid-phase transmission electron microscopy, molecular dynamics simulations and other emerging techniques are revolutionizing our understanding of active and adaptive nanomaterials with life-like functions. This Review provides the visualization toolbox and futuristic vision to tap the potential of dynamic nanomaterials.© 2022 Wiley-VCH GmbH.
JTD Keywords: electron-microscopy, fluorescence microscopy, in-situ, mechanical-properties, molecular simulations, nanostructures, polymerization, polymers, stimulated-emission, super-resolution microscopy, supramolecular chemistry, systems chemistry, water, Atomic-force microscopy, Liquid tem, Nanostructures, Super-resolution microscopy, Supramolecular chemistry, Systems chemistry
De Lama-Odría, MD, del Valle, LJ, Puiggalí, J, (2023). Lanthanides-Substituted Hydroxyapatite for Biomedical Applications INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 24, 3446
Lately, there has been an increasing demand for materials that could improve tissue regenerative therapies and provide antimicrobial effects. Similarly, there is a growing need to develop or modify biomaterials for the diagnosis and treatment of different pathologies. In this scenario, hydroxyapatite (HAp) appears as a bioceramic with extended functionalities. Nevertheless, there are certain disadvantages related to the mechanical properties and lack of antimicrobial capacity. To circumvent them, the doping of HAp with a variety of cationic ions is emerging as a good alterative due to the different biological roles of each ion. Among many elements, lanthanides are understudied despite their great potential in the biomedical field. For this reason, the present review focuses on the biological benefits of lanthanides and how their incorporation into HAp can alter its morphology and physical properties. A comprehensive section of the applications of lanthanides-substituted HAp nanoparticles (HAp NPs) is presented to unveil the potential biomedical uses of these systems. Finally, the need to study the tolerable and non-toxic percentages of substitution with these elements is highlighted.
JTD Keywords: biolabeling, biomedicine, biosensors, bone regeneration, calcium, cancer treatment, cationic ions, cell imaging, cerium, doped hap, hydroxyapatite, implants, in-vitro bioactivity, lanthanides-substitutions, lanthanidessubstitutions, nanoparticles, radiation synovectomy, sm-153 particulate hydroxyapatite, structural-characterization, theragnostics, theranostic nanoplatforms, Europium-doped hydroxyapatite, Hydroxyapatite, Theragnostics
Alvarez, Z, Ortega, JA, Sato, K, Sasselli, IR, Kolberg-Edelbrock, AN, Qiu, RM, Marshall, KA, Nguyen, TP, Smith, CS, Quinlan, KA, Papakis, V, Syrgiannis, Z, Sather, NA, Musumeci, C, Engel, E, Stupp, SI, Kiskinis, E, (2023). Artificial extracellular matrix scaffolds of mobile molecules enhance maturation of human stem cell-derived neurons Cell Stem Cell 30, 219-238
Human induced pluripotent stem cell (hiPSC) technologies offer a unique resource for modeling neurological diseases. However, iPSC models are fraught with technical limitations including abnormal aggregation and inefficient maturation of differentiated neurons. These problems are in part due to the absence of synergistic cues of the native extracellular matrix (ECM). We report on the use of three artificial ECMs based on peptide amphiphile (PA) supramolecular nanofibers. All nanofibers display the laminin-derived IKVAV signal on their surface but differ in the nature of their non-bioactive domains. We find that nanofibers with greater intensity of internal supramolecular motion have enhanced bioactivity toward hiPSC-derived motor and cortical neurons. Proteomic, biochemical, and functional assays reveal that highly mobile PA scaffolds caused enhanced β1-integrin pathway activation, reduced aggregation, increased arborization, and matured electrophysiological activity of neurons. Our work highlights the importance of designing biomimetic ECMs to study the development, function, and dysfunction of human neurons.Copyright © 2022 Elsevier Inc. All rights reserved.
JTD Keywords: differentiation, force-field, laminin, migration, nanostructures, peptide amphiphiles, spinal-cord, statistical-model, supramolecular materials, Coarse-grained model, Dynamics, Extracellular matrix, Ikvav, Ipsc-derived neurons, Laminin, Neuronal maturation, Peptide amphiphiles, Supramolecular motion, Supramolecular nanofibers
Pizarek, JA, Fischer, NG, Aparicio, C, (2023). Immunomodulatory IL-23 receptor antagonist peptide nanocoatings for implant soft tissue healing DENTAL MATERIALS 39, 204-216
Peri-implantitis, caused by an inflammatory response to pathogens, is the leading cause of dental implant failure. Poor soft tissue healing surrounding implants - caused by inadequate surface properties - leads to infection, inflammation, and dysregulated keratinocyte and macrophage function. One activated inflammatory response, active around peri-implantitis compared to healthy sites, is the IL-23/IL-17A cytokine axis. Implant surfaces can be synthesized with peptide nanocoatings to present immunomodulatory motifs to target peri-implant keratinocytes to control macrophage polarization and regulate inflammatory axises toward enhancing soft tissue healing.We synthesized an IL-23 receptor (IL-23R) noncompetitive antagonist peptide nanocoating using silanization and evaluated keratinocyte secretome changes and macrophage polarization (M1-like "pro-inflammatory" vs. M2-like "pro-regenerative").IL-23R antagonist peptide nanocoatings were successfully synthesized on titanium, to model dental implant surfaces, and compared to nonfunctional nanocoatings and non-coated titanium. IL-23R antagonist nanocoatings significantly decreased keratinocyte IL-23, and downstream IL-17A, expression compared to controls. This peptide noncompetitive antagonistic function was demonstrated under lipopolysaccharide stimulation. Large scale changes in keratinocyte secretome content, toward a pro-regenerative milieu, were observed from keratinocytes cultured on the IL-23R antagonist nanocoatings compared to controls. Conditioned medium collected from keratinocytes cultured on the IL-23R antagonist nanocoatings polarized macrophages toward a M2-like phenotype, based on increased CD163 and CD206 expression and reduced iNOS expression, compared to controls.Our results support development of IL-23R noncompetitive antagonist nanocoatings to reduce the pro-inflammatory IL-23/17A pathway and augment macrophage polarization toward a pro-regenerative phenotype. Immunomodulatory implant surface engineering may promote soft tissue healing and thereby reduce rates of peri-implantitis.Copyright © 2023 Elsevier Inc. All rights reserved.
JTD Keywords: agents, alter, bioactivity, cells, dental implant, growth, keratinocyte, macrophage, peptide, peri -implant infection, peri-implant infection, Surface chemistry, Titanium
Lanzalaco, S, Mingot, J, Torras, J, Alemán, C, Armelin, E, (2023). Recent Advances in Poly(N-isopropylacrylamide) Hydrogels and Derivatives as Promising Materials for Biomedical and Engineering Emerging Applications ADVANCED ENGINEERING MATERIALS 25,
JTD Keywords: capacitive deionization, chitosan-based hydrogels, composite, desalination, n-isopropylacrylamide, poly(n-isopropylacrylamide), polymers, swelling behavior, thermosensitive hydrogels, walled carbon nanotubes, water cleaning, water evaporation, Biomedical sensors, Critical solution temperature
Pallares, ME, Pi-Jauma, I, Fortunato, IC, Grazu, V, Gomez-Gonzalez, M, Roca-Cusachs, P, de la Fuente, JM, Alert, R, Sunyer, R, Casademunt, J, Trepat, X, (2023). Stiffness-dependent active wetting enables optimal collective cell durotaxis Nature Physics 19, 279-289
The directed migration of cellular clusters enables morphogenesis, wound healing and collective cancer invasion. Gradients of substrate stiffness direct the migration of cellular clusters in a process called collective durotaxis, but the underlying mechanisms remain unclear. Here we unveil a connection between collective durotaxis and the wetting properties of cellular clusters. We show that clusters of cancer cells dewet soft substrates and wet stiff ones. At intermediate stiffness-at the crossover from low to high wettability-clusters on uniform-stiffness substrates become maximally motile, and clusters on stiffness gradients exhibit optimal durotaxis. Durotactic velocity increases with cluster size, stiffness gradient and actomyosin activity. We demonstrate this behaviour on substrates coated with the cell-cell adhesion protein E-cadherin and then establish its generality on substrates coated with extracellular matrix. We develop an active wetting model that explains collective durotaxis in terms of a balance between in-plane active traction and tissue contractility and out-of-plane surface tension. Finally, we show that the distribution of cluster displacements has a heavy tail, with infrequent but large cellular hops that contribute to durotactic migration. Our study demonstrates a physical mechanism of collective durotaxis, through both cell-cell and cell-substrate adhesion ligands, based on the wetting properties of active droplets.
JTD Keywords: Adhesion, Dynamics, E-cadherin, Gradient, Migration, Model, Motility, Movements, Rigidity, Substrate stiffness
Lolo, FN, Walani, N, Seemann, E, Zalvidea, D, Pavón, DM, Cojoc, G, Zamai, M, de Lesegno, CV, de Benito, FM, Sánchez-Alvarez, M, Uriarte, JJ, Echarri, A, Jiménez-Carretero, D, Escolano, JC, Sánchez, SA, Caiolfa, VR, Navajas, D, Trepat, X, Guck, J, Lamaze, C, Roca-Cusachs, P, Kessels, MM, Qualmann, B, Arroyo, M, Del Pozo, MA, (2023). Caveolin-1 dolines form a distinct and rapid caveolae-independent mechanoadaptation system NATURE CELL BIOLOGY 25, 120-133
In response to different types and intensities of mechanical force, cells modulate their physical properties and adapt their plasma membrane (PM). Caveolae are PM nano-invaginations that contribute to mechanoadaptation, buffering tension changes. However, whether core caveolar proteins contribute to PM tension accommodation independently from the caveolar assembly is unknown. Here we provide experimental and computational evidence supporting that caveolin-1 confers deformability and mechanoprotection independently from caveolae, through modulation of PM curvature. Freeze-fracture electron microscopy reveals that caveolin-1 stabilizes non-caveolar invaginations-dolines-capable of responding to low-medium mechanical forces, impacting downstream mechanotransduction and conferring mechanoprotection to cells devoid of caveolae. Upon cavin-1/PTRF binding, doline size is restricted and membrane buffering is limited to relatively high forces, capable of flattening caveolae. Thus, caveolae and dolines constitute two distinct albeit complementary components of a buffering system that allows cells to adapt efficiently to a broad range of mechanical stimuli.© 2022. The Author(s).
JTD Keywords: cavin, cell-migration, cholesterol, extracellular-matrix, nanoscale organization, particle-size, polarization, size distribution, tension, Plasma-membrane
Elosegui-Artola, A, Gupta, A, Najibi, AJ, Seo, BR, Garry, R, Tringides, CM, de Lazaro, I, Darnell, M, Guo, W, Zhou, Q, Weitze, DA, Mahadevan, L, Mooney, DJ, (2023). Matrix viscoelasticity controls spatiotemporal tissue organization NATURE MATERIALS 22, 117-127
Biomolecular and physical cues of the extracellular matrix environment regulate collective cell dynamics and tissue patterning. Nonetheless, how the viscoelastic properties of the matrix regulate collective cell spatial and temporal organization is not fully understood. Here we show that the passive viscoelastic properties of the matrix encapsulating a spheroidal tissue of breast epithelial cells guide tissue proliferation in space and in time. Matrix viscoelasticity prompts symmetry breaking of the spheroid, leading to the formation of invading finger-like protrusions, YAP nuclear translocation and epithelial-to-mesenchymal transition both in vitro and in vivo in a Arp2/3-complex-dependent manner. Computational modelling of these observations allows us to establish a phase diagram relating morphological stability with matrix viscoelasticity, tissue viscosity, cell motility and cell division rate, which is experimentally validated by biochemical assays and in vitro experiments with an intestinal organoid. Altogether, this work highlights the role of stress relaxation mechanisms in tissue growth dynamics, a fundamental process in morphogenesis and oncogenesis.© 2022. The Author(s), under exclusive licence to Springer Nature Limited.
JTD Keywords: in-vitro, migration, morphogenesis, stiffness, Elasticity, Epithelial cells, Extracellular matrix, Intestinal stem-cell, Viscosity
Zhang, KX, Klingner, A, Le Gars, Y, Misra, S, Magdanz, V, Khalil, ISM, (2023). Locomotion of bovine spermatozoa during the transition from individual cells to bundles PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 120, e2211911120
Various locomotion strategies employed by microorganisms are observed in complex biological environments. Spermatozoa assemble into bundles to improve their swimming efficiency compared to individual cells. However, the dynamic mechanisms for the formation of sperm bundles have not been fully characterized. In this study, we numerically and experimentally investigate the locomotion of spermatozoa during the transition from individual cells to bundles of two cells. Three consecutive dynamic behaviors are found across the course of the transition: hydrodynamic attraction/repulsion, alignment, and synchronization. The hydrodynamic attraction/repulsion depends on the relative orientation and distance between spermatozoa as well as their flagellar wave patterns and phase shift. Once the heads are attached, we find a stable equilibrium of the rotational hydrodynamics resulting in the alignment of the heads. The synchronization results from the combined influence of hydrodynamic and mechanical cell-to-cell interactions. Additionally, we find that the flagellar beat is regulated by the interactions during the bundle formation, whereby spermatozoa can synchronize their beats to enhance their swimming velocity.
JTD Keywords: behavior, cilia, collective locomotion, collective motion, competition, flagellar propulsion, hydrodynamics, motility, propulsion, sperm cooperation, tracking, Collective locomotion, Flagellar propulsion, Flagellar synchronization, Spermatozoa bundle
Moussa, DG, Sharma, AK, Mansour, TA, Witthuhn, B, Perdigao, J, Rudney, JD, Aparicio, C, Gomez, A, (2022). Functional signatures of ex-vivo dental caries onset Journal of Oral Microbiology 14, 2123624
The etiology of dental caries remains poorly understood. With the advent of next-generation sequencing, a number of studies have focused on the microbial ecology of the disease. However, taxonomic associations with caries have not been consistent. Researchers have also pursued function-centric studies of the caries microbial communities aiming to identify consistently conserved functional pathways. A major question is whether changes in microbiome are a cause or a consequence of the disease. Thus, there is a critical need to define conserved functional signatures at the onset of dental caries.Since it is unethical to induce carious lesions clinically, we developed an innovative longitudinal ex-vivo model integrated with the advanced non-invasive multiphoton second harmonic generation bioimaging to spot the very early signs of dental caries, combined with 16S rRNA short amplicon sequencing and liquid chromatography-mass spectrometry-based targeted metabolomics.For the first time, we induced longitudinally monitored caries lesions validated with the scanning electron microscope. Consequently, we spotted the caries onset and, associated with it, distinguished five differentiating metabolites - Lactate, Pyruvate, Dihydroxyacetone phosphate, Glyceraldehyde 3-phosphate (upregulated) and Fumarate (downregulated). Those metabolites co-occurred with certain bacterial taxa; Streptococcus, Veillonella, Actinomyces, Porphyromonas, Fusobacterium, and Granulicatella, regardless of the abundance of other taxa.These findings are crucial for understanding the etiology and dynamics of dental caries, and devising targeted interventions to prevent disease progression.© 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
JTD Keywords: bacteria, biofilms, children, dental caries, generation, genomics, longitudinal model, metabolism, metabolomics, microscopy, non-invasive bioimaging, oral microbiome, plaque, restorations, signatures, Dental caries, Field-emission sem, Signatures
Ferrer, I, Andrés-Benito, P, Carmona, M, del Rio, JA, (2022). Common and Specific Marks of Different Tau Strains Following Intra-Hippocampal Injection of AD, PiD, and GGT Inoculum in hTau Transgenic Mice INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 23, 15940
Heterozygous hTau mice were used for the study of tau seeding. These mice express the six human tau isoforms, with a high predominance of 3Rtau over 4Rtau. The following groups were assessed: (i) non-inoculated mice aged 9 months (n = 4); (ii) Alzheimer's Disease (AD)-inoculated mice (n = 4); (iii) Globular Glial Tauopathy (GGT)-inoculated mice (n = 4); (iv) Pick's disease (PiD)-inoculated mice (n = 4); (v) control-inoculated mice (n = 4); and (vi) inoculated with vehicle alone (n = 2). AD-inoculated mice showed AT8-immunoreactive neuronal pre-tangles, granular aggregates, and dots in the CA1 region of the hippocampus, dentate gyrus (DG), and hilus, and threads and dots in the ipsilateral corpus callosum. GGT-inoculated mice showed unique or multiple AT8-immunoreactive globular deposits in neurons, occasionally extended to the proximal dendrites. PiD-inoculated mice showed a few loose pre-tangles in the CA1 region, DG, and cerebral cortex near the injection site. Coiled bodies were formed in the corpus callosum in AD-inoculated mice, but GGT-inoculated mice lacked globular glial inclusions. Tau deposits in inoculated mice co-localized active kinases p38-P and SAPK/JNK-P, thus suggesting active phosphorylation of the host tau. Tau deposits were absent in hTau mice inoculated with control homogenates and vehicle alone. Deposits in AD-inoculated hTau mice contained 3Rtau and 4Rtau; those in GGT-inoculated mice were mainly stained with anti-4Rtau antibodies, but a small number of deposits contained 3Rtau. Deposits in PiD-inoculated mice were stained with anti-3Rtau antibodies, but rare neuronal, thread-like, and dot-like deposits showed 4Rtau immunoreactivity. These findings show that tau strains produce different patterns of active neuronal seeding, which also depend on the host tau. Unexpected 3Rtau and 4Rtau deposits after inoculation of homogenates from 4R and 3R tauopathies, respectively, suggests the regulation of exon 10 splicing of the host tau during the process of seeding, thus modulating the plasticity of the cytoskeleton.
JTD Keywords: alzheimer's disease (ad), alzheimers-disease, brain, corticobasal degeneration, globular glial tauopathy (ggt), htau, isoforms, pathological tau, pick's disease (pid), picks-disease, propagation, protein, seeding, tau splicing, tauopathy, Alzheimer disease, Alzheimer’s disease (ad), Animals, Brain, Globular glial tauopathy (ggt), Hippocampus, Htau, Humans, Mice, Mice, transgenic, Paired helical filaments, Pick disease of the brain, Pick’s disease (pid), Seeding, Tau, Tau proteins, Tau splicing, Tauopathies
Manzano-Munoz, A, Yeste, J, Ortega, MA, Martin, F, Lopez, A, Rosell, J, Castro, S, Serrano, C, Samitier, J, Ramon-Azcon, J, Montero, J, (2022). Microfluidic-based dynamic BH3 profiling predicts anticancer treatment efficacy npj Precision Oncology 6, 90
Precision medicine is starting to incorporate functional assays to evaluate anticancer agents on patient-isolated tissues or cells to select for the most effective. Among these new technologies, dynamic BH3 profiling (DBP) has emerged and extensively been used to predict treatment efficacy in different types of cancer. DBP uses synthetic BH3 peptides to measure early apoptotic events ('priming') and anticipate therapy-induced cell death leading to tumor elimination. This predictive functional assay presents multiple advantages but a critical limitation: the cell number requirement, that limits drug screening on patient samples, especially in solid tumors. To solve this problem, we developed an innovative microfluidic-based DBP (µDBP) device that overcomes tissue limitations on primary samples. We used microfluidic chips to generate a gradient of BIM BH3 peptide, compared it with the standard flow cytometry based DBP, and tested different anticancer treatments. We first examined this new technology's predictive capacity using gastrointestinal stromal tumor (GIST) cell lines, by comparing imatinib sensitive and resistant cells, and we could detect differences in apoptotic priming and anticipate cytotoxicity. We then validated µDBP on a refractory GIST patient sample and identified that the combination of dactolisib and venetoclax increased apoptotic priming. In summary, this new technology could represent an important advance for precision medicine by providing a fast, easy-to-use and scalable microfluidic device to perform DBP in situ as a routine assay to identify the best treatment for cancer patients.© 2022. The Author(s).
JTD Keywords: biomarkers, cancer drugs, chemotherapy, chip, models, platform, sensitivity, strategy, tumor-cells, Precision medicine
Mesquida-Veny, F, Martínez-Torres, S, Del Río, JA, Hervera, A, (2022). Genetic control of neuronal activity enhances axonal growth only on permissive substrates MOLECULAR MEDICINE 28, 97
Abstract Background Neural tissue has limited regenerative ability. To cope with that, in recent years a diverse set of novel tools has been used to tailor neurostimulation therapies and promote functional regeneration after axonal injuries. Method In this report, we explore cell-specific methods to modulate neuronal activity, including opto- and chemogenetics to assess the effect of specific neuronal stimulation in the promotion of axonal regeneration after injury. Results Opto- and chemogenetic stimulations of neuronal activity elicited increased in vitro neurite outgrowth in both sensory and cortical neurons, as well as in vivo regeneration in the sciatic nerve, but not after spinal cord injury. Mechanistically, inhibitory substrates such as chondroitin sulfate proteoglycans block the activity induced increase in axonal growth. Conclusions We found that genetic modulations of neuronal activity on both dorsal root ganglia and corticospinal motor neurons increase their axonal growth capacity but only on permissive environments.
JTD Keywords: activation, chemogenetics, electrical-stimulation, expression, functional recovery, increases, injury, motor cortex, neuronal activity, optogenetics, permissive substrate, promotes recovery, regeneration, Optogenetics, Regeneration, Spinal-cord
Elyaderani, AK, De Lama-Odría, MD, Del Valle, LJ, Puiggalí, J, (2022). Multifunctional Scaffolds Based on Emulsion and Coaxial Electrospinning Incorporation of Hydroxyapatite for Bone Tissue Regeneration INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 23, 15016
Tissue engineering is nowadays a powerful tool to restore damaged tissues and recover their normal functionality. Advantages over other current methods are well established, although a continuous evolution is still necessary to improve the final performance and the range of applications. Trends are nowadays focused on the development of multifunctional scaffolds with hierarchical structures and the capability to render a sustained delivery of bioactive molecules under an appropriate stimulus. Nanocomposites incorporating hydroxyapatite nanoparticles (HAp NPs) have a predominant role in bone tissue regeneration due to their high capacity to enhance osteoinduction, osteoconduction, and osteointegration, as well as their encapsulation efficiency and protection capability of bioactive agents. Selection of appropriated polymeric matrices is fundamental and consequently great efforts have been invested to increase the range of properties of available materials through copolymerization, blending, or combining structures constituted by different materials. Scaffolds can be obtained from different processes that differ in characteristics, such as texture or porosity. Probably, electrospinning has the greater relevance, since the obtained nanofiber membranes have a great similarity with the extracellular matrix and, in addition, they can easily incorporate functional and bioactive compounds. Coaxial and emulsion electrospinning processes appear ideal to generate complex systems able to incorporate highly different agents. The present review is mainly focused on the recent works performed with Hap-loaded scaffolds having at least one structural layer composed of core/shell nanofibers.
JTD Keywords: bone tissue, coaxial electrospinning, composite nanofibers, drug-release behavior, emulsion electrospinning, hydroxyapatite, in-vitro evaluation, mechanical-properties, osteogenic differentiation, pickering emulsions, protein adsorption, structured scaffolds, surface-initiated polymerization, tissue regeneration, Bone tissue, Coaxial electrospinning, Emulsion electrospinning, Hydroxyapatite, Multifunctional scaffolds, Poly(3-hydroxybutyrate) phb patches, Tissue regeneration
Fischer, NG, Aparicio, C, (2022). Junctional epithelium and hemidesmosomes: Tape and rivets for solving the “percutaneous device dilemma” in dental and other permanent implants Bioactive Materials 18, 178-198
The percutaneous device dilemma describes etiological factors, centered around the disrupted epithelial tissue surrounding non-remodelable devices, that contribute to rampant percutaneous device infection. Natural percutaneous organs, in particular their extracellular matrix mediating the “device”/epithelium interface, serve as exquisite examples to inspire longer lasting long-term percutaneous device design. For example, the tooth's imperviousness to infection is mediated by the epithelium directly surrounding it, the junctional epithelium (JE). The hallmark feature of JE is formation of hemidesmosomes, cell/matrix adhesive structures that attach surrounding oral gingiva to the tooth's enamel through a basement membrane. Here, the authors survey the multifaceted functions of the JE, emphasizing the role of the matrix, with a particular focus on hemidesmosomes and their five main components. The authors highlight the known (and unknown) effects dental implant – as a model percutaneous device – placement has on JE regeneration and synthesize this information for application to other percutaneous devices. The authors conclude with a summary of bioengineering strategies aimed at solving the percutaneous device dilemma and invigorating greater collaboration between clinicians, bioengineers, and matrix biologists. © 2022 The Authors
JTD Keywords: amino-acid-sequence, bioinspired surfaces, cell-secreted protein, growth-factor receptor, hemidesmosome, integrin beta-4 subunit, junctional epithelium, keratinocyte-derived chemokine, laminin-binding integrins, marginal bone loss, percutaneous device, percutaneous implant, pressure wound therapy, soft-tissue integration, Bioinspired surfaces, Bullous-pemphigoid antigen, Hemidesmosome, Junctional epithelium, Percutaneous device, Percutaneous implant
Cable, J, Arlotta, P, Parker, KK, Hughes, AJ, Goodwin, K, Mummery, CL, Kamm, RD, Engle, SJ, Tagle, DA, Boj, SF, Stanton, AE, Morishita, Y, Kemp, ML, Norfleet, DA, May, EE, Lu, A, Bashir, R, Feinberg, AW, Hull, SM, Gonzalez, AL, Blatchley, MR, Pulido, NM, Morizane, R, McDevitt, TC, Mishra, D, Mulero-Russe, A, (2022). Engineering multicellular living systems-A Keystone Symposia report Annals of the New York Academy of Sciences 1518, 183-195
The ability to engineer complex multicellular systems has enormous potential to inform our understanding of biological processes and disease and alter the drug development process. Engineering living systems to emulate natural processes or to incorporate new functions relies on a detailed understanding of the biochemical, mechanical, and other cues between cells and between cells and their environment that result in the coordinated action of multicellular systems. On April 3-6, 2022, experts in the field met at the Keystone symposium "Engineering Multicellular Living Systems" to discuss recent advances in understanding how cells cooperate within a multicellular system, as well as recent efforts to engineer systems like organ-on-a-chip models, biological robots, and organoids. Given the similarities and common themes, this meeting was held in conjunction with the symposium "Organoids as Tools for Fundamental Discovery and Translation".
JTD Keywords: computational, engineered living, engineered organs, multicellular, Brain organoids, Cell diversity, Computational, Dynamics, Engineered living, Engineered organs, Heart, Maturation, Model, Multicellular, Mycobacterium-tuberculosis, Quantitative-analysis, Systems, Tissue deformation
Fortunato, IC, Sunyer, R, (2022). The Forces behind Directed Cell Migration Biophysica 2, 548-563
Directed cell migration is an essential building block of life, present when an embryo develops, a dendritic cell migrates toward a lymphatic vessel, or a fibrotic organ fails to restore its normal parenchyma. Directed cell migration is often guided by spatial gradients in a physicochemical property of the cell microenvironment, such as a gradient in chemical factors dissolved in the medium or a gradient in the mechanical properties of the substrate. Single cells and tissues sense these gradients, establish a back-to-front polarity, and coordinate the migration machinery accordingly. Central to these steps we find physical forces. In some cases, these forces are integrated into the gradient sensing mechanism. Other times, they transmit information through cells and tissues to coordinate a collective response. At any time, they participate in the cellular migratory system. In this review, we explore the role of physical forces in gradient sensing, polarization, and coordinating movement from single cells to multicellular collectives. We use the framework proposed by the molecular clutch model and explore to what extent asymmetries in the different elements of the clutch can lead to directional migration.
JTD Keywords: Cell migration, Cell traction forces, Chemotaxis, Contact guidance, Curvotaxis, Cytoskeleton, Durotaxis, Extracellular-matrix, Focal adhesions, Guidance, Haptotaxis, Leading-edge, Mechanotaxis, Membrane tension, Molecular clutch model, Myosin-ii, Reduced inequalities, Rigidity, Stress fibers, Traction
Gomila, AMJ, Pérez-Mejías, G, Nin-Hill, A, Guerra-Castellano, A, Casas-Ferrer, L, Ortiz-Tescari, S, Díaz-Quintana, A, Samitier, J, Rovira, C, De la Rosa, MA, Díaz-Moreno, I, Gorostiza, P, Giannotti, M, Lagunas, A, (2022). Phosphorylation disrupts long-distance electron transport in cytochrome c Nature Communications 13, 7100
It has been recently shown that electron transfer between mitochondrial cytochrome c and the cytochrome c1 subunit of the cytochrome bc1 can proceed at long-distance through the aqueous solution. Cytochrome c is thought to adjust its activity by changing the affinity for its partners via Tyr48 phosphorylation, but it is unknown how it impacts the nanoscopic environment, interaction forces, and long-range electron transfer. Here, we constrain the orientation and separation between cytochrome c1 and cytochrome c or the phosphomimetic Y48pCMF cytochrome c, and deploy an array of single-molecule, bulk, and computational methods to investigate the molecular mechanism of electron transfer regulation by cytochrome c phosphorylation. We demonstrate that phosphorylation impairs long-range electron transfer, shortens the long-distance charge conduit between the partners, strengthens their interaction, and departs it from equilibrium. These results unveil a nanoscopic view of the interaction between redox protein partners in electron transport chains and its mechanisms of regulation.© 2022. The Author(s).
JTD Keywords: apoptosis, binding, cardiolipin, complex, dynamics, force, respiration, structural basis, tyrosine phosphorylation, Histone chaperone activity
Cañellas-Socias, A, Cortina, C, Hernando-Momblona, X, Palomo-Ponce, S, Mulholland, EJ, Turon, G, Mateo, L, Conti, S, Roman, O, Sevillano, M, Slebe, F, Stork, D, Caballé-Mestres, A, Berenguer-Llergo, A, Alvarez-Varela, A, Fenderico, N, Novellasdemunt, L, Jiménez-Gracia, L, Sipka, T, Bardia, L, Lorden, P, Colombelli, J, Heyn, H, Trepat, X, Tejpar, S, Sancho, E, Tauriello, DVF, Leedham, S, Attolini, CSO, Batlle, E, (2022). Metastatic recurrence in colorectal cancer arises from residual EMP1+ cells NATURE 611, 603-613
Around 30-40% of patients with colorectal cancer (CRC) undergoing curative resection of the primary tumour will develop metastases in the subsequent years1. Therapies to prevent disease relapse remain an unmet medical need. Here we uncover the identity and features of the residual tumour cells responsible for CRC relapse. An analysis of single-cell transcriptomes of samples from patients with CRC revealed that the majority of genes associated with a poor prognosis are expressed by a unique tumour cell population that we named high-relapse cells (HRCs). We established a human-like mouse model of microsatellite-stable CRC that undergoes metastatic relapse after surgical resection of the primary tumour. Residual HRCs occult in mouse livers after primary CRC surgery gave rise to multiple cell types over time, including LGR5+ stem-like tumour cells2-4, and caused overt metastatic disease. Using Emp1 (encoding epithelial membrane protein 1) as a marker gene for HRCs, we tracked and selectively eliminated this cell population. Genetic ablation of EMP1high cells prevented metastatic recurrence and mice remained disease-free after surgery. We also found that HRC-rich micrometastases were infiltrated with T cells, yet became progressively immune-excluded during outgrowth. Treatment with neoadjuvant immunotherapy eliminated residual metastatic cells and prevented mice from relapsing after surgery. Together, our findings reveal the cell-state dynamics of residual disease in CRC and anticipate that therapies targeting HRCs may help to avoid metastatic relapse.© 2022. The Author(s), under exclusive licence to Springer Nature Limited.
JTD Keywords: colonization, defines, human colon, mutations, plasticity, retrieval, stem-cells, subtypes, underlie, Animal, Animal cell, Animal experiment, Animal model, Animal tissue, Animals, Article, Cancer, Cancer growth, Cancer immunotherapy, Cancer inhibition, Cancer recurrence, Cancer staging, Cell, Cell adhesion, Cell migration, Cell population, Cell surface receptor, Cohort analysis, Colorectal cancer, Colorectal neoplasms, Colorectal tumor, Comprehensive molecular characterization, Controlled study, Crispr-cas9 system, Cytoskeleton, Disease exacerbation, Disease progression, Dynamics, Emp1 gene, Epithelial membrane protein-1, Extracellular matrix, Flow cytometry, Fluorescence intensity, Gene expression, Genetics, Human, Human cell, Humans, Immune response, Immunofluorescence, In situ hybridization, Marker gene, Metastasis potential, Mice, Minimal residual disease, Mouse, Neoplasm proteins, Neoplasm recurrence, local, Neoplasm, residual, Nonhuman, Pathology, Phenotype, Prevention and control, Protein, Receptors, cell surface, Single cell rna seq, Tumor, Tumor protein, Tumor recurrence
Ulldemolins, A, Jurado, A, Herranz-Diez, C, Gavara, N, Otero, J, Farré, R, Almendros, I, (2022). Lung Extracellular Matrix Hydrogels-Derived Vesicles Contribute to Epithelial Lung Repair Polymers 14, 4907
The use of physiomimetic decellularized extracellular matrix-derived hydrogels is attracting interest since they can modulate the therapeutic capacity of numerous cell types, including mesenchymal stromal cells (MSCs). Remarkably, extracellular vesicles (EVs) derived from MSCs display similar functions as their parental cells, mitigating tissue damage in lung diseases. However, recent data have shown that ECM-derived hydrogels could release other resident vesicles similar to EVs. Here, we aim to better understand the contribution of EVs and ECM-vesicles released from MSCs and/or lung-derived hydrogel (L-HG) in lung repair by using an in vitro lung injury model. L-HG derived-vesicles and MSCs EVs cultured either in L-HG or conventional plates were isolated and characterized. The therapeutic capacity of vesicles obtained from each experimental condition was tested by using an alveolar epithelial wound-healing assay. The number of ECM-vesicles released from acellular L-HG was 10-fold greater than EVs from conventional MSCs cell culture revealing that L-HG is an important source of bioactive vesicles. MSCs-derived EVs and L-HG vesicles have similar therapeutic capacity in lung repair. However, when wound closure rate was normalized by total proteins, the MSCs-derived EVs shows higher therapeutic potential to those released by L-HG. The EVs released from L-HG must be considered when HG is used as substrate for cell culture and EVs isolation.
JTD Keywords: cell, extracellular vesicles, hydrogel, lung epithelial cells, lung repair, mesenchymal stem cells, Extracellular matrix, Extracellular vesicles, Hydrogel, Lung epithelial cells, Lung repair, Mesenchymal stem cells, Respiratory-distress-syndrome
Burgués, J, Doñate, S, Esclapez, MD, Saúco, L, Marco, S, (2022). Characterization of odour emissions in a wastewater treatment plant using a drone-based chemical sensor system SCIENCE OF THE TOTAL ENVIRONMENT 846, 157290
Conventionally, odours emitted by different sources present in wastewater treatment plants (WWTPs) are measured by dynamic olfactometry, where a human panel sniffs and analyzes air bags collected from the plant. Although the method is considered the gold standard, the process is costly, slow, and infrequent, which does not allow operators to quickly identify and respond to problems. To better monitor and map WWTP odour emissions, here we propose a small rotary-wing drone equipped with a lightweight (1.3-kg) electronic nose. The "sniffing drone" sucks in air via a ten-meter (33-foot) tube and delivers it to a sensor chamber where it is analyzed in real-time by an array of 21 gas sensors. From the sensor signals, machine learning (ML) algorithms predict the odour concentration that a human panel using the EN13725 methodology would report. To calibrate and validate the predictive models, the drone also carries a remotely controlled sampling device (compliant with EN13725:2022) to collect sample air in bags for post-flight dynamic olfactometry. The feasibility of the proposed system is assessed in a WWTP in Spain through several measurement campaigns covering diverse operating regimes of the plant and meteorological conditions. We demonstrate that training the ML algorithms with dynamic (transient) sensor signals measured in flight conditions leads to better performance than the traditional approach of using steady-state signals measured in the lab via controlled exposures to odour bags. The comparison of the electronic nose predictions with dynamic olfactometry measurements indicates a negligible bias between the two measurement techniques and 95 % limits of agreement within a factor of four. This apparently large disagreement, partly caused by the high uncertainty of olfactometric measurements (typically a factor of two), is more than offset by the immediacy of the predictions and the practical advantages of using a drone-based system.Copyright © 2022. Published by Elsevier B.V.
JTD Keywords: calibration, chemical sensors, drone, dynamic olfactometry, electronic nose, odourquantification, olfaction, volatile organic-compounds, wwtp, Calibration, Chemical sensors, Drone, Dynamic olfactometry, Electronic nose, Environmental monitoring, Odour quantification, Olfaction, Variable selection methods, Wwtp
Ahmad, J, Ellis, C, Leech, R, Voytek, B, Garces, P, Jones, E, Buitelaar, J, Loth, E, dos Santos, FP, Amil, AF, Verschure, PFMJ, Murphy, D, McAlonan, G, (2022). From mechanisms to markers: novel noninvasive EEG proxy markers of the neural excitation and inhibition system in humans Translational Psychiatry 12, 467
Brain function is a product of the balance between excitatory and inhibitory (E/I) brain activity. Variation in the regulation of this activity is thought to give rise to normal variation in human traits, and disruptions are thought to potentially underlie a spectrum of neuropsychiatric conditions (e.g., Autism, Schizophrenia, Downs' Syndrome, intellectual disability). Hypotheses related to E/I dysfunction have the potential to provide cross-diagnostic explanations and to combine genetic and neurological evidence that exists within and between psychiatric conditions. However, the hypothesis has been difficult to test because: (1) it lacks specificity-an E/I dysfunction could pertain to any level in the neural system- neurotransmitters, single neurons/receptors, local networks of neurons, or global brain balance - most researchers do not define the level at which they are examining E/I function; (2) We lack validated methods for assessing E/I function at any of these neural levels in humans. As a result, it has not been possible to reliably or robustly test the E/I hypothesis of psychiatric disorders in a large cohort or longitudinal patient studies. Currently available, in vivo markers of E/I in humans either carry significant risks (e.g., deep brain electrode recordings or using Positron Emission Tomography (PET) with radioactive tracers) and/or are highly restrictive (e.g., limited spatial extent for Transcranial Magnetic Stimulation (TMS) and Magnetic Resonance Spectroscopy (MRS). More recently, a range of novel Electroencephalography (EEG) features has been described, which could serve as proxy markers for E/I at a given level of inference. Thus, in this perspective review, we survey the theories and experimental evidence underlying 6 novel EEG markers and their biological underpinnings at a specific neural level. These cheap-to-record and scalable proxy markers may offer clinical utility for identifying subgroups within and between diagnostic categories, thus directing more tailored sub-grouping and, therefore, treatment strategies. However, we argue that studies in clinical populations are premature. To maximize the potential of prospective EEG markers, we first need to understand the link between underlying E/I mechanisms and measurement techniques.
JTD Keywords: Cortical networks, Direction selectivity, Excitation/inhibition balance, Fast network oscillations, Gaba concentration, Gamma oscillation frequency, Neuronal oscillations, Range temporal correlations, Self-organized criticality, Theta-oscillations
Casanellas, I, Jiang, HK, David, CM, Vida, Y, Pérez-Inestrosa, E, Samitier, J, Lagunas, A, (2022). Substrate adhesion determines migration during mesenchymal cell condensation in JOURNAL OF CELL SCIENCE 135, 260241
Mesenchymal condensation is a prevalent morphogenetic transition that is essential in chondrogenesis. However, the current understanding of condensation mechanisms is limited. In vivo, progenitor cells directionally migrate from the surrounding loose mesenchyme towards regions of increasing matrix adherence (the condensation centers), which is accompanied by the upregulation of fibronectin. Here, we focused on the mechanisms of cell migration during mesenchymal cell condensation and the effects of matrix adherence. Dendrimer-based nanopatterns of the cell-adhesive peptide arginine-glycine-aspartic acid (RGD), which is present in fibronectin, were used to regulate substrate adhesion. We recorded collective and single-cell migration of mesenchymal stem cells, under chondrogenic induction, using live-cell imaging. Our results show that the cell migration mode of single cells depends on substrate adhesiveness, and that cell directionality controls cell condensation and the fusion of condensates. Inhibition experiments revealed that cell???cell interactions mediated by N-cadherin (also known as CDH2) are also pivotal for directional migration of cell condensates by maintaining cell???cell cohesion, thus suggesting a fine interplay between cell???matrix and cell???cell adhesions. Our results shed light on the role of cell interactions with a fibronectin-depositing matrix during chondrogenesis in vitro, with possible applications in regenerative medicine.
JTD Keywords: Alpha-v-beta-3, Arginine-glycine-aspartic acid, Cell migration, Chondrogenesis, Dynamics, Expression, Fibronectin, Gastrulation, Involvement, Mechanisms, Mesenchymal condensation, Model, N-cadherin, Nanopatterned substrates, Rgd
Bonany, M, Pérez-Berná, AJ, Ducic, T, Pereiro, E, Martin-Gómez, H, Mas-Moruno, C, van Rijt, S, Zhao, ZT, Espanol, M, Ginebra, MP, (2022). Hydroxyapatite nanoparticles-cell interaction: New approaches to disclose the fate of membrane-bound and internalised nanoparticles BIOMATERIALS ADVANCES 142, 213148
Hydroxyapatite nanoparticles are popular tools in bone regeneration, but they have also been used for gene delivery and as anticancer drugs. Understanding their mechanism of action, particularly for the latter application, is crucial to predict their toxicity. To this end, we aimed to elucidate the importance of nanoparticle membrane interactions in the cytotoxicity of MG-63 cells using two different types of nanoparticles. In addition, conventional techniques for studying nanoparticle internalisation were evaluated and compared with newer and less exploited approaches. Hydroxyapatite and magnesium-doped hydroxyapatite nanoparticles were used as suspensions or compacted as specular discs. Comparison between cells seeded on the discs and those supplemented with the nanoparticles allowed direct interaction of the cell membrane with the material to be ruled out as the main mechanism of toxicity. In addition, standard techniques such as flow cytometry were inconclusive when used to assess nanoparticles toxicity. Interestingly, the use of intracellular calcium fluorescent probes revealed the presence of a high number of calcium-rich vesicles after nanoparticle supplementation in cell culture. These structures could not be detected by transmission electron microscopy due to their liquid content. However, by using cryo-soft X-ray imaging, which was used to visualise the cellular ultrastructure without further treatment other than vitrification and to quantify the linear absorption coefficient of each organelle, it was possible to identify them as multivesicular bodies, potentially acting as calcium stores. In the study, an advanced state of degradation of the hydroxyapatite and magnesium-doped hydroxyapatite nanoparticles within MG-63 cells was observed. Overall, we demonstrate that the combination of fluorescent calcium probes together with cryo-SXT is an excellent approach to investigate intracellular calcium, especially when found in its soluble form.Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.
JTD Keywords: adsorption, cryo-soft x-ray tomography, cytotoxicity, expression, flow cytometry, internalisation, intracellular calcium, magnesium, nano, nanomaterials, nanoparticles, proliferation, protein corona, ultrastructure, Calcium-phosphate nanoparticles, Cryo-soft x-ray tomography, Flow cytometry, Hydroxyapatite, Internalisation, Intracellular calcium, Nanoparticles
Zambarda, C, Gonzalez, CP, Schoenit, A, Veits, N, Schimmer, C, Jung, RM, Ollech, D, Christian, J, Roca-Cusachs, P, Trepat, X, Cavalcanti-Adam, EA, (2022). Epithelial cell cluster size affects force distribution in response to EGF-induced collective contractility EUROPEAN JOURNAL OF CELL BIOLOGY 101, 151274
Several factors present in the extracellular environment regulate epithelial cell adhesion and dynamics. Among them, growth factors such as EGF, upon binding to their receptors at the cell surface, get internalized and directly activate the acto-myosin machinery. In this study we present the effects of EGF on the contractility of epithelial cancer cell colonies in confined geometry of different sizes. We show that the extent to which EGF triggers contractility scales with the cluster size and thus the number of cells. Moreover, the collective contractility results in a radial distribution of traction forces, which are dependent on integrin β1 peripheral adhesions and transmitted to neighboring cells through adherens junctions. Taken together, EGF-induced contractility acts on the mechanical crosstalk and linkage between the cell-cell and cell-matrix compartments, regulating collective responses.Copyright © 2022 The Authors. Published by Elsevier GmbH.. All rights reserved.
JTD Keywords: actin, activation, actomyosin, adherens junctions, adhesion, e-cadherin, egf, maturation, mechanical regulation, micropatterning, migration, traction forces, transduction, transmission, Actomyosin, Adherens junctions, Cell adhesion, Cell membrane, Collective contractility, Egf, Epidermal growth factor, Epidermal-growth-factor, Epithelial cells, Micropatterning, Myosins, Traction forces
Andrade, F, Roca-Melendres, MM, Llaguno, M, Hide, D, Raurell, I, Martell, M, Vijayakumar, S, Oliva, M, Schwartz, S, Duran-Lara, EF, Rafael, D, Abasolo, I, (2022). Smart and eco-friendly N-isopropylacrylamide and cellulose hydrogels as a safe dual-drug local cancer therapy approach CARBOHYDRATE POLYMERS 295, 119859
Local cancer treatment by in situ injections of thermo-responsive hydrogels (HG) offers several advantages over conventional systemic anti-cancer treatments. In this work, a biodegradable and multicompartmental HG composed of N-isopropylacrylamide, cellulose, citric acid, and ceric ammonium nitrate was developed for the controlled release of hydrophilic (doxorubicin) and hydrophobic (niclosamide) drugs. The formulation presented ideal properties regarding thermo-responsiveness, rheological behavior, drug release profile, biocompatibility, and biological activity in colon and ovarian cancer cells. Cellulose was found to retard drugs release rate, being only 4 % of doxorubicin and 30 % of niclosamide released after 1 week. This low release was sufficient to cause cell death in both cell lines. Moreover, HG demonstrated a proper injectability, in situ prevalence, and safety profile in vivo. Overall, the HG properties, together with its natural and eco-friendly composition, create a safe and efficient platform for the local treatment of non-resectable tumors or tumors requiring pre-surgical adjuvant therapy.
JTD Keywords: biodegradable, cellulose, controlled-release formulation, drug delivery systems, hydrogel, thermo-responsiveness, Ammonium-nitrate, Biodegradable, Cancer treatment, Cellulose, Controlled-release formulation, Delivery, Drug delivery systems, Hydrogel, Reduce, Thermo-responsiveness
Widhe, M, Diez-Escudero, A, Liu, YL, Ringstrom, N, Ginebra, MP, Persson, C, Hedhammar, M, Mestres, G, (2022). Functionalized silk promotes cell migration into calcium phosphate cements by providing macropores and cell adhesion motifs CERAMICS INTERNATIONAL 48, 31449-31460
Calcium phosphate cements (CPCs) are attractive synthetic bone grafts as they possess osteoconductive and osteoinductive properties. Their biomimetic synthesis grants them an intrinsic nano-and microporosity that resembles natural bone and is paramount for biological processes such as protein adhesion, which can later enhance cell adhesion. However, a main limitation of CPCs is the lack of macroporosity, which is crucial to allow cell colonization throughout the scaffold. Moreover, CPCs lack specific motifs to guide cell interactions through their membrane proteins. In this study, we explore a strategy targeting simultaneously both macroporosity and cell binding motifs within CPCs by the use of recombinant silk. A silk protein functionalized with the cell binding motif RGD serves as foaming template of CPCs to achieve biomimetic hydroxyapatite (HA) scaffolds with multiscale porosity. The synergies of RGD-motifs in the silk macroporous template and the biomimetic features of HA are explored for their potential to enhance mesenchymal stem cell adhesion, proliferation, migration and differentiation. Macroporous Silk-HA scaffolds improve initial cell adhesion compared to a macroporous HA in the absence of silk, and importantly, the presence of silk greatly enhances cell migration into the scaffold. Additionally, cell proliferation and osteogenic differentiation are achieved in the scaffolds.
JTD Keywords: Bioceramics, Bone, Bone regeneration, Composites, Degradation, Fabrication, Hydroxyapatite, Hydroxyapatite scaffolds, Injectability, Porosity, Recombinant spider silk, Rgd motifs, Silk, Stem-cells
Larrañaga, E, Fernández-Majada, V, Ojosnegros, S, Comelles, J, Martinez, E, (2022). Ephrin Micropatterns Exogenously Modulate Cell Organization in Organoid‐Derived Intestinal Epithelial Monolayers Advanced Materials Interfaces 9, 2201301
JTD Keywords: adhesion, attachment, growth, ligands, membrane, microcontact printing, migration, organoid-derived intestinal epithelia, receptor, tissue organization, Eph-ephrin, Stem-cells
Altay, G, Abad-Lázaro, A, Gualda, EJ, Folch, J, Insa, C, Tosi, S, Hernando-Momblona, X, Batlle, E, Loza-Alvarez, P, Fernández-Majada, V, Martinez, E, (2022). Modeling biochemical gradients in vitro to control cell compartmentalization in a microengineered 3d model of the intestinal epithelium Advanced Healthcare Materials 11, 2201172
Gradients of signaling pathways within the intestinal stem cell (ISC) niche are instrumental for cellular compartmentalization and tissue function, yet how are they sensed by the epithelium is still not fully understood. Here a new in vitro model of the small intestine based on primary epithelial cells (i), apically accessible (ii), with native tissue mechanical properties and controlled mesh size (iii), 3D villus-like architecture (iv), and precisely controlled biomolecular gradients of the ISC niche (v) is presented. Biochemical gradients are formed through hydrogel-based scaffolds by free diffusion from a source to a sink chamber. To confirm the establishment of spatiotemporally controlled gradients, light-sheet fluorescence microscopy and in-silico modeling are employed. The ISC niche biochemical gradients coming from the stroma and applied along the villus axis lead to the in vivo-like compartmentalization of the proliferative and differentiated cells, while changing the composition and concentration of the biochemical factors affects the cellular organization along the villus axis. This novel 3D in vitro intestinal model derived from organoids recapitulates both the villus-like architecture and the gradients of ISC biochemical factors, thus opening the possibility to study in vitro the nature of such gradients and the resulting cellular response.© 2022 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.
JTD Keywords: 3d architectures, biomolecular gradients, colon, crypt, engineering organoids, hydrogels, identification, in silico modeling, intestinal stem cell niches, light sheet fluorescence microscopy, niche, permeability, photolithography, regeneration, villus, wnt, 3d architectures, Biomolecular gradients, Engineering organoids, In silico modeling, Intestinal stem cell niches, Light sheet fluorescence microscopy, Photolithography, Stem-cell
García-Torres, J, Colombi, S, Macor, LP, Alemán, C, (2022). Multitasking smart hydrogels based on the combination of alginate and poly(3,4-ethylenedioxythiophene) properties: A review INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES 219, 312-332
Poly(3,4-ethylenedioxythiophene) (PEDOT), a very stable and biocompatible conducting polymer, and alginate (Alg), a natural water-soluble polysaccharide mainly found in the cell wall of various species of brown algae, exhibit very different but at the same complementary properties. In the last few years, the remarkable capacity of Alg to form hydrogels and the electro-responsive properties of PEDOT have been combined to form not only layered composites (PEDOT-Alg) but also interpenetrated multi-responsive PEDOT/Alg hydrogels. These materials have been found to display outstanding properties, such as electrical conductivity, piezoelectricity, biocompatibility, self-healing and re-usability properties, pH and thermoelectric responsiveness, among others. Consequently, a wide number of applications are being proposed for PEDOT-Alg composites and, especially, PEDOT/Alg hydrogels, which should be considered as a new kind of hybrid material because of the very different chemical nature of the two polymeric components. This review summarizes the applications of PEDOT-Alg and PEDOT/Alg in tissue interfaces and regeneration, drug delivery, sensors, microfluidics, energy storage and evaporators for desalination. Special attention has been given to the discussion of multi-tasking applications, while the new challenges to be tackled based on aspects not yet considered in either of the two polymers have also been highlighted.Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.
JTD Keywords: aerogels, composite, conducting polymer, conducting polymers, electrodes, pedotpss, ph, platform, release, scaffold, semi-interpenetrated hydrogels, Alginates, Alginic acid, Bridged bicyclo compounds, heterocyclic, Conducting polymer, Drug-delivery, Hydrogels, Poly(3,4-ethylene dioxythiophene), Polymers, Polysaccharides, Semi-interpenetrated hydrogels, Water
Mochi, F, Scatena, E, Rodriguez, D, Ginebra, MP, Del Gaudio, C, (2022). Scaffold-based bone tissue engineering in microgravity: potential, concerns and implications NPJ Microgravity 8, 45
One of humanity's greatest challenges is space exploration, which requires an in-depth analysis of the data continuously collected as a necessary input to fill technological gaps and move forward in several research sectors. Focusing on space crew healthcare, a critical issue to be addressed is tissue regeneration in extreme conditions. In general, it represents one of the hottest and most compelling goals of the scientific community and the development of suitable therapeutic strategies for the space environment is an urgent need for the safe planning of future long-term manned space missions. Osteopenia is a commonly diagnosed disease in astronauts due to the physiological adaptation to altered gravity conditions. In order to find specific solutions to bone damage in a reduced gravity environment, bone tissue engineering is gaining a growing interest. With the aim to critically investigate this topic, the here presented review reports and discusses bone tissue engineering scenarios in microgravity, from scaffolding to bioreactors. The literature analysis allowed to underline several key points, such as the need for (i) biomimetic composite scaffolds to better mimic the natural microarchitecture of bone tissue, (ii) uniform simulated microgravity levels for standardized experimental protocols to expose biological materials to the same testing conditions, and (iii) improved access to real microgravity for scientific research projects, supported by the so-called democratization of space.© 2022. The Author(s).
JTD Keywords: biomaterials, collagen/hydroxyapatite, composite scaffolds, in-vitro, mineralization, proliferation, regenerative medicine, stem-cells, vivo, Hydroxyapatite scaffolds
Romero, D, Calvo, M, Le Rolle, V, Behar, N, Mabo, P, Hernandez, A, (2022). Multivariate ensemble classification for the prediction of symptoms in patients with Brugada syndrome MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING 60, 81-94
Identification of asymptomatic patients at higher risk for suffering cardiac events remains controversial and challenging in Brugada syndrome (BS). In this work, we proposed an ECG-based classifier to predict BS-related symptoms, by merging the most predictive electrophysiological features derived from the ventricular depolarization and repolarization periods, along with autonomic-related markers. The initial feature space included local and dynamic ECG markers, assessed during a physical exercise test performed in 110 BS patients (25 symptomatic). Morphological, temporal and spatial properties quantifying the ECG dynamic response to exercise and recovery were considered. Our model was obtained by proposing a two-stage feature selection process that combined a resampled-based regularization approach with a wrapper model assessment for balancing, simplicity and performance. For the classification step, an ensemble was constructed by several logistic regression base classifiers, whose outputs were fused using a performance-based weighted average. The most relevant predictors corresponded to the repolarization interval, followed by two autonomic markers and two other makers of depolarization dynamics. Our classifier allowed for the identification of novel symptom-related markers from autonomic and dynamic ECG responses during exercise testing, suggesting the need for multifactorial risk stratification approaches in order to predict future cardiac events in asymptomatic BS patients.
JTD Keywords: brugada syndrome, depolarization disorders, ensemble classifier, heart-rate recovery, Acute myocardial-ischemia, Autonomic nervous system, Autonomics, Brugada syndrome, Brugadum syndrome, Cardiac death, Death, sudden, cardiac, Depolarization, Depolarization disorder, Depolarization disorders, Dynamic ecg, Electrocardiography, Electrophysiology, Ensemble classifier, Ensemble-classifier, Events, Exercise, Exercise test, Forecasting, Heart, Heart rate, Heart-rate, Heart-rate recovery, Humans, Prognosis, Qrs, Quantification, Recovery, Repolarization, Sudden cardiac death
El Hauadi, K, Resina, L, Zanuy, D, Esteves, T, Ferreira, FC, Pérez-Madrigal, MM, Alemán, C, (2022). Dendritic Self-assembled Structures from Therapeutic Charged Pentapeptides LANGMUIR 38, 12905-12914
CRENKA [Cys-Arg-(NMe)Glu-Lys-Ala, where (NMe)Glu refers to N-methyl-Glu], an anti-cancer pentapeptide that induces prostate tumor necrosis and significant reduction in tumor growth, was engineered to increase the resistance to endogenous proteases of its parent peptide, CREKA (Cys-Arg-Glu-Lys-Ala). Considering their high tendency to aggregate, the self-assembly of CRENKA and CREKA into well-defined and ordered structures has been examined as a function of peptide concentration and pH. Spectroscopic studies and atomistic molecular dynamics simulations reveal significant differences between the secondary structures of CREKA and CRENKA. Thus, the restrictions imposed by the (NMe)Glu residue reduce the conformational variability of CRENKA with respect to CREKA, which significantly affects the formation of well-defined and ordered self-assembly morphologies. Aggregates with poorly defined morphology are obtained from solutions with low and moderate CREKA concentrations at pH 4, whereas well-defined dendritic microstructures with fractal geometry are obtained from CRENKA solutions with similar peptide concentrations at pH 4 and 7. The formation of dendritic structures is proposed to follow a two-step mechanism: (1) pseudo-spherical particles are pre-nucleated through a diffusion-limited aggregation process, pre-defining the dendritic geometry, and (2) such pre-nucleated structures coalesce by incorporating conformationally restrained CRENKA molecules from the solution to their surfaces, forming a continuous dendritic structure. Instead, no regular assembly is obtained from solutions with high peptide concentrations, as their dynamics is dominated by strong repulsive peptide-peptide electrostatic interactions, and from solutions at pH 10, in which the total peptide charge is zero. Overall, results demonstrate that dendritic structures are only obtained when the molecular charge of CRENKA, which is controlled through the pH, favors kinetics over thermodynamics during the self-assembly process.
JTD Keywords: aggregation, amphiphilic peptides, breast-cancer, cells, design, oxidative stress, resistance, strategy, Molecular dynamics simulation, Molecular-dynamics, Peptide hydrolases, Peptides, Protein structure, secondary, Thermodynamics
Donker, L, Houtekamer, R, Vliem, M, Sipieter, F, Canever, H, Gómez-González, M, Bosch-Padrós, M, Pannekoek, WJ, Trepat, X, Borghi, N, Gloerich, M, (2022). A mechanical G2 checkpoint controls epithelial cell division through E-cadherin-mediated regulation of Wee1-Cdk1 Cell Reports 41, 111475
Epithelial cell divisions are coordinated with cell loss to preserve epithelial integrity. However, how epithelia adapt their rate of cell division to changes in cell number, for instance during homeostatic turnover or wounding, is not well understood. Here, we show that epithelial cells sense local cell density through mechanosensitive E-cadherin adhesions to control G2/M cell-cycle progression. As local cell density increases, tensile forces on E-cadherin adhesions are reduced, which prompts the accumulation of the G2 checkpoint kinase Wee1 and downstream inhibitory phosphorylation of Cdk1. Consequently, dense epithelia contain a pool of cells that are temporarily halted in G2 phase. These cells are readily triggered to divide following epithelial wounding due to the consequent increase in intercellular forces and resulting degradation of Wee1. Our data collectively show that epithelial cell division is controlled by a mechanical G2 checkpoint, which is regulated by cell-density-dependent intercellular forces sensed and transduced by E-cadherin adhesions.Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.
JTD Keywords: Adherens junction, Cadherins, Cell cycle, Cell cycle proteins, Cell division, Cp: cell biology, E-cadherin, Epithelial cells, Epithelial homeostasis, G2 checkpoint, G2 phase cell cycle checkpoints, Mechanical forces, Mechanotransduction, Mitosis, Phosphorylation, Proliferation
Soler, PMI, Hidalgo, C, Fekete, Z, Zalanyi, L, Khalil, ISM, Yeste, M, Magdanz, V, (2022). Bundle formation of sperm: Influence of environmental factors Frontiers in Endocrinology 13, 957684
Cooperative behaviour of sperm is one of the mechanisms that plays a role in sperm competition. It has been observed in several species that spermatozoa interact with each other to form agglomerates or bundles. In this study, we investigate the effect of physical and biochemical factors that will most likely promote bundle formation in bull sperm. These factors include fluid viscosity, swim-up process, post-thaw incubation time and media additives which promote capacitation. While viscosity does not seem to influence the degree of sperm bundling, swim-up, post-thaw migration time and suppressed capacitation increase the occurrence of sperm bundles. This leads to the conclusion that sperm bundling is a result of hydrodynamic and adhesive interactions between the cells which occurs frequently during prolonged incubation times.Copyright © 2022 Morcillo i Soler, Hidalgo, Fekete, Zalanyi, Khalil, Yeste and Magdanz.
JTD Keywords: acrosome reaction, adhesion, bundling, capacitation, cell-cell interaction, cooperation, cooperative behaviour, fertilization, mammals, membrane, motility, progesterone, sperm competition, sperm migration, sperm selection, Bovine spermatozoa, Bundling, Cell-cell interaction, Cooperative behaviour, Sperm competition, Sperm migration, Sperm selection, Spermatozoa
Hino, N, Matsuda, K, Jikko, Y, Maryu, G, Sakai, K, Imamura, R, Tsukiji, S, Aoki, K, Terai, K, Hirashima, T, Trepat, X, Matsuda, M, (2022). A feedback loop between lamellipodial extension and HGF-ERK signaling specifies leader cells during collective cell migration DEVELOPMENTAL CELL 57, 2290-2304
Upon the initiation of collective cell migration, the cells at the free edge are specified as leader cells; however, the mechanism underlying the leader cell specification remains elusive. Here, we show that lamellipodial extension after the release from mechanical confinement causes sustained extracellular signal-regulated kinase (ERK) activation and underlies the leader cell specification. Live-imaging of Madin-Darby canine kidney (MDCK) cells and mouse epidermis through the use of Förster resonance energy transfer (FRET)-based biosensors showed that leader cells exhibit sustained ERK activation in a hepatocyte growth factor (HGF)-dependent manner. Meanwhile, follower cells exhibit oscillatory ERK activation waves in an epidermal growth factor (EGF) signaling-dependent manner. Lamellipodial extension at the free edge increases the cellular sensitivity to HGF. The HGF-dependent ERK activation, in turn, promotes lamellipodial extension, thereby forming a positive feedback loop between cell extension and ERK activation and specifying the cells at the free edge as the leader cells. Our findings show that the integration of physical and biochemical cues underlies the leader cell specification during collective cell migration.Copyright © 2022 Elsevier Inc. All rights reserved.
JTD Keywords: activation, c-met, contact inhibition, focal adhesions, heparan-sulfate, mechanical forces, morphogenesis, rho, stress fibers, Collective cell migration, Erk, Feedback regulation, Fret, Growth-factor receptor, Hgf, Lamellipodia, Leader cell specification, Signal transduction, Traction force, Wound healing
Hutson, TH, Hervera, A, (2022). Editorial: Biochemical and genetic tools to investigate the underlying mechanisms and treatment of sensorimotor pathologies Frontiers in Molecular Neuroscience 15, 1041458
Sala-Jarque, J, Zimkowska, K, Avila, J, Ferrer, I, del Rio, JA, (2022). Towards a Mechanistic Model of Tau-Mediated Pathology in Tauopathies: What Can We Learn from Cell-Based In Vitro Assays? INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 23, 11527
Tauopathies are a group of neurodegenerative diseases characterized by the hyperphosphorylation and deposition of tau proteins in the brain. In Alzheimer's disease, and other related tauopathies, the pattern of tau deposition follows a stereotypical progression between anatomically connected brain regions. Increasing evidence suggests that tau behaves in a "prion-like" manner, and that seeding and spreading of pathological tau drive progressive neurodegeneration. Although several advances have been made in recent years, the exact cellular and molecular mechanisms involved remain largely unknown. Since there are no effective therapies for any tauopathy, there is a growing need for reliable experimental models that would provide us with better knowledge and understanding of their etiology and identify novel molecular targets. In this review, we will summarize the development of cellular models for modeling tau pathology. We will discuss their different applications and contributions to our current understanding of the "prion-like" nature of pathological tau.
JTD Keywords: neurodegeneration, seeding, spreading, Culture model, Efficient generation, Extracellular tau, Familial alzheimers-disease, Microtubule-associated protein, Mouse model, Neurodegeneration, Neurofibrillary tangles, Paired helical filaments, Pathogenic tau, Pluripotent stem-cells, Seeding, Spreading, Tauopathies
Fernández-Garibay, X, Gómez-Florit, M, Domingues, RMA, Gomes, ME, Fernández-Costa, JM, Ramón-Azcón, J, (2022). Xeno-free bioengineered human skeletal muscle tissue using human platelet lysate-based hydrogels Biofabrication 14, 45015
Abstract Bioengineered human skeletal muscle tissues have emerged in the last years as new in vitro systems for disease modeling. These bioartificial muscles are classically fabricated by encapsulating human myogenic precursor cells in a hydrogel scaffold that resembles the extracellular matrix. However, most of these hydrogels are derived from xenogenic sources, and the culture media is supplemented with animal serum, which could interfere in drug testing assays. On the contrary, xeno-free biomaterials and culture conditions in tissue engineering offer increased relevance for developing human disease models. In this work, we used human platelet lysate-based nanocomposite hydrogels (HUgel) as scaffolds for human skeletal muscle tissue engineering. These hydrogels consist of human platelet lysate reinforced with cellulose nanocrystals (a-CNC) that allow tunable mechanical, structural, and biochemical properties for the 3D culture of stem cells. Here, we developed hydrogel casting platforms to encapsulate human muscle satellite stem cells in HUgel. The a-CNC content was modulated to enhance matrix remodeling, uniaxial tension, and self-organization of the cells, resulting in the formation of highly aligned, long myotubes expressing sarcomeric proteins. Moreover, the bioengineered human muscles were subjected to electrical stimulation, and the exerted contractile forces were measured in a non-invasive manner. Overall, our results demonstrated that the bioengineered human skeletal muscles could be built in xeno-free cell culture platforms to assess tissue functionality, which is promising for drug development applications.
JTD Keywords: 3d culture, generation, identification, image, manipulate, matrigel, mechanics, model, platelet lysate, scaffolds, skeletal muscle, tissue engineering, xeno-free, 3d culture, Animals, Extracellular matrix, Humans, Hydrogels, Muscle development, Muscle, skeletal, Platelet lysate, Platform, Skeletal muscle, Tissue engineering, Tissue scaffolds, Xeno-free
Oliver-Cervelló, L, Martin-Gómez, H, Mandakhbayar, N, Jo, YW, Cavalcanti-Adam, EA, Kim, HW, Ginebra, MP, Lee, JH, Mas-Moruno, C, (2022). Mimicking Bone Extracellular Matrix: From BMP-2-Derived Sequences to Osteogenic-Multifunctional Coatings Advanced Healthcare Materials 11, e2201339
Cell-material interactions are regulated by mimicking bone extracellular matrix on the surface of biomaterials. In this regard, reproducing the extracellular conditions that promote integrin and growth factor (GF) signaling is a major goal to trigger bone regeneration. Thus, the use of synthetic osteogenic domains derived from bone morphogenetic protein 2 (BMP-2) is gaining increasing attention, as this strategy is devoid of the clinical risks associated with this molecule. In this work, the wrist and knuckle epitopes of BMP-2 are screened to identify peptides with potential osteogenic properties. The most active sequences (the DWIVA motif and its cyclic version) are combined with the cell adhesive RGD peptide (linear and cyclic variants), to produce tailor-made biomimetic peptides presenting the bioactive cues in a chemically and geometrically defined manner. Such multifunctional peptides are next used to functionalize titanium surfaces. Biological characterization with mesenchymal stem cells demonstrates the ability of the biointerfaces to synergistically enhance cell adhesion and osteogenic differentiation. Furthermore, in vivo studies in rat calvarial defects prove the capacity of the biomimetic coatings to improve new bone formation and reduce fibrous tissue thickness. These results highlight the potential of mimicking integrin-GF signaling with synthetic peptides, without the need for exogenous GFs.© 2022 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.
JTD Keywords: adhesion formation, bmp-2, cell adhesions, in-vivo, integrin, mesenchymal stem-cells, morphogenetic protein-2, multifunctionality, osteoblastic differentiation, osteogenic differentiation, rgd-dwiva, rgd-peptides, titanium biofunctionalization, titanium surfaces, Animals, Biocompatible materials, Biomimetic peptides, Bone morphogenetic protein 2, Bone regeneration, Cell adhesions, Cell differentiation, Epitopes, Extracellular matrix, Integrins, Marrow stromal cells, Multifunctionality, Osteogenesis, Osteogenic differentiation, Peptides, Rats, Rgd-dwiva, Titanium, Titanium biofunctionalization
Lopez-Canosa, A, Perez-Amodio, S, Engel, E, Castano, O, (2022). Microfluidic 3D Platform to Evaluate Endothelial Progenitor Cell Recruitment by Bioactive Materials Acta Biomaterialia 151, 264-277
Most of the conventional in vitro models to test biomaterial-driven vascularization are too simplistic to recapitulate the complex interactions taking place in the actual cell microenvironment, which results in a poor prediction of the in vivo performance of the material. However, during the last decade, cell culture models based on microfluidic technology have allowed attaining unprecedented levels of tissue biomimicry. In this work, we propose a microfluidic-based 3D model to evaluate the effect of bioactive biomaterials capable of releasing signalling cues (such as ions or proteins) in the recruitment of endogenous endothelial progenitor cells, a key step in the vascularization process. The usability of the platform is demonstrated using experimentally-validated finite element models and migration and proliferation studies with rat endothelial progenitor cells (rEPCs) and bone marrow-derived rat mesenchymal stromal cells (BM-rMSCs). As a proof of concept of biomaterial evaluation, the response of rEPCs to an electrospun composite made of polylactic acid with calcium phosphates nanoparticles (PLA+CaP) was compared in a co-culture microenvironment with BM-rMSC to a regular PLA control. Our results show a significantly higher rEPCs migration and the upregulation of several pro-inflammatory and proangiogenic proteins in the case of the PLA+CaP. The effects of osteopontin (OPN) on the rEPCs migratory response were also studied using this platform, suggesting its important role in mediating their recruitment to a calcium-rich microenvironment. This new tool could be applied to screen the capacity of a variety of bioactive scaffolds to induce vascularization and accelerate the preclinical testing of biomaterials. STATEMENT OF SIGNIFICANCE: : For many years researchers have used neovascularization models to evaluate bioactive biomaterials both in vitro, with low predictive results due to their poor biomimicry and minimal control over cell cues such as spatiotemporal biomolecule signaling, and in vivo models, presenting drawbacks such as being highly costly, time-consuming, poor human extrapolation, and ethically controversial. We describe a compact microphysiological platform designed for the evaluation of proangiogenesis in biomaterials through the quantification of the level of sprouting in a mimicked endothelium able to react to gradients of biomaterial-released signals in a fibrin-based extracellular matrix. This model is a useful tool to perform preclinical trustworthy studies in tissue regeneration and to better understand the different elements involved in the complex process of vascularization.Copyright © 2022. Published by Elsevier Ltd.
JTD Keywords: angiogenesis, bioactive materials, bone regeneration, bone-formation, calcium-phosphate, extracellular calcium, in-vitro, interstitial flow, ion release, microfluidic model, signalling gradient, substitutes, tissue engineering, vascularization, vegf, Ion release, Mesenchymal stem-cells, Tissue engineering, Vascularization
Clark, AG, Maitra, A, Jacques, C, Bergert, M, Perez-Gonzalez, C, Simon, A, Lederer, L, Diz-Munoz, A, Trepat, X, Voituriez, R, Vignjevic, DM, (2022). Self-generated gradients steer collective migration on viscoelastic collagen networks NATURE MATERIALS 21, 1200-1210
Growing evidence suggests that the physical properties of the cellular microenvironment influence cell migration. However, it is not currently understood how active physical remodelling by cells affects migration dynamics. Here we report that cell clusters seeded on deformable collagen-I networks display persistent collective migration despite not showing any apparent intrinsic polarity. Clusters generate transient gradients in collagen density and alignment due to viscoelastic relaxation of the collagen networks. Combining theory and experiments, we show that crosslinking collagen networks or reducing cell cluster size results in reduced network deformation, shorter viscoelastic relaxation time and smaller gradients, leading to lower migration persistence. Traction force and Brillouin microscopy reveal asymmetries in force distributions and collagen stiffness during migration, providing evidence of mechanical cross-talk between cells and their substrate during migration. This physical model provides a mechanism for self-generated directional migration on viscoelastic substrates in the absence of internal biochemical polarity cues.; Cell clusters mechanically reorganize viscoelastic collagen networks, resulting in transient gradients in collagen density, alignment and stiffness that promote spontaneous persistent migration.
JTD Keywords: Cell-migration, Design, Invasion, Limits, Mechanics, Microscopy, Morphogenesis, Motility, Rear, Rigidity
Romero, D, Blanco-Almazan, D, Groenendaal, W, Lijnen, L, Smeets, C, Ruttens, D, Catthoor, F, Jane, R, (2022). Predicting 6-minute walking test outcomes in patients with chronic obstructive pulmonary disease without physical performance measures COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 225, 107020
Chronic obstructive pulmonary disease (COPD) requires a multifactorial assessment, evaluating the airflow limitation and symptoms of the patients. The 6-min walk test (6MWT) is commonly used to evaluate the functional exercise capacity in these patients. This study aims to propose a novel predictive model of the major 6MWT outcomes for COPD assessment, without physical performance measurements.Cardiopulmonary and clinical parameters were obtained from fifty COPD patients. These parameters were used as inputs of a Bayesian network (BN), which integrated three multivariate models including the 6-min walking distance (6MWD), the maximum HR (HRmax) after the walking, and the HR decay 3 min after (HRR3). The use of BN allows the assessment of the patients' status by predicting the 6MWT outcomes, but also inferring disease severity parameters based on actual patient's 6MWT outcomes.Firstly, the correlation obtained between the estimated and actual 6MWT measures was strong (R = 0.84, MAPE = 8.10% for HRmax) and moderate (R = 0.58, MAPE = 15.43% for 6MWD and R = 0.58, MAPE = 32.49% for HRR3), improving the classical methods to estimate 6MWD. Secondly, the classification of disease severity showed an accuracy of 78.3% using three severity groups, which increased up to 84.4% for two defined severity groups.We propose a powerful two-way assessment tool for COPD patients, capable of predicting 6MWT outcomes without the need for an actual walking exercise. This model-based tool opens the way to implement a continuous monitoring system for COPD patients at home and to provide more personalized care.Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.
JTD Keywords: 6mwt, bayesian networks, copd, distance, exercise capacity, physical capacity, reference equations, severity, survival, wearables, 6mwt, Bayes theorem, Bayesian networks, Copd, Exercise test, Exercise tolerance, Heart-rate recovery, Humans, Physical capacity, Physical functional performance, Pulmonary disease, chronic obstructive, Walking, Wearables
Hodásová, L, Morena, AG, Tzanov, T, Fargas, G, Llanes, L, Alemán, C, Armelin, E, (2022). 3D-Printed Polymer-Infiltrated Ceramic Network with Antibacterial Biobased Silver Nanoparticles ACS Applied Bio Materials 5, 4803-4813
This work aimed at the antimicrobial functionalization of 3D-printed polymer-infiltrated biomimetic ceramic networks (PICN). The anti-microbial properties of the polymer-ceramic composites were achieved by coating them with human-and environmentally safe silver nanoparticles trapped in a phenolated lignin matrix (Ag@PL NPs). Lignin was enzymatically phenolated and used as a biobased reducing agent to obtain stable Ag@PL NPs, which were then formulated in a silane (gamma-MPS) solution and deposited to the PICN surface. The presence of the NPs and their proper attachment to the surface were analyzed with spectroscopic methods (FTIR and Raman) and X-ray photoelectron spectroscopy (XPS). Homogeneous distribution of 13.4 +/- 3.2 nm NPs was observed in the transmission electron microscopy (TEM) images. The functionalized samples were tested against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria, validating their antimicrobial efficiency in 24 h. The bacterial reduction of S. aureus was 90% in comparison with the pristine surface of PICN. To confirm that the Ag-functionalized PICN scaffold is a safe material to be used in the biomedical field, its biocompatibility was demonstrated with human fibroblast (BJ-5ta) and keratinocyte (HaCaT) cells, which was higher than 80% in both cell lines.
JTD Keywords: accuracy, antibacterial activity, disease, facile, laccase enzyme, lignin, polyacrylates, polymer-infiltrated ceramic network, silver nanoparticles, zirconia, Mechanical-properties, Mechanical-properties,zirconia,lignin,accuracy,disease,facil, Polymer-infiltrated ceramic network, Polymer-infiltrated ceramic network,polyacrylates,lignin,laccase enzyme,silver nanoparticles,antibacterial activit, Silver nanoparticles
Phuyal, S, Djaerff, E, Le Roux, AL, Baker, MJ, Fankhauser, D, Mahdizadeh, SJ, Reiterer, V, Parizadeh, A, Felder, E, Kahlhofer, JC, Teis, D, Kazanietz, MG, Geley, S, Eriksson, L, Roca-Cusachs, P, Farhan, H, (2022). Mechanical strain stimulates COPII-dependent secretory trafficking via Rac1 EMBO JOURNAL 41, e110596
Cells are constantly exposed to various chemical and physical stimuli. While much has been learned about the biochemical factors that regulate secretory trafficking from the endoplasmic reticulum (ER), much less is known about whether and how this trafficking is subject to regulation by mechanical signals. Here, we show that subjecting cells to mechanical strain both induces the formation of ER exit sites (ERES) and accelerates ER-to-Golgi trafficking. We found that cells with impaired ERES function were less capable of expanding their surface area when placed under mechanical stress and were more prone to develop plasma membrane defects when subjected to stretching. Thus, coupling of ERES function to mechanotransduction appears to confer resistance of cells to mechanical stress. Furthermore, we show that the coupling of mechanotransduction to ERES formation was mediated via a previously unappreciated ER-localized pool of the small GTPase Rac1. Mechanistically, we show that Rac1 interacts with the small GTPase Sar1 to drive budding of COPII carriers and stimulates ER-to-Golgi transport. This interaction therefore represents an unprecedented link between mechanical strain and export from the ER.© 2022 The Authors. Published under the terms of the CC BY 4.0 license.
JTD Keywords: cells, copii, docking, endoplasmic reticulum, endoplasmic-reticulum, er, gtpase, mechanobiology, proliferation, protein, reticulum exit sites, web server, Copii, Fast interaction refinement, Mechanobiology
López-Soldado, I, Guinovart, JJ, Duran, J, (2022). Hepatic overexpression of protein targeting to glycogen attenuates obesity and improves hyperglycemia in db/db mice Frontiers in Endocrinology 13, 969924
Increased liver glycogen content has been shown to reduce food intake, attenuate obesity, and improve glucose tolerance in a mouse model of high-fat diet (HFD)-induced obesity. Here we studied the contribution of liver glycogen to the regulation of obesity and glucose metabolism in a model of type 2 diabetes and obesity, namely the db/db mouse. To this end, we crossed db/db mice with animals overexpressing protein targeting to glycogen (PTG) in the liver to generate db/db mice with increased liver glycogen content (db/db-PTG). Hepatic PTG overexpression reduced food intake and fat weight and attenuated obesity and hyperglycemia in db/db mice. Db/db-PTG mice showed similar energy expenditure and physical activity to db/db mice. PTG overexpression reduced liver phosphoenolpyruvate carboxykinase (PEPCK) protein levels and repressed hepatic glucose production in db/db mice. Moreover, increased liver glycogen elevated hepatic ATP content in these animals. However, lipid metabolism was not modified by PTG overexpression. In conclusion, increased liver glycogen content ameliorates the diabetic and obesity phenotype in db/db mice.Copyright © 2022 López-Soldado, Guinovart and Duran.
JTD Keywords: atp, db, dyslipidemia, food intake, glucose, homeostasis, liver, metabolism, mouse, receptor, Atp, Db/db, Food intake, Food-intake, Glucose, Glycogen, Liver
Rivas, EI, Linares, J, Zwick, M, Gómez-Llonin, A, Guiu, M, Labernadie, A, Badia-Ramentol, J, Lladó, A, Bardia, L, Pérez-Núñez, I, Martínez-Ciarpaglini, C, Tarazona, N, Sallent-Aragay, A, Garrido, M, Celià-Terrassa, T, Burgués, O, Gomis, RR, Albanell, J, Calon, A, (2022). Targeted immunotherapy against distinct cancer-associated fibroblasts overcomes treatment resistance in refractory HER2+ breast tumors Nature Communications 13, 5310
About 50% of human epidermal growth factor receptor 2 (HER2)+ breast cancer patients do not benefit from HER2-targeted therapy and almost 20% of them relapse after treatment. Here, we conduct a detailed analysis of two independent cohorts of HER2+ breast cancer patients treated with trastuzumab to elucidate the mechanisms of resistance to anti-HER2 monoclonal antibodies. In addition, we develop a fully humanized immunocompetent model of HER2+ breast cancer recapitulating ex vivo the biological processes that associate with patients’ response to treatment. Thanks to these two approaches, we uncover a population of TGF-beta-activated cancer-associated fibroblasts (CAF) specific from tumors resistant to therapy. The presence of this cellular subset related to previously described myofibroblastic (CAF-S1) and podoplanin+ CAF subtypes in breast cancer associates with low IL2 activity. Correspondingly, we find that stroma-targeted stimulation of IL2 pathway in unresponsive tumors restores trastuzumab anti-cancer efficiency. Overall, our study underscores the therapeutic potential of exploiting the tumor microenvironment to identify and overcome mechanisms of resistance to anti-cancer treatment.
JTD Keywords: activation, cells, efficacy, enrichment analysis, expression, infiltrating lymphocytes, survival, therapy, trastuzumab, Her2-positive breast-cancer
Zamora, RA, López-Ortiz, M, Sales-Mateo, M, Hu, C, Croce, R, Maniyara, RA, Pruneri, V, Giannotti, M, Gorostiza, P, (2022). Light- and Redox-Dependent Force Spectroscopy Reveals that the Interaction between Plastocyanin and Plant Photosystem I Is Favored when One Partner Is Ready for Electron Transfer ACS Nano 16, 15155-15164
Photosynthesis is a fundamental process that converts photons into chemical energy, driven by large protein complexes at the thylakoid membranes of plants, cyanobacteria, and algae. In plants, water-soluble plastocyanin (Pc) is responsible for shuttling electrons between cytochrome b6f complex and the photosystem I (PSI) complex in the photosynthetic electron transport chain (PETC). For an efficient turnover, a transient complex must form between PSI and Pc in the PETC, which implies a balance between specificity and binding strength. Here, we studied the binding frequency and the unbinding force between suitably oriented plant PSI and Pc under redox control using single molecule force spectroscopy (SMFS). The binding frequency (observation of binding-unbinding events) between PSI and Pc depends on their respective redox states. The interaction between PSI and Pc is independent of the redox state of PSI when Pc is reduced, and it is disfavored in the dark (reduced P700) when Pc is oxidized. The frequency of interaction between PSI and Pc is higher when at least one of the partners is in a redox state ready for electron transfer (ET), and the post-ET situation (PSIRed-PcOx) leads to lower binding. In addition, we show that the binding of ET-ready PcRed to PSI can be regulated externally by Mg2+ ions in solution.
JTD Keywords: architecture, binding-site, complexes, ferredoxin, force spectroscopy, induced structural-changes, interprotein electron transfer, light-dependent interaction, mg2+ concentration, photosystem i, plastocyanin, probe, recognition, reduction, Force spectroscopy, Interprotein electron transfer, Light-dependent interaction, Photosynthetic reaction-center, Photosystem i, Plastocyanin, Single molecule measurements
Tas, B, Kalk, NJ, Lozano-Garcia, M, Rafferty, GF, Cho, PSP, Kelleher, M, Moxham, J, Strang, J, Jolley, C, (2022). Risk factors for respiratory depression in Opioid Use Disorder EUROPEAN RESPIRATORY JOURNAL 60, 2791
De Corato, M, Arroyo, M, (2022). A theory for the flow of chemically responsive polymer solutions: Equilibrium and shear-induced phase separation JOURNAL OF RHEOLOGY 66, 813-835
Chemically responsive polymers are macromolecules that respond to local variations of the chemical composition of the solution by changing their conformation, with notable examples including polyelectrolytes, proteins, and DNA. The polymer conformation changes can occur in response to changes in the pH, the ionic strength, or the concentration of a generic solute that interacts with the polymer. These chemical stimuli can lead to drastic variations of the polymer flexibility and even trigger a transition from a coil to a globule polymer conformation. In many situations, the spatial distribution of the chemical stimuli can be highly inhomogeneous, which can lead to large spatial variations of polymer conformation and of the rheological properties of the mixture. In this paper, we develop a theory for the flow of a mixture of solute and chemically responsive polymers. The approach is valid for generic flows and inhomogeneous distributions of polymers and solutes. To model the polymer conformation changes introduced by the interactions with the solute, we consider the polymers as linear elastic dumbbells whose spring stiffness depends on the solute concentration. We use Onsager's variational formalism to derive the equations governing the evolution of the variables, which unveils novel couplings between the distribution of dumbbells and that of the solute. Finally, we use a linear stability analysis to show that the governing equations predict an equilibrium phase separation and a distinct shear-induced phase separation whereby a homogeneous distribution of solute and dumbbells spontaneously demix. Similar phase transitions have been observed in previous experiments using stimuli-responsive polymers and may play an important role in living systems. (C) 2022 The Society of Rheology.
JTD Keywords: Coil-globule transition, Constitutive equation, Dilute-solutions, Dumbbell model, Dynamics, Macromolecules, Nonequilibrium thermodynamics, Polyelectrolytes, Polymer migration, Polymer phase separation, Polymers, Predictions, Rheology, Shear-induced phase separation, Solute-polymer interactions, Stress, Viscoelasticity
Checa, M, Jin, X, Millan-Solsona, R, Neumayer, SM, Susner, MA, McGuire, MA, O'Hara, A, Gomila, G, Maksymovych, P, Pantelides, ST, Collins, L, (2022). Revealing Fast Cu-Ion Transport and Enhanced Conductivity at the CuInP2S6?In4/3P2S6 Heterointerface ACS Nano 16, 15347-15357
Van der Waals layered ferroelectrics, such as CuInP2S6 (CIPS), offer a versatile platform for miniaturization of ferroelectric device technologies. Control of the targeted composition and kinetics of CIPS synthesis enables the formation of stable self-assembled heterostructures of ferroelectric CIPS and nonferroelectric In4/3P2S6 (IPS). Here, we use quantitative scanning probe microscopy methods combined with density functional theory (DFT) to explore in detail the nanoscale variability in dynamic functional properties of the CIPS-IPS heterostructure. We report evidence of fast ionic transport which mediates an appreciable out-of-plane electromechanical response of the CIPS surface in the paraelectric phase. Further, we map the nanoscale dielectric and ionic conductivity properties as we thermally stimulate the ferroelectric-paraelectric phase transition, recovering the local dielectric behavior during this phase transition. Finally, aided by DFT, we reveal a substantial and tunable conductivity enhancement at the CIPS/IPS interface, indicating the possibility of engineering its interfacial properties for next generation device applications.
JTD Keywords: copper indium thiophosphate, diffusion, elastic band method, ferroelectrics, ionic conductor, migration, nanoscale, phase transition, piezoresponse force microscopy, scanning dielectric microscopy, transition, Copper indium thiophosphate, Initio molecular-dynamics, Scanning dielectric microscopy
Ferrer, I, Andres-Benito, P, Ausin, K, Cartas-Cejudo, P, Lachen-Montes, M, del Rio, JA, Fernandez-Irigoyen, J, Santamaria, E, (2022). Dysregulated Protein Phosphorylation in a Mouse Model of FTLD-Tau JOURNAL OF NEUROPATHOLOGY AND EXPERIMENTAL NEUROLOGY 81, 696-706
The neocortex of P301S mice, used as a model of fronto-temporal lobar degeneration linked to tau mutation (FTLD-tau), and wild-type mice, both aged 9 months, were analyzed with conventional label-free phosphoproteomics and SWATH-MS (sequential window acquisition of all theoretical fragment ion spectra mass spectrometry) to assess the (phospho)proteomes. The total number of identified dysregulated phosphoproteins was 328 corresponding to 524 phosphorylation sites. The majority of dysregulated phosphoproteins, most of them hyperphosphorylated, were proteins of the membranes, synapses, membrane trafficking, membrane vesicles linked to endo- and exocytosis, cytoplasmic vesicles, and cytoskeleton. Another group was composed of kinases. In contrast, proteins linked to DNA, RNA metabolism, RNA splicing, and protein synthesis were hypophosphorylated. Other pathways modulating energy metabolism, cell signaling, Golgi apparatus, carbohydrates, and lipids are also targets of dysregulated protein phosphorylation in P301S mice. The present results, together with accompanying immunohistochemical and Western-blotting studies, show widespread abnormal phosphorylation of proteins, in addition to protein tau, in P301S mice. These observations point to dysregulated protein phosphorylation as a relevant contributory pathogenic component of tauopathies.
JTD Keywords: (phospho)proteomics, cytoskeleton, kinases, membranes, tau, (phospho)proteomics, Animals, Cytoskeleton, Disease models, animal, Frontotemporal lobar degeneration, Kinases, Membranes, Mice, Mice, transgenic, Networks, Oxidative stress, Pathology, Phosphoproteins, Phosphoproteome analysis, Phosphorylation, Tau, Tau proteins, Tauopathies, Tauopathy
Ordoño, J, Pérez-Amodio, S, Ball, K, Aguirre, A, Engel, E, (2022). The generation of a lactate-rich environment stimulates cell cycle progression and modulates gene expression on neonatal and hiPSC-derived cardiomyocytes BIOMATERIALS ADVANCES 139, 213035
In situ tissue engineering strategies are a promising approach to activate the endogenous regenerative potential of the cardiac tissue helping the heart to heal itself after an injury. However, the current use of complex reprogramming vectors for the activation of reparative pathways challenges the easy translation of these therapies into the clinic. Here, we evaluated the response of mouse neonatal and human induced pluripotent stem cell-derived cardiomyocytes to the presence of exogenous lactate, thus mimicking the metabolic environment of the fetal heart. An increase in cardiomyocyte cell cycle activity was observed in the presence of lactate, as determined through Ki67 and Aurora-B kinase. Gene expression and RNA-sequencing data revealed that cardiomyocytes incubated with lactate showed upregulation of BMP10, LIN28 or TCIM in tandem with downregulation of GRIK1 or DGKK among others. Lactate also demonstrated a capability to modulate the production of inflammatory cytokines on cardiac fibroblasts, reducing the production of Fas, Fraktalkine or IL-12p40, while stimulating IL-13 and SDF1a. In addition, the generation of a lactate-rich environment improved ex vivo neonatal heart culture, by affecting the contractile activity and sarcomeric structures and inhibiting epicardial cell spreading. Our results also suggested a common link between the effect of lactate and the activation of hypoxia signaling pathways. These findings support a novel use of lactate in cardiac tissue engineering, modulating the metabolic environment of the heart and thus paving the way to the development of lactate-releasing platforms for in situ cardiac regeneration.Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.
JTD Keywords: cardiac regeneration, cardiac tissue engineering, cell cycle, failure, growth, heart regeneration, induced pluripotent stem cells, ischemia, lactate, metabolic environment, metabolism, mouse, proliferation, repair, Bone morphogenetic protein-10, Cardiac tissue engineering, Cardiomyocytes, Cell cycle, Induced pluripotent stem cells, Lactate, Metabolic environment
Farre, R, Rodriguez-Lazaro, MA, Gozal, D, Trias, G, Solana, G, Navajas, D, Otero, J, (2022). Simple low-cost construction and calibration of accurate pneumotachographs for monitoring mechanical ventilation in low-resource settings Frontiers in Medicine 9, 938949
Assessing tidal volume during mechanical ventilation is critical to improving gas exchange while avoiding ventilator-induced lung injury. Conventional flow and volume measurements are usually carried out by built-in pneumotachographs in the ventilator or by stand-alone flowmeters. Such flow/volume measurement devices are expensive and thus usually unaffordable in low-resource settings. Here, we aimed to design and test low-cost and technically-simple calibration and assembly pneumotachographs. The proposed pneumotachographs are made by manual perforation of a plate with a domestic drill. Their pressure-volume relationship is characterized by a quadratic equation with parameters that can be tailored by the number and diameter of the perforations. We show that the calibration parameters of the pneumotachographs can be measured through two maneuvers with a conventional resuscitation bag and by assessing the maneuver volumes with a cheap and straightforward water displacement setting. We assessed the performance of the simplified low-cost pneumotachographs to measure flow/volume during mechanical ventilation as carried out under typical conditions in low-resource settings, i.e., lacking gold standard expensive devices. Under realistic mechanical ventilation settings (pressure- and volume-control; 200-600 mL), inspiratory tidal volume was accurately measured (errors of 2.1% on average and <4% in the worst case). In conclusion, a simple, low-cost procedure facilitates the construction of affordable and accurate pneumotachographs for monitoring mechanical ventilation in low- and middle-income countries.
JTD Keywords: calibration, flow measurement, low- and middle-income countries, mechanical ventilation, pneumotachograph, Calibration, Flow, Flow measurement, Low- and middle-income countries, Lung injury, Mechanical ventilation, Pneumotachograph, Pressure-drop, Resistance, Tidal volume
Seuma, M, Bolognesi, B, (2022). Understanding and evolving prions by yeast multiplexed assays CURRENT OPINION IN GENETICS & DEVELOPMENT 75, 101941
Yeast genetics made it possible to derive the first fundamental insights into prion composition, conformation, and propagation. Fast-forward 30 years and the same model organism is now proving an extremely powerful tool to comprehensively explore the impact of mutations in prion sequences on their function, toxicity, and physical properties. Here, we provide an overview of novel multiplexed strategies where deep mutagenesis is combined to a range of tailored selection assays in yeast, which are particularly amenable for investigating prions and prion-like sequences. By mimicking evolution in a flask, these multiplexed approaches are revealing mechanistic insights on the consequences of prion self-assembly, while also reporting on the structure prion sequences adopt in vivo.Copyright © 2022 Elsevier Ltd. All rights reserved.
JTD Keywords: aggregation, appearance, domains, inheritance, mutations, nucleation, physical basis, propagation, protein, Phase-separation
Mesquida-Veny, F, Martinez-Torres, S, Del Rio, JA, Hervera, A, (2022). Nociception-Dependent CCL21 Induces Dorsal Root Ganglia Axonal Growth via CCR7-ERK Activation Frontiers in Immunology 13, 880647
While chemokines were originally described for their ability to induce cell migration, many studies show how these proteins also take part in many other cell functions, acting as adaptable messengers in the communication between a diversity of cell types. In the nervous system, chemokines participate both in physiological and pathological processes, and while their expression is often described on glial and immune cells, growing evidence describes the expression of chemokines and their receptors in neurons, highlighting their potential in auto- and paracrine signalling. In this study we analysed the role of nociception in the neuronal chemokinome, and in turn their role in axonal growth. We found that stimulating TRPV1(+) nociceptors induces a transient increase in CCL21. Interestingly we also found that CCL21 enhances neurite growth of large diameter proprioceptors in vitro. Consistent with this, we show that proprioceptors express the CCL21 receptor CCR7, and a CCR7 neutralizing antibody dose-dependently attenuates CCL21-induced neurite outgrowth. Mechanistically, we found that CCL21 binds locally to its receptor CCR7 at the growth cone, activating the downstream MEK-ERK pathway, that in turn activates N-WASP, triggering actin filament ramification in the growth cone, resulting in increased axonal growth.
JTD Keywords: axonal growth, ccl21, ccr7, mek-erk, Actin dynamics, Axonal growth, Ccl21, Ccr7, Cell-migration, Central-nervous-system, Chemokine, Ligands, Mek-erk, Microglia, Neurons, Neuropathic pain, Nociception, Phosphorylation, Regeneration
Sole-Marti, X, Vilella, T, Labay, C, Tampieri, F, Ginebra, MP, Canal, C, (2022). Thermosensitive hydrogels to deliver reactive species generated by cold atmospheric plasma: a case study with methylcellulose Biomaterials Science 10, 3845-3855
Hydrogels have been recently proposed as suitable materials to generate reactive oxygen and nitrogen species (RONS) upon gas-plasma treatment, and postulated as promising alternatives to conventional cancer therapies. Acting as delivery vehicles that allow a controlled release of RONS to the diseased site, plasma-treated hydrogels can overcome some of the limitations presented by plasma-treated liquids in in vivo therapies. In this work, we optimized the composition of a methylcellulose (MC) hydrogel to confer it with the ability to form a gel at physiological temperatures while remaining in the liquid phase at room temperature to allow gas-plasma treatment with suitable formation of plasma-generated RONS. MC hydrogels demonstrated the capacity for generation, prolonged storage and release of RONS. This release induced cytotoxic effects on the osteosarcoma cancer cell line MG-63, reducing its cell viability in a dose-response manner. These promising results postulate plasma-treated thermosensitive hydrogels as good candidates to provide local anticancer therapies.
JTD Keywords: Case-control studies, Cellulose, Hydrogels, Methylcellulose, Phase-separation, Plasma gases, Reactive oxygen species, Stability, Substituent, Temperature, Thermoreversible gelation
Varea, O, Guinovart, JJ, Duran, J, (2022). Malin restoration as proof of concept for gene therapy for Lafora disease Brain Communications 4, fcac168
Abstract Lafora disease is a fatal neurodegenerative childhood dementia caused by loss-of-function mutations in either the laforin or malin gene. The hallmark of the disease is the accumulation of abnormal glycogen aggregates known as Lafora bodies (LBs) in the brain and other tissues. These aggregates are responsible for the pathological features of the disease. As a monogenic disorder, Lafora disease is a good candidate for gene therapy-based approaches. However, most patients are diagnosed after the appearance of the first symptoms and thus when LBs are already present in the brain. In this context, it was not clear whether the restoration of a normal copy of the defective gene (either laforin or malin) would prove effective. Here we evaluated the effect of restoring malin in a malin-deficient mouse model of Lafora disease as a proof of concept for gene replacement therapy. To this end, we generated a malin-deficient mouse in which malin expression can be induced at a certain time. Our results reveal that malin restoration at an advanced stage of the disease arrests the accumulation of LBs in brain and muscle, induces the degradation of laforin and glycogen synthase bound to the aggregates, and ameliorates neuroinflammation. These results identify malin restoration as the first therapeutic strategy to show effectiveness when applied at advanced stages of Lafora disease.
JTD Keywords: accumulation, gene therapy, glycogen, lafora disease, neurodegeneration, neuroinflammation, neurons, targets, Carbohydrate-binding domain, Glycogen, Neuroinflammation
Verschure, PFMJ, Wierenga, S, (2022). Future memory: a digital humanities approach for the preservation and presentation of the history of the Holocaust and Nazi crimes Holocaust Studies 28, 331-357
We describe the concepts, methodology, technology, and practice of a user-centric and historical space-oriented approach towards Historical and Cultural Learning (HCL). The Future Memory project pursues the unifying hypothesis that physical space can play a critical role in the authentication and education of this singular historical event, or space as a frame for memory formation and a source of authentication. We illustrate these aspects in the context of concrete Future Memory projects realized over the last ten years in collaboration with several memorial sites, museums, and archives. Based on these experiences, we subsequently analyze the lessons learned and future challenges.
JTD Keywords: Augmented reality, Behavior, Commemoration, Design, Digital heritage, Experience, Framework, Future memory, Mobile, Navigation, Place cells, Post-wtiness era, Space, Virtual reality
Rubies, C, Batlle, M, Sanz-de la Garza, M, Dantas, AP, Jorba, I, Fernandez, G, Sanguesa, G, Abuli, M, Brugada, J, Sitges, M, Navajas, D, Mont, L, Guasch, E, (2022). Long-term strenuous exercise promotes vascular injury by selectively damaging the tunica media: experimental evidence JACC-Basic to Translational Science 7, 681-693
Moderate exercise has well-founded benefits in cardiovascular health. However, increasing, yet controversial, evidence suggests that extremely trained athletes may not be protected from cardiovascular events as much as moderately trained individuals. In our rodent model, intensive but not moderate training promoted aorta and carotid stiffening and elastic lamina ruptures, tunica media thickening of intramyocardial arteries, and an imbalance between vasoconstrictor and relaxation agents. An up-regulation of angiotensin-converter enzyme, miR-212, miR-132, and miR-146b might account for this deleterious remodeling. Most changes remained after a 4-week detraining. In conclusion, our results suggest that intensive training blunts the benefits of moderate exercise. (C) 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.
JTD Keywords: atherosclerosis, cacs, coronary artery calcium score, cad, coronary artery disease, coronary artery disease, cv, cardiovascular, endurance exercise, extreme sport, mmp9, matrix metalloproteinase 9, no, nitric oxide, phe, phenylephrine, vsmc, vascular smooth muscle cell, Age, Atherosclerosis, Cacs, coronary artery calcium score, Cad, coronary artery disease, Coronary artery disease, Coronary atherosclerosis, Cv, cardiovascular, Disease, Endurance exercise, Extreme sport, Metalloproteinases, Micrornas, Mmp9, matrix metalloproteinase 9, No, nitric oxide, Phe, phenylephrine, Physical-activity, Prevalence, Rats, Relevance, Risk, Vascular stiffening, Vsmc, vascular smooth muscle cell
Lozano-Garcia, M, Estrada-Petrocelli, L, Blanco-Almazan, D, Tas, B, Cho, PSP, Moxham, J, Rafferty, GF, Torres, A, Jane, R, Jolley, CJ, (2022). Noninvasive Assessment of Neuromechanical and Neuroventilatory Coupling in COPD IEEE Journal of Biomedical and Health Informatics 26, 3385-3396
This study explored the use of parasternal second intercostal space and lower intercostal space surface electromyogram (sEMG) and surface mechanomyogram (sMMG) recordings (sEMGpara and sMMGpara, and sEMGlic and sMMGlic, respectively) to assess neural respiratory drive (NRD), neuromechanical (NMC) and neuroventilatory (NVC) coupling, and mechanical efficiency (MEff) noninvasively in healthy subjects and chronic obstructive pulmonary disease (COPD) patients. sEMGpara, sMMGpara, sEMGlic, sMMGlic, mouth pressure (Pmo), and volume (Vi) were measured at rest, and during an inspiratory loading protocol, in 16 COPD patients (8 moderate and 8 severe) and 9 healthy subjects. Myographic signals were analyzed using fixed sample entropy and normalized to their largest values (fSEsEMGpara%max, fSEsMMGpara%max, fSEsEMGlic%max, and fSEsMMGlic%max). fSEsMMGpara%max, fSEsEMGpara%max, and fSEsEMGlic%max were significantly higher in COPD than in healthy participants at rest. Parasternal intercostal muscle NMC was significantly higher in healthy than in COPD participants at rest, but not during threshold loading. Pmo-derived NMC and MEff ratios were lower in severe patients than in mild patients or healthy subjects during threshold loading, but differences were not consistently significant. During resting breathing and threshold loading, Vi-derived NVC and MEff ratios were significantly lower in severe patients than in mild patients or healthy subjects. sMMG is a potential noninvasive alternative to sEMG for assessing NRD in COPD. The ratios of Pmo and Vi to sMMG and sEMG measurements provide wholly noninvasive NMC, NVC, and MEff indices that are sensitive to impaired respiratory mechanics in COPD and are therefore of potential value to assess disease severity in clinical practice. Author
JTD Keywords: biomedical measurement, chronic obstructive pulmonary disease, couplings, diaphragm, disease severity, efficiency, electromyography, exacerbations, healthy volunteers, inspiratory muscles, loading, mechanomyography, obstructive pulmonary-disease, pressure measurement, protocols, respiratory mechanics, respiratory muscles, responsiveness, spirometry, stimulation, volume measurement, At rests, Biomedical measurement, Biomedical measurements, Chronic obstructive pulmonary disease, Couplings, Disease severity, Efficiency ratio, Electromyography, Healthy subjects, Healthy volunteers, Loading, Mechanical efficiency, Mechanomyogram, Muscle, Muscles, Neural respiratory drive, Noninvasive medical procedures, Pressure measurement, Protocols, Pulmonary diseases, Surface electromyogram, Volume measurement
Kaurin, D, Bal, PK, Arroyo, M, (2022). Peeling dynamics of fluid membranes bridged by molecular bonds: moving or breaking Journal of the Royal Society Interface 19, 20220183
Biological adhesion is a critical mechanical function of complex organisms. At the scale of cell-cell contacts, adhesion is remarkably tunable to enable both cohesion and malleability during development, homeostasis and disease. It is physically supported by transient and laterally mobile molecular bonds embedded in fluid membranes. Thus, unlike specific adhesion at solid-solid or solid-fluid interfaces, peeling at fluid-fluid interfaces can proceed by breaking bonds, by moving bonds or by a combination of both. How the additional degree of freedom provided by bond mobility changes the mechanics of peeling is not understood. To address this, we develop a theoretical model coupling diffusion, reactions and mechanics. Mobility and reaction rates determine distinct peeling regimes. In a diffusion-dominated Stefan-like regime, bond motion establishes self-stabilizing dynamics that increase the effective fracture energy. In a reaction-dominated regime, peeling proceeds by travelling fronts where marginal diffusion and unbinding control peeling speed. In a mixed reaction-diffusion regime, strengthening by bond motion competes with weakening by bond breaking in a force-dependent manner, defining the strength of the adhesion patch. In turn, patch strength depends on molecular properties such as bond stiffness, force sensitivity or crowding. We thus establish the physical rules enabling tunable cohesion in cellular tissues and in engineered biomimetic systems.
JTD Keywords: cell–cell adhesion, peeling, Adhesive contact, Cadherins, Cell-cell adhesion, Detachment, Detailed mechanics, Diffusion, Growth, Kinetics, Peeling, Red-blood-cells, Repulsion, Separation, Vesicle adhesion
Blanco-Fernandez, B, Rey-Vinolas, S, Bagci, G, Rubi-Sans, G, Otero, J, Navajas, D, Perez-Amodio, S, Engel, E, (2022). Bioprinting Decellularized Breast Tissue for the Development of Three-Dimensional Breast Cancer Models ACS Applied Materials & Interfaces 14, 29467-29482
The tumor extracellular matrix (ECM) plays a vital role in tumor progression and drug resistance. Previous studies have shown that breast tissue-derived matrices could be an important biomaterial to recreate the complexity of the tumor ECM. We have developed a method for decellularizing and delipidating a porcine breast tissue (TDM) compatible with hydrogel formation. The addition of gelatin methacrylamide and alginate allows this TDM to be bioprinted by itself with good printability, shape fidelity, and cytocompatibility. Furthermore, this bioink has been tuned to more closely recreate the breast tumor by incorporating collagen type I (Col1). Breast cancer cells (BCCs) proliferate in both TDM bioinks forming cell clusters and spheroids. The addition of Col1 improves the printability of the bioink as well as increases BCC proliferation and reduces doxorubicin sensitivity due to a downregulation of HSP90. TDM bioinks also allow a precise three-dimensional printing of scaffolds containing BCCs and stromal cells and could be used to fabricate artificial tumors. Taken together, we have proven that these novel bioinks are good candidates for biofabricating breast cancer models.
JTD Keywords: 3d in vitro cancer model, bioprinting, breast tissue, 3d in vitro cancer model, Bioink, Bioprinting, Breast tissue, Crosstalk, Decellularization, Extracellular-matrix, Growth, Hydrogels, In-vitro, Inhibition, Mechanical-properties, Metastasis, Proliferation
Yazici, N, Opar, E, Kodal, M, Tanören, B, Sezen, M, Özkoc, G, (2022). A novel practical approach for monitoring the crosslink density of an ethylene propylene diene monomer compound: Complementary scanning acoustic microscopy and FIB-SEM-EDS analyses POLYMERS & POLYMER COMPOSITES 30, 9673911221074192
Tuning of the crosslink density (CLD) in the rubber compounds is very crucial for optimizing the physical and mechanical properties of the ultimate rubber products. Conventionally, CLD can be measured via rheological methods such as moving die rheometer (MDR), via mechanical tests such as temperature scanning stress relaxation analysis (TSSR), or via direct swelling experiments using Flory–Rehner approach. In the current study, two novel techniques, focused ion beam - scanning electron microscopy (FIB-SEM) processing, with simultaneous energy dispersive X-ray spectrometry (EDS) mapping analysis and scanning acoustic microscopy (SAM) were combined and correlated to conventional methods on a model recipe of ethylene propylene diene monomer (EPDM) compound having different sulphur contents. Depending on the applied technique, the increase in the crosslink density with sulphur content was found to be 1.7 fold for the Flory–Rehner approach and 1.2 fold for both TSSR and MDR. It is directly monitored from the FIB-SEM-EDS analysis that the sulphur distribution and agglomeration behavior increased in line with ZnO content, which is an indirect indication of the rise in crosslink density. The impedance maps of the crosslinked samples obtained through SAM analysis revealed that the impedance of the samples increased with the increasing sulphur content, which can be attributed to higher level of crosslink density. A quantified correlation was obtained between SAM images and the crosslink density of the samples. It was shown that SAM is a promising tool for practical and non-destructive analysis for determining the formation of crosslink density of the rubbers. © The Author(s) 2022.
JTD Keywords: blends, compressibility, crosslink density, cure characteristics, ethylene propylene diene monomer, focused ion beam, mechanical-properties, morphology, natural-rubber, particles, scanning acoustic microscopy, scanning electron microscopy, sulfur, thermal-stability, vulcanization, Composite soft materials, Cross-link densities, Crosslink density, Crosslinking, Density (specific gravity), Ethylene, Ethylene propylene diene monomer, Flory-rehner, Focused ion beam - scanning electron microscopy, Focused ion beam-scanning electron microscopies, Ii-vi semiconductors, Monomers, Moving die rheometers, Physical and mechanical properties, Propylene, Relaxation analysis, Rubber, Scanning acoustic microscopy, Scanning electron microscopy, Stress relaxation, Sulfur contents, Temperature scanning stress relaxations, Zinc oxide
Vilela, D, Guix, M, Parmar, J, Blanco-Blanes, A, Sánchez, S, (2022). Micromotor‐in‐Sponge Platform for Multicycle Large‐Volume Degradation of Organic Pollutants Small 18, 2107619
The presence of organic pollutants in the environment is a global threat to human health and ecosystems due to their bioaccumulation and long-term persistence. Hereby a micromotor-in-sponge concept is presented that aims not only at pollutant removal, but towards an efficient in situ degradation by exploiting the synergy between the sponge hydrophobic nature and the rapid pollutant degradation promoted by the cobalt-ferrite (CFO) micromotors embedded at the sponge's core. Such a platform allows the use of extremely low fuel concentration (0.13% H2 O2 ), as well as its reusability and easy recovery. Moreover, the authors demonstrate an efficient multicycle pollutant degradation and treatment of large volumes (1 L in 15 min) by using multiple sponges. Such a fast degradation process is due to the CFO bubble-propulsion motion mechanism, which induces both an enhanced fluid mixing within the sponge and an outward flow that allows a rapid fluid exchange. Also, the magnetic control of the system is demonstrated, guiding the sponge position during the degradation process. The micromotor-in-sponge configuration can be extrapolated to other catalytic micromotors, establishing an alternative platform for an easier implementation and recovery of micromotors in real environmental applications.© 2022 Wiley-VCH GmbH.
JTD Keywords: effective removal, fabrication, microbots, microjets, organic pollutants, propelled micromotors, self-propelled micromotors, sponges, water treatment, Oil-water separation, Organic pollutants, Water treatment
Raymond, Y, Lehmann, C, Thorel, E, Benitez, R, Riveiro, A, Pou, J, Manzanares, MC, Franch, J, Canal, C, Ginebra, MP, (2022). 3D printing with star-shaped strands: A new approach to enhance in vivo bone regeneration BIOMATERIALS ADVANCES 137, 212807
Concave surfaces have shown to promote bone regeneration in vivo. However, bone scaffolds obtained by direct ink writing, one of the most promising approaches for the fabrication of personalized bone grafts, consist mostly of convex surfaces, since they are obtained by microextrusion of cylindrical strands. By modifying the geometry of the nozzle, it is possible to print 3D structures composed of non-cylindrical strands and favor the presence of concave surfaces. In this work, we compare the in vivo performance of 3D-printed calcium phosphate scaffolds with either conventional cylindrical strands or star-shaped strands, in a rabbit femoral condyle model. Mono cortical defects, drilled in contralateral positions, are randomly grafted with the two scaffold configurations, with identical composition. The samples are explanted eight weeks post-surgery and assessed by ??-CT and resin embedded histological observations. The results reveal that the scaffolds containing star-shaped strands have better osteoconductive properties, guiding the newly formed bone faster towards the core of the scaffolds, and enhance bone regeneration, although the increase is not statistically significant (p > 0.05). This new approach represents a turning point towards the optimization of pore shape in 3D-printed bone grafts, further boosting the possibilities that direct ink writing technology offers for patient-specific applications.
JTD Keywords: 3d printing, biomimetic calcium phosphate, bone regeneration, in vivo, pore architecture, 3d printing, Architecture, Biomimetic calcium phosphate, Bone regeneration, Calcium-phosphate scaffolds, Geometry, Growth, Implants, In vivo, Induction, Microporosity, Osteoinduction, Pore architecture, Scaffold, Surfaces, Tissue
Mir, M, Palma-Florez, S, Lagunas, A, López-Martínez, MJ, Samitier, J, (2022). Biosensors Integration in Blood-Brain Barrier-on-a-Chip: Emerging Platform for Monitoring Neurodegenerative Diseases ACS Sensors 7, 1237-1247
Over the most recent decades, the development of new biological platforms to study disease progression and drug efficacy has been of great interest due to the high increase in the rate of neurodegenerative diseases (NDDs). Therefore, blood-brain barrier (BBB) as an organ-on-a-chip (OoC) platform to mimic brain-barrier performance could offer a deeper understanding of NDDs as well as a very valuable tool for drug permeability testing for new treatments. A very attractive improvement of BBB-oC technology is the integration of detection systems to provide continuous monitoring of biomarkers in real time and a fully automated analysis of drug permeably, rendering more efficient platforms for commercialization. In this Perspective, an overview of the main BBB-oC configurations is introduced and a critical vision of the BBB-oC platforms integrating electronic read out systems is detailed, indicating the strengths and weaknesses of current devices, proposing the great potential for biosensors integration in BBB-oC. In this direction, we name potential biomarkers to monitor the evolution of NDDs related to the BBB and/or drug cytotoxicity using biosensor technology in BBB-oC.
JTD Keywords: biosensors, blood−brain barrier (bbb), neurodegenerative diseases (ndds), organ-on-a-chip (ooc), Bbb, Biosensors, Blood-brain barrier (bbb), Electrical-resistance, Electrochemical biosensors, Endothelial-cells, In-vitro model, Matrix metalloproteinases, Mechanisms, Neurodegenerative diseases (ndds), Organ-on-a-chip (ooc), Permeability, Stress, Transendothelial electrical resistance (teer), Transepithelial, Transepithelial/transendothelial electrical resistance (teer), Transport
Rätze, MAK, Koorman, T, Sijnesael, T, Bassey-Archibong, B, van de Ven, R, Enserink, L, Visser, D, Jaksani, S, Viciano, I, Bakker, ERM, Richard, F, Tutt, A, O'Leary, L, Fitzpatrick, A, Roca-Cusachs, P, van Diest, PJ, Desmedt, C, Daniel, JM, Isacke, CM, Derksen, PWB, (2022). Loss of E-cadherin leads to Id2-dependent inhibition of cell cycle progression in metastatic lobular breast cancer ONCOGENE 41, 2932-2944
Invasive lobular breast carcinoma (ILC) is characterized by proliferative indolence and long-term latency relapses. This study aimed to identify how disseminating ILC cells control the balance between quiescence and cell cycle re-entry. In the absence of anchorage, ILC cells undergo a sustained cell cycle arrest in G0/G1 while maintaining viability. From the genes that are upregulated in anchorage independent ILC cells, we selected Inhibitor of DNA binding 2 (Id2), a mediator of cell cycle progression. Using loss-of-function experiments, we demonstrate that Id2 is essential for anchorage independent survival (anoikis resistance) in vitro and lung colonization in mice. Importantly, we find that under anchorage independent conditions, E-cadherin loss promotes expression of Id2 in multiple mouse and (organotypic) human models of ILC, an event that is caused by a direct p120-catenin/Kaiso-dependent transcriptional de-repression of the canonical Kaiso binding sequence TCCTGCNA. Conversely, stable inducible restoration of E-cadherin expression in the ILC cell line SUM44PE inhibits Id2 expression and anoikis resistance. We show evidence that Id2 accumulates in the cytosol, where it induces a sustained and CDK4/6-dependent G0/G1 cell cycle arrest through interaction with hypo-phosphorylated Rb. Finally, we find that Id2 is indeed enriched in ILC when compared to other breast cancers, and confirm cytosolic Id2 protein expression in primary ILC samples. In sum, we have linked mutational inactivation of E-cadherin to direct inhibition of cell cycle progression. Our work indicates that loss of E-cadherin and subsequent expression of Id2 drive indolence and dissemination of ILC. As such, E-cadherin and Id2 are promising candidates to stratify low and intermediate grade invasive breast cancers for the use of clinical cell cycle intervention drugs.
JTD Keywords: anoikis resistance, carcinoma, d1, differentiation, gene-expression, growth, id2, proliferation, repression, Mammary epithelial-cells
Lopez-Mengual, A, Segura-Feliu, M, Sunyer, R, Sanz-Fraile, H, Otero, J, Mesquida-Veny, F, Gil, V, Hervera, A, Ferrer, I, Soriano, J, Trepat, X, Farre, R, Navajas, D, del Rio, JA, (2022). Involvement of Mechanical Cues in the Migration of Cajal-Retzius Cells in the Marginal Zone During Neocortical Development Frontiers in Cell and Developmental Biology 10, 886110
Emerging evidence points to coordinated action of chemical and mechanical cues during brain development. At early stages of neocortical development, angiogenic factors and chemokines such as CXCL12, ephrins, and semaphorins assume crucial roles in orchestrating neuronal migration and axon elongation of postmitotic neurons. Here we explore the intrinsic mechanical properties of the developing marginal zone of the pallium in the migratory pathways and brain distribution of the pioneer Cajal-Retzius cells. These neurons are generated in several proliferative regions in the developing brain (e.g., the cortical hem and the pallial subpallial boundary) and migrate tangentially in the preplate/marginal zone covering the upper portion of the developing cortex. These cells play crucial roles in correct neocortical layer formation by secreting several molecules such as Reelin. Our results indicate that the motogenic properties of Cajal-Retzius cells and their perinatal distribution in the marginal zone are modulated by both chemical and mechanical factors, by the specific mechanical properties of Cajal-Retzius cells, and by the differential stiffness of the migratory routes. Indeed, cells originating in the cortical hem display higher migratory capacities than those generated in the pallial subpallial boundary which may be involved in the differential distribution of these cells in the dorsal-lateral axis in the developing marginal zone.
JTD Keywords: atomic force microscopy, cajal-retzius cells, cortical development, marginal zone, mechanical cues, Atomic force microscopy, Cajal-retzius cells, Central-nervous-system, Cortical development, Cortical hem, Developing cerebral-cortex, Expression, Growth, Marginal zone, Mechanical cues, Mouse, Neuronal migration, Nogo receptor, Olfactory ensheathing cells, Tangential migration, Traction force microscopy
Noguchi, H, Tozzi, C, Arroyo, M, (2022). Binding of anisotropic curvature-inducing proteins onto membrane tubes Soft Matter 18, 3384-3394
Montero, J, Haq, R, (2022). Adapted to Survive: Targeting Cancer Cells with BH3 Mimetics Cancer Discovery 12, 1217-1232
A hallmark of cancer is cell death evasion, underlying suboptimal responses to chemotherapy, targeted agents, and immunotherapies. The approval of the anti apoptotic BCL2 antagonist venetoclax has fi nally validated the potential of targeting apoptotic pathways in patients with cancer. Nevertheless, pharmacologic modulators of cell death have shown markedly varied responses in preclinical and clinical studies. Here, we review emerging concepts in the use of this class of therapies. Building on these observations, we propose that treatment-induced changes in apoptotic dependency, rather than pretreatment dependencies, will need to be recognized and targeted to realize the precise deployment of these new pharmacologic agents. Signifi cance: Targeting antiapoptotic family members has proven effi cacious and tolerable in some cancers, but responses are infrequent, particularly for patients with solid tumors. Biomarkers to aid patient selection have been lacking. Precision functional approaches that overcome adaptive resistance to these compounds could drive durable responses to chemotherapy, targeted therapy, and immunotherapies.
JTD Keywords: Anti-apoptotic mcl-1, Bcl-x-l, Bim expression, Chemotherapy sensitivity, Combination strategies, Family proteins, Multiple-myeloma, Oblimersen sodium, Phase-i, Venetoclax resistance
Marti, D, Martin-Martinez, E, Torras, J, Betran, O, Turon, P, Aleman, C, (2022). In silico study of substrate chemistry effect on the tethering of engineered antibodies for SARS-CoV-2 detection: Amorphous silica vs gold COLLOIDS AND SURFACES B-BIOINTERFACES 213, 112400
The influence of the properties of different solid substrates on the tethering of two antibodies, IgG1-CR3022 and IgG1-S309, which were specifically engineered for the detection of SARS-CoV-2, has been examined at the molecular level using conventional and accelerated Molecular Dynamics (cMD and aMD, respectively). Two surfaces with very different properties and widely used in immunosensors for diagnosis, amorphous silica and the most stable facet of the face-centered cubic gold structure, have been considered. The effects of such surfaces on the structure and orientation of the immobilized antibodies have been determined by quantifying the tilt and hinge angles that describe the orientation and shape of the antibody, respectively, and the dihedrals that measure the relative position of the antibody arms with respect to the surface. Results show that the interactions with amorphous silica, which are mainly electrostatic due to the charged nature of the surface, help to preserve the orientation and structure of the antibodies, especially of the IgG1-CR3022, indicating that the primary sequence of those antibodies also plays some role. Instead, short-range van der Waals interactions with the inert gold surface cause a higher degree tilting and fraying of the antibodies with respect to amorphous silica. The interactions between the antibodies and the surface also affect the correlation among the different angles and dihedrals, which increases with their strength. Overall, results explain why amorphous silica substrates are frequently used to immobilize antibodies in immunosensors. © 2022 The Authors
JTD Keywords: amorphous silica, antibody immobilization, enzyme, gol d, gold, immobilization, immunosensor, molecu l a r dynamics, molecular dynamics, protein adsorption, sars-cov-2 immunosensor, simulations, spike protein, surface interactions, target, vaccine, Amorphous silica, Antibodies, Antibody engineering, Antibody immobilization, Antibody structure, Article, Chemical detection, Computer model, Controlled study, Dihedral angle, Gold, In-silico, Molecular dynamics, Molecular levels, Molecular-dynamics, Nonhuman, Property, Sars, Sars-cov-2 immunosensor, Severe acute respiratory syndrome coronavirus 2, Silica, Silico studies, Silicon dioxide, Solid substrates, Structure analysis, Substrate chemistry, Substrates, Van der waals forces, Virus detection
Tas, B, Kalk, NJ, Lozano-García, M, Rafferty, GF, Cho, PSP, Kelleher, M, Moxham, J, Strang, J, Jolley, CJ, (2022). Undetected Respiratory Depression in People with Opioid Use Disorder DRUG AND ALCOHOL DEPENDENCE 234, 109401
Background: Opioid-related deaths are increasing globally. Respiratory complications of opioid use and underlying respiratory disease in people with Opioid Use Disorder (OUD) are potential contributory factors. Individual variation in susceptibility to overdose is, however, incompletely understood. This study investigated the prevalence of respiratory depression (RD) in OUD treatment and compared this to patients with chronic obstructive pulmonary disease (COPD) of equivalent severity. We also explored the contribution of opioid agonist treatment (OAT) dosage, and type, to the prevalence of RD. Methods: There were four groups of participants: 1) OUD plus COPD (‘OUD-COPD’, n = 13); 2) OUD without COPD (‘OUD’, n = 7); 3) opioid-naïve COPD patients (‘COPD'n = 13); 4) healthy controls (‘HC'n = 7). Physiological indices, including pulse oximetry (SpO2%), end-tidal CO2 (ETCO2), transcutaneous CO2 (TcCO2), respiratory airflow and second intercostal space parasternal muscle electromyography (EMGpara), were recorded continuously over 40 min whilst awake at rest. Significant RD was defined as: SpO2%< 90% for > 10 s, ETCO2 per breath > 6.6 kPa, TcCO2 overall mean > 6 kPa, respiratory pauses > 10 s Results: At least one indicator was observed in every participant with OUD (n = 20). This compared to RD episode occurrence in only 2/7 HC and 2/13 COPD participants (p < 0.05,Fisher's exact test). The occurrence of RD was similar in OUD participants prescribed methadone (n = 6) compared to those prescribed buprenorphine (n = 12). Conclusions: Undetected RD is common in OUD cohorts receiving OAT and is significantly more severe than in opioid-naïve controls. RD can be assessed using simple objective measures. Further studies are required to determine the association between RD and overdose risk. © 2022 Elsevier B.V.
JTD Keywords: buprenorphine, comorbidity, deaths, drive, heroin, lung disease, opioid substitution treatment, opioids, overdose, pulse oximetry, respiratory depression, risk, Acute exacerbations, Comorbidity, Lung disease, Opioid substitution treatment, Opioids, Overdose, Respiratory depression
Madrid-Gambin, F, Gomez-Gomez, A, Busquets-Garcia, A, Haro, N, Marco, S, Mason, NL, Reckweg, JT, Mallaroni, P, Kloft, L, van Oorsouw, K, Toennes, SW, de la Torre, R, Ramaekers, JG, Van Oorsouw, K, Toennes, SW, De la Torre, R, Ramaekers, JG, Pozo, OJ, (2022). Metabolomics and integrated network analysis reveal roles of endocannabinoids and large neutral amino acid balance in the ayahuasca experience BIOMEDICINE & PHARMACOTHERAPY 149, 112845
There has been a renewed interest in the potential use of psychedelics for the treatment of psychiatric conditions. Nevertheless, little is known about the mechanism of action and molecular pathways influenced by ayahuasca use in humans. Therefore, for the first time, our study aims to investigate the human metabolomics signature after consumption of a psychedelic, ayahuasca, and its connection with both the psychedelic-induced subjective effects and the plasma concentrations of ayahuasca alkaloids. Plasma samples of 23 individuals were collected both before and after ayahuasca consumption. Samples were analysed through targeted metabolomics and further integrated with subjective ratings of the ayahuasca experience (i.e., using the 5-Dimension Altered States of Consciousness Rating Scale [ASC]), and plasma ayahuasca-alkaloids using integrated network analysis. Metabolic pathways enrichment analysis using diffusion algorithms for specific KEGG modules was performed on the metabolic output. Compared to baseline, the consumption of ayahuasca increased N-acyl-ethanolamine endocannabinoids, decreased 2-acyl-glycerol endocannabinoids, and altered several large-neutral amino acids (LNAAs). Integrated network results indicated that most of the LNAAs were inversely associated with 9 out of the 11 subscales of the ASC, except for tryptophan which was positively associated. Several endocannabinoids and hexosylceramides were directly associated with the ayahuasca alkaloids. Enrichment analysis confirmed dysregulation in several pathways involved in neurotransmission such as serotonin and dopamine synthesis. In conclusion, a crosstalk between the circulating LNAAs and the subjective effects is suggested, which is independent of the alkaloid concentrations and provides insights into the specific metabolic fingerprint and mechanism of action underlying ayahuasca experiences. © 2022 The Authors
JTD Keywords: anxiety, ayahuasca, dimethyltryptamine, integrative network analysis, metabolism, metabolomics, psychedelics, rats, subjective effects, system, tryptophan, Ayahuasca, Dimethyltryptamine, Integrative network analysis, Metabolomics, Psychedelics, Serotonin 5-ht2a, Subjective effects
Karkali, K, Tiwari, P, Singh, A, Tlili, S, Jorba, I, Navajas, D, Munoz, JJ, Saunders, TE, Martin-Blanco, E, (2022). Condensation of the Drosophila nerve cord is oscillatory and depends on coordinated mechanical interactions DEVELOPMENTAL CELL 57, 867-+
During development, organs reach precise shapes and sizes. Organ morphology is not always obtained through growth; a classic counterexample is the condensation of the nervous system during Drosophila embryogenesis. The mechanics underlying such condensation remain poorly understood. Here, we characterize the condensation of the embryonic ventral nerve cord (VNC) at both subcellular and tissue scales. This analysis reveals that condensation is not a unidirectional continuous process but instead occurs through oscillatory contractions. The VNC mechanical properties spatially and temporally vary, and forces along its longitudinal axis are spatially heterogeneous. We demonstrate that the process of VNC condensation is dependent on the coordinated mechanical activities of neurons and glia. These outcomes are consistent with a viscoelastic model of condensation, which incorporates time delays and effective frictional interactions. In summary, we have defined the progressive mechanics driving VNC condensation, providing insights into how a highly viscous tissue can autonomously change shape and size.
JTD Keywords: actomyosin, central nervous system, drosophila, glia, mechanics, morphogenesis, neuron, ventral nerve cord, Actomyosin, Animals, Central nervous system, Collagen-iv, Contraction, Drosophila, Embryonic development, Forces, Gene, Glia, Glial-cells, Mechanics, Migration, Morphogenesis, Neuroglia, Neuron, Neurons, Quantification, System, Tissue, Ventral nerve cord, Viscolelastic model
Schieber, R, Mas-Moruno, C, Lasserre, F, Roa, JJ, Ginebra, MP, Mücklich, F, Pegueroles, M, (2022). Effectiveness of Direct Laser Interference Patterning and Peptide Immobilization on Endothelial Cell Migration for Cardio-Vascular Applications: An In Vitro Study Nanomaterials 12, 1217
Endothelial coverage of an exposed cardiovascular stent surface leads to the occurrence of restenosis and late-stent thrombosis several months after implantation. To overcome this difficulty, modification of stent surfaces with topographical or biochemical features may be performed to increase endothelial cells’ (ECs) adhesion and/or migration. This work combines both strategies on cobalt-chromium (CoCr) alloy and studies the potential synergistic effect of linear patterned surfaces that are obtained by direct laser interference patterning (DLIP), coupled with the use of Arg-Gly-Asp (RGD) and Tyr-Ile-Gly-Ser-Arg (YIGSR) peptides. An extensive characterization of the modified surfaces was performed by using AFM, XPS, surface charge, electrochemical analysis and fluorescent methods. The biological response was studied in terms of EC adhesion, migration and proliferation assays. CoCr surfaces were successfully patterned with a periodicity of 10 µm and two different depths, D (≈79 and 762 nm). RGD and YIGSR were immobilized on the surfaces by CPTES silanization. Early EC adhesion was increased on the peptide-functionalized surfaces, especially for YIGSR compared to RGD. High-depth patterns generated 80% of ECs’ alignment within the topographical lines and enhanced EC migration. It is noteworthy that the combined use of the two strategies synergistically accelerated the ECs’ migration and proliferation, proving the potential of this strategy to enhance stent endothelialization.
JTD Keywords: adhesion, bare-metal, biofunctionalization, biomaterials, cell adhesive peptides, cobalt-chromium alloy, direct laser interference patterning (dlip), endothelial cell migration, functionalization, matrix, proliferation, selectivity, shear-stress, surfaces, Biofunctionalization, Cell adhesive peptides, Cobalt-chromium alloy, Direct laser interference patterning (dlip), Drug-eluting stents, Endothelial cell migration
Sans, J, Arnau, M, Sanz, V, Turon, P, Alemán, C, (2022). Hydroxyapatite-based biphasic catalysts with plasticity properties and its potential in carbon dioxide fixation CHEMICAL ENGINEERING JOURNAL 433, 133512
The design of catalysts with controlled selectivity at will, also known as catalytic plasticity, is a very attractive approach for the recycling of carbon dioxide (CO2). In this work, we study how catalytically active hydroxyapatite (HAp) and brushite (Bru) interact synergistically, allowing the production of formic acid or acetic acid depending on the HAp/Bru ratio in the catalyst. Raman, wide angle X-ray scattering, X-ray photoelectron spectroscopy, scanning electron microscopy and electrochemical impedance spectroscopy studies, combined with an exhaustive revision of the crystalline structure of the catalyst at the atomic level, allowed to discern how the Bru phase can be generated and stabilized at high temperatures. Results clearly indicate that the presence of OH– groups to maintain the crystalline structural integrity in conjunction with Ca2+ ions less bonded to the lattice fixate carbon into C1, C2 and C3 molecules from CO2 and allow the evolution from formic to acetic acid and acetone. In this way, the plasticity of the HAp-Bru system is demonstrated, representing a promising green alternative to the conventional metal-based electrocatalysts used for CO2 fixation. Thus, the fact that no electric voltage is necessary for the CO2 reduction has a very favorable impact in the final energetic net balance of the carbon fixation reaction. © 2021
JTD Keywords: ethanol production & nbsp
, brushite, co2 reduction, conversion, electrocatalytic reduction, electrode, formate, heterogeneous catalysis & nbsp, hydrogen evolution, insights, monetite, polarized hydroxyapatite,
,
Acetic acid,
Acetone,
Biphasic catalyst,
Brushite,
Calcium phosphate,
Carbon dioxide,
Carbon dioxide fixation,
Catalysis,
Catalyst selectivity,
Co 2 reduction,
Co2 reduction,
Electrocatalysts,
Electrochemical impedance spectroscopy,
Electrochemical reduction,
Electrochemical-impedance spectroscopies,
Ethanol production,
Formic acid,
Heterogeneous catalysis,
Hydroxyapatite,
Ph,
Polarized hydroxyapatite,
Property,
Reduction,
Scanning electron microscopy,
Temperature programmed desorption,
Wide angle x-ray scattering,
X ray photoelectron spectroscopy,
X ray scattering,
]+ catalyst
Marte, L, Boronat, S, Barrios, R, Barcons-Simon, A, Bolognesi, B, Cabrera, M, Ayté, J, Hidalgo, E, (2022). Expression of Huntingtin and TDP-43 Derivatives in Fission Yeast Can Cause Both Beneficial and Toxic Effects INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 23, 3950
Many neurodegenerative disorders display protein aggregation as a hallmark, Huntingtin and TDP-43 aggregates being characteristic of Huntington disease and amyotrophic lateral sclerosis, respectively. However, whether these aggregates cause the diseases, are secondary by-products, or even have protective effects, is a matter of debate. Mutations in both human proteins can modulate the structure, number and type of aggregates, as well as their toxicity. To study the role of protein aggregates in cellular fitness, we have expressed in a highly tractable unicellular model different variants of Huntingtin and TDP-43. They each display specific patterns of aggregation and toxicity, even though in both cases proteins have to be very highly expressed to affect cell fitness. The aggregation properties of Huntingtin, but not of TDP-43, are affected by chaperones such as Hsp104 and the Hsp40 couple Mas5, suggesting that the TDP-43, but not Huntingtin, derivatives have intrinsic aggregation propensity. Importantly, expression of the aggregating form of Huntingtin causes a significant extension of fission yeast lifespan, probably as a consequence of kidnapping chaperones required for maintaining stress responses off. Our study demonstrates that in general these prion-like proteins do not cause toxicity under normal conditions, and in fact they can protect cells through indirect mechanisms which up-regulate cellular defense pathways. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
JTD Keywords: aggregation, antioxidant, degradation, features, fission yeast, gene, huntingtin, neurodegenerative diseases, pap1, polyglutamine toxicity, protein aggregation, proteins, stress, tdp-43, Amyotrophic-lateral-sclerosis, Chaperone, Chemistry, Dna binding protein, Dna-binding proteins, Fission yeast, Genetics, Human, Humans, Huntingtin, Metabolism, Molecular chaperones, Neurodegenerative diseases, Prion, Prions, Protein aggregate, Protein aggregates, Protein aggregation, Schizosaccharomyces, Tdp-43
Bonilla-Pons, SA, Nakagawa, S, Bahima, EG, Fernández-Blanco, A, Pesaresi, M, D'Antin, JC, Sebastian-Perez, R, Greco, D, Domínguez-Sala, E, Gómez-Riera, R, Compte, RIB, Dierssen, M, Pulido, NM, Cosma, MP, (2022). Müller glia fused with adult stem cells undergo neural differentiation in human retinal models EBioMedicine 77, 103914
Visual impairments are a critical medical hurdle to be addressed in modern society. Müller glia (MG) have regenerative potential in the retina in lower vertebrates, but not in mammals. However, in mice, in vivo cell fusion between MG and adult stem cells forms hybrids that can partially regenerate ablated neurons.We used organotypic cultures of human retina and preparations of dissociated cells to test the hypothesis that cell fusion between human MG and adult stem cells can induce neuronal regeneration in human systems. Moreover, we established a microinjection system for transplanting human retinal organoids to demonstrate hybrid differentiation.We first found that cell fusion occurs between MG and adult stem cells, in organotypic cultures of human retina as well as in cell cultures. Next, we showed that the resulting hybrids can differentiate and acquire a proto-neural electrophysiology profile when the Wnt/beta-catenin pathway is activated in the adult stem cells prior fusion. Finally, we demonstrated the engraftment and differentiation of these hybrids into human retinal organoids.We show fusion between human MG and adult stem cells, and demonstrate that the resulting hybrid cells can differentiate towards neural fate in human model systems. Our results suggest that cell fusion-mediated therapy is a potential regenerative approach for treating human retinal dystrophies.This work was supported by La Caixa Health (HR17-00231), Velux Stiftung (976a) and the Ministerio de Ciencia e Innovación, (BFU2017-86760-P) (AEI/FEDER, UE), AGAUR (2017 SGR 689, 2017 SGR 926).Published by Elsevier B.V.
JTD Keywords: cell fusion, expression, fusion, ganglion-cells, in-vitro, mouse, müller glia, neural differentiation, organoids, regeneration, retina regeneration, stem cells, stromal cells, transplantation, 4',6 diamidino 2 phenylindole, 5' nucleotidase, Agarose, Alcohol, Arpe-19 cell line, Article, Beta catenin, Beta tubulin, Bone-marrow-cells, Bromophenol blue, Buffer, Calcium cell level, Calcium phosphate, Calretinin, Canonical wnt signaling, Cd34 antigen, Cell culture, Cell fusion, Cell viability, Coculture, Complementary dna, Confocal microscopy, Cornea transplantation, Cryopreservation, Cryoprotection, Crystal structure, Current clamp technique, Dimethyl sulfoxide, Dodecyl sulfate sodium, Edetic acid, Electrophysiology, Endoglin, Fetal bovine serum, Fibroblast growth factor 2, Flow cytometry, Fluorescence activated cell sorting, Fluorescence intensity, Glyceraldehyde 3 phosphate dehydrogenase, Glycerol, Glycine, Hoe 33342, Immunofluorescence, Immunohistochemistry, Incubation time, Interleukin 1beta, Lentivirus vector, Matrigel, Mercaptoethanol, Microinjection, Mueller cell, Müller glia, N methyl dextro aspartic acid, Nerve cell differentiation, Neural differentiation, Nitrogen, Nonhuman, Organoids, Paraffin, Paraffin embedding, Paraformaldehyde, Patch clamp technique, Penicillin derivative, Phenolsulfonphthalein, Phenotype, Phosphate buffered saline, Phosphoprotein phosphatase inhibitor, Polyacrylamide gel electrophoresis, Potassium chloride, Povidone iodine, Promoter region, Proteinase inhibitor, Real time polymerase chain reaction, Receptor type tyrosine protein phosphatase c, Restriction endonuclease, Retina, Retina dystrophy, Retina regeneration, Retinol, Rhodopsin, Rna extraction, Stem cell, Stem cells, Subcutaneous fat, Tunel assay, Visual impairment, Western blotting
Dias, JMS, Estima, D, Punte, H, Klingner, A, Marques, L, Magdanz, V, Khalil, ISM, (2022). Modeling and Characterization of the Passive Bending Stiffness of Nanoparticle-Coated Sperm Cells using Magnetic Excitation Advanced Theory And Simulations 5, 2100438
Of all the various locomotion strategies in low- (Formula presented.), traveling-wave propulsion methods with an elastic tail are preferred because they can be developed using simple designs and fabrication procedures. The only intrinsic property of the elastic tail that governs the form and rate of wave propagation along its length is the bending stiffness. Such traveling wave motion is performed by spermatozoa, which possess a tail that is characterized by intrinsic variable stiffness along its length. In this paper, the passive bending stiffness of the magnetic nanoparticle-coated flagella of bull sperm cells is measured using a contactless electromagnetic-based excitation method. Numerical elasto-hydrodynamic models are first developed to predict the magnetic excitation and relaxation of nanoparticle-coated nonuniform flagella. Then solutions are provided for various groups of nonuniform flagella with disparate nanoparticle coatings that relate their bending stiffness to their decay rate after the magnetic field is removed and the flagellum restores its original configuration. The numerical models are verified experimentally, and capture the effect of the nanoparticle coating on the bending stiffness. It is also shown that electrostatic self-assembly enables arbitrarily magnetizable cellular segments with variable stiffness along the flagellum. The bending stiffness is found to depend on the number and location of the magnetized cellular segments. © 2022 The Authors. Advanced Theory and Simulations published by Wiley-VCH GmbH.
JTD Keywords: cilia, flagella, flagellar propulsion, low reynolds numbers, magnetic, microswimmers, passive, sperm cell, Bending stiffness, Cells, Cellulars, Coatings, Decay (organic), Electric excitation, Excited states, Flagellar propulsion, Locomotion strategies, Low reynolds numbers, Magnetic, Magnetic excitations, Nanoparticle coatings, Passive, Propulsion methods, Self assembly, Simple++, Sperm cell, Sperm cells, Stiffness, Travelling waves, Variable stiffness, Wave propagation, Younǵs modulus
Dhiman, S, Andrian, T, Gonzalez, BS, Tholen, MME, Wang, YY, Albertazzi, L, (2022). Can super-resolution microscopy become a standard characterization technique for materials chemistry? Chemical Science 13, 2152-2166
The characterization of newly synthesized materials is a cornerstone of all chemistry and nanotechnology laboratories. For this purpose, a wide array of analytical techniques have been standardized and are used routinely by laboratories across the globe. With these methods we can understand the structure, dynamics and function of novel molecular architectures and their relations with the desired performance, guiding the development of the next generation of materials. Moreover, one of the challenges in materials chemistry is the lack of reproducibility due to improper publishing of the sample preparation protocol. In this context, the recent adoption of the reporting standard MIRIBEL (Minimum Information Reporting in Bio–Nano Experimental Literature) for material characterization and details of experimental protocols aims to provide complete, reproducible and reliable sample preparation for the scientific community. Thus, MIRIBEL should be immediately adopted in publications by scientific journals to overcome this challenge. Besides current standard spectroscopy and microscopy techniques, there is a constant development of novel technologies that aim to help chemists unveil the structure of complex materials. Among them super-resolution microscopy (SRM), an optical technique that bypasses the diffraction limit of light, has facilitated the study of synthetic materials with multicolor ability and minimal invasiveness at nanometric resolution. Although still in its infancy, the potential of SRM to unveil the structure, dynamics and function of complex synthetic architectures has been highlighted in pioneering reports during the last few years. Currently, SRM is a sophisticated technique with many challenges in sample preparation, data analysis, environmental control and automation, and moreover the instrumentation is still expensive. Therefore, SRM is currently limited to expert users and is not implemented in characterization routines. This perspective discusses the potential of SRM to transition from a niche technique to a standard routine method for material characterization. We propose a roadmap for the necessary developments required for this purpose based on a collaborative effort from scientists and engineers across disciplines.
JTD Keywords: blinking, fluorophore, intramolecular spirocyclization, localization, nanoparticles, resolution limit, reveals, single-molecule fluorescence, stimulated-emission, Characterization techniques, Diffraction, Distributed computer systems, Environmental management, Information reporting, Material chemistry, Materials characterization, Minimum information, Optical reconstruction microscopy, Optical resolving power, Sample preparation, Structure dynamics, Structure functions, Super-resolution microscopy, Synthesized materials
Pérez-González, C, Ceada, G, Matejcic, M, Trepat, X, (2022). Digesting the mechanobiology of the intestinal epithelium CURRENT OPINION IN GENETICS & DEVELOPMENT 72, 82-90
The dizzying life of the homeostatic intestinal epithelium is governed by a complex interplay between fate, form, force and function. This interplay is beginning to be elucidated thanks to advances in intravital and ex vivo imaging, organoid culture, and biomechanical measurements. Recent discoveries have untangled the intricate organization of the forces that fold the monolayer into crypts and villi, compartmentalize cell types, direct cell migration, and regulate cell identity, proliferation and death. These findings revealed that the dynamic equilibrium of the healthy intestinal epithelium relies on its ability to precisely coordinate tractions and tensions in space and time. In this review, we discuss recent findings in intestinal mechanobiology, and highlight some of the many fascinating questions that remain to be addressed in this emerging field.Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.
JTD Keywords: crypt fission, designer matrices, differentiation, growth, gut, migration, model, scaffold, tissue mechanics, Biophysics, Cell migration, Cell movement, Cell proliferation, Ex vivo study, Human tissue, Intestinal mucosa, Intestine epithelium, Monolayer culture, Organoid, Organoids, Review, Stem-cell, Tension, Traction therapy
Raymond, Y, Johansson, L, Thorel, E, Ginebra, MP, (2022). Translation of three-dimensional printing of ceramics in bone tissue engineering and drug delivery MRS BULLETIN 47, 59-69
JTD Keywords: augmentation, calcium-phosphate, expansion, fabrication, hydroxyapatite, made artificial bones, osteogenesis, reconstruction, regeneration, 3-d printing, 3d printers, 3d printing, 3d-printing, Abstracting, Additives, Biomaterial, Bone, Bone regeneration, Bone substitution, Bone tissue engineering, Ceramic, Ceramics, Clinic, Controlled drug delivery, Personalized medicines, Surgical planning, Targeted drug delivery, Three-dimensional-printing, Tricalcium phosphate scaffolds
Pellegrini, P, Hervera, A, Varea, O, Brewer, MK, López-Soldado, I, Guitart, A, Aguilera, M, Prats, N, del Río, JA, Guinovart, JJ, Duran, J, (2022). Lack of p62 Impairs Glycogen Aggregation and Exacerbates Pathology in a Mouse Model of Myoclonic Epilepsy of Lafora MOLECULAR NEUROBIOLOGY 59, 1214-1229
Lafora disease (LD) is a fatal childhood-onset dementia characterized by the extensive accumulation of glycogen aggregates—the so-called Lafora Bodies (LBs)—in several organs. The accumulation of LBs in the brain underlies the neurological phenotype of the disease. LBs are composed of abnormal glycogen and various associated proteins, including p62, an autophagy adaptor that participates in the aggregation and clearance of misfolded proteins. To study the role of p62 in the formation of LBs and its participation in the pathology of LD, we generated a mouse model of the disease (malinKO) lacking p62. Deletion of p62 prevented LB accumulation in skeletal muscle and cardiac tissue. In the brain, the absence of p62 altered LB morphology and increased susceptibility to epilepsy. These results demonstrate that p62 participates in the formation of LBs and suggest that the sequestration of abnormal glycogen into LBs is a protective mechanism through which it reduces the deleterious consequences of its accumulation in the brain. © 2021, The Author(s).
JTD Keywords: accumulation, astrocytes, autophagy receptors, contributes, deficient mice, epilepsy, glycogen, lafora bodies, lafora disease, malin, metabolism, neurodegeneration, neuroinflammation, p62, polyglucosan bodies, temporal-lobe epilepsy, Epilepsy, Glycogen, Inclusion-body formation, Lafora bodies, Lafora disease, Malin, Neuroinflammation, P62
Sans, J, Arnau, M, Sanz, V, Turon, P, Alemán, C, (2022). Polarized Hydroxyapatite: New Insights and Future Perspectives Through Systematic Electrical Characterization at the Interface Advanced Materials Interfaces 9, 2101631
JTD Keywords: amino-acids, catalysis, dopant-free hydroxyapatite, electrical properties, electrophotosynthesis, nitrogen, thermally-stimulated polarization, Advanced materials, Biocompatibility, Biomedical applications, Brushite, Doped hydroxyapatites, Electric voltage, Electrical characterization, Electrochemical impedance spectroscopy, Equivalent circuits, Future perspectives, Highest temperature, Hydroxyapatite, Interfaces (materials), Material interfaces, Medical applications, Polarization, Polarization conditions, Surface-charges, Technological applications
Boda, SK, Aparicio, C, (2022). Dual keratinocyte-attachment and anti-inflammatory coatings for soft tissue sealing around transmucosal oral implants Biomaterials Science 10, 665-677
Unlike the attachment of soft epithelial skin tissue to penetrating solid natural structures like fingernails and teeth, sealing around percutaneous/permucosal devices such as dental implants is hindered by inflammation and epidermal down growth. Here, we employed a dual keratinocyte-adhesive peptide and anti-inflammatory biomolecule coating on titanium to promote oral epithelial tissue attachment. For minimizing inflammation-triggered epidermal down growth, we coated pristine and oxygen plasma pre-treated polished titanium (pTi) with conjugated linoleic acid (CLA). Further, in order to aid in soft tissue attachment via the formation of hemidesmosomes, adhesive structures by oral keratinocytes, we coated the anionic linoleic acid (LA) adsorbed titanium with cationic cell adhesive peptides (CAP), LamLG3, a peptide derived from Laminin 332, the major extracellular matrix component of the basement membrane in skin tissue and Net1, derived from Netrin-1, a neural chemoattractant capable of epithelial cell attachment via alpha 6 beta 4 integrins. The dual CLA-CAP coatings on pTi were characterized by X-ray photoelectron spectroscopy and dynamic water contact angle measurements. The proliferation of human oral keratinocytes (TERT-2/OKF6) was accelerated on the peptide coated titanium while also promoting the expression of Col XVII and beta-4 integrin, two markers for hemidesmosomes. Simultaneously, CLA coating suppressed the production of inducible nitric oxide synthase (anti-iNOS); a pro-inflammatory M1 marker expressed in lipopolysaccharide (LPS) stimulated murine macrophages (RAW 264.7) and elevated expression of anti-CD206, associated to an anti-inflammatory M2 macrophage phenotype. Taken together, the dual keratinocyte-adhesive peptide and anti-inflammatory biomolecule coating on titanium can help reduce inflammation and promote permucosal/peri-implant soft tissue sealing.
JTD Keywords: Adhesives, Animal, Animals, Anti-inflammatories, Anti-inflammatory agents, Antiinflammatory agent, Biomolecules, Bone, Cell adhesion, Cell-adhesives, Coatings, Conjugated linoleic acid, Conjugated linoleic-acid, Contact angle, Hemidesmosome, Hemidesmosomes, Human, Humans, Hydroxyapatite, Inflammation, Integrins, Keratinocyte, Keratinocytes, Linoleic acid, Macrophages, Mice, Mouse, Nitric oxide, Oral implants, Pathology, Peptides, Skin tissue, Soft tissue, Supplementation, Surface properties, Surface property, Tissue, Titania, Titanium, X ray photoelectron spectroscopy
Solorzano, A, Eichmann, J, Fernandez, L, Ziems, B, Jimenez-Soto, JM, Marco, S, Fonollosa, J, (2022). Early fire detection based on gas sensor arrays: Multivariate calibration and validation SENSORS AND ACTUATORS B-CHEMICAL 352, 130961
Smoldering fires are characterized by the production of early gas emissions that can include high levels of CO and Volatile Organic Compounds (VOCs) due to pyrolysis or thermal degradation. Nowadays, standalone CO sensors, smoke detectors, or a combination of these, are standard components for fire alarm systems. While gas sensor arrays together with pattern recognition techniques are a valuable alternative for early fire detection, in practice they have certain drawbacks-they can detect early gas emissions, but can show low immunity to nuisances, and sensor time drift can render calibration models obsolete. In this work, we explore the performance of a gas sensor array for detecting smoldering and plastic fires while ensuring the rejection of a set of nuisances. We conducted variety of fire and nuisance experiments in a validated standard fire room (240 m(3)). Using PLS-DA and SVM, we evaluate the performance of different multivariate calibration models for this dataset. We show that calibration models remain predictive after several months, but perfect performance is not achieved. For example, 4 months after calibration, a PLS-DA model provides 100% specificity and 85% sensitivity since the system has difficulties in detecting plastic fires, whose signatures are close to nuisance scenarios. Nevertheless, our results show that systems based on gas sensor arrays are able to provide faster fire alarm response than conventional smoke-based fire alarms. We also propose the use of small-scale fire experiments to increase the number of calibration conditions at a reduced cost. Our results show that this is an effective way to increase the performance of the model, even when evaluated on a standard fire room. Finally, the acquired datasets are made publicly available to the community (doi: 10.5281/zenodo.5643074).
JTD Keywords: Calibration, Chemical sensors, Co2, Early fire, Early fire detection, En-54, Fire alarm, Fire detection, Fire room, Fires, Gas detectors, Gas emissions, Gas sensors, Pattern recognition, Public dataset, Sensor arrays, Sensors array, Signatures, Smoke, Smoke detector, Smoke detectors, Standard fire, Standard fire room, Support vector machines, Temperature, Toxicity, Volatile organic compounds
Beltran, G, Navajas, D, García-Aznar, JM, (2022). Mechanical modeling of lung alveoli: From macroscopic behaviour to cell mechano-sensing at microscopic level Journal of the Mechanical Behavior of Biomedical Materials 126, 105043
The mechanical signals sensed by the alveolar cells through the changes in the local matrix stiffness of the extracellular matrix (ECM) are determinant for regulating cellular functions. Therefore, the study of the mechanical response of lung tissue becomes a fundamental aspect in order to further understand the mechanosensing signals perceived by the cells in the alveoli. This study is focused on the development of a finite element (FE) model of a decellularized rat lung tissue strip, which reproduces accurately the mechanical behaviour observed in the experiments by means of a tensile test. For simulating the complex structure of the lung parenchyma, which consists of a heterogeneous and non-uniform network of thin-walled alveoli, a 3D model based on a Voronoi tessellation is developed. This Voronoi-based model is considered very suitable for recreating the geometry of cellular materials with randomly distributed polygons like in the lung tissue. The material model used in the mechanical simulations of the lung tissue was characterized experimentally by means of AFM tests in order to evaluate the lung tissue stiffness on the micro scale. Thus, in this study, the micro (AFM test) and the macro scale (tensile test) mechanical behaviour are linked through the mechanical simulation with the 3D FE model based on Voronoi tessellation. Finally, a micro-mechanical FE-based model is generated from the Voronoi diagram for studying the stiffness sensed by the alveolar cells in function of two independent factors: the stretch level of the lung tissue and the geometrical position of the cells on the extracellular matrix (ECM), distinguishing between pneumocyte type I and type II. We conclude that the position of the cells within the alveolus has a great influence on the local stiffness perceived by the cells. Alveolar cells located at the corners of the alveolus, mainly type II pneumocytes, perceive a much higher stiffness than those located in the flat areas of the alveoli, which correspond to type I pneumocytes. However, the high stiffness, due to the macroscopic lung tissue stretch, affects both cells in a very similar form, thus no significant differences between them have been observed. © 2021 The Authors
JTD Keywords: rat, scaffolds, stiffness, Afm, Animal cell, Animal experiment, Animal model, Animal tissue, Article, Biological organs, Cell function, Cells, Computational geometry, Cytology, Extracellular matrices, Extracellular matrix, Extracellular-matrix, Geometry, High stiffness, Human, Lung alveolus cell type 1, Lung alveolus cell type 2, Lung parenchyma, Lung tissue, Male, Mechanical behavior, Mechanical modeling, Mechanical simulations, Mechanosensing, Model-based opc, Nonhuman, Physical model, Rat, Rigidity, Stiffness, Stiffness matrix, Tensile testing, Thin walled structures, Three dimensional finite element analysis, Tissue, Type ii, Voronoi tessellations
Martí, D, Alemán, C, Ainsley, J, Ahumada, O, Torras, J, (2022). IgG1-b12–HIV-gp120 Interface in Solution: A Computational Study Journal of Chemical Information and Modeling 62, 359-371
The use of broadly neutralizing antibodies against human immunodeficiency virus type 1 (HIV-1) has been shown to be a promising therapeutic modality in the prevention of HIV infection. Understanding the b12-gp120 binding mechanism under physiological conditions may assist the development of more broadly effective antibodies. In this work, the main conformations and interactions between the receptor-binding domain (RBD) of spike glycoprotein gp120 of HIV-1 and the IgG1-b12 mAb are studied. Accelerated molecular dynamics (aMD) and ab initio hybrid molecular dynamics have been combined to determine the most persistent interactions between the most populated conformations of the antibody-antigen complex under physiological conditions. The results show the most persistent receptor-binding mapping in the conformations of the antibody-antigen interface in solution. The binding-free-energy decomposition reveals a small enhancement in the contribution played by the CDR-H3 region to the b12-gp120 interface compared to the crystal structure.
JTD Keywords: antibody, complex, functionals, gp120 envelope glycoprotein, hiv, immunodeficiency-virus, noncovalent interactions, simulations, software integration, Ab initio, Accelerated molecular dynamics, Accelerated molecular-dynamics, Antibodies, Antigens, Binding energy, Binding mechanisms, Computational studies, Crystal structure, Diseases, Free energy, Hiv infection, Human immunodeficiency virus, Molecular dynamics, Neutralizing antibodies, Physiological condition, Physiology, Receptor-binding domains, Therapeutic modality, Viruses
Gawish, R, Starkl, P, Pimenov, L, Hladik, A, Lakovits, K, Oberndorfer, F, Cronin, SJF, Ohradanova-Repic, A, Wirnsberger, G, Agerer, B, Endler, L, Capraz, T, Perthold, JW, Cikes, D, Koglgruber, R, Hagelkruys, A, Montserrat, N, Mirazimi, A, Boon, L, Stockinger, H, Bergthaler, A, Oostenbrink, C, Penninger, JM, Knapp, S, (2022). ACE2 is the critical in vivo receptor for SARS-CoV-2 in a novel COVID-19 mouse model with TNF-and IFNy-driven immunopathology eLife 11, e74623
Despite tremendous progress in the understanding of COVID-19, mechanistic insight into immunological, disease-driving factors remains limited. We generated maVie16, a mouse-adapted SARS-CoV-2, by serial passaging of a human isolate. In silico modeling revealed how only three Spike mutations of maVie16 enhanced interaction with murine ACE2. maVie16 induced profound pathology in BALB/c and C57BL/6 mice, and the resulting mouse COVID-19 (mCOVID-19) replicated critical aspects of human disease, including early lymphopenia, pulmonary immune cell infiltration, pneumonia, and specific adaptive immunity. Inhibition of the proinflammatory cyto-kines IFN? and TNF substantially reduced immunopathology. Importantly, genetic ACE2-deficiency completely prevented mCOVID-19 development. Finally, inhalation therapy with recombinant ACE2 fully protected mice from mCOVID-19, revealing a novel and efficient treatment. Thus, we here present maVie16 as a new tool to model COVID-19 for the discovery of new therapies and show that disease severity is determined by cytokine-driven immunopathology and critically dependent on ACE2 in vivo. © Gawish et al.
JTD Keywords: covid-19 mouse model, covid-19 therapy, cytokine storm, immunology, inflammation, mavie16, mouse, mouse-adapted sars-cov-2, program, recombinant soluble ace2, tmprss2, Adaptive immunity, Angiotensin converting enzyme 2, Angiotensin-converting enzyme 2, Animal, Animal cell, Animal experiment, Animal model, Animal tissue, Animals, Apoptosis, Article, Bagg albino mouse, Breathing rate, Bronchoalveolar lavage fluid, C57bl mouse, Cell composition, Cell infiltration, Controlled study, Coronavirus disease 2019, Coronavirus spike glycoprotein, Covid-19, Cytokeratin 18, Cytokine production, Dipeptidyl carboxypeptidase, Disease model, Disease models, animal, Disease severity, Drosophila-melanogaster, Enzyme linked immunosorbent assay, Expression vector, Flow cytometry, Gamma interferon, Gene editing, Gene expression, Gene mutation, Genetic engineering, Genetics, Glycosylation, High mobility group b1 protein, Histology, Histopathology, Immune response, Immunocompetent cell, Immunology, Immunopathology, Interferon-gamma, Interleukin 2, Metabolism, Mice, inbred balb c, Mice, inbred c57bl, Mouse-adapted sars-cov-2, Myeloperoxidase, Neuropilin 1, Nonhuman, Nucleocapsid protein, Pathogenicity, Peptidyl-dipeptidase a, Pyroptosis, Recombinant soluble ace2, Renin angiotensin aldosterone system, Rna extraction, Rna isolation, Sars-cov-2, Severe acute respiratory syndrome coronavirus 2, Spike glycoprotein, coronavirus, T lymphocyte activation, Trabecular meshwork, Tumor necrosis factor, Virology, Virus load, Virus replication, Virus transmission, Virus virulence
Andrés-Benito, P, Carmona, M, Jordán, M, Fernández-Irigoyen, J, Santamaría, E, del Rio, JA, Ferrer, I, (2022). Host Tau Genotype Specifically Designs and Regulates Tau Seeding and Spreading and Host Tau Transformation Following Intrahippocampal Injection of Identical Tau AD Inoculum INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 23, 718
Several studies have demonstrated the different characteristics of tau seeding and spreading following intracerebral inoculation in murine models of tau-enriched fractions of brain homogenates from AD and other tauopathies. The present study is centered on the importance of host tau in tau seeding and the molecular changes associated with the transformation of host tau into abnormal tau. The brains of three adult murine genotypes expressing different forms of tau—WT (murine 4Rtau), hTau (homozygous transgenic mice knock-out for murine tau protein and heterozygous expressing human forms of 3Rtau and 4Rtau proteins), and mtWT (homozygous transgenic mice knock-out for murine tau protein)—were analyzed following unilateral hippocampal inoculation of sarkosyl-insoluble tau fractions from the same AD and control cases. The present study reveals that (a) host tau is mandatory for tau seeding and spreading following tau inoculation from sarkosyl-insoluble fractions obtained from AD brains; (b) tau seeding does not occur following intracerebral inoculation of sarkosyl-insoluble fractions from controls; (c) tau seeding and spreading are characterized by variable genotype-dependent tau phosphorylation and tau nitration, MAP2 phosphorylation, and variable activation of kinases that co-localize with abnormal tau deposits; (d) transformation of host tau into abnormal tau is an active process associated with the activation of specific kinases; (e) tau seeding is accompanied by modifications in tau splicing, resulting in the expression of new 3Rtau and 4Rtau isoforms, thus indicating that inoculated tau seeds have the capacity to model exon 10 splicing of the host mapt or MAPT with a genotype-dependent pattern; (e) selective regional and cellular vulnerabilities, and different molecular compositions of the deposits, are dependent on the host tau of mice injected with identical AD tau inocula.
JTD Keywords: 3rtau and 4rtau, alzheimer's disease, alzheimer’s disease, brains, granulovacuolar degeneration, host tau, htau, intranuclear distribution, messenger-rna, pathological tau, propagation, protein-kinases, seeding and spreading, tauopathies, transmission, 3rtau and 4rtau, Alzheimer disease, Alzheimers-disease, Alzheimer’s disease, Animals, Biomarkers, Brain, Disease models, animal, Disease susceptibility, Fluorescent antibody technique, Genotype, Hippocampus, Host tau, Htau, Humans, Immunohistochemistry, Mice, Mice, knockout, Mice, transgenic, Mutation, Neurons, Seeding and spreading, Tau proteins, Tauopathies
Zeinali, R, del Valle, LJ, Franco, L, Yousef, I, Rintjema, J, Aleman, C, Bravo, F, Kleij, AW, Puiggali, J, (2022). Biobased Terpene Derivatives: Stiff and Biocompatible Compounds to Tune Biodegradability and Properties of Poly(butylene succinate) Polymers 14, 161--
Different copolymers incorporating terpene oxide units (e.g., limonene oxide) have been evaluated considering thermal properties, degradability, and biocompatibility. Thus, polycarbonates and polyesters derived from aromatic, monocyclic and bicyclic anhydrides have been considered. Furthermore, ring substitution with myrcene terpene has been evaluated. All polymers were amorphous when evaluated directly from synthesis. However, spherulites could be observed after the slow evaporation of diluted chloroform solutions of polylimonene carbonate, with all isopropene units possessing an R configuration. This feature was surprising considering the reported information that suggested only the racemic polymer was able to crystallize. All polymers were thermally stable and showed a dependence of the maximum degradation rate temperature (from 242 °C to 342 °C) with the type of terpene oxide. The graduation of glass transition temperatures (from 44 °C to 172 °C) was also observed, being higher than those corresponding to the unsubstituted polymers. The chain stiffness of the studied polymers hindered both hydrolytic and enzymatic degradation while a higher rate was detected when an oxidative medium was assayed (e.g., weight losses around 12% after 21 days of exposure). All samples were biocompatible according to the adhesion and proliferation tests performed with fibroblast cells. Hydrophobic and mechanically consistent films (i.e., contact angles between 90° and 110°) were obtained after the evaporation of chloroform from the solutions, having different ratios of the studied biobased polyterpenes and poly(butylene succinate) (PBS). The blend films were comparable in tensile modulus and tensile strength with the pure PBS (e.g., values of 330 MPa and 7 MPa were determined for samples incorporating 30 wt.% of poly(PA-LO), the copolyester derived from limonene oxide and phthalic anhydride. Blends were degradable, biocompatible and appropriate to produce oriented-pore and random-pore scaffolds via a thermally-induced phase separation (TIPS) method and using 1,4-dioxane as solvent. The best results were attained with the blend composed of 70 wt.% PBS and 30 wt.% poly(PA-LO). In summary, the studied biobased terpene derivatives showed promising properties to be used in a blended form for biomedical applications such as scaffolds for tissue engineering.
JTD Keywords: alternating copolymerization, biobased materials, biodegradability, composites, crystallization, cyclohexene oxide, induced phase-separation, limonene oxide, mechanical-properties, polyesters, scaffolds, spherulites, terpene derivatives, thermal properties, thermally-induced phase separation, Acetone, Bio-based, Bio-based materials, Biobased materials, Biocompatibility, Biodegradability, Butenes, Cell culture, Chlorine compounds, Degradation, Evaporation, Glass transition, Limonene oxide, Monoterpenes, Phase separation, Poly (butylenes succinate), Polybutylene succinate, Property, Ring-opening copolymerization, Scaffolds, Spheru-lites, Tensile strength, Terpene derivatives, Thermal properties, Thermally induced phase separation, Thermally-induced phase separation, Thermally?induced phase separation, Thermodynamic properties, Thermogravimetric analysis
Sierra-Agudelo, J, Rodriguez-Trujillo, R, Samitier, J, (2022). Microfluidics for the Isolation and Detection of Circulating Tumor Cells NEW TRENDS IN CANCER FOR THE 21ST CENTURY 1379, 389-412
Nowadays, liquid biopsy represents one of the most promising techniques for early diagnosis, monitoring, and therapy screening of cancer. This novel methodology includes, among other techniques, the isolation, capture, and analysis of circulating tumor cells (CTCs). Nonetheless, the identification of CTC from whole blood is challenging due to their extremely low concentration (1-100 per ml of whole blood), and traditional methods result insufficient in terms of purity, recovery, throughput and/or viability of the processed sample. In this context, the development of microfluidic devices for detecting and isolating CTCs offers a wide range of new opportunities due to their excellent properties for cell manipulation and the advantages to integrate and bring different laboratory processes into the microscale improving the sensitivity, portability, reducing cost and time. This chapter explores current and recent microfluidic approaches that have been developed for the analysis and detection of CTCs, which involve cell capture methods based on affinity binding and label-free methods and detection based on electrical, chemical, and optical sensors. All the exposed technologies seek to overcome the limitations of commercial systems for the analysis and isolation of CTCs, as well as to provide extended analysis that will allow the development of novel and more efficient diagnostic tools.
JTD Keywords: Cancer detection, Cancer diagnosis, Cancer-cells, Capture, Chip, Circulating tumor cells, Enrichment, Label-free isolation, Liquid biopsy, Microchannel, Microfluidics, Separation, Ultra-fast
Burgués, J, Esclapez, MD, Doñate, S, Marco, S, (2021). RHINOS: A lightweight portable electronic nose for real-time odor quantification in wastewater treatment plants iScience 24, 103371
Quantification of odor emissions in wastewater treatment plants (WWTPs) is key to minimize odor impact to surrounding communities. Odor measurements in WWTPs are usually performed via either expensive and discontinuous olfactometry hydrogen sulfide detectors or via fixed electronic noses. We propose a portable lightweight electronic nose specially designed for real-time odor monitoring in WWTPs using small drones. The so-called RHINOS e-nose allows odor measurements with high spatial resolution, and its accuracy is only slightly worse than that of dynamic olfactometry. The device has been calibrated using odor samples collected in a WWTP in Spain over a period of six months and validated in the same WWTP three weeks after calibration. The promising results obtained support the suitability of the proposed instrument to identify the odor sources having the highest emissions, which may give a useful indication to the plant managers as regards odor control and abatement.© 2021 The Author(s).
JTD Keywords: biofiltration, calibration transfer, chemical sensor arrays, chemistry, drift compensation, engineering, environmental chemical engineering, h2s, model, oxide gas sensors, removal, sensor, system, Chemistry, Engineering, Environmental chemical engineering, Sensor, Sensor system, Variable selection methods
Arboleda, A, Amado, L, Rodriguez, J, Naranjo, F, Giraldo, BF, (2021). A new protocol to compare successful versus failed patients using the electromyographic diaphragm signal in extubation process Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference , 5646-5649
In clinical practice, when a patient is undergoing mechanical ventilation, it is important to identify the optimal moment for extubation, minimizing the risk of failure. However, this prediction remains a challenge in the clinical process. In this work, we propose a new protocol to study the extubation process, including the electromyographic diaphragm signal (diaEMG) recorded through 5-channels with surface electrodes around the diaphragm muscle. First channel corresponds to the electrode on the right. A total of 40 patients in process of withdrawal of mechanical ventilation, undergoing spontaneous breathing tests (SBT), were studied. According to the outcome of the SBT, the patients were classified into two groups: successful (SG: 19 patients) and failure (FG: 21 patients) groups. Parameters extracted from the envelope of each channel of diaEMG in time and frequency domain were studied. After analyzing all channels, the second presented maximum differences when comparing the two groups of patients, with parameters related to root mean square (p = 0.005), moving average (p = 0.001), and upward slope (p = 0.017). The third channel also presented maximum differences in parameters as the time between maximum peak (p = 0.004), and the skewness (p = 0.027). These results suggest that diaphragm EMG signal could contribute to increase the knowledge of the behaviour of respiratory system in these patients and improve the extubation process.Clinical Relevance - This establishes the characterization of success and failure patients in the extubation process. © 2021 IEEE.
JTD Keywords: classification, recognition, Airway extubation, Artificial ventilation, Clinical practices, Clinical process, Diaphragm, Diaphragm muscle, Diaphragms, Electrodes, Electromyographic, Extubation, Frequency domain analysis, Human, Humans, Maximum differences, Mechanical ventilation, New protocol, Respiration, artificial, Respiratory system, Risk of failure, Spontaneous breathing, Surface electrode, Surface emg signals, Thorax, Ventilation, Ventilator weaning
Estrada-Petrocelli, L, Lozano-Garcia, M, Jane, R, Torres, A, (2021). Assessment of the Non-linear Response of the fSampEn on Simulated EMG Signals Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 2021, 5582-5585
Fixed sample entropy (fSampEn) is a promising technique for the analysis of respiratory electromyographic (EMG) signals. Its use has shown outperformance of amplitude-based estimators such as the root mean square (RMS) in the evaluation of respiratory EMG signals with cardiac noise and a high correlation with respiratory signals, allowing changes in respiratory muscle activity to be tracked. However, the relationship between the fSampEn response to a given muscle activation has not been investigated. The aim of this study was to analyze the nature of the fSampEn measurements that are produced as the EMG activity increases linearly. Simulated EMG signals were generated and increased linearly. The effect of the parameters r and the size of the moving window N of the fSampEn were evaluated and compared with those obtained using the RMS. The RMS showed a linear trend throughout the study. A non-linear, sigmoidal-like behavior was found when analyzing the EMG signals using the fSampEn. The lower the values of r, the higher the non-linearity observed in the fSampEn results. Greater moving windows reduced the variation produced by too small values of r.Clinical Relevance - Understanding the inherent non-linear relationship produced when using the fSampEn in EMG recordings will contribute to the improvement of the respiratory muscle activation assessment at different levels of respiratory effort in patients with respiratory conditions, particularly during the inspiratory phase © 2021 IEEE.
JTD Keywords: Breathing muscle, Breathing rate, Electromyography, Entropy, Heart, Human, Humans, Respiratory muscles, Respiratory rate
Ferrer-Lluis, I, Castillo-Escario, Y, Glos, M, Fietze, I, Penzel, T, Jane, R, (2021). Sleep Apnea & Chronic Obstructive Pulmonary Disease: Overlap Syndrome Dynamics in Patients from an Epidemiological Study Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 2021, 5574-5577
Obstructive sleep apnea (OSA) is a sleep disorder in which repetitive upper airway obstructive events occur during sleep. These events can induce hypoxia, which is a risk factor for multiple cardiovascular and cerebrovascular diseases. Chronic obstructive pulmonary disease (COPD) is a disorder which induces a persistent inflammation of the lungs. This condition produces hypoventilation, affecting the blood oxygenation, and leads to an increased risk of developing lung cancer and heart disease. In this study, we evaluated how COPD affects the severity and characteristics of OSA in a multivariate demographic database including polysomnographic signals. Results showed SpO2 subtle variations, such as more non-recovered desaturations and increased time below a 90% SpO2 level, which, in the long term, could worsen the risk to suffer cardiovascular and cerebrovascular diseases.Clinical Relevance - COPD increases the OSA risk due to hypoventilation and altered SpO2 behavior. © 2021 IEEE.
JTD Keywords: Chronic obstructive lung disease, Complication, Epidemiologic studies, Epidemiology, Human, Humans, Oxygen saturation, Pulmonary disease, chronic obstructive, Sleep apnea, obstructive, Sleep disordered breathing, Syndrome
Romero, D, Jane, R, (2021). Relationship between Sleep Stages and HRV response in Obstructive Sleep Apnea Patients Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 2021, 5535-5538
Patients suffering from obstructive sleep apnea (OSA) usually present an increased sympathetic activity caused by the intermittent hypoxia effect on autonomic control. This study evaluated the relationship between sleep stages and the apnea duration, frequency, and type, as well as their impact on HRV markers in different groups of disease severity. The hypnogram and R-R interval signals were extracted in 81 OSA patients from night polysomnographic (PSG) recordings. The apnea-hypopnea index (AHI) defined patient classification as mild-moderate (AHI< 30, n 44) or severe (AHI>30, n 37). The normalized power in VLH, LF, and HF bands of RR series were estimated by a time-frequency approach and averaged in 1-min epochs of normal and apnea segments. The autonomic response and the impact of sleep stages were assessed in both segments to compare patient groups. Deeper sleep stages (particularly S2) concentrated the shorter and mild apnea episodes (from 10 to 40 s) compared to light (SWS) and REM sleep. Longer episodes (>50 s) although less frequent, were of similar incidence in all stages. This pattern was more pronounced for the group of severe patients. Moreover, during apnea segments, LF nu was higher (p 0.044) for the severe group, since V LF nu and HF nu presented the greatest changes when compared to normal segments. The non-REM sleep seems to better differentiate OSA patients groups, particularly through VLF nu and HF nu (p<0.001). A significant difference in both sympathetic and vagal modulation between REM and non-REM sleep was only found within the severe group. These results confirm the importance of considering sleep stages for HRV analysis to further assess OSA disease severity, beyond the traditional and clinically limited AHI values.Clinical relevance - Accounting for sleep stages during HRV analysis could better assess disease severity in OSA patients. © 2021 IEEE.
JTD Keywords: blood-pressure, genomic consequences, intermittent hypoxia, rapid-eye-movement, sympathetic activity, Heart rate, Heart-rate-variability, Human, Humans, Polysomnography, Rem sleep, Sleep apnea, obstructive, Sleep disordered breathing, Sleep stage, Sleep stages, Sleep, rem
Guasch-Girbau, A, Fernandez-Busquets, X, (2021). Review of the current landscape of the potential of nanotechnology for future malaria diagnosis, treatment, and vaccination strategies Pharmaceutics 13, 2189
Malaria eradication has for decades been on the global health agenda, but the causative agents of the disease, several species of the protist parasite Plasmodium, have evolved mechanisms to evade vaccine-induced immunity and to rapidly acquire resistance against all drugs entering clinical use. Because classical antimalarial approaches have consistently failed, new strategies must be explored. One of these is nanomedicine, the application of manipulation and fabrication technology in the range of molecular dimensions between 1 and 100 nm, to the development of new medical solutions. Here we review the current state of the art in malaria diagnosis, prevention, and therapy and how nanotechnology is already having an incipient impact in improving them. In the second half of this review, the next generation of antimalarial drugs currently in the clinical pipeline is presented, with a definition of these drugs’ target product profiles and an assessment of the potential role of nanotechnology in their development. Opinions extracted from interviews with experts in the fields of nanomedicine, clinical malaria, and the economic landscape of the disease are included to offer a wider scope of the current requirements to win the fight against malaria and of how nanoscience can contribute to achieve them. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
JTD Keywords: antibody-bearing liposomes, antimalarial drugs, combination therapies, drug-delivery strategies, malaria diagnosis, malaria prophylaxis, malaria therapy, nanocarriers, nanomedicine, nanoparticles, nanotechnology, plasmodium, plasmodium-falciparum, red-blood-cells, targeted delivery, targeted drug delivery, vitro antimalarial activity, Antimalarial drugs, Isothermal amplification lamp, Malaria diagnosis, Malaria prophylaxis, Malaria therapy, Nanocarriers, Nanomedicine, Nanotechnology, Plasmodium, Targeted drug delivery
Chausse, V, Schieber, R, Raymond, Y, Ségry, B, Sabaté, R, Kolandaivelu, K, Ginebra, MP, Pegueroles, M, (2021). Solvent-cast direct-writing as a fabrication strategy for radiopaque stents Additive Manufacturing 48, 102392
JTD Keywords: biocompatibility, bioresorbable stents, degradation, mechanical-properties, poly(epsilon-caprolactone), poly-l-lactic acid, polylactide, radiopacity, thermogel, x-ray imaging, Barium sulfate, Biocompatibility, Bioresorbable, Bioresorbable scaffolds, Bioresorbable stent, Bioresorbable stents, Blood vessels, Computerized tomography, Controlled drug delivery, Coronary heart disease, Direct-writing, Endothelial cells, Fabrication strategies, Injection molding, Lactic acid, Poly-l-lactic acid, Poly-l-lactic acids, Radiopacity, Scaffolds (biology), Solvent cast, Solvent-cast direct-writing, Solvents, Stents, Struts, Sulfur compounds, Targeted drug delivery, X-ray imaging
Raymond, Y, Pastorino, D, Ginebreda, I, Maazouz, Y, Ortiz, M, Manzanares, MC, Ginebra, MP, (2021). Computed tomography and histological evaluation of xenogenic and biomimetic bone grafts in three-wall alveolar defects in minipigs Clinical Oral Investigations 25, 6695-6706
Objectives This study aimed to compare the performance of a xenograft (XG) and a biomimetic synthetic graft (SG) in three-wall alveolar defects in minipigs by means of 3D computerised tomography and histology. Materials and methods Eight minipigs were used. A total of eight defects were created in the jaw of each animal, three of which were grafted with XGs, three with SGs, and two were left empty as a negative control. The allocation of the different grafts was randomised. Four animals were euthanised at 6 weeks and four at 12 weeks. The grafted volume was then measured by spiral computed tomography to assess volume preservation. Additionally, a histological analysis was performed in undecalcified samples by backscattered scanning electron microscopy and optical microscopy after Masson's trichrome staining. Results A linear mixed-effects model was applied considering four fixed factors (bone graft type, regeneration time, anatomic position, and maxilla/mandible) and one random factor (animal). The SG exhibited significantly larger grafted volume (19%) than the XG. The anterior sites preserved better the grafted volume than the posterior ones. Finally, regeneration time had a positive effect on the grafted volume. Histological observations revealed excellent osseointegration and osteoconductive properties for both biomaterials. Some concavities found in the spheroidal morphologies of SGs were associated with osteoclastic resorption. Conclusions Both biomaterials met the requirements for bone grafting, i.e. biocompatibility, osseointegration, and osteoconduction. Granule morphology was identified as an important factor to ensure a good volume preservation.
JTD Keywords: bone graft, bone regeneration, in vivo, miniature swine, synthetic graft, 3-dimensional changes, Anorganic bovine bone, Autogenous bone, Bio-oss, Biomaterials, Bone graft, Bone regeneration, Calcium-phosphate, Hydroxyapatite, In vivo, Miniature swine, Sinus floor augmentation, Substitute, Synthetic graft, Volume, Xenograft
García-Mintegui, C, Córdoba, LC, Buxadera-Palomero, J, Marquina, A, Jiménez-Piqué, E, Ginebra, MP, Cortina, JL, Pegueroles, M, (2021). Zn-Mg and Zn-Cu alloys for stenting applications: From nanoscale mechanical characterization to in vitro degradation and biocompatibility Bioactive Materials 6, 4430-4446
In the recent decades, zinc (Zn) and its alloys have been drawing attention as promising candidates for bioresorbable cardiovascular stents due to its degradation rate more suitable than magnesium (Mg) and iron (Fe) alloys. However, its mechanical properties need to be improved in order to meet the criteria for vascular stents. This work investigates the mechanical properties, biodegradability and biocompatibility of Zn-Mg and Zn-Cu alloys in order to determine a proper alloy composition for optimal stent performance. Nanoindentation measurements are performed to characterize the mechanical properties at the nanoscale as a function of the Zn microstructure variations induced by alloying. The biodegradation mechanisms are discussed and correlated to microstructure, mechanical performance and bacterial/cell response. Addition of Mg or Cu alloying elements refined the microstructure of Zn and enhanced yield strength (YS) and ultimate tensile strength (UTS) proportional to the volume fraction of secondary phases. Zn-1Mg showed the higher YS and UTS and better performance in terms of degradation stability in Hanks’ solution. Zn-Cu alloys presented an antibacterial effect for S. aureus controlled by diffusion mechanisms and by contact. Biocompatibility was dependent on the degradation rate and the nature of the corrosion products.
JTD Keywords: behavior, biocompatibility, biodegradable metals, bioresorbable metals, bioresorbable scaffold, copper, corrosion properties, elastic-modulus, galvanic corrosion, microstructure, nanoindentation, redox homeostasis, zinc, Biocompatibility, Bioresorbable metals, Galvanic corrosion, Nanoindentation, Room-temperature superplasticity, Zinc alloys
Lopez-Muñoz, GA, Fernández-Costa, JM, Ortega, MA, Balaguer-Trias, J, Martin-Lasierra, E, Ramón-Azcón, J, (2021). Plasmonic nanocrystals on polycarbonate substrates for direct and label-free biodetection of Interleukin-6 in bioengineered 3D skeletal muscles Nanophotonics 10, 4477-4488
Abstract The development of nanostructured plasmonic biosensors has been widely widespread in the last years, motivated by the potential benefits they can offer in integration, miniaturization, multiplexing opportunities, and enhanced performance label-free biodetection in a wide field of applications. Between them, engineering tissues represent a novel, challenging, and prolific application field for nanostructured plasmonic biosensors considering the previously described benefits and the low levels of secreted biomarkers (?pM–nM) to detect. Here, we present an integrated plasmonic nanocrystals-based biosensor using high throughput nanostructured polycarbonate substrates. Metallic film thickness and incident angle of light for reflectance measurements were optimized to enhance the detection of antibody–antigen biorecognition events using numerical simulations. We achieved an enhancement in biodetection up to 3× as the incident angle of light decreases, which can be related to shorter evanescent decay lengths. We achieved a high reproducibility between channels with a coefficient of variation below 2% in bulk refractive index measurements, demonstrating a high potential for multiplexed sensing. Finally, biosensing potential was demonstrated by the direct and label-free detection of interleukin-6 biomarker in undiluted cell culture media supernatants from bioengineered 3D skeletal muscle tissues stimulated with different concentrations of endotoxins achieving a limit of detection (LOD) of ? 0.03 ng/mL (1.4 pM).
JTD Keywords: assay, crystals, drug, label-free biosensing, molecules, plasmonic nanostructures, sensors, skeletal muscle, tissue engineering, Biodetection, Biomarkers, Biosensors, Cell culture, Cells, Chemical detection, Histology, Interleukin-6, Interleukin6 (il6), Label free, Label-free biosensing, Muscle, Nano-structured, Nanocrystals, Plasmonic nanocrystals, Plasmonic nanostructures, Plasmonics, Polycarbonate substrates, Polycarbonates, Refractive index, Sensitivity, Skeletal muscle, Tissue engineering, Tissues engineerings
Maiti, B, Nandi, M, Bonardd, S, Franco, L, Puiggali, J, Enshaei, H, Aleman, C, Diaz, DD, (2021). Efficient One-Pot Preparation of Thermoresponsive Polyurethanes with Lower Critical Solution Temperatures ChemPlusChem 86, 1570-1576
This work reports a simple and scalable strategy to prepare a series of thermoresponsive polyurethanes synthesized via copolymerization of dicyclohexyl diisocyanate with glycerol ethoxylate in a single one-pot system. These polyurethanes exhibit lower critical solution temperatures (LCST) at 57 degrees C. The LCST of synthesized polyurethane was determined from Dynamic Scanning Calorimetry and UV-vis measurements. Both the LCST and T-g of synthesized polyurethane was tuned by varying the ratio between hard segment (dicyclohexyl diisocyanate) and soft segment (glycerol ethoxylate). Thus, T-g values could be tuned from -54.6 degrees C to -19.9 degrees C for samples with different flexibility. The swelling and deswelling studies were done at room temperature and above the LCST respectively. The results showed that the swelling ratio increases with the increase of soft segment (glycerol ethoxylate) in synthesized polyurethanes. Furthermore, the mechanical properties of the membrane were studied by universal tensile testing measurements. Specifically, stress at break values varied from 0.35 +/- 0.07 MPa to 0.91 +/- 0.15 MPa for the tested membranes, whereas elongation at break data ranged from 101.9 +/- 20.9 % to 192.4 +/- 24.4 %, and Young's modulus varied from 0.35 +/- 0.03 MPa to 1.85 +/- 0.19 MPa. Tensile strength of the films increased with the increase of the hard segment and elongation at break decreased.
JTD Keywords: copolymerization, critical solution temperatures, polyurethanes, tensile strength, Biodegradable polyurethanes, Copolymerization, Critical solution temperatures, Glycol), Polymers, Polyurethanes, Solvent-free, Tensile strength, Thermoresponsive materials
Garreta, E, Nauryzgaliyeva, Z, Montserrat, N, (2021). Human induced pluripotent stem cell-derived kidney organoids toward clinical implementations Current Opinion in Biomedical Engineering 20, 100346
The generation of kidney organoids from human pluripotent stem cells (hPSCs) has represented a relevant scientific achievement in the organoid field. Importantly, hPSC-derived kidney organoids contain multiple nephron-like structures that exhibit some renal functional characteristics and have the capacity to respond to nephrotoxic agents. In this review, we first discuss how bioengineering approaches can help overcome current kidney organoid challenges. Next, we focus on recent works exploiting kidney organoids for drug screening and disease modeling applications. Finally, we provide a state of the art on current research toward the potential application of kidney organoids and renal cells derived from hPSCs for future renal replacement therapies.
JTD Keywords: Bioengineering, Converting enzyme-ii, Crispr/cas9 gene editing, Disease, Disease modeling, Extracellular-matrix, Generation, Human pluripotent stem cells, Kidney organoids, Kidney regeneration, Model, Mouse, Reveals, Scaffold, Transplantation
Farre, R, Rodriguez-Lazaro, MA, Dinh-Xuan, AT, Pons-Odena, M, Navajas, D, Gozal, D, (2021). A low-cost, easy-to-assemble device to prevent infant hyperthermia under conditions of high thermal stress International Journal of Environmental Research and Public Health 18, 13382
High ambient temperature and humidity greatly increase the risk of hyperthermia and mortality, particularly in infants, who are especially prone to dehydration. World areas at high risk of heat stress include many of the low-and middle-income countries (LMICs) where most of their inhabitants have no access to air conditioning. This study aimed to design, evaluate, and test a novel low-cost and easy-to-assemble device aimed at preventing the risk of infant hyperthermia in LMICs. The device is based on optimizing negative heat transfer from a small amount of ice and transferring it directly to the infant by airflow of refrigerated air. As a proof of concept, a device was assembled mainly using recycled materials, and its performance was assessed under laboratory-controlled conditions in a climatic chamber mimicking realistic stress conditions of high temperature and humidity. The device, which can be assembled by any layperson using easily available materials, provided sufficient refrigerating capacity for several hours from just 1–2 kg of ice obtained from a domestic freezer. Thus, application of this novel device may serve to attenuate the adverse effects of heat stress in infants, particularly in the context of the evolving climatic change trends. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
JTD Keywords: air conditioning, ambient-temperature, death, heat, heat index, heat shock, heatwave, high ambient temperature, hyperthermia, low-cost refrigeration, low-middle income countries, mortality, negative heat transfer, Air conditioning, Algorithm, Article, Climate change, Cost benefit analysis, Environmental temperature, Heat index, Heat shock, Heat stress, Heat transfer, Heating, Heatwave, High ambient temperature, High temperature, Humidity, Hyperthermia, Low income country, Low-cost refrigeration, Low-middle income countries, Middle income country, Middle-income countries, Negative heat transfer, Prevention study, Refrigeration, Temperature stress, Thawing
Song, S, Mason, AF, Post, RAJ, De Corato, M, Mestre, R, Yewdall, NA, Cao, S, van der Hofstad, RW, Sanchez, S, Abdelmohsen, LKEA, van Hest, JCM, (2021). Engineering transient dynamics of artificial cells by stochastic distribution of enzymes Nature Communications 12, 6897
Here the authors develop a coacervate micromotor that can display autonomous motion as a result of stochastic distribution of propelling units. This stochastic-induced mobility is validated and explained through experiments and theory. Random fluctuations are inherent to all complex molecular systems. Although nature has evolved mechanisms to control stochastic events to achieve the desired biological output, reproducing this in synthetic systems represents a significant challenge. Here we present an artificial platform that enables us to exploit stochasticity to direct motile behavior. We found that enzymes, when confined to the fluidic polymer membrane of a core-shell coacervate, were distributed stochastically in time and space. This resulted in a transient, asymmetric configuration of propulsive units, which imparted motility to such coacervates in presence of substrate. This mechanism was confirmed by stochastic modelling and simulations in silico. Furthermore, we showed that a deeper understanding of the mechanism of stochasticity could be utilized to modulate the motion output. Conceptually, this work represents a leap in design philosophy in the construction of synthetic systems with life-like behaviors.
JTD Keywords: Artificial cells, Cell, Cell component, Computer simulation, Enzyme, Enzyme activity, Enzymes, Membrane, Membrane fluidity, Models, biological, Motion, Philosophy, Polymer, Stochastic processes, Stochasticity, Substrate
Castillo-Escario, Y, Kumru, H, Ferrer-Lluis, I, Vidal, J, Jané, R, (2021). Detection of Sleep-Disordered Breathing in Patients with Spinal Cord Injury Using a Smartphone SENSORS 21, 7182
Patients with spinal cord injury (SCI) have an increased risk of sleep-disordered breathing (SDB), which can lead to serious comorbidities and impact patients’ recovery and quality of life. However, sleep tests are rarely performed on SCI patients, given their multiple health needs and the cost and complexity of diagnostic equipment. The objective of this study was to use a novel smartphone system as a simple non-invasive tool to monitor SDB in SCI patients. We recorded pulse oximetry, acoustic, and accelerometer data using a smartphone during overnight tests in 19 SCI patients and 19 able-bodied controls. Then, we analyzed these signals with automatic algorithms to detect desaturation, apnea, and hypopnea events and monitor sleep position. The apnea–hypopnea index (AHI) was significantly higher in SCI patients than controls (25 ± 15 vs. 9 ± 7, p < 0.001). We found that 63% of SCI patients had moderate-to-severe SDB (AHI ? 15) in contrast to 21% of control subjects. Most SCI patients slept predominantly in supine position, but an increased occurrence of events in supine position was only observed for eight patients. This study highlights the problem of SDB in SCI and provides simple cost-effective sleep monitoring tools to facilitate the detection, understanding, and management of SDB in SCI patients.
JTD Keywords: apnea syndrome, biomedical signal processing, individuals, mhealth, monitoring, nasal resistance, people, position, prevalence, questionnaire, sample, sleep apnea, sleep position, sleep-disordered breathing, smartphone, time, Apnea-hypopnea indices, Biomedical signal processing, Biomedical signals processing, Cost effectiveness, Diagnosis, Mhealth, Monitoring, Noninvasive medical procedures, Oximeters, Oxygen-saturation, Patient rehabilitation, Simple++, Sleep apnea, Sleep position, Sleep research, Sleep-disordered breathing, Smart phones, Smartphone, Smartphones, Spinal cord injury, Spinal cord injury patients
Villasante, A, Godier-Furnemont, A, Hernandez-Barranco, A, Le Coq, J, Boskovic, J, Peinado, H, Mora, J, Samitier, J, Vunjak-Novakovic, G, (2021). Horizontal transfer of the stemness-related markers EZH2 and GLI1 by neuroblastoma-derived extracellular vesicles in stromal cells Translational Research 237, 82-97
Neuroblastoma (NB) is the most common extracranial pediatric solid cancer originating from undifferentiated neural crest cells. NB cells express EZH2 and GLI1 genes that are known to maintain the undifferentiated phenotype of cancer stem cells (CSC) in NB. Recent studies suggest that tumor-derived extracellular vesicles (EVs) can regulate the transformation of surrounding cells into CSC by transferring tumor-specific molecules they contain. However, the horizontal transfer of EVs molecules in NB remains largely unknown. We report the analysis of NB-derived EVs in bioengineered models of NB that are based on a collagen 1/hyaluronic acid scaffold designed to mimic the native tumor niche. Using these models, we observed an enrichment of GLI1 and EZH2 mRNAs in NB-derived EVs. As a consequence of the uptake of NB-derived EVs, the host cells increased the expression levels of GLI1 and EZH2. These results suggest the alteration of the expression profile of stromal cells through an EV-based mechanism, and point the GLI1 and EZH2 mRNAs in the EV cargo as diagnostic biomarkers in NB.
JTD Keywords: exosomes, genes, lines, maintenance, pathway, proliferation, rna, stemness, tumor, Cancer
Brennan, MA, Monahan, DS, Brulin, B, Gallinetti, S, Humbert, P, Tringides, C, Canal, C, Ginebra, MP, Layrolle, P, (2021). Biomimetic versus sintered macroporous calcium phosphate scaffolds enhanced bone regeneration and human mesenchymal stromal cell engraftment in calvarial defects Acta Biomaterialia 135, 689-704
In contrast to sintered calcium phosphates (CaPs) commonly employed as scaffolds to deliver mesenchymal stromal cells (MSCs) targeting bone repair, low temperature setting conditions of calcium deficient hydroxyapatite (CDHA) yield biomimetic topology with high specific surface area. In this study, the healing capacity of CDHA administering MSCs to bone defects is evaluated for the first time and compared with sintered beta-tricalcium phosphate (β-TCP) constructs sharing the same interconnected macroporosity. Xeno-free expanded human bone marrow MSCs attached to the surface of the hydrophobic β-TCP constructs, while infiltrating the pores of the hydrophilic CDHA. Implantation of MSCs on CaPs for 8 weeks in calvaria defects of nude mice exhibited complete healing, with bone formation aligned along the periphery of β-TCP, and conversely distributed within the pores of CDHA. Human monocyte-osteoclast differentiation was inhibited in vitro by direct culture on CDHA compared to β-TCP biomaterials and indirectly by administration of MSC-conditioned media generated on CDHA, while MSCs increased osteoclastogenesis in both CaPs in vivo. MSC engraftment was significantly higher in CDHA constructs, and also correlated positively with bone in-growth in scaffolds. These findings demonstrate that biomimetic CDHA are favorable carriers for MSC therapies and should be explored further towards clinical bone regeneration strategies. Statement of significance: Delivery of mesenchymal stromal cells (MSCs) on calcium phosphate (CaP) biomaterials enhances reconstruction of bone defects. Traditional CaPs are produced at high temperature, but calcium deficient hydroxyapatite (CDHA) prepared at room temperature yields a surface structure more similar to native bone mineral. The objective of this study was to compare the capacity of biomimetic CDHA scaffolds with sintered β-TCP scaffolds for bone repair mediated by MSCs for the first time. In vitro, greater cell infiltration occurred in CDHA scaffolds and following 8 weeks in vivo, MSC engraftment was higher in CDHA compared to β-TCP, as was bone in-growth. These findings demonstrate the impact of material features such as surface structure, and highlight that CDHA should be explored towards clinical bone regeneration strategies.
JTD Keywords: beta-tricalcium phosphate, bone regeneration, calcium deficient hydroxyapatite, differentiation, engraftment, human bone marrow mesenchymal stromal cells, hydroxyapatite scaffolds, in-vitro, inhibition, osteogenesis, osteoinduction, stem-cells, surface-topography, tissue, Animals, Beta-tricalcium phosphate, Biomimetics, Bone regeneration, Calcium deficient hydroxyapatite, Calcium phosphate, Calcium phosphates, Cell differentiation, Engraftment, Human bone marrow mesenchymal stromal cells, Humans, Mesenchymal stem cells, Mice, Mice, nude, Osteogenesis, Tissue scaffolds
Raymond, Y, Bonany, M, Lehmann, C, Thorel, E, Benítez, R, Franch, J, Espanol, M, Solé-Martí, X, Manzanares, MC, Canal, C, Ginebra, MP, (2021). Hydrothermal processing of 3D-printed calcium phosphate scaffolds enhances bone formation in vivo: a comparison with biomimetic treatment Acta Biomaterialia 135, 671-688
Hydrothermal (H) processes accelerate the hydrolysis reaction of α-tricalcium phosphate (α-TCP) compared to the long-established biomimetic (B) treatments. They are of special interest for patient-specific 3D-printed bone graft substitutes, where the manufacturing time represents a critical constraint. Altering the reaction conditions has implications for the physicochemical properties of the reaction product. However, the impact of the changes produced by the hydrothermal reaction on the in vivo performance was hitherto unknown. The present study compares the bone regeneration potential of 3D-printed α-TCP scaffolds hardened using these two treatments in rabbit condyle monocortical defects. Although both consolidation processes resulted in biocompatible scaffolds with osseointegrative and osteoconductive properties, the amount of newly formed bone increased by one third in the hydrothermal vs the biomimetic samples. B and H scaffolds consisted mostly of high specific surface area calcium-deficient hydroxyapatite (38 and 27 m2 g-1, respectively), with H samples containing also 10 wt.% β-tricalcium phosphate (β-TCP). The shrinkage produced during the consolidation process was shown to be very small in both cases, below 3%, and smaller for H than for B samples. The differences in the in vivo performance were mainly attributed to the distinct crystallisation nanostructures, which proved to have a major impact on permeability and protein adsorption capacity, using BSA as a model protein, with B samples being highly impermeable. Given the crucial role that soluble proteins play in osteogenesis, this is proposed to be a relevant factor behind the distinct in vivo performances observed for the two materials. Statement of significance: The possibility to accelerate the consolidation of self-setting calcium phosphate inks through hydrothermal treatments has aroused great interest due to the associated advantages for the development of 3D-printed personalised bone scaffolds. Understanding the implications of this approach on the in vivo performance of the scaffolds is of paramount importance. This study compares, for the first time, this treatment to the long-established biomimetic setting strategy in terms of osteogenic potential in vivo in a rabbit model, and relates the results obtained to the physicochemical properties of the 3D-printed scaffolds (composition, crystallinity, nanostructure, nanoporosity) and their interaction with soluble proteins.
JTD Keywords: 3d printing, behavior, biomimetic, bone scaffolds, calcium phosphate, deficient hydroxyapatite, design, graft, hydrothermal, in vivo, morbidity, osteoinduction, porosity, standard, tricalcium phosphate, 3d printing, Animals, Biomimetic, Biomimetics, Bone regeneration, Bone scaffolds, Calcium phosphate, Calcium phosphates, Fibula free-flap, Humans, Hydrothermal, In vivo, Osteogenesis, Printing, three-dimensional, Rabbits, Tissue scaffolds
Caddeo, C, Lucchesi, D, Fernàndez-Busquets, X, Valenti, D, Penno, G, Fadda, AM, Pucci, L, (2021). Efficacy of a resveratrol nanoformulation based on a commercially available liposomal platform INTERNATIONAL JOURNAL OF PHARMACEUTICS 608, 121086
Scalability is one of the important factors slowing down or even impeding the clinical translation of nanoparticle-based systems. The latter need to be manufactured at a high level of quality, with batch-to-batch reproducibility, and need to be stable after the manufacturing process, during long-term storage and upon clinical administration. In this study, a vesicular formulation intended for cutaneous applications was developed by the easy reconstitution of a commercially available liposomal platform. Resveratrol, a naturally occurring compound with potent antioxidant activity, and Tween80, a hydrophilic non-ionic surfactant, were included in the formulation. The physico-chemical properties of the vesicles were assessed using light scattering and cryogenic transmission electron microscopy. Nanosized (around 80 nm) spherical and elongated, unilamellar vesicles were produced, with remarkable storage stability. The incorporation of resveratrol in the vesicular system did not alter its strong antioxidant activity, as demonstrated by antioxidant colorimetric assays (DPPH and FRAP). Furthermore, the resveratrol liposomes were cytocompatible with fibroblasts and capable of protecting skin cells from oxidative stress by reducing both endogenous and chemically induced reactive oxygen species more effectively than free resveratrol. Therefore, the proposed formulation, based on the use of a commercially available liposomal platform, represents an easy-to-prepare, reproducible, up-scaled and efficient means of delivering resveratrol and potentiating its biological activity in vitro.
JTD Keywords: antioxidant, commercial liposomes, resveratrol, skin cells, skin delivery, Antioxidant, Commercial liposomes, Drug-delivery, Resveratrol, Skin cells, Skin delivery
Konka, J, Buxadera-Palomero, J, Espanol, M, Ginebra, MP, (2021). 3D printing of hierarchical porous biomimetic hydroxyapatite scaffolds: Adding concavities to the convex filaments Acta Biomaterialia 134, 744-759
Porosity plays a key role on the osteogenic performance of bone scaffolds. Direct Ink Writing (DIW) allows the design of customized synthetic bone grafts with patient-specific architecture and controlled macroporosity. Being an extrusion-based technique, the scaffolds obtained are formed by arrays of cylindrical filaments, and therefore have convex surfaces. This may represent a serious limitation, as the role of surface curvature and more specifically the stimulating role of concave surfaces in osteoinduction and bone growth has been recently highlighted. Hence the need to design strategies that allow the introduction of concave pores in DIW scaffolds. In the current study, we propose to add gelatin microspheres as a sacrificial material in a self-setting calcium phosphate ink. Neither the phase transformation responsible for the hardening of the scaffold nor the formation of characteristic network of needle-like hydroxyapatite crystals was affected by the addition of gelatin microspheres. The partial dissolution of the gelatin resulted in the creation of spherical pores throughout the filaments and exposed on the surface, increasing filament porosity from 0.2 % to 67.9 %. Moreover, the presence of retained gelatin proved to have a significant effect on the mechanical properties, reducing the strength but simultaneously giving the scaffolds an elastic behavior, despite the high content of ceramic as a continuous phase. Notwithstanding the inherent difficulty of in vitro cultures with this highly reactive material an enhancement of MG-63 cell proliferation, as well as better spreading of hMSCs was recorded on the developed scaffolds. Statement of significance: Recent studies have stressed the role that concave surfaces play in tissue regeneration and, more specifically, in osteoinduction and osteogenesis. Direct ink writing enables the production of patient-specific bone grafts with controlled architecture. However, besides many advantages, it has the serious limitation that the surfaces obtained are convex. In this article, for the first time we develop a strategy to introduce concave pores in the printed filaments of biomimetic hydroxyapatite by incorporation and partial dissolution of gelatin microspheres. The retention of part of the gelatin results in a more elastic behavior compared to the brittleness of hydroxyapatite scaffolds, while the needle-shaped nanostructure of biomimetic hydroxyapatite is maintained and gelatin-coated concave pores on the surface of the filaments enhance cell spreading. © 2021 The Authors
JTD Keywords: 3d printing, bioceramics, biomimetic, bone, bone regeneration, concavity, concavity, bone regeneration, gelatin, hydrogel, hydroxyapatite, microspheres, osteoinduction, porosity, porous filament, substitutes, tissue-growth, 3d printing, Biomimetic, Biomimetics, Calcium-phosphate scaffolds, Concavity, bone regeneration, Durapatite, Gelatin, Humans, Hydroxyapatite, Porosity, Porous filament, Printing, three-dimensional, Tissue engineering, Tissue scaffolds
Grechuta, K, Costa, JD, Ballester, BR, Verschure, P, (2021). Challenging the Boundaries of the Physical Self: Distal Cues Impact Body Ownership Frontiers in Human Neuroscience 15, 704414
The unique ability to identify one's own body and experience it as one's own is fundamental in goal-oriented behavior and survival. However, the mechanisms underlying the so-called body ownership are yet not fully understood. Evidence based on Rubber Hand Illusion (RHI) paradigms has demonstrated that body ownership is a product of reception and integration of self and externally generated multisensory information, feedforward and feedback processing of sensorimotor signals, and prior knowledge about the body. Crucially, however, these designs commonly involve the processing of proximal modalities while the contribution of distal sensory signals to the experience of ownership remains elusive. Here we propose that, like any robust percept, body ownership depends on the integration and prediction across all sensory modalities, including distal sensory signals pertaining to the environment. To test our hypothesis, we created an embodied goal-oriented Virtual Air Hockey Task, in which participants were to hit a virtual puck into a goal. In two conditions, we manipulated the congruency of distal multisensory cues (auditory and visual) while preserving proximal and action-driven signals entirely predictable. Compared to a fully congruent condition, our results revealed a significant decrease on three dimensions of ownership evaluation when distal signals were incongruent, including the subjective report as well as physiological and kinematic responses to an unexpected threat. Together, these findings support the notion that the way we represent our body is contingent upon all the sensory stimuli, including distal and action-independent signals. The present data extend the current framework of body ownership and may also find applications in rehabilitation scenarios.
JTD Keywords:
active perception,
body ownership,
distal sensory cues,
embodied cognition,
forward model,
Active perception,
Adult,
Article,
Body ownership,
Brain,
Cortex,
Distal sensory cues,
Embodied cognition,
Feel,
Female,
Forward model,
Hockey,
Human,
Human experiment,
Integration,
Male,
Models,
Neurons,
Perception,
Peripersonal space,
Prediction,
Rehabilitation,
Rubber hand illusion,
Sensory prediction error,
Touch
Torabi, N, Qiu, XK, López-Ortiz, M, Loznik, M, Herrmann, A, Kermanpur, A, Ashrafi, A, Chiechi, RC, (2021). Fullerenes enhance self-assembly and electron injection of photosystem I in biophotovoltaic devices LANGMUIR 37, 11465-11473
This paper describes the fabrication of microfluidic devices with a focus on controlling the orientation of photosystem I (PSI) complexes, which directly affects the performance of biophotovoltaic devices by maximizing the efficiency of the extraction of electron/hole pairs from the complexes. The surface chemistry of the electrode on which the complexes assemble plays a critical role in their orientation. We compared the degree of orientation on self-assembled monolayers of phenyl-C61-butyric acid and a custom peptide on nanostructured gold electrodes. Biophotovoltaic devices fabricated with the C61 fulleroid exhibit significantly improved performance and reproducibility compared to those utilizing the peptide, yielding a 1.6-fold increase in efficiency. In addition, the C61-based devices were more stable under continuous illumination. Our findings show that fulleroids, which are well-known acceptor materials in organic photovoltaic devices, facilitate the extraction of electrons from PSI complexes without sacrificing control over the orientation of the complexes, highlighting this combination of traditional organic semiconductors with biomolecules as a viable approach to coopting natural photosynthetic systems for use in solar cells.
JTD Keywords: architecture, arrays, construction, metal, nanotubes, performance, photosynthetic proteins, polymer-fullerene, solar-cells, Photocurrent generation
Elosegui-Artola, A, (2021). The extracellular matrix viscoelasticity as a regulator of cell and tissue dynamics CURRENT OPINION IN CELL BIOLOGY 72, 10-18
The extracellular matrix mechanical properties regulate processes in development, cancer, and fibrosis. Among the distinct mechanical properties, the vast majority of research has focused on the extracellular matrix's elasticity as the primary determinant of cell and tissue behavior. However, both cells and the extracellular matrix are not only elastic but also viscous. Despite viscoelasticity being a universal feature of living tissues, our knowledge of the influence of the extracellular matrix's viscoelasticity in cell behavior is limited. This mini-review describes some of the recent findings that have highlighted the role of the extracellular matrix's viscoelasticity in cell and tissue dynamics.
JTD Keywords: behavior, cell adhesion, cell mechanics, cell migration, deformability, extracellular matrix, extracellular matrix mechanics, fluidity, forces, hydrogels, mechanobiology, mechanotransduction, tissue mechanics, viscoelasticity, viscosity, Cell adhesion, Cell mechanics, Cell migration, Elasticity, Extracellular matrix, Extracellular matrix mechanics, Fluidity, Mechanobiology, Mechanotransduction, Migration, Tissue mechanics, Viscoelasticity, Viscosity
Nyga, A, Munoz, JJ, Dercksen, S, Fornabaio, G, Uroz, M, Trepat, X, Baum, B, Matthews, HK, Conte, V, (2021). Oncogenic RAS instructs morphological transformation of human epithelia via differential tissue mechanics Science Advances 7, eabg6467
[Figure: see text].
JTD Keywords: activation, cell extrusion, contraction, drives, homeostasis, interface, junctions, kinase, tension, Adhesion, Article, Cell membranes, Chemical activation, Cytology, E-cadherin, Epithelial monolayers, Epithelium, Homoeostasis, Human, Mechanical instabilities, Monolayers, Morphological transformations, Morphology, Normal tissue, Oncogenics, Soft substrates, Substrates, Tissue, Tissue mechanics, Tissue morphology, Tumor development
Avalos-Padilla, Y, Georgiev, VN, Dimova, R, (2021). ESCRT-III induces phase separation in model membranes prior to budding and causes invagination of the liquid-ordered phase BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1863, 183689
Membrane fission triggered by the endosomal sorting complex required for transport (ESCRT) is an important process observed in several pathogenic and non-pathogenic cellular events. From a synthetic-biology viewpoint, ESCRT proteins represent an interesting machinery for the construction of cell mimetic sub-compartments produced by fission. Since their discovery, the studies on ESCRT-III-mediated action, have mainly focused on protein dynamics, ignoring the role of lipid organization and membrane phase state. Recently, it has been suggested that membrane buds formed by the action of ESCRT-III are generated from transient microdomains in endosomal membranes. However, the interplay between membrane domain formation and ESCRT remodeling pathways has not been investigated. Here, giant unilamellar vesicles made of ternary lipid mixtures, either homogeneous in phase or exhibiting liquid-ordered/liquid-disordered phase coexistence, were employed as a model membrane system. These vesicles were incubated with purified recombinant ESCRT-III proteins from the parasite Entamoeba histolytica. In homogeneous membranes, we observe that EhVps32 can trigger domain formation while EhVps20 preferentially co-localizes in the liquid disordered phase. The addition of EhVps24 appears to induce the formation of intraluminal vesicles produced from the liquid-ordered phase. In phase separated membranes, the intraluminal vesicles are also generated from the liquid-ordered phase and presumably emerge from the phase boundary region. Our findings reinforce the hypothesis that ESCRT-mediated remodeling depends on the membrane phase state. Furthermore, the obtained results point to a potential synthetic biology approach for establishing eukaryotic mimics of artificial cells with microcompartments of specific membrane composition, which can also differ from that of the mother vesicle.
JTD Keywords: cell-membranes, coexistence, complex, escrt-iii, fission, guvs, lipid domains, lipid rafts, membrane fission, microcompartments, microscopy, phase separation, plasma-membrane, protein microarrays, structural basis, ternary mixtures, Escrt-iii, Giant unilamellar vesicles, Guvs, Lipid domains, Membrane fission, Microcompartments, Phase separation, Ternary mixtures
Mestre, R, García, N, Patiño, T, Guix, M, Fuentes, J, Valerio-Santiago, M, Almiñana, N, Sánchez, S, (2021). 3D-bioengineered model of human skeletal muscle tissue with phenotypic features of aging for drug testing purposes Biofabrication 13, 45011
Three-dimensional engineering of skeletal muscle is becoming increasingly relevant for tissue engineering, disease modeling and bio-hybrid robotics, where flexible, versatile and multidisciplinary approaches for the evaluation of tissue differentiation, functionality and force measurement are required. This works presents a 3D-printed platform of bioengineered human skeletal muscle which can efficiently model the three-dimensional structure of native tissue, while providing information about force generation and contraction profiles. Proper differentiation and maturation of myocytes is demonstrated by the expression of key myo-proteins using immunocytochemistry and analyzed by confocal microscopy, and the functionality assessed via electrical stimulation and analysis of contraction kinetics. To validate the flexibility of this platform for complex tissue modeling, the bioengineered muscle is treated with tumor necrosis factor α to mimic the conditions of aging, which is supported by morphological and functional changes. Moreover, as a proof of concept, the effects of Argireline® Amplified peptide, a cosmetic ingredient that causes muscle relaxation, are evaluated in both healthy and aged tissue models. Therefore, the results demonstrate that this 3D-bioengineered human muscle platform could be used to assess morphological and functional changes in the aging process of muscular tissue with potential applications in biomedicine, cosmetics and bio-hybrid robotics.
JTD Keywords: 3d bioprinting, bio-actuator, drug testing, human skeletal muscle, muscle ageing, platform, tnf-alpha, 3d bioprinting, Aged, Aging, Bio-actuator, Bioprinting, Drug testing, Human skeletal muscle, Humans, Muscle ageing, Muscle, skeletal, Necrosis-factor-alpha, Pharmaceutical preparations, Tissue engineering
Rodríguez-Contreras, A, Torres, D, Rafik, B, Ortiz-Hernandez, M, Ginebra, MP, Calero, JA, Manero, JM, Ruperez, E, (2021). Bioactivity and antibacterial properties of calcium- and silver-doped coatings on 3D printed titanium scaffolds SURFACE & COATINGS TECHNOLOGY 421, 127476
One of the major problems faced by metallic implants is the high probability of bacterial infections, with significant consequences for the patient. In this work, a thermochemical treatment is proposed to obtain silver-doped calcium titanate coatings on the Ti surface to improve the bioactivity of porous 3D-printed Ti structures and simultaneously provide them with antibacterial properties. A complete characterization of the new coating, the study of the ion release and the analysis of its cytotoxicity were carried out together with evaluation of the natural apatite forming in simulated body fluid (SBF). Moreover, the antibacterial properties of the coatings were assessed against Pseudomona aeruginosa and Escherichia coli as gram-negative and Staphylococcus aureus and Staphylococcus epidermidis as gram-positive bacterial strains. Ag ions were integrated into the Ca titanate layer and Ag nanoparticles were formed within the entire 3D Ti surface. Ca and Ag ions were released from both porous and solid samples into the Hanks' solution for 48 h. The treated surfaces showed no cytotoxicity and an apatite layer precipitated on the entire porous surface when the samples were immersed in SBF. The release of Ag from the surface had a strong antibacterial effect and prevented bacterial adhesion and proliferation on the surface. Moreover, the nanostructured topography of the coating resulted also in a reduction of bacterial adhesion and proliferation, even in absence of Ag. In conclusion, the cost-effective approach here reported provided protection against the most predominant bacterial colonizers to the Ti porous implants, while maintaining their bioactivity.
JTD Keywords: 3d-printing, alkaline, antibacterial activity, arthroplasty, bacterial adhesion, biomaterials, generation, ions, nanoparticles, osseointegration, silver, surface-layer, titanium implants, toxicity, 3d-printing, Antibacterial activity, Biomaterials, Porous structures, Silver, Ti metal, Titanium implants
Berishvili, E, Casiraghi, F, Amarelli, C, Scholz, H, Piemonti, L, Berney, T, Montserrat, N, (2021). Mini-organs forum: how to advance organoid technology to organ transplant community TRANSPLANT INTERNATIONAL 34, 1588-1593
The generation of human mini-organs, the so-called organoids, is one of the biggest scientific advances in regenerative medicine. This technology exploits traditional three-dimensional culture techniques that support cell-autonomous self-organization responses of stem cells to derive micrometer to millimeter size versions of human organs. The convergence of the organoid technology with organ transplantation is still in its infancy but this alliance is expected to open new venues to change the way we conduct both transplant and organoid research. In this Forum we provide a summary on early achievements facilitating organoid derivation and culture. We further discuss on early advances of organoid transplantation also offering a comprehensive overview of current limitations and challenges to instruct organoid maturation. We expect that this Forum sets the ground for initial discussions between stem cell biologists, bioengineers, and the transplant community to better direct organoid basic research to advance the organ transplantation field.
JTD Keywords: in-vitro, matrix, mice, organoids, regenerative medicine, vivo, Intestinal stem-cell, Organoids, Regenerative medicine
de Oliveira, LF, Braga, SCGN, Augusto, F, Poppi, RJ, (2021). Correlating comprehensive two-dimensional gas chromatography volatile profiles of chocolate with sensory analysis Brazilian Journal of Analytical Chemistry 8, 131-140
The identification of key components relevant to sensory perception of quality from commercial chocolate samples was accomplished after chemometric processing of GC×GC-MS (Comprehensive Two-dimensional Gas Chromatography with Mass Spectrometric Detection) profiles corresponding to HS-SPME (Headspace Solid Phase Microextraction) extracts of the samples. Descriptive sensory evaluation of samples was carried out using Optimized Descriptive Profile (ODP) procedures, where sensory attributes of 24 commercial chocolate samples were used to classify them in two classes (low and high chocolate flavor). 2D Fisher Ratio analysis was applied to four-way chromatographic data tensors (1st dimension retention time 1tR × 2nd dimension retention time 2tR × m/z × sample), to identify the crucial areas on the chromatograms that resulted on ODP class separation on Principal Component Analysis (PCA) scores plot. Comparing the relevant sections of the chromatograms to the analysis of the corresponding mass spectra, it was possible to assess that most of the information regarding the sample main sensory attributes can be related to only 14 compounds (2,5-dimethylpyrazine, 2,6-dimethyl-4-heptanol, 1-octen-3-ol, trimethylpyrazine, β-pinene, o-cimene, 2-ethyl-3,5-dimethylpyrazine, tetramethylpyrazine, benzaldehyde, 1,3,5-trimethylbenzene, 6-methyl-5-hepten-2-one, limonene, benzeneethanol and 1,1-dimethylbutylbenzene) among the complex blend of volatiles found on these extremely complex samples.
JTD Keywords: classification, cocoa, dark chocolate, feature-selection, fisher ratio, gcxgc-ms, impact, olfactometry, principal component analysis, sensorial analysis, Chocolate flavor, Fisher ratio, Flight mass-spectrometry, Gc×gc-ms, Principal component analysis, Sensorial analysis
Konka, J, Espanol, M, Bosch, BM, de Oliveira, E, Ginebra, MP, (2021). Maturation of biomimetic hydroxyapatite in physiological fluids: a physicochemical and proteomic study MATERIALS TODAY BIO 12, 100137
Biomimetic calcium-deficient hydroxyapatite (CDHA) as a bioactive material exhibits exceptional intrinsic osteoinductive and osteogenic properties because of its nanostructure and composition, which promote a favorable microenvironment. Its high reactivity has been hypothesized to play a relevant role in the in vivo performance, mediated by the interaction with the biological fluids, which is amplified by its high specific surface area. Paradoxically, this high reactivity is also behind the in vitro cytotoxicity of this material, especially pro-nounced in static conditions. The present work explores the structural and physicochemical changes that CDHA undergoes in contact with physiological fluids and to investigate its interaction with proteins. Calcium-deficient hydroxyapatite discs with different micro/nanostructures, coarse (C) and fine (F), were exposed to cell-free complete culture medium over extended periods of time: 1, 7, 14, 21, 28, and 50 days. Precipitate formation was not observed in any of the materials in contact with the physiological fluid, which would indicate that the ionic exchanges were linked to incorporation into the crystal structure of CDHA or in the hydrated layer. In fact, CDHA experienced a maturation process, with a progressive increase in crystallinity and the Ca/P ratio, accompanied by an uptake of Mg and a B-type carbonation process, with a gradual propagation into the core of the samples. However, the reactivity of biomimetic hydroxyapatite was highly dependent on the specific surface area and was amplified in nanosized needle-like crystal structures (F), whereas in coarse specimens the ionic exchanges were restricted to the surface, with low penetration in the material bulk. In addition to showing a higher protein adsorption on F substrates, the proteomics study revealed the existence of protein selectivity to-ward F or C microstructures, as well as the capability of CDHA, and more remarkably of F-CDHA, to concentrate specific proteins from the culture medium. Finally, a substantial improvement in the material's ability to support cell proliferation was observed after the CDHA maturation process.
JTD Keywords: calcium phosphates, ion exchange, nanostructure, protein adsorption, Biological-systems, Biomaterials, Biomimetic hydroxyapatites, Biomimetics, Bone-formation, Calcium deficient hydroxyapatite, Calcium phosphate, Calcium phosphates, Cell proliferation, Crystal structure, Crystallinity, Crystals structures, Culture medium, Growth, High reactivity, Hydroxyapatite, In-vitro, Ion exchange, Ionic exchange, Molecular biology, Nanocrystalline apatites, Nanostructure, Nanostructures, Octacalcium phosphate, Physicochemical studies, Physiological fluids, Physiology, Protein adsorption, Proteins, Proteomic studies, Raman spectroscopy, Serum-albumin, Specific surface area
Hamouda, I, Labay, C, Cvelbar, U, Ginebra, MP, Canal, C, (2021). Selectivity of direct plasma treatment and plasma-conditioned media in bone cancer cell lines Scientific Reports 11, 17521
Atmospheric pressure plasma jets have been shown to impact several cancer cell lines, both in vitro and in vivo. These effects are based on the biochemistry of the reactive oxygen and nitrogen species generated by plasmas in physiological liquids, referred to as plasma-conditioned liquids. Plasma-conditioned media are efficient in the generation of reactive species, inducing selective cancer cell death. However, the concentration of reactive species generated by plasma in the cell culture media of different cell types can be highly variable, complicating the ability to draw precise conclusions due to the differential sensitivity of different cells to reactive species. Here, we compared the effects of direct and indirect plasma treatment on non-malignant bone cells (hOBs and hMSCs) and bone cancer cells (SaOs-2s and MG63s) by treating the cells directly or exposing them to previously treated cell culture medium. Biological effects were correlated with the concentrations of reactive species generated in the liquid. A linear increase in reactive species in the cell culture medium was observed with increased plasma treatment time independent of the volume treated. Values up to 700 µM for H2O2 and 140 µM of NO2− were attained in 2 mL after 15 min of plasma treatment in AdvDMEM cell culture media. Selectivity towards bone cancer cells was observed after both direct and indirect plasma treatments, leading to a decrease in bone cancer cell viability at 72 h to 30% for the longest plasma treatment times while maintaining the survival of non-malignant cells. Therefore, plasma-conditioned media may represent the basis for a potentially novel non-invasive technique for bone cancer therapy.
JTD Keywords: expression, in-vitro, jet, mechanisms, nitrate, nitrite, osteosarcoma cells, reactive oxygen, Cold atmospheric plasma
Duran, J, Hervera, A, Markussen, KH, Varea, O, Lopez-Soldado, I, Sun, RC, del Rio, JA, Gentry, MS, Guinovart, JJ, (2021). Astrocytic glycogen accumulation drives the pathophysiology of neurodegeneration in Lafora disease BRAIN 144, 2349-2360
The hallmark of Lafora disease, a fatal neurodegenerative disorder, is the accumulation of intracellular glycogen aggregates called Lafora bodies. Until recently, it was widely believed that brain Lafora bodies were present exclusively in neurons and thus that Lafora disease pathology derived from their accumulation in this cell population. However, recent evidence indicates that Lafora bodies are also present in astrocytes. To define the role of astrocytic Lafora bodies in Lafora disease pathology, we deleted glycogen synthase specifically from astrocytes in a mouse model of the disease (malin(KO)). Strikingly, blocking glycogen synthesis in astrocytes-thus impeding Lafora bodies accumulation in this cell type-prevented the increase in neurodegeneration markers, autophagy impairment, and metabolic changes characteristic of the malin(KO) model. Conversely, mice that over-accumulate glycogen in astrocytes showed an increase in these markers. These results unveil the deleterious consequences of the deregulation of glycogen metabolism in astrocytes and change the perspective that Lafora disease is caused solely by alterations in neurons.
JTD Keywords: Bodies, Deficient mice, Epilepsy, Glycogen, Impairment, Lafora disease, Malin, Modulation, Mouse model, Neurodegeneration, Neuroinflammation, Neurons, Progressive myoclonus epilepsy, Seizure susceptibility, Synthase
Castillo-Escario, Y, Kumru, H, Valls-Solé, J, García-Alen, L, Jané, R, Vidal, J, (2021). Quantitative evaluation of trunk function and the StartReact effect during reaching in patients with cervical and thoracic spinal cord injury Journal of Neural Engineering 18, 0460d2
Objective. Impaired trunk stability is frequent in spinal cord injury (SCI), but there is a lack of quantitative measures for assessing trunk function. Our objectives were to: (a) evaluate trunk muscle activity and movement patterns during a reaching task in SCI patients, (b) compare the impact of cervical (cSCI) and thoracic (tSCI) injuries in trunk function, and (c) investigate the effects of a startling acoustic stimulus (SAS) in these patients. Approach. Electromyographic (EMG) and smartphone accelerometer data were recorded from 15 cSCI patients, nine tSCI patients, and 24 healthy controls, during a reaching task requiring trunk tilting. We calculated the response time (RespT) until pressing a target button, EMG onset latencies and amplitudes, and trunk tilt, lateral deviation, and other movement features from accelerometry. Statistical analysis was applied to analyze the effects of group (cSCI, tSCI, control) and condition (SAS, non-SAS) in each outcome measure. Main results. SCI patients, especially those with cSCI, presented significantly longer RespT and EMG onset latencies than controls. Moreover, in SCI patients, forward trunk tilt was accompanied by significant lateral deviation. RespT and EMG latencies were remarkably shortened by the SAS (the so-called StartReact effect) in tSCI patients and controls, but not in cSCI patients, who also showed higher variability. Significance. The combination of EMG and smartphone accelerometer data can provide quantitative measures for the assessment of trunk function in SCI. Our results show deficits in postural control and compensatory strategies employed by SCI patients, including delayed responses and higher lateral deviations, possibly to improve sitting balance. This is the first study investigating the StartReact responses in trunk muscles in SCI patients and shows that the SAS significantly accelerates RespT in tSCI, but not in cSCI, suggesting an increased cortical control exerted by these patients.
JTD Keywords: accelerometer, electromyography, impairment, individuals, movements, postural stability, reaction-time, reliability, sitting balance, smartphone, spinal cord injury, startle, startreact, strategies, stroke, trunk, Accelerometer, Electromyography, Sitting balance, Smartphone, Spinal cord injury, Startreact, Trunk
Campo-Pérez, V, Cendra, MD, Julián, E, Torrents, E, (2021). Easily applicable modifications to electroporation conditions improve the transformation efficiency rates for rough morphotypes of fast-growing mycobacteria New Biotechnology 63, 10-18
© 2021 Elsevier B.V. Electroporation is the most widely used and efficient method to transform mycobacteria. Through this technique, fast- and slow-growing mycobacteria with smooth and rough morphotypes have been successfully transformed. However, transformation efficiencies differ widely between species and strains. In this study, the smooth and rough morphotypes of Mycobacteroides abscessus and Mycolicibacterium brumae were used to improve current electroporation procedures for fast-growing rough mycobacteria. The focus was on minimizing three well-known and challenging limitations: the mycobacterial restriction-modification systems, which degrade foreign DNA; clump formation of electrocompetent cells before electroporation; and electrical discharges during pulse delivery, which were reduced by using salt-free DNA solution. Herein, different strategies are presented that successfully address these three limitations and clearly improve the electroporation efficiencies over the current procedures. The results demonstrated that combining the developed strategies during electroporation is highly recommended for the transformation of fast-growing rough mycobacteria.
JTD Keywords: clump, desalted dna, electroporation, mycobacteria, mycobacteroides abscessus, mycolicibacterium brumae, Clump, Desalted dna, Electroporation, Mycobacteria, Mycobacteroides abscessus, Mycolicibacterium brumae
Andreu, I, Falcones, B, Hurst, S, Chahare, N, Quiroga, X, Le Roux, AL, Kechagia, Z, Beedle, AEM, Elosegui-Artola, A, Trepat, X, Farre, R, Betz, T, Almendros, I, Roca-Cusachs, P, (2021). The force loading rate drives cell mechanosensing through both reinforcement and cytoskeletal softening Nature Communications 12, 4229
Cell response to force regulates essential processes in health and disease. However, the fundamental mechanical variables that cells sense and respond to remain unclear. Here we show that the rate of force application (loading rate) drives mechanosensing, as predicted by a molecular clutch model. By applying dynamic force regimes to cells through substrate stretching, optical tweezers, and atomic force microscopy, we find that increasing loading rates trigger talin-dependent mechanosensing, leading to adhesion growth and reinforcement, and YAP nuclear localization. However, above a given threshold the actin cytoskeleton softens, decreasing loading rates and preventing reinforcement. By stretching rat lungs in vivo, we show that a similar phenomenon may occur. Our results show that cell sensing of external forces and of passive mechanical parameters (like tissue stiffness) can be understood through the same mechanisms, driven by the properties under force of the mechanosensing molecules involved. Cells sense mechanical forces from their environment, but the precise mechanical variable sensed by cells is unclear. Here, the authors show that cells can sense the rate of force application, known as the loading rate, with effects on YAP nuclear localization and cytoskeletal stiffness remodelling.
JTD Keywords: Actin cytoskeleton, Actin filament, Actin-filament, Adhesion, Animal, Animals, Atomic force microscopy, Breathing, Cell, Cell adhesion, Cell culture, Cell nucleus, Cells, cultured, Cytoplasm, Extracellular-matrix, Fibroblast, Fibroblasts, Fibronectin, Frequency, Gene knockdown, Gene knockdown techniques, Genetics, Germfree animal, Integrin, Intracellular signaling peptides and proteins, Knockout mouse, Lung, Male, Mechanotransduction, Mechanotransduction, cellular, Metabolism, Mice, Mice, knockout, Microscopy, atomic force, Mouse, Optical tweezers, Paxillin, Physiology, Primary cell culture, Pxn protein, mouse, Rat, Rats, Rats, sprague-dawley, Respiration, Signal peptide, Softening, Specific pathogen-free organisms, Sprague dawley rat, Stress, Substrate, Substrate rigidity, Talin, Talin protein, mouse, Tln1 protein, mouse, Tln2 protein, mouse, Traction, Transmission, Ultrastructure, Yap-signaling proteins, Yap1 protein, rat
Riefolo, F, Sortino, R, Matera, C, Claro, E, Preda, B, Vitiello, S, Traserra, S, Jimenez, M, Gorostiza, P, (2021). Rational Design of Photochromic Analogues of Tricyclic Drugs JOURNAL OF MEDICINAL CHEMISTRY 64, 9259-9270
Tricyclic chemical structures are the core of many important drugs targeting all neurotransmitter pathways. These medicines enable effective therapies to treat from peptic ulcer disease to psychiatric disorders. However, when administered systemically, they cause serious adverse effects that limit their use. To obtain localized and on-demand pharmacological action using light, we have designed photoisomerizable ligands based on azobenzene that mimic the tricyclic chemical structure and display reversibly controlled activity. Pseudo-analogues of the tricyclic antagonist pirenzepine demonstrate that this is an effective strategy in muscarinic acetylcholine receptors, showing stronger inhibition upon illumination both in vitro and in cardiac atria ex vivo. Despite the applied chemical modifications to make pirenzepine derivatives sensitive to light stimuli, the most potent candidate of the set, cryptozepine-2, maintained a moderate but promising M-1 vs M-2 subtype selectivity. These photoswitchable crypto-azologs of tricyclic drugs might open a general way to spatiotemporally target their therapeutic action while reducing their systemic toxicity and adverse effects.
JTD Keywords: Binding, Dose-response relationship, drug, Drug design, Humans, M1, Molecular structure, Muscarinic antagonists, Pirenzepine, Rat-brain, Receptor, Receptors, muscarinic, Structure-activity relationship
Velasco-Mallorqui, F, Rodriguez-Comas, J, Ramon-Azcon, J, (2021). Cellulose-based scaffolds enhance pseudoislets formation and functionality Biofabrication 13, 35044
In vitro research for the study of type 2 diabetes (T2D) is frequently limited by the availability of a functional model for islets of Langerhans. To overcome the limitations of obtaining pancreatic islets from different sources, such as animal models or human donors, immortalized cell lines as the insulin-producing INS1E beta-cells have appeared as a valid alternative to model insulin-related diseases. However, immortalized cell lines are mainly used in flat surfaces or monolayer distributions, not resembling the spheroid-like architecture of the pancreatic islets. To generate islet-like structures, the use of scaffolds appeared as a valid tool to promote cell aggregations. Traditionally-used hydrogel encapsulation methods do not accomplish all the requisites for pancreatic tissue engineering, as its poor nutrient and oxygen diffusion induces cell death. Here, we use cryogelation technology to develop a more resemblance scaffold with the mechanical and physical properties needed to engineer pancreatic tissue. This study shows that carboxymethyl cellulose (CMC) cryogels prompted cells to generate beta-cell clusters in comparison to gelatin-based scaffolds, that did not induce this cell organization. Moreover, the high porosity achieved with CMC cryogels allowed us to create specific range pseudoislets. Pseudoislets formed within CMC-scaffolds showed cell viability for up to 7 d and a better response to glucose over conventional monolayer cultures. Overall, our results demonstrate that CMC-scaffolds can be used to control the organization and function of insulin-producing beta-cells, representing a suitable technique to generate beta-cell clusters to study pancreatic islet function.
JTD Keywords: biomaterial, cryogel, pancreatic islets, scaffold, tissue engineering, ?-cell, Animals, Architecture, Beta-cell, Beta-cell heterogeneity, Biomaterial, Carboxymethyl cellulose, Cell culture, Cell death, Cell engineering, Cell organization, Cells, Cellulose, Cryogel, Cryogels, Cytoarchitecture, Delivery, Diabetes mellitus, type 2, Encapsulation methods, Gelation, Gene-expression, Humans, Immortalized cells, Insulin, Insulin secretory responses, Islets of langerhans, Islets of langerhans transplantation, Mechanical and physical properties, Monolayer culture, Monolayers, Pancreatic islets, Pancreatic tissue, Pancreatic-islets, Proliferation, Scaffold, Scaffolds, Scaffolds (biology), Size, Tissue, Tissue engineering, Tissue scaffolds, Β-cell
Molina, BG, Valle, LJ, Casanovas, J, Lanzalaco, S, Pérez-Madrigal, MM, Turon, P, Armelin, E, Alemán, C, (2021). Plasma-Functionalized Isotactic Polypropylene Assembled with Conducting Polymers for Bacterial Quantification by NADH Sensing Advanced Healthcare Materials 10, 2100425
Rapid detection of bacterial presence on implantable medical devices is essential to prevent biofilm formation, which consists of densely packed bacteria colonies able to withstand antibiotic-mediated killing. In this work, a smart approach is presented to integrate electrochemical sensors for detecting bacterial infections in biomedical implants made of isotactic polypropylene (i-PP) using chemical assembly. The electrochemical detection is based on the capacity of conducting polymers (CPs) to detect extracellular nicotinamide adenine dinucleotide (NADH) released from cellular respiration of bacteria, which allows distinguishing prokaryotic from eukaryotic cells. Oxygen plasma-functionalized free-standing i-PP, coated with a layer (≈1.1 µm in thickness) of CP nanoparticles obtained by oxidative polymerization, is used as working electrode for the anodic polymerization of a second CP layer (≈8.2 µm in thickness), which provides very high electrochemical activity and stability. The resulting layered material, i-PP /CP , detects the electro-oxidation of NADH in physiological media with a sensitivity 417 µA cm and a detection limit up to 0.14 × 10 m, which is below the concentration of extracellular NADH found for bacterial cultures of biofilm-positive and biofilm-negative strains. f 2 −2 −3
JTD Keywords: bacteria respiration, bacteria sensors, biomedical implants, flexible sensors, poly(3,4-ethylenedioxythiophene), Bacteria respiration, Bacteria sensors, Biomedical implants, Flexible sensors, Poly(3,4-ethylenedioxythiophene)
Cereta, AD, Oliveira, VR, Costa, IP, Guimaraes, LL, Afonso, JPR, Fonseca, AL, de Sousa, ART, Silva, GAM, Mello, DACPG, de Oliveira, LVF, da Palma, RK, (2021). Early Life Microbial Exposure and Immunity Training Effects on Asthma Development and Progression Frontiers in Medicine 8, 662262
Asthma is the most common inflammatory disease affecting the lungs, which can be caused by intrauterine or postnatal insults depending on the exposure to environmental factors. During early life, the exposure to different risk factors can influence the microbiome leading to undesired changes to the immune system. The modulations of the immunity, caused by dysbiosis during development, can increase the susceptibility to allergic diseases. On the other hand, immune training approaches during pregnancy can prevent allergic inflammatory diseases of the airways. In this review, we focus on evidence of risk factors in early life that can alter the development of lung immunity associated with dysbiosis, that leads to asthma and affect childhood and adult life. Furthermore, we discuss new ideas for potential prevention strategies that can be applied during pregnancy and postnatal period.
JTD Keywords: asthma, dysbiosis, early life immunity, lung microbiome, Adulthood, Antibiotic exposure, Asthma, Childhood, Disease, Disease exacerbation, Dysbiosis, Early life immunity, Gut microbiome, Human, Immunity, Intestine flora, Lung development, Lung microbiome, Lung microbiota, Nonhuman, Perinatal period, Pregnancy, Prevention, Prevention strategies, Review, Risk, Risk factor, Sensitization, Supplementation, Vitamin-d, Wheeze
Parra-Monreal, V, Ortega-Machuca, MA, Ramin-Azcin, J, Svendsen, W, Romano-Rodriguez, A, Moreno-Sereno, M, (2021). Detection of cytokines in skeletal muscle tissue using optical SPR sensing platform Proceedings of the 2021 13th Spanish Conference on Electron Devices, CDE 2021 , 102-105
In this work we have explored the use of a Surface Plasmon resonance (SPR) phenomenon for the detection of interleukin-6 (IL-6), a pro-inflammatory cytokine. It plays an important role in the muscle tissues, having direct relation with muscle contraction and, thus, it is considered a biomarker for some types of muscular dystrophies. Here we show that SPR can be used as a real-time monitoring of the shift of the reflectance dip of a gold diffraction grating in front to the antibody adhesion to gold.
JTD Keywords: antibodies, gratings, interleukin-6 (il-6), proteins, Antibodies, Gratings, Interleukin-6 (il-6), Proteins, Surface plasmon resonance
Covington, JA, Marco, S, Persaud, KC, Schiffman, SS, Nagle, HT, (2021). Artificial Olfaction in the 21st Century IEEE SENSORS JOURNAL 21, 12969-12990
The human olfactory system remains one of the most challenging biological systems to replicate. Humans use it without thinking, where it can equally offer protection from harm and bring enjoyment in equal measure. It is the system’s ability to detect and analyze complex odors, without the need for specialized infra-structure, that is the envy of many scientists. The field of artificial olfaction has recruited and stimulated interdisciplinary research and commercial development for several applications that include malodor measurement, medical diagnostics, food and beverage quality, environment and security. Over the last century, innovative engineers and scientists have been focused on solving a range of problems associated with measurement and control of odor. The IEEE Sensors Journal has published Special Issues on olfaction in 2002 and 2012. Here we continue that coverage. In this article, we summarize early work in the 20th Century that served as the foundation upon which we have been building our odor-monitoring instrumental and measurement systems. We then examine the current state of the art that has been achieved over the last two decades as we have transitioned into the 21st Century. Much has been accomplished, but great progress is needed in sensor technology, system design, product manufacture and performance standards. In the final section, we predict levels of performance and ubiquitous applications that will be realized during in the mid to late 21st Century.
JTD Keywords: air-quality, breath analysis, calibration transfer, chemical sensor arrays, chemosensor arrays, drift compensation, electronic nose, gas sensors, headspace sampling, machine learning, machine olfaction, odor detection, plume structure, voc analysis, Artificial olfaction, Electrodes, Electronic nose, Electronic nose technology, Headspace sampling, Instruments, Machine learning, Machine olfaction, Monitoring, Odor detection, Olfactory, Sensor phenomena and characterization, Sensors, Temperature sensors, Voc analysis
Torp, N, Israelsen, M, Madsen, B, Lutz, P, Jansen, C, Strassburg, C, Mortensen, C, Knudsen, AW, Sorensen, GL, Holmskov, U, Schlosser, A, Thiele, M, Trebicka, J, Krag, A, (2021). Level of MFAP4 in ascites independently predicts 1-year transplant-free survival in patients with cirrhosis JHEP Reports 3, 100287
Background & Aims: Prognostic models of cirrhosis underestimate disease severity for patients with cirrhosis and ascites. Microfibrillar-associated protein 4 (MFAP4) is an extracellular matrix protein linked to hepatic neoangiogenesis and fibrogenesis. We investigated ascites MFAP4 as a predictor of transplant-free survival in patients with cirrhosis and ascites. Methods: A dual-centre observational study of patients with cirrhosis and ascites recruited consecutively in relation to a paracentesis was carried out. Patients were followed up for 1 year, until death or liver transplantation (LTx). Ascites MFAP4 was tested with the model for end-stage liver disease (MELD-Na), CLIF Consortium Acute Decompensation (CLIF-C AD), and Child-Pugh score in Cox regression models. Results: Ninety-three patients requiring paracentesis were included. Median ascites MFAP4 was 29.7 U/L [22.3–41.3], and MELD-Na was 19 [16–23]. A low MELD-Na score (<20) was observed in 49 patients (53%). During follow-up, 20 patients died (22%), and 6 received LTx (6%). High ascites MFAP4 (>29.7 U/L) was associated with 1-year transplant-free survival (p = 0.002). In Cox regression, ascites MFAP4 and MELD-Na independently predicted 1-year transplant-free survival (hazard ratio [HR] = 0.97, p = 0.03, and HR = 1.08, p = 0.01, respectively). Ascites MFAP4 and CLIF-C AD also predicted survival independently (HR = 0.96, p = 0.02, and HR = 1.05, p = 0.03, respectively), whereas only ascites MFAP4 did, controlling for the Child-Pugh score (HR = 0.97, p = 0.03, and HR = 1.18, p = 0.16, respectively). For patients with MELD-Na <20, ascites MFAP4 but not ascites protein predicted 1-year transplant-free survival (HR 0.91, p = 0.02, and HR = 0.94, p = 0.17, respectively). Conclusions: Ascites MFAP4 predicts 1-year transplant-free survival in patients with cirrhosis and ascites. In patients with low MELD-Na scores, ascites MFAP4, but not total ascites protein, significantly predicted 1-year transplant-free survival. Lay summary: Patients with cirrhosis who have fluid in the abdomen, ascites, are at an increased risk of death and in need for liver transplantation. Our study identified patients with ascites and a poor prognosis by measuring microfibrillar associated protein 4 (MFAP4), a protein present in the abdominal fluid. Patients with low levels of the MFAP4 protein are at particularly increased risk of death or liver transplantation, suggesting that clinical care should be intensified in this group of patients. © 2021 The Authors
JTD Keywords: biomarker, clif-c ad, clif consortium acute decompensation, cps, child-pugh score, crp, c-reactive protein, ct, computed tomography, decompensated, ecm, extracellular matrix, fibrosis, fluid protein, gfr, glomerular filtration rate, hr, hazard ratio, inr, internationalised normal ratio, liver disease, liver-cirrhosis, ltx, liver transplantation, markers, meld-na, model for end-stage liver disease, mfap4, microfibrillar associated protein 4, mortality, nash, non-alcoholic steatohepatitis, natural-history, prognosis, risk-factors, sbp, spontaneous bacterial peritonitis, scores, stage, Biomarker, Decompensated, Egfr, estimated gfr, Fibrosis, Liver disease, Mortality, Prognosis, Spontaneous bacterial peritonitis
Minguela, J, Muller, DW, Mucklich, F, Llanes, L, Ginebra, MP, Roa, JJ, Mas-Moruno, C, (2021). Peptidic biofunctionalization of laser patterned dental zirconia: A biochemical-topographical approach Materials Science & Engineering C-Materials for Biological Applications 125, 112096
A dual approach employing peptidic biofunctionalization and laser micro-patterns on dental zirconia was explored, with the aim of providing a flexible tool to improve tissue integration of restorations. Direct laser interference patterning with a femtosecond Ti:Sapphire laser was employed, and two periodic grooved patterns were produced with a periodicity of 3 and 10 μm. A platform containing the cell-adhesive RGD and the osteogenic DWIVA peptides was used to functionalize the grooved surfaces. Topography and surface damage were characterized by confocal laser scanning (CLSM), scanning electron and scanning transmission electron microscopy techniques. The surface patterns exhibited a high homogeneity and subsurface damage was found in the form of nano-cracks and nano-pores, at the bottom of the valleys. Accelerated tests in water steam were carried out to assess hydrothermal degradation resistance, which slightly decreased after the laser treatment. Interestingly, the detrimental effects of the laser modification were reverted by a post-laser thermal treatment. The attachment of the molecule was verified trough fluorescence CLSM and X-ray photoelectron spectroscopy. Finally, the biological properties of the surfaces were studied in human mesenchymal stem cells. Cell adhesion, morphology, migration and differentiation were investigated. Cells on grooved surfaces displayed an elongated morphology and aligned along the patterns. On these surfaces, migration was greatly enhanced along the grooves, but also highly restricted in the perpendicular direction as compared to flat specimens. After biofunctionalization, cell number and cell area increased and well-developed cell cytoskeletons were observed. However, no effects on cell migration were found for the peptidic platform. Although some osteogenic potential was found in specimens grooved with a periodicity of 10 μm, the largest effects were observed from the biomolecule, which favored upregulation of several genes related to osteoblastic differentiation in all the surfaces.
JTD Keywords: alumina toughened zirconia, cell alignment, grain-size, implants, interference, laser patterning, osteogenic differentiation, osteointegration, peptides, surface functionalization, surface-topography, tissue, titanium surface, Laser patterning, Low-temperature degradation, Osteointegration, Peptides, Surface functionalization, Zirconia
Checa, M, Millan-Solsona, R, Mares, AG, Pujals, S, Gomila, G, (2021). Dielectric imaging of fixed hela cells by in‐liquid scanning dielectric force volume microscopy Nanomaterials 11, 1402
Mapping the dielectric properties of cells with nanoscale spatial resolution can be an im-portant tool in nanomedicine and nanotoxicity analysis, which can complement structural and mechanical nanoscale measurements. Recently we have shown that dielectric constant maps can be obtained on dried fixed cells in air environment by means of scanning dielectric force volume mi-croscopy. Here, we demonstrate that such measurements can also be performed in the much more challenging case of fixed cells in liquid environment. Performing the measurements in liquid media contributes to preserve better the structure of the fixed cells, while also enabling accessing the local dielectric properties under fully hydrated conditions. The results shown in this work pave the way to address the nanoscale dielectric imaging of living cells, for which still further developments are required, as discussed here.
JTD Keywords: atomic force microscopy (afm), capacitance, constant, dielectric properties, electrostatic force microscopy (efm), functional microscopy, nanoscale, scanning dielectric microscopy (sdm), Atomic force microscopy (afm), Dielectric properties, Dielectrophoretic separation, Electrostatic force microscopy (efm), Functional micros-copy, Functional microscopy, Scanning dielectric microscopy (sdm), Scanning probe microscopy (spm)
Mesquida-Veny, F, Del Río, JA, Hervera, A, (2021). Macrophagic and microglial complexity after neuronal injury PROGRESS IN NEUROBIOLOGY 200, 101970
© 2020 Elsevier Ltd Central nervous system (CNS) injuries do not heal properly in contrast to normal tissue repair, in which functional recovery typically occurs. The reason for this dichotomy in wound repair is explained in part by macrophage and microglial malfunction, affecting both the extrinsic and intrinsic barriers to appropriate axonal regeneration. In normal healing tissue, macrophages promote the repair of injured tissue by regulating transitions through different phases of the healing response. In contrast, inflammation dominates the outcome of CNS injury, often leading to secondary damage. Therefore, an understanding of the molecular mechanisms underlying this dichotomy is critical to advance in neuronal repair therapies. Recent studies highlight the plasticity and complexity of macrophages and microglia beyond the classical view of the M1/M2 polarization paradigm. This plasticity represents an in vivo continuous spectrum of phenotypes with overlapping functions and markers. Moreover, macrophage and microglial plasticity affect many events essential for neuronal regeneration after injury, such as myelin and cell debris clearance, inflammation, release of cytokines, and trophic factors, affecting both intrinsic neuronal properties and extracellular matrix deposition. Until recently, this complexity was overlooked in the translation of therapies modulating these responses for the treatment of neuronal injuries. However, recent studies have shed important light on the underlying molecular mechanisms of this complexity and its transitions and effects on regenerative events. Here we review the complexity of macrophages and microglia after neuronal injury and their roles in regeneration, as well as the underlying molecular mechanisms, and we discuss current challenges and future opportunities for treatment.
JTD Keywords: chemokines and cytokines, macrophages, microglia, neuroinflammation, neuronal injury, regeneration, Chemokines and cytokines, Macrophages, Microglia, Neuroinflammation, Neuronal injury, Regeneration
Blanco-Fernandez, B, Castano, O, Mateos-Timoneda, MA, Engel, E, Perez-Amodio, S, (2021). Nanotechnology Approaches in Chronic Wound Healing Advances in Wound Care 10, 234-256
Significance: The incidence of chronic wounds is increasing due to our aging population and the augment of people afflicted with diabetes. With the extended knowledge on the biological mechanisms underlying these diseases, there is a novel influx of medical technologies into the conventional wound care market. Recent Advances: Several nanotechnologies have been developed demonstrating unique characteristics that address specific problems related to wound repair mechanisms. In this review, we focus on the most recently developed nanotechnology-based therapeutic agents and evaluate the efficacy of each treatment in in vivo diabetic models of chronic wound healing. Critical Issues: Despite the development of potential biomaterials and nanotechnology-based applications for wound healing, this scientific knowledge is not translated into an increase of commercially available wound healing products containing nanomaterials. Future Directions: Further studies are critical to provide insights into how scientific evidences from nanotechnology-based therapies can be applied in the clinical setting.
JTD Keywords: chronic, diabetes, liposomes, nanofibers, nanoparticles, Chronic, Chronic wound, Diabetes, Diabetic wound, Diabetic-rats, Dressings, Drug mechanism, Extracellular-matrix, Growth-factor, Human, In-vitro, Liposome, Liposomes, Mesenchymal stem-cells, Metal nanoparticle, Nanofiber, Nanofibers, Nanofibrous scaffolds, Nanoparticles, Nanotechnology, Nonhuman, Polyester, Polymer, Polysaccharide, Priority journal, Protein, Review, Self assembled protein nanoparticle, Silk fibroin, Skin wounds, Wound healing, Wound healing promoting agent
Olmo, C, Franco, L, Vidal, A, del Valle, LJ, Puiggalí, J, (2021). Ultrasound micromolding of porous polylactide/hydroxyapatite scaffolds Express Polymer Letters 15, 389-403
© BME-PT. Ultrasound micromolding (USM) preparation of hybrid scaffolds based on polylactide (PLA) and hydroxyapatite (HAp) particles has been evaluated. PLA was stable under the applied ultrasound source since a minimum degradation was detected. Porous materials were achieved using polyethylene glycol (PEG) and NaCl salts to the initial PLA and the subsequent leaching of the micromolded specimens. To avoid cavitation and decomposition problems during micromolding, it was necessary to use HAp free of typical synthesis impurities like carbonate and nitrate compounds. Compact PLA/HAp pieces allowed a maximum HAp load of 60 wt%, while porous specimens could be obtained with a maximum load of 38 wt%. Physical characterization of new scaffolds was performed by X-ray diffraction, spectroscopic and calorimetric techniques, stress-strain tests and contact angle measurements. Results indicated that a degree of porosity of 35% and relatively good mechanical properties could be achieved (i.e., 580 MPa, 4%, and 15.6 MPa for the Young modulus, elongation at break, and tensile strength, respectively). Scaffolds showed the positive effect of HAp and porosity on cell proliferation; this latter was 40% higher than that detected for non-porous PLA specimens.
JTD Keywords: apatite, conformation, fabrication, hydroxyapatite, micropieces, polymers, porous scaffolds, proliferation, tissue, ultrasound micromolding, vibration, Composite scaffolds, Hydroxyapatite, Micropieces, Porous scaffolds, Processing technologies, Ultrasound micromolding
Santos-Pata, D, Amil, AF, Raikov, IG, Rennó-Costa, C, Mura, A, Soltesz, I, Verschure, PFMJ, (2021). Entorhinal mismatch: A model of self-supervised learning in the hippocampus iScience 24, 102364
The hippocampal formation displays a wide range of physiological responses to different spatial manipulations of the environment. However, very few attempts have been made to identify core computational principles underlying those hippocampal responses. Here, we capitalize on the observation that the entorhinal-hippocampal complex (EHC) forms a closed loop and projects inhibitory signals “countercurrent” to the trisynaptic pathway to build a self-supervised model that learns to reconstruct its own inputs by error backpropagation. The EHC is then abstracted as an autoencoder, with the hidden layers acting as an information bottleneck. With the inputs mimicking the firing activity of lateral and medial entorhinal cells, our model is shown to generate place cells and to respond to environmental manipulations as observed in rodent experiments. Altogether, we propose that the hippocampus builds conjunctive compressed representations of the environment by learning to reconstruct its own entorhinal inputs via gradient descent.
JTD Keywords: cognitive neuroscience, grid cells, long-term, networks, neural networks, novelty, oscillations, pattern separation, region, representation, working-memory, Cognitive neuroscience, Neural networks, Rat dentate gyrus, Systems neuroscience
Blaya, D, Pose, E, Coll, M, Lozano, JJ, Graupera, I, Schierwagen, R, Jansen, C, Castro, P, Fernandez, S, Sidorova, J, Vasa-Nicotera, M, Sola, E, Caballeria, J, Trebicka, J, Gines, P, Sancho-Bru, P, (2021). Profiling circulating microRNAs in patients with cirrhosis and acute-on-chronic liver failure JHEP Reports 3, 100233
Background & Aims: MicroRNAs (miRNAs) circulate in several body fluids and can be useful biomarkers. The aim of this study was to identify blood-circulating miRNAs associated with cirrhosis progression and acute-on-chronic liver failure (ACLF). Methods: Using high-throughput screening of 754 miRNAs, serum samples from 45 patients with compensated cirrhosis, decompensated cirrhosis, or ACLF were compared with those from healthy individuals (n = 15). miRNA levels were correlated with clinical parameters, organ failure, and disease progression and outcome. Dysregulated miRNAs were evaluated in portal and hepatic vein samples (n = 33), liver tissues (n = 17), and peripheral blood mononuclear cells (PBMCs) (n = 16). Results: miRNA screening analysis revealed that circulating miRNAs are dysregulated in cirrhosis progression, with 51 miRNAs being differentially expressed among all groups of patients. Unsupervised clustering and principal component analysis indicated that the main differences in miRNA expression occurred at decompensation, showing similar levels in patients with decompensated cirrhosis and those with ACLF. Of 43 selected miRNAs examined for differences among groups, 10 were differentially expressed according to disease progression. Moreover, 20 circulating miRNAs were correlated with model for end-stage liver disease and Child-Pugh scores. Notably, 11 dysregulated miRNAs were associated with kidney or liver failure, encephalopathy, bacterial infection, and poor outcomes. The most severely dysregulated miRNAs (i.e. miR-146a5p, miR-26a-5p, and miR-191-5p) were further evaluated in portal and hepatic vein blood and liver tissue, but showed no differences. However, PBMCs from patients with cirrhosis showed significant downregulation of miR-26 and miR-146a, suggesting a extrahepatic origin of some circulating miRNAs. Conclusions: This study is a repository of circulating miRNA data following cirrhosis progression and ACLF. Circulating miRNAs were profoundly dysregulated during the progression of chronic liver disease, were associated with failure of several organs and could have prognostic utility. Lay summary: Circulating miRNAs are small molecules in the blood that can be used to identify or predict a clinical condition. Our study aimed to identify miRNAs for use as biomarkers in patients with cirrhosis or acute-on-chronic liver failure. Several miRNAs were found to be dysregulated during the progression of disease, and some were also related to organ failure and disease-related outcomes. (C) 2021 The Author(s). Published by Elsevier B.V. on behalf of European Association for the Study of the Liver (EASL).
JTD Keywords: aclf, acute-on-chronic liver failure, alt, alanine aminotransferase, ast, aspartate aminotransferase, biomarkers, chronic liver disease, cxcl10, c-x-c motif chemokine ligand 10, ef clif, european foundation for the study of chronic liver failure, foxo, forkhead box o, inr, international normalised ratio, ldh, lactate dehydrogenase, liver decompensation, mapk, mitogen-activated protein kinase, meld, model for end-stage liver disease, nash, non-alcoholic steatohepatitis, non-coding rnas, pbmcs, peripheral blood mononuclear cells, pca, principal component analysis, tgf, transforming growth factor, tips, transjugular intrahepatic portosystemic shunt, Biomarkers, Chronic liver disease, Expression, Liver decompensation, Markers, Mir-146a, Non-coding rnas, Qpcr, quantitative pcr
Zeinali, R, del Valle, LJ, Torras, J, Puiggalí, J, (2021). Recent progress on biodegradable tissue engineering scaffolds prepared by thermally-induced phase separation (Tips) INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 22, 3504
Porous biodegradable scaffolds provide a physical substrate for cells allowing them to attach, proliferate and guide the formation of new tissues. A variety of techniques have been developed to fabricate tissue engineering (TE) scaffolds, among them the most relevant is the thermally-induced phase separation (TIPS). This technique has been widely used in recent years to fabricate three-dimensional (3D) TE scaffolds. Low production cost, simple experimental procedure and easy processability together with the capability to produce highly porous scaffolds with controllable architecture justify the popularity of TIPS. This paper provides a general overview of the TIPS methodology applied for the preparation of 3D porous TE scaffolds. The recent advances in the fabrication of porous scaffolds through this technique, in terms of technology and material selection, have been reviewed. In addition, how properties can be effectively modified to serve as ideal substrates for specific target cells has been specifically addressed. Additionally, examples are offered with re-spect to changes of TIPS procedure parameters, the combination of TIPS with other techniques and innovations in polymer or filler selection.
JTD Keywords: biodegradable polymer, composites, morphology, pore structure, porosity, processing parameters, thermally induced phase separation, Biodegradable polymer, Composites, Morphology, Pore structure, Porosity, Processing parameters, Thermally induced phase separation, Tissue engineering scaffold
Oliver-Cervelló, L, Martin-Gómez, H, Reyes, L, Noureddine, F, Cavalcanti-Adam, EA, Ginebra, MP, Mas-Moruno, C, (2021). An Engineered Biomimetic Peptide Regulates Cell Behavior by Synergistic Integrin and Growth Factor Signaling Advanced Healthcare Materials 10, e2001757
© 2020 Wiley-VCH GmbH Recreating the healing microenvironment is essential to regulate cell–material interactions and ensure the integration of biomaterials. To repair bone, such bioactivity can be achieved by mimicking its extracellular matrix (ECM) and by stimulating integrin and growth factor (GF) signaling. However, current approaches relying on the use of GFs, such as bone morphogenetic protein 2 (BMP-2), entail clinical risks. Here, a biomimetic peptide integrating the RGD cell adhesive sequence and the osteogenic DWIVA motif derived from the wrist epitope of BMP-2 is presented. The approach offers the advantage of having a spatial control over the single binding of integrins and BMP receptors. Such multifunctional platform is designed to incorporate 3,4-dihydroxyphenylalanine to bind metallic oxides with high affinity in a one step process. Functionalization of glass substrates with the engineered peptide is characterized by physicochemical methods, proving a successful surface modification. The biomimetic interfaces significantly improve the adhesion of C2C12 cells, inhibit myotube formation, and activate the BMP-dependent signaling via p38. These effects are not observed on surfaces displaying only one bioactive motif, a mixture of both motifs or soluble DWIVA. These data prove the biological potential of recreating the ECM and engaging in integrin and GF crosstalk via molecular-based mimics.
JTD Keywords: binding, biomaterials, biomimetic peptides, bone, cell adhesion, cell differentiation, differentiation, dwiva, multifunctional coatings, osseointegration, osteoblasts, rgd, surface, surface functionalization, Biomimetic peptides, Biomimetics, Cell adhesion, Cell differentiation, Dwiva, Integrins, Intercellular signaling peptides and proteins, Matrix-bound bmp-2, Peptides, Rgd, Surface functionalization
Castaño, O, López-Mengual, A, Reginensi, D, Matamoros-Angles, A, Engel, E, del Rio, JA, (2021). Chemotactic TEG3 Cells’ Guiding Platforms Based on PLA Fibers Functionalized With the SDF-1α/CXCL12 Chemokine for Neural Regeneration Therapy Frontiers in Bioengineering and Biotechnology 9, 627805
(Following spinal cord injury, olfactory ensheathing cell (OEC) transplantation is a promising therapeutic approach in promoting functional improvement. Some studies report that the migratory properties of OECs are compromised by inhibitory molecules and potentiated by chemical concentration differences. Here we compare the attachment, morphology, and directionality of an OEC-derived cell line, TEG3 cells, seeded on functionalized nanoscale meshes of Poly(l/dl-lactic acid; PLA) nanofibers. The size of the nanofibers has a strong effect on TEG3 cell adhesion and migration, with the PLA nanofibers having a 950 nm diameter being the ones that show the best results. TEG3 cells are capable of adopting a bipolar morphology on 950 nm fiber surfaces, as well as a highly dynamic behavior in migratory terms. Finally, we observe that functionalized nanofibers, with a chemical concentration increment of SDF-1α/CXCL12, strongly enhance the migratory characteristics of TEG3 cells over inhibitory substrates.
JTD Keywords: cell migration, cxcl12, electrospinning, gradients, pla nanofibers, sdf-1alpha, Cell migration, Cxcl12, Electrospinning, Gradients, Olfactory ensheathing cells, Pla nanofibers, Sdf-1alpha
Hortelao, AC, Simó, C, Guix, M, Guallar-Garrido, S, Julián, E, Vilela, D, Rejc, L, Ramos-Cabrer, P, Cossío, U, Gómez-Vallejo, V, Patiño, T, Llop, J, Sánchez, S, (2021). Swarming behavior and in vivo monitoring of enzymatic nanomotors within the bladder Science Robotics 6, eabd2823
Enzyme-powered nanomotors are an exciting technology for biomedical applications due to their ability to navigate within biological environments using endogenous fuels. However, limited studies into their collective behavior and demonstrations of tracking enzyme nanomotors in vivo have hindered progress toward their clinical translation. Here, we report the swarming behavior of urease-powered nanomotors and its tracking using positron emission tomography (PET), both in vitro and in vivo. For that, mesoporous silica nanoparticles containing urease enzymes and gold nanoparticles were used as nanomotors. To image them, nanomotors were radiolabeled with either I on gold nanoparticles or F-labeled prosthetic group to urease. In vitro experiments showed enhanced fluid mixing and collective migration of nanomotors, demonstrating higher capability to swim across complex paths inside microfabricated phantoms, compared with inactive nanomotors. In vivo intravenous administration in mice confirmed their biocompatibility at the administered dose and the suitability of PET to quantitatively track nanomotors in vivo. Furthermore, nanomotors were administered directly into the bladder of mice by intravesical injection. When injected with the fuel, urea, a homogeneous distribution was observed even after the entrance of fresh urine. By contrast, control experiments using nonmotile nanomotors (i.e., without fuel or without urease) resulted in sustained phase separation, indicating that the nanomotors’ self-propulsion promotes convection and mixing in living reservoirs. Active collective dynamics, together with the medical imaging tracking, constitute a key milestone and a step forward in the field of biomedical nanorobotics, paving the way toward their use in theranostic applications. 124 18
JTD Keywords: cell, reversal, silica nanoparticles, size, step, transport, Administration, intravesical, Animals, Equipment design, Female, Gold, Metal nanoparticles, Mice, Mice, inbred c57bl, Motion, Phantoms, imaging, Positron emission tomography computed tomography, Precision medicine, Propelled micromotors, Robotics, Translational research, biomedical, Urease, Urinary bladder
Garcia, J, Fernández-Pradas, JM, Lladó, A, Serra, P, Zalvidea, D, Kogan, MJ, Giralt, E, Sánchez-Navarro, M, (2021). The combined use of gold nanoparticles and infrared radiation enables cytosolic protein delivery CHEMISTRY-A EUROPEAN JOURNAL 27, 4670-4675
© 2020 Wiley-VCH GmbH Cytosolic protein delivery remains elusive. The inability of most proteins to cross the cellular membrane is a huge hurdle. Here we explore the unique photothermal properties of gold nanorods (AuNRs) to trigger cytosolic delivery of proteins. Both partners, protein and AuNRs, are modified with a protease-resistant cell-penetrating peptide with nuclear targeting properties to induce internalization. Once internalized, spatiotemporal control of protein release is achieved by near-infrared laser irradiation in the safe second biological window. Importantly, catalytic amounts of AuNRs are sufficient to trigger cytosolic protein delivery. To the best of our knowledge, this is the first time that AuNRs with their maximum of absorption in the second biological window are used to deliver proteins into the intracellular space. This strategy represents a powerful tool for the cytosolic delivery of virtually any class of protein.
JTD Keywords: cell-penetrating peptide, cytosolic delivery, gold nanorod, near-infrared irradiation, Cell line, tumor, Cell-penetrating peptide, Cytosolic delivery, Gold, Gold nanorod, Metal nanoparticles, Nanotubes, Near-infrared irradiation, Phototherapy
Rubi-Sans, G, Cano-Torres, I, Perez-Amodio, S, Blanco-Fernandez, B, Mateos-Timoneda, MA, Engel, E, (2021). Development and Angiogenic Potential of Cell-Derived Microtissues Using Microcarrier-Template Biomedicines 9, 232
Tissue engineering and regenerative medicine approaches use biomaterials in combination with cells to regenerate lost functions of tissues and organs to prevent organ transplantation. However, most of the current strategies fail in mimicking the tissue's extracellular matrix properties. In order to mimic native tissue conditions, we developed cell-derived matrix (CDM) microtissues (MT). Our methodology uses poly-lactic acid (PLA) and Cultispher(R) S microcarriers' (MCs') as scaffold templates, which are seeded with rat bone marrow mesenchymal stem cells (rBM-MSCs). The scaffold template allows cells to generate an extracellular matrix, which is then extracted for downstream use. The newly formed CDM provides cells with a complex physical (MT architecture) and biochemical (deposited ECM proteins) environment, also showing spontaneous angiogenic potential. Our results suggest that MTs generated from the combination of these two MCs (mixed MTs) are excellent candidates for tissue vascularization. Overall, this study provides a methodology for in-house fabrication of microtissues with angiogenic potential for downstream use in various tissue regenerative strategies.
JTD Keywords: angiogenesis, cell-derived matrix, cultispher® s, microtissue, poly-lactic acid microcarriers, Angiogenesis, Cell-derived matrix, Cultispher (r) s, Cultispher® s, Microtissue, Poly-lactic acid microcarriers, Rat bone marrow mesenchymal stem cells
Estrada-Petrocelli, L, Torres, A, Sarlabous, L, Rafols-de-Urquia, M, Ye-Lin, Y, Prats-Boluda, G, Jane, R, Garcia-Casado, J, (2021). Evaluation of Respiratory Muscle Activity by Means of Concentric Ring Electrodes IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 68, 1005-1014
© 1964-2012 IEEE. Surface electromyography (sEMG) can be used for the evaluation of respiratory muscle activity. Recording sEMG involves the use of surface electrodes in a bipolar configuration. However, electrocardiographic (ECG) interference and electrode orientation represent considerable drawbacks to bipolar acquisition. As an alternative, concentric ring electrodes (CREs) can be used for sEMG acquisition and offer great potential for the evaluation of respiratory muscle activity due to their enhanced spatial resolution and simple placement protocol, which does not depend on muscle fiber orientation. The aim of this work was to analyze the performance of CREs during respiratory sEMG acquisitions. Respiratory muscle sEMG was applied to the diaphragm and sternocleidomastoid muscles using a bipolar and a CRE configuration. Thirty-two subjects underwent four inspiratory load spontaneous breathing tests which was repeated after interchanging the electrode positions. We calculated parameters such as (1) spectral power and (2) median frequency during inspiration, and power ratios of inspiratory sEMG without ECG in relation to (3) basal sEMG without ECG (Rins/noise), (4) basal sEMG with ECG (Rins/cardio) and (5) expiratory sEMG without ECG (Rins/exp). Spectral power, Rins/noise and Rins/cardio increased with the inspiratory load. Significantly higher values (p < 0.05) of Rins/cardio and significantly higher median frequencies were obtained for CREs. Rins/noise and Rins/exp were higher for the bipolar configuration only in diaphragm sEMG recordings, whereas no significant differences were found in the sternocleidomastoid recordings. Our results suggest that the evaluation of respiratory muscle activity by means of sEMG can benefit from the remarkably reduced influence of cardiac activity, the enhanced detection of the shift in frequency content and the axial isotropy of CREs which facilitates its placement.
JTD Keywords: atmospheric measurements, concentric ring electrodes, electrocardiography, electrodes, electromyography, laplacian potential, non-invasive respiratory monitoring, particle measurements, respiratory muscles, surface electromyography, Concentric ring electrodes, Diaphragm, Electrocardiography, Electrodes, Electromyography, Humans, Laplacian potential, Muscle, skeletal, Muscles, Non-invasive respiratory monitoring, Respiratory muscles, Surface electromyography
Lozano-García, M, Estrada-Petrocelli, L, Torres, A, Rafferty, GF, Moxham, J, Jolley, CJ, Jané, R, (2021). Noninvasive assessment of neuromechanical coupling and mechanical efficiency of parasternal intercostal muscle during inspiratory threshold loading SENSORS 21, 1781
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This study aims to investigate noninvasive indices of neuromechanical coupling (NMC) and mechanical efficiency (MEff) of parasternal intercostal muscles. Gold standard assessment of diaphragm NMC requires using invasive techniques, limiting the utility of this procedure. Nonin-vasive NMC indices of parasternal intercostal muscles can be calculated using surface mechano-myography (sMMGpara) and electromyography (sEMGpara). However, the use of sMMGpara as an in-spiratory muscle mechanical output measure, and the relationships between sMMGpara, sEMGpara, and simultaneous invasive and noninvasive pressure measurements have not previously been eval-uated. sEMGpara, sMMGpara, and both invasive and noninvasive measurements of pressures were recorded in twelve healthy subjects during an inspiratory loading protocol. The ratios of sMMGpara to sEMGpara, which provided muscle-specific noninvasive NMC indices of parasternal intercostal muscles, showed nonsignificant changes with increasing load, since the relationships between sMMGpara and sEMGpara were linear (R2 = 0.85 (0.75–0.9)). The ratios of mouth pressure (Pmo) to sEMGpara and sMMGpara were also proposed as noninvasive indices of parasternal intercostal muscle NMC and MEff, respectively. These indices, similar to the analogous indices calculated using invasive transdiaphragmatic and esophageal pressures, showed nonsignificant changes during threshold loading, since the relationships between Pmo and both sEMGpara (R2 = 0.84 (0.77–0.93)) and sMMGpara (R2 = 0.89 (0.85–0.91)) were linear. The proposed noninvasive NMC and MEff indices of parasternal intercostal muscles may be of potential clinical value, particularly for the regular assessment of patients with disordered respiratory mechanics using noninvasive wearable and wireless devices.
JTD Keywords: inspiratory threshold loading, neuromechanical coupling, parasternal intercostal muscles, respiratory pressure, surface electromyography, surface mechanomyography, Inspiratory threshold loading, Neuromechanical coupling, Parasternal intercostal mus-cles, Respiratory pressure, Surface electromyography, Surface mechanomyography
Puiggali-Jou, A, Ordoño, J, del Valle, LJ, Pérez-Amodio, S, Engel, E, Alemán, C, (2021). Tuning multilayered polymeric self-standing films for controlled release of L-lactate by electrical stimulation JOURNAL OF CONTROLLED RELEASE 330, 669-683
© 2020 Elsevier B.V. We examine different approaches for the controlled release of L-lactate, which is a signaling molecule that participates in tissue remodeling and regeneration, such as cardiac and muscle tissue. Robust, flexible, and self-supported 3-layers films made of two spin-coated poly(lactic acid) (PLA) layers separated by an electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) layer, are used as loading and delivery systems. Films with outer layers prepared using homochiral PLA and with nanoperforations of diameter 146 ± 70 experience more bulk erosion, which also contributes to the release of L-lactic acid, than those obtained using heterochiral PLA and with nanoperforations of diameter 66 ± 24. Moreover, the release of L-lactic acid as degradation product is accelerated by applying biphasic electrical pulses. The four approaches used for loading extra L-lactate in the 3-layered films were: incorporation of L-lactate at the intermediate PEDOT layer as primary dopant agent using (1) organic or (2) basic water solutions as reaction media; (3) substitution at the PEDOT layer of the ClO4− dopant by L-lactate using de-doping and re-doping processes; and (4) loading of L-lactate at the outer PLA layers during the spin-coating process. Electrical stimuli were applied considering biphasic voltage pulses and constant voltages (both negative and positive). Results indicate that the approach used to load the L-lactate has a very significant influence in the release regulation process, affecting the concentration of released L-lactate up to two orders of magnitude. Among the tested approaches, the one based on the utilization of the outer layers for loading, approach (4), can be proposed for situations requiring prolonged and sustained L-lactate release over time. The biocompatibility and suitability of the engineered films for cardiac tissue engineering has also been confirmed using cardiac cells.
JTD Keywords: biphasic voltage pulse, cardiac tissue regeneration, cardiomyocytes proliferation, conducting polymer, nanoperforated films, sustained delivery, Biphasic voltage pulse, Cardiac tissue regeneration, Cardiomyocytes proliferation, Conducting polymer, Nanoperforated films, Sustained delivery
Seuma, M, Faure, AJ, Badia, M, Lehner, B, Bolognesi, B, (2021). The genetic landscape for amyloid beta fibril nucleation accurately discriminates familial Alzheimer's disease mutations eLife 10, e63364
Plaques of the amyloid beta (A beta) peptide are a pathological hallmark of Alzheimer's disease (AD), the most common form of dementia. Mutations in A beta also cause familial forms of AD (fAD). Here, we use deep mutational scanning to quantify the effects of >14,000 mutations on the aggregation of A beta. The resulting genetic landscape reveals mechanistic insights into fibril nucleation, including the importance of charge and gatekeeper residues in the disordered region outside of the amyloid core in preventing nucleation. Strikingly, unlike computational predictors and previous measurements, the empirical nucleation scores accurately identify all known dominant fAD mutations in A beta, genetically validating that the mechanism of nucleation in a cell-based assay is likely to be very similar to the mechanism that causes the human disease. These results provide the first comprehensive atlas of how mutations alter the formation of any amyloid fibril and a resource for the interpretation of genetic variation in A beta.
JTD Keywords: aggregation, kinetics, oligomers, onset, rates, state, Aggregation, Alzheimer disease, Alzheimer's, Amyloid, Amyloid beta-peptides, Computational biology, Deep mutagenesis, Dna mutational analysis, Genetics, Genomics, High-throughput nucleotide sequencing, Kinetics, Mutation, Nucleation, Oligomers, Onset, Plasmids, Precursor protein, Rates, S. cerevisiae, Saccharomyces cerevisiae, State, Systems biology
Woythe, L, Tito, NB, Albertazzi, L, (2021). A quantitative view on multivalent nanomedicine targeting ADVANCED DRUG DELIVERY REVIEWS 169, 1-21
© 2020 The Authors Although the concept of selective delivery has been postulated over 100 years ago, no targeted nanomedicine has been clinically approved so far. Nanoparticles modified with targeting ligands to promote the selective delivery of therapeutics towards a specific cell population have been extensively reported. However, the rational design of selective particles is still challenging. One of the main reasons for this is the lack of quantitative theoretical and experimental understanding of the interactions involved in cell targeting. In this review, we discuss new theoretical models and experimental methods that provide a quantitative view of targeting. We show the new advancements in multivalency theory enabling the rational design of super-selective nanoparticles. Furthermore, we present the innovative approaches to obtain key targeting parameters at the single-cell and single molecule level and their role in the design of targeting nanoparticles. We believe that the combination of new theoretical multivalent design and experimental methods to quantify receptors and ligands aids in the rational design and clinical translation of targeted nanomedicines.
JTD Keywords: binding-kinetics, biological identity, biomolecular corona, blood-brain-barrier, drug-delivery, gold nanoparticles, multivalency, nanotechnology, protein corona, quantitative characterization, rational design, super-selectivity, superresolution microscopy, tumor heterogeneity, Ligand-receptor interactions, Multivalency, Nanotechnology, Quantitative characterization, Rational design, Super-selectivity
Feiner-Gracia, N, Mares, AG, Buzhor, M, Rodriguez-Trujillo, R, Marti, JS, Amir, RJ, Pujals, S, Albertazzi, L, (2021). Real-Time Ratiometric Imaging of Micelles Assembly State in a Microfluidic Cancer-on-a-Chip ACS Applied Bio Materials 4, 669-681
© 2020 American Chemical Society. The performance of supramolecular nanocarriers as drug delivery systems depends on their stability in the complex and dynamic biological media. After administration, nanocarriers are challenged by physiological barriers such as shear stress and proteins present in blood, endothelial wall, extracellular matrix, and eventually cancer cell membrane. While early disassembly will result in a premature drug release, extreme stability of the nanocarriers can lead to poor drug release and low efficiency. Therefore, comprehensive understanding of the stability and assembly state of supramolecular carriers in each stage of delivery is the key factor for the rational design of these systems. One of the main challenges is that current 2D in vitro models do not provide exhaustive information, as they fail to recapitulate the 3D tumor microenvironment. This deficiency in the 2D model complexity is the main reason for the differences observed in vivo when testing the performance of supramolecular nanocarriers. Herein, we present a real-time monitoring study of self-assembled micelles stability and extravasation, combining spectral confocal microscopy and a microfluidic cancer-on-a-chip. The combination of advanced imaging and a reliable 3D model allows tracking of micelle disassembly by following the spectral properties of the amphiphiles in space and time during the crucial steps of drug delivery. The spectrally active micelles were introduced under flow and their position and conformation continuously followed by spectral imaging during the crossing of barriers, revealing the interplay between carrier structure, micellar stability, and extravasation. Integrating the ability of the micelles to change their fluorescent properties when disassembled, spectral confocal imaging and 3D microfluidic tumor blood vessel-on-a-chip resulted in the establishment of a robust testing platform suitable for real-time imaging and evaluation of supramolecular drug delivery carrier's stability.
JTD Keywords: cancer-on-a-chip, complex, delivery, endothelial-cells, in-vitro, microfluidic, model, nanoparticle, penetration, shear-stress, stability, supramolecular, Cancer-on-a-chip, Cell-culture, Micelle, Microfluidic, Nanoparticle, Stability, Supramolecular
Caddeo, C, Gabriele, M, Nácher, A, Fernàndez-Busquets, X, Valenti, D, Fadda, AM, Pucci, L, Manconi, M, (2021). Resveratrol and artemisinin eudragit-coated liposomes: A strategy to tackle intestinal tumors INTERNATIONAL JOURNAL OF PHARMACEUTICS 592, 120083
© 2020 Elsevier B.V. Resveratrol and artemisinin, two naturally occurring compounds with a wide range of biological activities, have been reported to exert antitumor effects against several types of cancer. In this work, Eudragit-coated liposomes were developed to safely transport resveratrol and artemisinin through the gastrointestinal tract and target the intestine. The physico-chemical properties of the Eudragit-coated liposomes were assessed by light scattering and cryogenic transmission electron microscopy. Nanosized (around 100 nm), spherical or elongated, unilamellar vesicles were produced. The protective effect of the Eudragit coating was confirmed by assessing the physical stability of the vesicles in fluids mimicking the gastrointestinal environment. Furthermore, the vesicles were found to exert a pro-oxidant activity in intestinal adenocarcinoma cells, which resulted in a marked mortality due to the generation of reactive oxygen species (ROS). A time- and dose-dependent cell growth inhibitory effect was detected, with elevated ROS levels when resveratrol and artemisinin were combined. Therefore, the proposed formulations may represent a valuable means to counteract intestinal tumor growth.
JTD Keywords: antitumor, artemisinin, eudragit, intestinal delivery, liposomes, Antitumor, Artemisinin, Eudragit, Intestinal delivery, Liposomes, Resveratrol
Blanco-Almazán, D, Groenendaal, W, Lozano-García, M, Estrada-Petrocelli, L, Lijnen, L, Smeets, C, Ruttens, D, Catthoor, F, Jané, R, (2021). Combining Bioimpedance and Myographic Signals for the Assessment of COPD during Loaded Breathing IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 68, 298-307
© 1964-2012 IEEE. Chronic Obstructive Pulmonary Disease (COPD) is one of the most common chronic conditions. The current assessment of COPD requires a maximal maneuver during a spirometry test to quantify airflow limitations of patients. Other less invasive measurements such as thoracic bioimpedance and myographic signals have been studied as an alternative to classical methods as they provide information about respiration. Particularly, strong correlations have been shown between thoracic bioimpedance and respiratory volume. The main objective of this study is to investigate bioimpedance and its combination with myographic parameters in COPD patients to assess the applicability in respiratory disease monitoring. We measured bioimpedance, surface electromyography and surface mechanomyography in forty-three COPD patients during an incremental inspiratory threshold loading protocol. We introduced two novel features that can be used to assess COPD condition derived from the variation of bioimpedance and the electrical and mechanical activity during each respiratory cycle. These features demonstrate significant differences between mild and severe patients, indicating a lower inspiratory contribution of the inspiratory muscles to global respiratory ventilation in the severest COPD patients. In conclusion, the combination of bioimpedance and myographic signals provides useful indices to noninvasively assess the breathing of COPD patients.
JTD Keywords: Bioimpedance, Chronic obstructive pulmonary disease, Inspiratory threshold protocol, Myographic signals, Wearables
Keridou, I, Franco, L, del Valle, LJ, Martínez, JC, Funk, L, Turon, P, Puiggalí, J, (2021). Hydrolytic and enzymatic degradation of biobased poly(4-hydroxybutyrate) films. Selective etching of spherulites POLYMER DEGRADATION AND STABILITY 183, 109451
© 2020 Hydrolytic degradation of poly(4-hydroxybutyrate) (P4HB) films has been studied considering media of different pH values (i.e., 3, 7 and 10) and temperatures (i.e., 37 and 55 °C). Enzymatic degradation has also been evaluated at physiological conditions using two different lipases: Pseudomonas cepacia and Rhizopus oryzae. Different bulk and surface erosion mechanisms with random chain scissions and successive removal of monomer units have been supported through weight loss measurements, molecular weight determinations by GPC and NMR spectroscopy and changes on thermal properties by DSC. Thermal annealing during exposure to different media and even degradation influenced on the melting temperature and crystallinity of samples, as well as on the lamellar geometrical parameters as evaluated by SAXS. Enzymatic degradation was ideal to selectively eliminate the amorphous regions and highlight the spherulitic morphology. Presence of ringed textures were therefore evident in bright field optical micrographs in addition to SEM images, namely observations under polarized light was not necessary to distinguish the presence of banded spherulites. Rhizopus oryzae was revealed to be the most suitable enzyme to crop out the P4HB spherulites that form part of the initial smooth surfaces of solvent casting films. After determining the appropriate activity and exposure time, the presence of rings constituted by cooperative C-shaped edge-on lamellae and flat-on lamellae was highlighted.
JTD Keywords: biodegradable polymers, enzymatic degradation, films, hydrolytic degradation, microstructure, thermal properties, Biodegradable polymers, Enzymatic degradation, Films, Hydrolytic degradation, Microstructure, Poly(4-hydroxybutyrate), Thermal properties
Martí, D, Torras, J, Bertran, O, Turon, P, Alemán, C, (2021). Temperature effect on the SARS-CoV-2: A molecular dynamics study of the spike homotrimeric glycoprotein Computational and Structural Biotechnology Journal 19, 1848-1862
Rapid spread of SARS-CoV-2 virus have boosted the need of knowledge about inactivation mechanisms to minimize the impact of COVID-19 pandemic. Recent studies have shown that SARS-CoV-2 virus can be disabled by heating, the exposure time for total inactivation depending on the reached temperature (e.g. more than 45 min at 329 K or less than 5 min at 373 K. In spite of recent crystallographic structures, little is known about the molecular changes induced by the temperature. Here, we unravel the molecular basis of the effect of the temperature over the SARS-CoV-2 spike glycoprotein, which is a homotrimer with three identical monomers, by executing atomistic molecular dynamics (MD) simulations at 298, 310, 324, 338, 358 and 373 K. Furthermore, both the closed down and open up conformational states, which affect the accessibility of receptor binding domain, have been considered. Our results suggest that the spike homotrimer undergoes drastic changes in the topology of the hydrogen bonding interactions and important changes on the secondary structure of the receptor binding domain (RBD), while electrostatic interactions (i.e. salt bridges) are mainly preserved. The proposed inactivation mechanism has important implications for engineering new approaches to fight the SARS-CoV-2 coronavirus, as for example, cleaving or reorganizing the hydrogen bonds through chaotropic agents or nanoparticles with local surface resonant plasmon effect.
JTD Keywords: atomistic simulations, coronaviruses, denaturation, homotrimeric protein, inactivation, proteins, receptor binding domain, salt bridges, simulation, thermal inactivation, virus spike, Atomistic simulations, Homotrimeric protein, Receptor binding domain, Secondary-structure, Thermal inactivation, Virus spike
Romero, D, Jané, R, (2021). Global and Transient Effects of Intermittent Hypoxia on Heart Rate Variability Markers: Evaluation using an Obstructive Sleep Apnea Model IEEE Access 9, 19043-19052
CCBY Intermittent hypoxia (IH) produces autonomic dysfunction that promotes the development of arrhythmia and hypertension in patients with obstructive sleep apnea (OSA). This paper investigated different heart rate variability (HRV) indices in the context of IH using a rat model for OSA. Linear and non-linear HRV parameters were assessed from ultra-short (15-s segments) and short-term (5 min) analyses of heartbeat time-series. Transient changes observed from pre-apnea segments to hypoxia episodes were evaluated, besides the relative and global impact of IH, as a function of its severity. Results showed an overall increase in ultra-short HRV markers as immediate response to hypoxia: standard deviation of normal RR intervals, SDNN=1.2 ms (IQR: 1.1-2.1) vs 1.4 ms (IQR: 1.2-2.2), p=0.015; root mean square of the successive differences, RMSSD=1.7 ms (IQR: 1.5-2.2) vs 1.9 ms (IQR: 1.6-2.4), p=0.031. The power in the very low frequency (VLF) band also showed a significant increase: 0.09 ms2 (IQR: 0.05-0.20) vs 0.16 ms2 (IQR: 0.12-0.23), p=0.016, probably associated with the potentiation of the carotid body chemo-sensory response to hypoxia. Moreover, a clear link between severity of IH and short-term HRV measures was found in VLF and LF power, besides their progressive increase seen throughout the experiment after each apnea sequence. However, only those markers quantifying fragmentation levels in RR series were significantly affected when the experiment ended, as compared to baseline measures: percentage of inflection points, PIP=49% (IQR: 45-51) vs 53% (IQR: 47-53), p=0.031; percentage of short (≥3 RR intervals) accelerated/decelerated segments, PSS=75% (IQR: 51-81) vs 87% (IQR: 51-90), p=0.046. These findings suggest a significant deterioration of cardiac rhythm with a more erratic behavior beyond the normal sinus arrhythmia, that may lead to a future cardiac condition.
JTD Keywords: artificial intelligence, atmospheric modeling, electrocardiography, heart rate variability, hypoxia rat model, intermittent hypoxia, obstructive apneas, protocols, radio access technologies, Artificial intelligence, Atmospheric modeling, Electrocardiography, Heart rate variability, Hypoxia rat model, Intermittent hypoxia, Obstructive apneas, Protocols, Radio access technologies, Rats
Conti, S, Kato, T, Park, D, Sahai, E, Trepat, X, Labernadie, A, (2021). CAFs and cancer cells co-migration in 3D spheroid invasion assay Methods in Molecular Biology 2179, 243-256
© 2020, Springer Science+Business Media, LLC, part of Springer Nature. In many solid tumors, collective cell invasion prevails over single-cell dissemination strategies. Collective modes of invasion often display specific front/rear cellular organization, where invasive leader cells arise from cancer cell populations or the tumor stroma. Collective invasion involves coordinated cellular movements which require tight mechanical crosstalk through specific combinations of cell–cell interactions and cell–matrix adhesions. Cancer Associated Fibroblasts (CAFs) have been recently reported to drive the dissemination of epithelial cancer cells through ECM remodeling and direct intercellular contact. However, the cooperation between tumor and stromal cells remains poorly understood. Here we present a simple spheroid invasion assay to assess the role of CAFs in the collective migration of epithelial tumor cells. This method enables the characterization of 3D spheroid invasion patterns through live cell fluorescent labeling combined with spinning disc microscopy. When embedded in extracellular matrix, the invasive strands of spheroids can be tracked and leader/follower organization of CAFs and cancer cells can be quantified.
JTD Keywords: 3d spheroid invasion, cancer associated fibroblasts, collective migration, dissemination, epithelial cancer cells, leader/follower cells, 3d spheroid invasion, Cancer associated fibroblasts, Cancer-associated fibroblasts, Cell culture techniques, Cell line, tumor, Cell movement, Cell tracking, Collective invasion, Collective migration, Epithelial cancer cells, Extracellular matrix, Humans, Imaging, three-dimensional, Leader/follower cells, Microscopy, fluorescence, Spheroids, cellular, Tumor cells, cultured
Blanco-Almazán, D, Groenendaal, W, Catthoor, F, Jané, R, (2021). Detection of Respiratory Phases to Estimate Breathing Pattern Parameters using Wearable Bioimpendace Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 2021, 5508-5511
Many studies have focused on novel noninvasive techniques to monitor respiratory rate such as bioimpedance. We propose an algorithm to detect respiratory phases using wearable bioimpedance to compute time parameters like respiratory rate, inspiratory and expiratory times, and duty cycle. The proposed algorithm was compared with two other algorithms from literature designed to estimate the respiratory rate using physiological signals like bioimpedance. We acquired bioimpedance and airflow from 50 chronic obstructive pulmonary disease (COPD) patients during an inspiratory loading protocol. We compared performance of the algorithms by computing accuracy and mean average percentage error (MAPE) between the bioimpedance parameters and the reference parameters from airflow. We found similar performance for the three algorithms in terms of accuracy (>0.96) and respiratory time and rate errors (<3.42 %). However, the proposed algorithm showed lower MAPE in duty cycle (10.18 %), inspiratory time (10.65 %) and expiratory time (8.61 %). Furthermore, only the proposed algorithm kept the statistical differences in duty cycle between COPD severity levels that were observed using airflow. Accordingly, we suggest bioimpedance to monitor breathing pattern parameters in home situations.Clinical relevance - This study exhibits the suitability of wearable thoracic bioimpedance to detect respiratory phases and to compute accurate breathing pattern parameters. © 2021 IEEE.
JTD Keywords: algorithms, copd, signals, Algorithm, Algorithms, Bioimpedance, Breathing rate, Chronic obstructive lung disease, Electronic device, Human, Humans, Lung, Pulmonary disease, chronic obstructive, Respiratory rate, Wearable electronic devices
Ben Hamouda, S, Vargas, A, Boivin, R, Miglino, MA, da Palma, RK, Lavoie, JP, (2021). Recellularization of Bronchial Extracellular Matrix With Primary Bronchial Smooth Muscle Cells JOURNAL OF EQUINE VETERINARY SCIENCE 96, 103313
© 2020 Elsevier Inc. Severe asthma is associated with an increased airway smooth muscle (ASM) mass and altered composition of the extracellular matrix (ECM). Studies have indicated that ECM-ASM cell interactions contribute to this remodeling and its limited reversibility with current therapy. Three-dimensional matrices allow the study of complex cellular responses to different stimuli in an almost natural environment. Our goal was to obtain acellular bronchial matrices and then develop a recellularization protocol with ASM cells. We studied equine bronchi as horses spontaneously develop a human asthma-like disease. The bronchi were decellularized using Triton/Sodium Deoxycholate. The obtained scaffolds retained their anatomical and histological properties. Using immunohistochemistry and a semi-quantitative score to compare native bronchi to scaffolds revealed no significant variation for matrixial proteins. DNA quantification and electrophoresis revealed that most DNA was 29.6 ng/mg of tissue ± 5.6, with remaining fragments of less than 100 bp. Primary ASM cells were seeded on the scaffolds. Histological analysis of the recellularizations showed that ASM cells migrated and proliferated primarily in the decellularized smooth muscle matrix, suggesting a chemotactic effect of the scaffolds. This is the first report of primary ASM cells preferentially repopulating the smooth muscle matrix layer in bronchial matrices. This protocol is now being used to study the molecular interactions occurring between the asthmatic ECMs and ASM to identify effectors of asthmatic bronchial remodeling.
JTD Keywords: 2d, airway smooth muscle cells, asthma, decellularization, disease, elastin, extracellular matrix, lung scaffolds, migration, peptide, recellularization, tissues, Airway smooth muscle cells, Animals, Asthma, Bronchi, Culture-systems, Decellularization, Extracellular matrix, Horse diseases, Horses, Muscle, smooth, Myocytes, smooth muscle, Recellularization
Vilanova, E., Ciodaro, P. J., Bezerra, F. F., Santos, G. R. C., Valle-Delgado, J. J., Anselmetti, D., Fernàndez-Busquets, X., Mourão, P. A. S., (2020). Adhesion of freshwater sponge cells mediated by carbohydrate-carbohydrate interactions requires low environmental calcium Glycobiology 30, (9), 710-721
Marine ancestors of freshwater sponges had to undergo a series of physiological adaptations to colonize harsh and heterogeneous limnic environments. Besides reduced salinity, river-lake systems also have calcium concentrations far lower than seawater. Cell adhesion in sponges is mediated by calcium-dependent multivalent self-interactions of sulfated polysaccharide components of membrane-bound proteoglycans named aggregation factors. Cells of marine sponges require seawater average calcium concentration (10 mM) to sustain adhesion promoted by aggregation factors. We demonstrate here that the freshwater sponge Spongilla alba can thrive in a calcium-poor aquatic environment and that their cells are able to aggregate and form primmorphs with calcium concentrations 40-fold lower than that required by marine sponges cells. We also find that their gemmules need calcium and other micronutrients to hatch and generate new sponges. The sulfated polysaccharide purified from S. alba has sulfate content and molecular size notably lower than those from marine sponges. Nuclear magnetic resonance analyses indicated that it is composed of a central backbone of non- and 2-sulfated α- and β-glucose units decorated with branches of α-glucose. Assessments with atomic force microscopy/single-molecule force spectroscopy show that S. alba glucan requires 10-fold less calcium than sulfated polysaccharides from marine sponges to self-interact efficiently. Such an ability to retain multicellular morphology with low environmental calcium must have been a crucial evolutionary step for freshwater sponges to successfully colonize inland waters.
JTD Keywords: Carbohydrate interactions, Evolutionary adaptation, Porifera, Proteoglycans, Sulfated polysaccharides
Keridou, I., Cailloux, J., Martínez, J. C., Santana, O., Maspoch, M. L., Puiggalí, J., Franco, L., (2020). Biphasic polylactide/polyamide 6,10 blends: Influence of composition on polyamide structure and polyester crystallization Polymer 202, 122676
Blends with different ratios of polylactide and polyamide 6,10 (PA610) have been prepared by melt-mixing using a Brabender mixer equipment. Previously, a rheologically modified polylactide (PLAREx) was obtained through reactive extrusion using a multifunctional epoxide agent. It was expected that unreacted epoxy groups of PLAREx were able to improve the compatibility between the two polymers. SEM observations revealed a logical dependence of the morphology of immiscible phases with composition, and more interestingly a co-continuity at relatively low PA content (around 50%) was detected. This result contrasts with previous observations performed with non-modified PLA. Confined PA domains increased with the PA content and hardly crystallized at the typical crystallization temperature of the pure PA (195 °C). Synchrotron X-ray diffraction studies indicated that a PA crystallization at a lower temperature close to 120 °C was enhanced and led to a pseudohexagonal γ phase that differs from the characteristic layered structure of PA610. SAXS data revealed also that well differentiated lamellar entities could be assigned at both immiscible polymer phases. Clear differences were observed in the spherulitic morphologies attained under isothermal melt crystallization experiments. Results indicated that the texture of PLAREx spherulites was modified by the presence of PA. Compatibilization of PA molecules on the crystal lamellar boundaries of PLAREx led to an enhancement of the lamellar twisting frequency. Optical microscopy results also indicated that the crystal growth rate of PLAREx increased by the incorporation of PA, but in contrast this had an adverse effect on the nucleation process.
JTD Keywords: Crystal growth rate, Epoxy modified polylactide, Nucleation, Polyamide 6,10, Polyamide crystalline structure, Polyamide/polylactide blend morphology, Thermal properties
Blancas, Maria, Maffei, Giovanni, Sánchez-Fibla, Martí, Vouloutsi, Vasiliki, Verschure, P., (2020). Collaboration variability in autism spectrum disorder Frontiers in Human Neuroscience 14, (412), 559793
This paper addresses how impairments in prediction in young adults with autism spectrum disorder (ASD) relate to their behavior during collaboration. To assess it, we developed a task where participants play in collaboration with a synthetic agent to maximize their score. The agent’s behavior changes during the different phases of the game, requiring participants to model the agent’s sensorimotor contingencies to play collaboratively. Our results (n = 30, 15 per group) show differences between autistic and neurotypical individuals in their behavioral adaptation to the other partner. Contrarily, there are no differences in the self-reports of that collaboration.
JTD Keywords: Autism, Prediction, Collaboration, Sensorimotor contingencies, Neurodiversity
Landa-Castro, Midori, Sebastián, Paula, Giannotti, Marina I., Serrà, Albert, Gómez, Elvira, (2020). Electrodeposition of nanostructured cobalt films from a deep eutectic solvent: Influence of the substrate and deposition potential range Electrochimica Acta 359, 136928
The purpose of this systematic study was to investigate the effects of specific substrates and potential conditions applied while tailoring the morphology and chemical composition of nanostructured Co films. In particular, Co electrodeposition in sustainable choline chloride-urea deep eutectic solvent was assessed, using glassy carbon and two metals widely employed in electrocatalysis and biocompatible purposes, Pt and Au, as substrates for modification with Co. Various in situ electrochemical techniques were combined with a broad range of ex-situ characterization and chemical-composition techniques for a detailed analysis of the prepared Co films. Among the results, nanostructured Co films with high extended active surface areas and variable composition of oxo and hydroxyl species could be tuned by simply modulating the applied potential limits, and without using additives or surfactant agents. The study highlights the effectiveness of using deep eutectic solvent as suitable electrolyte for surface modification by controlled deposition of nanostructured Co films with further application in electrocatalysis.
JTD Keywords: Cobalt electrodeposition, Deep eutectic solvent, First growth stages, Substrate influence
Hoogduijn, M.J., Montserrat, N., van der Laan, L.J.W., Dazzi, F., Perico, N., Kastrup, J., Gilbo, N., Ploeg, R.J., Roobrouck, V., Casiraghi, F., Johnson, C.L., Franquesa, M., Dahlke, M.H., Massey, E., Hosgood, S., Reinders, M.E.J., (2020). The emergence of regenerative medicine in organ transplantation: 1st European Cell Therapy and Organ Regeneration Section meeting Transplant International 33, (8), 833-840
Regenerative medicine is emerging as a novel field in organ transplantation. In September 2019, the European Cell Therapy and Organ Regeneration Section (ECTORS) of the European Society for Organ Transplantation (ESOT) held its first meeting to discuss the state-of-the-art of regenerative medicine in organ transplantation. The present article highlights the key areas of interest and major advances in this multidisciplinary field in organ regeneration and discusses its implications for the future of organ transplantation.
JTD Keywords: Cell therapy, Machine perfusion, Mesenchymal stromal cell, Organoid, Regeneration, Transplantation
Hino, N., Rossetti, L., Marín-Llauradó, A., Aoki, K., Trepat, X., Matsuda, M., Hirashima, T., (2020). ERK-mediated mechanochemical waves direct collective cell polarization Developmental Cell 53, (6), 646-660.e8
During collective migration of epithelial cells, the migration direction is aligned over a tissue-scale expanse. Although the collective cell migration is known to be directed by mechanical forces transmitted via cell-cell junctions, it remains elusive how the intercellular force transmission is coordinated with intracellular biochemical signaling to achieve collective movements. Here, we show that intercellular coupling of extracellular signal-regulated kinase (ERK)-mediated mechanochemical feedback yields long-distance transmission of guidance cues. Mechanical stretch activates ERK through epidermal growth factor receptor (EGFR) activation, and ERK activation triggers cell contraction. The contraction of the activated cell pulls neighboring cells, evoking another round of ERK activation and contraction in the neighbors. Furthermore, anisotropic contraction based on front-rear polarization guarantees unidirectional propagation of ERK activation, and in turn, the ERK activation waves direct multicellular alignment of the polarity, leading to long-range ordered migration. Our findings reveal that mechanical forces mediate intercellular signaling underlying sustained transmission of guidance cues for collective cell migration.
JTD Keywords: Collective cell migration, EGFR, ERK/MAPK, FRET, Front-rear polarity, Intercellular signal transfer, Mathematical model, Mechanochemical feedback, Mechanotransduction, wave propagation
Park, D., Wershof, E., Boeing, S., Labernadie, A., Jenkins, R. P., George, S., Trepat, X., Bates, P. A., Sahai, E., (2020). Extracellular matrix anisotropy is determined by TFAP2C-dependent regulation of cell collisions Nature Materials 19, 227-238
The isotropic or anisotropic organization of biological extracellular matrices has important consequences for tissue function. We study emergent anisotropy using fibroblasts that generate varying degrees of matrix alignment from uniform starting conditions. This reveals that the early migratory paths of fibroblasts are correlated with subsequent matrix organization. Combined experimentation and adaptation of Vicsek modelling demonstrates that the reorientation of cells relative to each other following collision plays a role in generating matrix anisotropy. We term this behaviour ‘cell collision guidance’. The transcription factor TFAP2C regulates cell collision guidance in part by controlling the expression of RND3. RND3 localizes to cell–cell collision zones where it downregulates actomyosin activity. Cell collision guidance fails without this mechanism in place, leading to isotropic matrix generation. The cross-referencing of alignment and TFAP2C gene expression signatures against existing datasets enables the identification and validation of several classes of pharmacological agents that disrupt matrix anisotropy.
JTD Keywords: Biomaterials – cells, Cell migration, Self-assembly, Tissues
Calvo, Mireia, González, Rubèn, Seijas, Núria, Vela, Emili, Hernández, Carme, Batiste, Guillem, Miralles, Felip, Roca, Josep, Cano, Isaac, Jané, Raimon, (2020). Health outcomes from home hospitalization: Multisource predictive modeling Journal of Medical Internet Research 22, (10), e21367
Background: Home hospitalization is widely accepted as a cost-effective alternative to conventional hospitalization for selected patients. A recent analysis of the home hospitalization and early discharge (HH/ED) program at Hospital Clínic de Barcelona over a 10-year period demonstrated high levels of acceptance by patients and professionals, as well as health value-based generation at the provider and health-system levels. However, health risk assessment was identified as an unmet need with the potential to enhance clinical decision making. Objective: The objective of this study is to generate and assess predictive models of mortality and in-hospital admission at entry and at HH/ED discharge. Methods: Predictive modeling of mortality and in-hospital admission was done in 2 different scenarios: at entry into the HH/ED program and at discharge, from January 2009 to December 2015. Multisource predictive variables, including standard clinical data, patients’ functional features, and population health risk assessment, were considered. Results: We studied 1925 HH/ED patients by applying a random forest classifier, as it showed the best performance. Average results of the area under the receiver operating characteristic curve (AUROC; sensitivity/specificity) for the prediction of mortality were 0.88 (0.81/0.76) and 0.89 (0.81/0.81) at entry and at home hospitalization discharge, respectively; the AUROC (sensitivity/specificity) values for in-hospital admission were 0.71 (0.67/0.64) and 0.70 (0.71/0.61) at entry and at home hospitalization discharge, respectively. Conclusions: The results showed potential for feeding clinical decision support systems aimed at supporting health professionals for inclusion of candidates into the HH/ED program, and have the capacity to guide transitions toward community-based care at HH discharge.
JTD Keywords: Home hospitalization, Health risk assessment, Predictive modeling, Chronic care, Integrated care, Modeling, Hospitalization, Health risk, Prediction, Mortality, Clinical decision support
Altay, Gizem, Tosi, Sébastien, García-Díaz, María, Martínez, Elena, (2020). Imaging the cell morphological response to 3D topography and curvature in engineered intestinal tissues Frontiers in Bioengineering and Biotechnology 8, 294
While conventional cell culture methodologies have relied on flat, two-dimensional cell monolayers, three-dimensional engineered tissues are becoming increasingly popular. Often, engineered tissues can mimic the complex architecture of native tissues, leading to advancements in reproducing physiological functional properties. In particular, engineered intestinal tissues often use hydrogels to mimic villi structures. These finger-like protrusions of a few hundred microns in height have a well-defined topography and curvature. Here, we examined the cell morphological response to these villus-like microstructures at single-cell resolution using a novel embedding method that allows for the histological processing of these delicate hydrogel structures. We demonstrated that by using photopolymerisable poly(ethylene) glycol as an embedding medium, the villus-like microstructures were successfully preserved after sectioning with vibratome or cryotome. Moreover, high-resolution imaging of these sections revealed that cell morphology, nuclei orientation, and the expression of epithelial polarization markers were spatially encoded along the vertical axis of the villus-like microstructures and that this cell morphological response was dramatically affected by the substrate curvature. These findings, which are in good agreement with the data reported for in vivo experiments on the native tissue, are likely to be the origin of more physiologically relevant barrier properties of engineered intestinal tissues when compared with standard monolayer cultures. By showcasing this example, we anticipate that the novel histological embedding procedure will have a positive impact on the study of epithelial cell behavior on three-dimensional substrates in both physiological and pathological situations.
JTD Keywords: Hydrogel scaffold, Confocal microscopy, Substrate curvature, Cell morphology, Cell orientation, Histological section, Small intestine, Villus
Monteil, Vanessa, Kwon, Hyesoo, Prado, Patricia, Hagelkrüys, Astrid, Wimmer, Reiner A., Stahl, Martin, Leopoldi, Alexandra, Garreta, Elena, Hurtado Del Pozo, Carmen, Prosper, Felipe, Romero, Juan Pablo, Wirnsberger, Gerald, Zhang, Haibo, Slutsky, Arthur S., Conder, Ryan, Montserrat, Nuria, Mirazimi, Ali, Penninger, Josef M., (2020). Inhibition of SARS-CoV-2 infections in engineered human tissues using clinical-grade soluble human ACE2 Cell 181, (4), 905-913.e7
We have previously provided the first genetic evidence that angiotensin converting enzyme 2 (ACE2) is the critical receptor for severe acute respiratory syndrome coronavirus (SARS-CoV), and ACE2 protects the lung from injury, providing a molecular explanation for the severe lung failure and death due to SARS-CoV infections. ACE2 has now also been identified as a key receptor for SARS-CoV-2 infections, and it has been proposed that inhibiting this interaction might be used in treating patients with COVID-19. However, it is not known whether human recombinant soluble ACE2 (hrsACE2) blocks growth of SARS-CoV-2. Here, we show that clinical grade hrsACE2 reduced SARS-CoV-2 recovery from Vero cells by a factor of 1,000-5,000. An equivalent mouse rsACE2 had no effect. We also show that SARS-CoV-2 can directly infect engineered human blood vessel organoids and human kidney organoids, which can be inhibited by hrsACE2. These data demonstrate that hrsACE2 can significantly block early stages of SARS-CoV-2 infections.
JTD Keywords: COVID-19, Angiotensin converting enzyme 2, Blood vessels, Human organoids, Kidney, Severe acute respiratory syndrome coronavirus, Spike glycoproteins, Treatment
Khurana, K., Guillem-Marti, J., Soldera, F., Mücklich, F., Canal, C., Ginebra, M. P., (2020). Injectable calcium phosphate foams for the delivery of Pitavastatin as osteogenic and angiogenic agent Journal of Biomedical Materials Research - Part B Applied Biomaterials 108, (3), 760-770
Apatitic bone cements have been used as a clinical bone substitutes and drug delivery vehicles for therapeutic agents in orthopedic applications. This has led to their combination with different drugs with known ability to foster bone formation. Recent studies have evaluated Simvastatin for its role in enhanced bone regeneration, but its lipophilicity hampers incorporation and release to and from the bone graft. In this study, injectable calcium phosphate foams (i-CPF) based on α-tricalcium phosphate were loaded for the first time with Pitavastatin. The stability of the drug in different conditions relevant to this study, the effect of the drug on the i-CPFs properties, the release profile, and the in vitro biological performance with regard to mineralization and vascularization were investigated. Pitavastatin did not cause any changes in neither the micro nor the macro structure of the i-CPFs, which retained their biomimetic features. PITA-loaded i-CPFs showed a dose-dependent drug release, with early stage release kinetics clearly affected by the evolving microstructure due to the setting of cement. in vitro studies showed dose-dependent enhancement of mineralization and vascularization. Our findings contribute towards the design of controlled release with low drug dosing bone grafts: i-CPFs loaded with PITA as osteogenic and angiogenic agent.
JTD Keywords: Controlled drug release, Endothelial progenitor cells, Mineralization, Rat mesenchymal stem cells, Vascularization
Diaz-Lucena, Daniela, Escaramis, G., Villar-Piqué, Anna, Hermann, Peter, Schmitz, Matthias, Varges, Daniela, Santana, Isabel, del Rio, José Antonio, Martí, E., Ferrer, Isidre, Baldeiras, I., Zerr, Inga, Llorens, Franc, (2020). A new tetra-plex fluorimetric assay for the quantification of cerebrospinal fluid β-amyloid42, total-tau, phospho-tau and α-synuclein in the differential diagnosis of neurodegenerative dementia Journal of Neurology 267, (9), 2567-2581
Background: Differential diagnosis of neurodegenerative dementia is currently supported by biomarkers including cerebrospinal fluid (CSF) tests. Among them, CSF total-tau (t-tau), phosphorylated tau (p-tau) and β-amyloid42 (Aβ42) are considered core biomarkers of neurodegeneration. In the present work, we hypothesize that simultaneous assessment of these biomarkers together with CSF α-synuclein (α-syn) will significantly improve the differential diagnostic of Alzheimer's disease and other dementias. To that aim, we characterized the analytical and clinical performance of a new tetra-plex immunoassay that simultaneously quantifies CSF Aβ42, t-tau, p-tau and α-syn in the differential diagnosis of neurodegenerative dementia.
Methods: Biomarkers' concentrations were measured in neurological controls (n = 38), Alzheimer's disease (n = 35), Creutzfeldt-Jakob disease (n = 37), vascular dementia (n = 28), dementia with Lewy bodies/Parkinson's disease dementia (n = 27) and frontotemporal dementia (n = 34) using the new tetra-plex assay and established single-plex assays. Biomarker's performance was evaluated and diagnostic accuracy in the discrimination of diagnostic groups was determined using partial least squares discriminant analysis.
Results: The tetra-plex assay presented accuracies similar to individual single-plex assays with acceptable analytical performance. Significant correlations were observed between tetra-plex and single-plex assays. Using partial least squares discriminant analysis, Alzheimer's disease and Creutzfeldt-Jakob disease were well differentiated, reaching high accuracies in the discrimination from the rest of diagnostic groups.
Conclusions: The new tetra-plex assay coupled with multivariate analytical approaches becomes a valuable asset for the differential diagnosis of neurodegenerative dementia and related applications.
JTD Keywords: Neurodegenerative dementia, Cerebrospinal fluid, Biomarker, Amyloid beta, Total-tau, Phospho-tau, α-Synuclein, Multiplexing
Valenti, S., Yousefzade, O., Puiggalí, J., Macovez, R., (2020). Phase-selective conductivity enhancement and cooperativity length in PLLA/TPU nanocomposite blends with carboxylated carbon nanotubes Polymer 191, 122279
Transmission electron microscopy, temperature-modulated differential scanning calorimetry, and broadband dielectric spectroscopy were employed to characterize ternary nanocomposites consisting of carboxylated carbon nanotubes (CNT) dispersed in a blend of two immiscible polymers, poly(L,lactide) (PLLA) and thermoplastic polyurethane (TPU). The nanocomposite blends were obtained by melt-compounding of PLLA and TPU in the presence of 0.2 wt-% CNT, either in the presence or absence of a Joncryl® ADR chain extender for PLLA, leading to reactive and non-reactive melt mixed samples. In both cases, the binary PLLA/TPU blend is characterized by phase separation into submicron TPU droplets dispersed in the PLLA matrix, and displays two separate glass transition temperatures. The carbon nanotubes are present either inside the TPU phase (samples obtained without chain extender), or at their boundaries (reactive-melt mixed samples). The effect of the sub-micron confinement of the TPU component is to decrease the cooperativity length of the primary segmental relaxation of this polymer, which is accentuated by the presence of the CNT fillers. Depending on the type of sample, five or six distinct relaxations are observed by means of dielectric spectroscopy, which we are able to assign to different dielectric phenomena. Our dielectric data show that the CNT fillers do not contribute directly to the long-range charge transport in the nanocomposite blends, consistent with the nanocomposites morphology, but rather result in a shift of the Maxwell-Wagner-Sillars space-charge frequency associated with charge accumulation at the PLLA/TPU boundary. Such shift testifies to a selective conductivity enhancement of the TPU phase due to the filler.
JTD Keywords: Conductivity enhancement, Cooperatively rearranging region, Dielectric spectroscopy, Glass transition, Maxwell-Wagner-Sillars relaxation, Nanofiller
Palacio, F., Fonollosa, J., Burgués, J., Gomez, J. M., Marco, S., (2020). Pulsed-temperature metal oxide gas sensors for microwatt power consumption IEEE Access 8, 70938-70946
Metal Oxide (MOX) gas sensors rely on chemical reactions that occur efficiently at high temperatures, resulting in too-demanding power requirements for certain applications. Operating the sensor under a Pulsed-Temperature Operation (PTO), by which the sensor heater is switched ON and OFF periodically, is a common practice to reduce the power consumption. However, the sensor performance is degraded as the OFF periods become larger. Other research works studied, generally, PTO schemes applying waveforms to the heater with time periods of seconds and duty cycles above 20%. Here, instead, we explore the behaviour of PTO sensors working under aggressive schemes, reaching power savings of 99% and beyond with respect to continuous heater stimulation. Using sensor sensitivity and the limit of detection, we evaluated four Ultra Low Power (ULP) sensors under different PTO schemes exposed to ammonia, ethylene, and acetaldehyde. Results show that it is possible to operate the sensors with total power consumption in the range of microwatts. Despite the aggressive power reduction, sensor sensitivity suffers only a moderate decline and the limit of detection may degrade up to a factor five. This is, however, gas-dependent and should be explored on a case-by-case basis since, for example, the same degradation has not been observed for ammonia. Finally, the run-in time, i.e., the time required to get a stable response immediately after switching on the sensor, increases when reducing the power consumption, from 10 minutes to values in the range of 10–20 hours for power consumptions smaller than 200 microwatts.
JTD Keywords: Robot sensing systems, Temperature sensors, Heating systems, Gas detectors, Power demand, Sensitivity, Electronic nose, gas sensors, low-power operation, machine olfaction, pulsed-temperature operation, temperature modulation
Xu, D., Wang, Y., Liang, C., You, Y., Sanchez, S., Ma, X., (2020). Self-propelled micro/nanomotors for on-demand biomedical cargo transportation Small 16, (27), 1902464
Micro/nanomotors (MNMs) are miniaturized machines that can perform assigned tasks at the micro/nanoscale. Over the past decade, significant progress has been made in the design, preparation, and applications of MNMs that are powered by converting different sources of energy into mechanical force, to realize active movement and fulfill on-demand tasks. MNMs can be navigated to desired locations with precise controllability based on different guidance mechanisms. A considerable research effort has gone into demonstrating that MNMs possess the potential of biomedical cargo loading, transportation, and targeted release to achieve therapeutic functions. Herein, the recent advances of self-propelled MNMs for on-demand biomedical cargo transportation, including their self-propulsion mechanisms, guidance strategies, as well as proof-of-concept studies for biological applications are presented. In addition, some of the major challenges and possible opportunities of MNMs are identified for future biomedical applications in the hope that it may inspire future research.
JTD Keywords: Biomedical applications, Cargo transportation, Guidance strategies, Micro/nanomotors, Self-propulsion
De Corato, M., Pagonabarraga, I., Abdelmohsen, L. K. E. A., Sánchez, S., Arroyo, M., (2020). Spontaneous polarization and locomotion of an active particle with surface-mobile enzymes Physical Review Fluids 5, (12), 122001
We examine a mechanism of locomotion of active particles whose surface is uniformly coated with mobile enzymes. The enzymes catalyze a reaction that drives phoretic flows but their homogeneous distribution forbids locomotion by symmetry. We find that the ability of the enzymes to migrate over the surface combined with self-phoresis can lead to a spontaneous symmetry-breaking instability whereby the homogeneous distribution of enzymes polarizes and the particle propels. The instability is driven by the advection of enzymes by the phoretic flows and occurs above a critical Péclet number. The transition to polarized motile states occurs via a supercritical or subcritical pitchfork bifurcations, the latter of which enables hysteresis and coexistence of uniform and polarized states.
JTD Keywords: Biomimetic & bio-inspired materials, Locomotion, Surface-driven phase separation
Vidal, E., Torres, D., Guillem-Marti, J., Scionti, G., Manero, J. M., Ginebra, M. P., Rodríguez, D., Rupérez, E., (2020). Titanium scaffolds by direct ink writing: Fabrication and functionalization to guide osteoblast behavior Metals 10, (9), 1156
Titanium (Ti) and Ti alloys have been used for decades for bone prostheses due to its mechanical reliability and good biocompatibility. However, the high stiffness of Ti implants and the lack of bioactivity are pending issues that should be improved to minimize implant failure. The stress shielding effect, a result of the stiffness mismatch between titanium and bone, can be reduced by introducing a tailored structural porosity in the implant. In this work, porous titanium structures were produced by direct ink writing (DIW), using a new Ti ink formulation containing a thermosensitive hydrogel. A thermal treatment was optimized to ensure the complete elimination of the binder before the sintering process, in order to avoid contamination of the titanium structures. The samples were sintered in argon atmosphere at 1200 °C, 1300 °C or 1400 °C, resulting in total porosities ranging between 72.3% and 77.7%. A correlation was found between the total porosity and the elastic modulus of the scaffolds. The stiffness and yield strength were similar to those of cancellous bone. The functionalization of the scaffold surface with a cell adhesion fibronectin recombinant fragment resulted in enhanced adhesion and spreading of osteoblastic-like cells, together with increased alkaline phosphatase expression and mineralization.
JTD Keywords: Direct ink writing, Osseointegration, Recombinant protein, Thermoresponsive binder, Titanium, Titanium scaffold
Romero, D., Jané, R., (2020). Hypoxia-induced effects on ECG depolarization by time warping analysis during recurrent obstructive apnea Engineering in Medicine & Biology Society (EMBC)
42nd Annual International Conference of the IEEE , IEEE (Montreal, Canada) , 2626-2629
In this work, we evaluated a non-linear approach to estimate morphological variations in ECG depolarization, in the context of intermittent hypoxia (IH). Obstructive apnea sequences were provoked for 15 minutes in anesthetized Sprague-Dawley rats, alternating with equal periods of normal breathing, in a recurrent obstructive sleep apnea (OSA) model. Each apnea episode lasted 15 s, while the frequency used for each sequence was randomly selected. Average heartbeats obtained before the start and at the end of each episode, were delineated to extract only the QRS wave. Then, the segmented QRS waves were non-linearly aligned using the dynamic time warping (DWT) algorithm. Morphological QRS changes in both the amplitude and temporal domains were estimated from this alignment procedure. The hypoxic and basal segments were analyzed using ECG (lead I) recordings acquired during the experiment. To assess the effects of IH over time, the changes relative to the basal QRS wave were determined, in the intervals prior to each successive events until the end of the experiment. The results showed a progressive increase in the amplitude and time-domain morphological markers of the QRS wave along the experiment, which were strongly correlated with the changes in traditional QRS markers (r ≈ 0.9). Significant changes were found between pre-apnea and hypoxic measures only for the time-domain analysis (p<0.001), probably due to the short duration of the simulated apnea episodes.Clinical relevance Increased variability in ECG depolarization morphology during recurrent hypoxic episodes would be closely related to the expression of cardiovascular dysfunction in OSA patients.
JTD Keywords: Electrocardiography, Rats, Heart rate variability, Sleep apnea, Protocols, Heuristic algorithms
Lozano-García, M., Nuhic, J., Moxham, J., Rafferty, G. F., Jolley, C. J., Jané, R., (2020). Performance evaluation of fixed sample entropy for lung sound intensity estimation Engineering in Medicine & Biology Society (EMBC)
42nd Annual International Conference of the IEEE , IEEE (Montreal, Canada) , 2740-2743
Lung sound (LS) signals are often contaminated by impulsive artifacts that complicate the estimation of lung sound intensity (LSI) using conventional amplitude estimators. Fixed sample entropy (fSampEn) has proven to be robust to cardiac artifacts in myographic respiratory signals. Similarly, fSampEn is expected to be robust to artifacts in LS signals, thus providing accurate LSI estimates. However, the choice of fSampEn parameters depends on the application and fSampEn has not previously been applied to LS signals. This study aimed to perform an evaluation of the performance of the most relevant fSampEn parameters on LS signals, and to propose optimal fSampEn parameters for LSI estimation. Different combinations of fSampEn parameters were analyzed in LS signals recorded in a heterogeneous population of healthy subjects and chronic obstructive pulmonary disease patients during loaded breathing. The performance of fSampEn was assessed by means of its cross-covariance with flow signals, and optimal fSampEn parameters for LSI estimation were proposed.
JTD Keywords: Large scale integration, Lung, Estimation, Entropy, Loading, Robustness, Diseases
Wang, S., Hu, Y., Burgués, J., Marco, S., Liu, S.-L., (2020). Prediction of gas concentration using gated recurrent neural networks
2nd IEEE International Conference on Artificial Intelligence Circuits and Systems (AICAS) , IEEE (Genova, Italy) , 178-182
Low-cost gas sensors allow for large-scale spatial monitoring of air quality in the environment. However they require calibration before deployment. Methods such as multivariate regression techniques have been applied towards sensor calibration. In this work, we propose instead, the use of deep learning methods, particularly, recurrent neural networks for predicting the gas concentrations based on the outputs of these sensors. This paper presents a first study of using Gated Recurrent Unit (GRU) neural network models for gas concentration prediction. The GRU networks achieve on average, a 44.69% and a 25.17% RMSE improvement in concentration prediction on a gas dataset when compared with Support Vector Regression (SVR) and Multilayer Perceptron (MLP) models respectively. With the current advances in deep network hardware accelerators, these networks can be combined with the sensors for a compact embedded system suitable for edge applications.
JTD Keywords: Robot sensing systems, Predictive models, Logic gates, Gas detectors, Training, Temperature measurement, Support vector machines
Blanco-Almazan, D., Romero, D., Groenendaal, W., Lijnen, L., Smeets, C., Ruttens, D., Catthoor, F., Jané, R., (2020). Relationship between heart rate recovery and disease severity in chronic obstructive pulmonary disease patients Computers in Cardiology (CinC)
2020 Computing in Cardiology , IEEE (Rimini, Italy) 47, 1-4
Chronic obstructive pulmonary disease (COPD) patients exhibit impaired autonomic control which can be assessed by heart rate variability analysis. The study aims to evaluate the cardiac autonomic responses of COPD patients after completing a conventional six-minute walk test (6MWT). Fifty COPD patients were included in the study, for which an ECG signal (lead II) was acquired by a wearable device, before, during, and after the test. We used the heart rate (HR) time-series to assess the heart rate dynamic during recovery. The heart rate recovery (HRR) marker was evaluated every 5 s after the 6MWT and showed different dynamic trends among severity groups. We compared the HRR among patient groups classified according to the GOLD standard. Significantly larger normalized HRR values (nHRR) were found in mild COPD patients (n=23, GOLD={1,2}; nHRR 1 =14.B±7.5 %, nHRR 2 =18.6±8.1 %) compared to those with more disease severity (n=23, GOLD={3,4}; nHRR 1 =9.3±5.8 %, p=0.002; and nHRR 2 = 13.7±6.7%, p=0.041). The largest differences were observed around the first 30 s of the recovery phase (nHRR=10.8±6.6 % vs. nHRR=5.6±4 % p=0.001). Our results showed a slower recovery for the severest patients, suggesting that cardiac parameters like the ones we propose here, may provide valuable information for a better characterization of COPD severity.
JTD Keywords: Pulmonary diseases, Wearable computers, Electrocardiography, Market research, Cardiology, Heart rate variability
Conti, S., Kato, T., Park, D., Sahai, E., Trepat, X., Labernadie, A., (2020). CAFs and cancer cells co-migration in 3D spheroid invasion assay
Methods in Molecular Biology (ed. Campbell, K., Thevenea, E.), Humana Press (New York, USA) 2179, 243-256
In many solid tumors, collective cell invasion prevails over single-cell dissemination strategies. Collective modes of invasion often display specific front/rear cellular organization, where invasive leader cells arise from cancer cell populations or the tumor stroma. Collective invasion involves coordinated cellular movements which require tight mechanical crosstalk through specific combinations of cell–cell interactions and cell–matrix adhesions. Cancer Associated Fibroblasts (CAFs) have been recently reported to drive the dissemination of epithelial cancer cells through ECM remodeling and direct intercellular contact. However, the cooperation between tumor and stromal cells remains poorly understood. Here we present a simple spheroid invasion assay to assess the role of CAFs in the collective migration of epithelial tumor cells. This method enables the characterization of 3D spheroid invasion patterns through live cell fluorescent labeling combined with spinning disc microscopy. When embedded in extracellular matrix, the invasive strands of spheroids can be tracked and leader/follower organization of CAFs and cancer cells can be quantified.
JTD Keywords: 3D spheroid invasion, Cancer associated fibroblasts, Collective migration, Epithelial cancer cells, Leader/follower cells
Kechagia, Jenny Z., Ivaska, Johanna, Roca-Cusachs, Pere, (2019). Integrins as biomechanical sensors of the microenvironment Nature Reviews Molecular Cell Biology 20, (8), 457-473
Integrins, and integrin-mediated adhesions, have long been recognized to provide the main molecular link attaching cells to the extracellular matrix (ECM) and to serve as bidirectional hubs transmitting signals between cells and their environment. Recent evidence has shown that their combined biochemical and mechanical properties also allow integrins to sense, respond to and interact with ECM of differing properties with exquisite specificity. Here, we review this work first by providing an overview of how integrin function is regulated from both a biochemical and a mechanical perspective, affecting integrin cell-surface availability, binding properties, activation or clustering. Then, we address how this biomechanical regulation allows integrins to respond to different ECM physicochemical properties and signals, such as rigidity, composition and spatial distribution. Finally, we discuss the importance of this sensing for major cell functions by taking cell migration and cancer as examples.
JTD Keywords: Cell migration, Extracellular matrix, Integrins, Mechanotransduction, Single-molecule biophysics
Bolognesi, Benedetta, Faure, Andre J., Seuma, Mireia, Schmiedel, Jörrn M., Tartaglia, Gian Gaetano, Lehner, Ben, (2019). The mutational landscape of a prion-like domain Nature Communications 10, (1), 4162
Insoluble protein aggregates are the hallmarks of many neurodegenerative diseases. For example, aggregates of TDP-43 occur in nearly all cases of amyotrophic lateral sclerosis (ALS). However, whether aggregates cause cellular toxicity is still not clear, even in simpler cellular systems. We reasoned that deep mutagenesis might be a powerful approach to disentangle the relationship between aggregation and toxicity. We generated >50,000 mutations in the prion-like domain (PRD) of TDP-43 and quantified their toxicity in yeast cells. Surprisingly, mutations that increase hydrophobicity and aggregation strongly decrease toxicity. In contrast, toxic variants promote the formation of dynamic liquid-like condensates. Mutations have their strongest effects in a hotspot that genetic interactions reveal to be structured in vivo, illustrating how mutagenesis can probe the in vivo structures of unstructured proteins. Our results show that aggregation of TDP-43 is not harmful but protects cells, most likely by titrating the protein away from a toxic liquid-like phase.
JTD Keywords: Computational biology and bioinformatics, Genomics, Mechanisms of disease, Neurodegeneration, Systems biology
Hervera, A., Zhou, L., Palmisano, I., McLachlan, E., Kong, G., Hutson, T. H., Danzi, M. C., Lemmon, V. P., Bixby, J. L., Matamoros-Angles, A., Forsberg, K., De Virgiliis, F., Matheos, D. P., Kwapis, J., Wood, M. A., Puttagunta, R., del Río, J. A., Di Giovanni, S., (2019). PP4-dependent HDAC3 dephosphorylation discriminates between axonal regeneration and regenerative failure EMBO Journal 38, (13), e101032
The molecular mechanisms discriminating between regenerative failure and success remain elusive. While a regeneration-competent peripheral nerve injury mounts a regenerative gene expression response in bipolar dorsal root ganglia (DRG) sensory neurons, a regeneration-incompetent central spinal cord injury does not. This dichotomic response offers a unique opportunity to investigate the fundamental biological mechanisms underpinning regenerative ability. Following a pharmacological screen with small-molecule inhibitors targeting key epigenetic enzymes in DRG neurons, we identified HDAC3 signalling as a novel candidate brake to axonal regenerative growth. In vivo, we determined that only a regenerative peripheral but not a central spinal injury induces an increase in calcium, which activates protein phosphatase 4 that in turn dephosphorylates HDAC3, thus impairing its activity and enhancing histone acetylation. Bioinformatics analysis of ex vivo H3K9ac ChIPseq and RNAseq from DRG followed by promoter acetylation and protein expression studies implicated HDAC3 in the regulation of multiple regenerative pathways. Finally, genetic or pharmacological HDAC3 inhibition overcame regenerative failure of sensory axons following spinal cord injury. Together, these data indicate that PP4-dependent HDAC3 dephosphorylation discriminates between axonal regeneration and regenerative failure.
JTD Keywords: Calcium, HDAC3, Nerve regeneration, Spinal cord injury, Transcription
Guillem-Marti, J., Gelabert, M., Heras-Parets, A., Pegueroles, M., Ginebra, M. P., Manero, J. M., (2019). RGD mutation of the heparin binding II fragment of fibronectin for guiding mesenchymal stem cell behavior on titanium surfaces ACS Applied Materials and Interfaces 11, (4), 3666-3678
Installing bioactivity on metallic biomaterials by mimicking the extracellular matrix (ECM) is crucial for stimulating specific cellular responses to ultimately promote tissue regeneration. Fibronectin is an ECM protein commonly used for biomaterial functionalization. The use of fibronectin recombinant fragments is an attractive alternate to the use of full-length fibronectin because of the relatively low cost and facility of purification. However, it is necessary to combine more than one fragment, for example, the cell attachment site and the heparin binding II (HBII), either mixed or in one molecule, to obtain complete activity. In the present study, we proposed to install adhesion capacity to the HBII fragment by an RGD gain-of-function DNA mutation, retaining its cell differentiation capacity and thereby producing a small and very active protein fragment. The novel molecule, covalently immobilized onto titanium surfaces, maintained the growth factor-binding capacity and stimulated cell spreading, osteoblastic cell differentiation, and mineralization of human mesenchymal stem cells compared to the HBII native protein. These results highlight the potential capacity of gain-of-function DNA mutations in the design of novel molecules for the improvement of osseointegration properties of metallic implant surfaces.
JTD Keywords: Fibronectin, Growth factor, Mutation, Osseointegration, Recombinant protein, Titanium
Pollastri, S., Jorba, I., Hawkins, T. J., Llusià , J., Michelozzi, M., Navajas, D., Peñuelas, J., Hussey, P. J., Knight, M. R., Loreto, F., (2019). Leaves of isoprene-emitting tobacco plants maintain PSII stability at high temperatures New Phytologist 223, (3), 1307-1318
At high temperatures, isoprene-emitting plants display a higher photosynthetic rate and a lower nonphotochemical quenching (NPQ) compared with nonemitting plants. The mechanism of this phenomenon, which may be very important under current climate warming, is still elusive. NPQ was dissected into its components, and chlorophyll fluorescence lifetime imaging microscopy (FLIM) was used to analyse the dynamics of excited chlorophyll relaxation in isoprene-emitting and nonemitting plants. Thylakoid membrane stiffness was also measured using atomic force microscope (AFM) to identify a possible mode of action of isoprene in improving photochemical efficiency and photosynthetic stability. We show that, when compared with nonemitters, isoprene-emitting tobacco plants exposed at high temperatures display a reduced increase of the NPQ energy-dependent component (qE) and stable (1) chlorophyll fluorescence lifetime; (2) amplitude of the fluorescence decay components; and (3) thylakoid membrane stiffness. Our study shows for the first time that isoprene maintains PSII stability at high temperatures by preventing the modifications of the surrounding environment, namely providing a more steady and homogeneous distribution of the light-absorbing centres and a stable thylakoid membrane stiffness. Isoprene photoprotects leaves with a mechanism alternative to NPQ, enabling plants to maintain a high photosynthetic rate at rising temperatures.
JTD Keywords: (High) temperature, Atomic force microscopy (AFM), Chlorophyll fluorescence (quenching and lifetime), Fluorescence lifetime imaging microscopy (FLIM), Isoprene, Nonphotochemical quenching (NPQ), Photosynthesis
Rafols-de-Urquia, M., Estrada, L., Estevez-Piorno, J., Sarlabous, L., Jane, R., Torres, A., (2019). Evaluation of a wearable device to determine cardiorespiratory parameters from surface diaphragm electromyography IEEE Journal of Biomedical and Health Informatics 23, (5), 1964-1971
The use of wearable devices in clinical routines could reduce healthcare costs and improve the quality of assessment in patients with chronic respiratory diseases. The purpose of this study is to evaluate the capacity of a Shimmer3 wearable device to extract reliable cardiorespiratory parameters from surface diaphragm electromyography (EMGdi). Twenty healthy volunteers underwent an incremental load respiratory test whilst EMGdi was recorded with a Shimmer3 wearable device (EMGdiW). Simultaneously, a second EMGdi (EMGdiL), inspiratory mouth pressure (Pmouth) and lead-I electrocardiogram (ECG) were recorded via a standard wired laboratory acquisition system. Different cardiorespiratory parameters were extracted from both EMGdiW and EMGdiL signals: heart rate, respiratory rate, respiratory muscle activity and mean frequency of EMGdi signals. Alongside these, similar parameters were also extracted from reference signals (Pmouth and ECG). High correlations were found between the data extracted from the EMGdiW and the reference signal data: heart rate (R = 0.947), respiratory rate (R = 0.940), respiratory muscle activity (R = 0.877), and mean frequency (R = 0.895). Moreover, similar increments in EMGdiW and EMGdiL activity were observed when Pmouth was raised, enabling the study of respiratory muscle activation. In summary, the Shimmer3 device is a promising and cost-effective solution for the ambulatory monitoring of respiratory muscle function in chronic respiratory diseases.
JTD Keywords: Cardiorespiratory monitoring, Chronic respiratory diseases, Fixed sample entropy, Non-invasive respiratory monitoring, Surface diaphragm electromyography, Wearable wireless device
Garcia-Puig, A., Mosquera, J. L., Jiménez-Delgado, S., García-Pastor, C., Jorba, I., Navajas, D., Canals, F., Raya, A., (2019). Proteomics analysis of extracellular matrix remodeling during zebrafish heart regeneration Molecular & cellular proteomics 18, (9), 1745-1755
Adult zebrafish, in contrast to mammals, are able to regenerate their hearts in response to injury or experimental amputation. Our understanding of the cellular and molecular bases that underlie this process, although fragmentary, has increased significantly over the last years. However, the role of the extracellular matrix (ECM) during zebrafish heart regeneration has been comparatively rarely explored. Here, we set out to characterize the ECM protein composition in adult zebrafish hearts, and whether it changed during the regenerative response. For this purpose, we first established a decellularization protocol of adult zebrafish ventricles that significantly enriched the yield of ECM proteins. We then performed proteomic analyses of decellularized control hearts and at different times of regeneration. Our results show a dynamic change in ECM protein composition, most evident at the earliest (7 days post-amputation) time-point analyzed. Regeneration associated with sharp increases in specific ECM proteins, and with an overall decrease in collagens and cytoskeletal proteins. We finally tested by atomic force microscopy that the changes in ECM composition translated to decreased ECM stiffness. Our cumulative results identify changes in the protein composition and mechanical properties of the zebrafish heart ECM during regeneration.
JTD Keywords: Animal models, Atomic force microscopy, Cardiovascular disease, Cardiovascular function or biology, Developmental biology, Extracellular matrix, Heart regeneration, Proteomic analysis
Valenti, S., Diaz, A., Romanini, M., del Valle, L. J., Puiggalí, J., Tamarit, J. L., Macovez, R., (2019). Amorphous binary dispersions of chloramphenicol in enantiomeric pure and racemic poly-lactic acid: Morphology, molecular relaxations, and controlled drug release International Journal of Pharmaceutics 568, 118565
We characterize amorphous solid dispersions (ASDs) of the Chloramphenicol antibiotic in two biodegradable polylactic acid polymers, namely a commercial sample of enantiomeric pure PLLA and a home-synthesized PDLLA copolymer, investigating in particular the effect of polylactic acid in stabilizing the amorphous form of the drug and controlling its release (e.g. for antitumoral purposes). Broadband dielectric spectroscopy and differential scanning calorimetry are employed to study the homogeneity, glass transition temperature and relaxation dynamics of solvent-casted ASD membranes with different drug concentrations. We observe improved physical stability of the ASDs with respect to the pure drug, as well as a plasticizing effect of the antibiotic on the polymer, well described by the Gordon-Taylor equation. The release of the active pharmaceutical ingredient from the films in a simulated body fluid is studied by UV/vis spectroscopy at two different drug concentrations (5 and 20% in weight). The amount of released drug is found to be proportional to the square root of time, with proportionality constant that is almost the same in both dispersions, despite the fact that the relaxation time and thus the viscosity of the two samples differ by four orders of magnitude at body temperature. Since the drug release kinetics does not display a significant dependence on the drug content in the carrier, it may be expected to remain roughly constant during longer release times.
JTD Keywords: Amorphous drug, Controlled liberation, Dielectric spectroscopy, Molecular mobility, Plasticizer, Polymer enantiomerism
Manconi, M., Manca, M. L., Escribano-Ferrer, E., Coma-Cros, E. M., Biosca, A., Lantero, E., Fernàndez-Busquets, X., Fadda, A. M., Caddeo, C., (2019). Nanoformulation of curcumin-loaded eudragit-nutriosomes to counteract malaria infection by a dual strategy: Improving antioxidant intestinal activity and systemic efficacy International Journal of Pharmaceutics 556, 82-88
In this paper, nutriosomes (phospholipid vesicles associated with Nutriose® FM06) were modified to obtain new systems aimed at enhancing the efficacy of curcumin in counteracting malaria infection upon oral administration. Eudragit® L100, a pH-sensitive co-polymer, was added to these vesicles, thus obtaining eudragit-nutriosomes, to improve their in vivo performances. Liposomes without eudragit and nutriose were also prepared as a reference. Cryo-TEM images showed the formation of multicompartment vesicles, with mean diameter around 300 nm and highly negative zeta potential. Vesicles were stable in fluids mimicking the gastro-intestinal content due to the high phospholipid concentration and the presence of gastro-resistant eudragit and digestion-resistant nutriose. Eudragit-nutriosomes disclosed promising performances in vitro and in vivo: they maximized the ability of curcumin to counteract oxidative stress in intestinal cells (Caco-2), which presumably reinforced its systemic efficacy. Orally-administered curcumin-loaded eudragit-nutriosomes increased significantly the survival of malaria-infected mice relative to free curcumin-treated controls.
JTD Keywords: Eudragit® L100, Nutriose® FM06, Nutriosomes, Curcumin, Oral administration, Malaria
De Chiara, F., Checcllo, C. U., Ramón-Azcón, J., (2019). High protein diet and metabolic plasticity in non-alcoholic fatty liver disease: Myths and truths Nutrients 11, (12), 2985
Non-alcoholic fatty liver disease (NAFLD) is characterized by lipid accumulation within the liver affecting 1 in 4 people worldwide. As the new silent killer of the twenty-first century, NAFLD impacts on both the request and the availability of new liver donors. The liver is the first line of defense against endogenous and exogenous metabolites and toxins. It also retains the ability to switch between different metabolic pathways according to food type and availability. This ability becomes a disadvantage in obesogenic societies where most people choose a diet based on fats and carbohydrates while ignoring vitamins and fiber. The chronic exposure to fats and carbohydrates induces dramatic changes in the liver zonation and triggers the development of insulin resistance. Common believes on NAFLD and different diets are based either on epidemiological studies, or meta-analysis, which are not controlled evidences; in most of the cases, they are biased on test-subject type and their lifestyles. The highest success in reverting NAFLD can be attributed to diets based on high protein instead of carbohydrates. In this review, we discuss the impact of NAFLD on body metabolic plasticity. We also present a detailed analysis of the most recent studies that evaluate high-protein diets in NAFLD with a special focus on the liver and the skeletal muscle protein metabolisms.
JTD Keywords: High protein diet, Low carbohydrates, NAFLD, NASH, Physical activity
Gil, Vanessa, del Río, José Antonio, (2019). Functions of plexins/neuropilins and their ligands during hippocampal development and neurodegeneration Cells 8, (3), 206
There is emerging evidence that molecules, receptors, and signaling mechanisms involved in vascular development also play crucial roles during the development of the nervous system. Among others, specific semaphorins and their receptors (neuropilins and plexins) have, in recent years, attracted the attention of researchers due to their pleiotropy of functions. Their functions, mainly associated with control of the cellular cytoskeleton, include control of cell migration, cell morphology, and synapse remodeling. Here, we will focus on their roles in the hippocampal formation that plays a crucial role in memory and learning as it is a prime target during neurodegeneration.
JTD Keywords: PlexinD1, Sema3E, Neuropilins, Neuronal migration, Synapse formation
Lozano-García, M., Estrada-Petrocelli, L., Moxham, J., Rafferty, G. F., Torres, A., Jolley, C. J., Jané, R. , (2019). Noninvasive assessment of inspiratory muscle neuromechanical coupling during inspiratory threshold loading IEEE Access 7, 183634-183646
Diaphragm neuromechanical coupling (NMC), which reflects the efficiency of conversion of neural activation to transdiaphragmatic pressure (Pdi), is increasingly recognized to be a useful clinical index of diaphragm function and respiratory mechanics in neuromuscular weakness and cardiorespiratory disease. However, the current gold standard assessment of diaphragm NMC requires invasive measurements of Pdi and crural diaphragm electromyography (oesEMGdi), which complicates the measurement of diaphragm NMC in clinical practice. This is the first study to compare invasive measurements of diaphragm NMC (iNMC) using the relationship between Pdi and oesEMGdi, with noninvasive assessment of NMC (nNMC) using surface mechanomyography (sMMGlic) and electromyography (sEMGlic) of lower chest wall inspiratory muscles. Both invasive and noninvasive measurements were recorded in twelve healthy adult subjects during an inspiratory threshold loading protocol. A linear relationship between noninvasive sMMGlic and sEMGlic measurements was found, resulting in little change in nNMC with increasing inspiratory load. By contrast, a curvilinear relationship between invasive Pdi and oesEMGdi measurements was observed, such that there was a progressive increase in iNMC with increasing inspiratory threshold load. Progressive recruitment of lower ribcage muscles, serving to enhance the mechanical advantage of the diaphragm, may explain the more linear relationship between sMMGlic and sEMGlic (both representing lower intercostal plus costal diaphragm activity) than between Pdi and crural oesEMGdi. Noninvasive indices of NMC derived from sEMGlic and sMMGlic may prove to be useful indices of lower chest wall inspiratory muscle NMC, particularly in settings that do not have access to invasive measures of diaphragm function.
JTD Keywords: Cardiovascular system, Diaphragms, Diseases, Electromyography, Medical signal processing, Neurophysiology, Patient monitoring, Pneumodynamics, Inspiratory muscle neuromechanical coupling, Diaphragm neuromechanical coupling, Neural activation, Transdiaphragmatic pressure, Diaphragm function, Respiratory mechanics, Diaphragm NMC, Invasive measurements, Crural diaphragm electromyography, iNMC, Noninvasive assessment, nNMC, Lower chest wall inspiratory muscles, Inspiratory threshold loading protocol, Noninvasive sMMGlic measurements, sEMGlic measurements, oesEMGdi measurements, Inspiratory threshold load, Lower ribcage muscles, Lower intercostal plus costal diaphragm activity, Crural oesEMGdi, Noninvasive indices, sEMGlic sMMGlic, Lower chest wall inspiratory muscle NMC, Surface mechanomyography, Electromyography, Inspiratory threshold loading, Mechanomyography, Neuromechanical coupling, Respiratory muscles
Blanco-Almazan, D., Groenendaal, W., Catthoor, F., Jane, R., (2019). Wearable bioimpedance measurement for respiratory monitoring during inspiratory loading IEEE Access 7, 89487-89496
Bioimpedance is an unobtrusive noninvasive technique to measure respiration and has a linear relation with volume during normal breathing. The objective of this paper was to assess this linear relation during inspiratory loading protocol and determine the best electrode configuration for bioimpedance measurement. The inspiratory load is a way to estimate inspiratory muscle function and has been widely used in studies of respiratory mechanics. Therefore, this protocol permitted us to evaluate bioimpedance performance under breathing pattern changes. We measured four electrode configurations of bioimpedance and airflow simultaneously in ten healthy subjects using a wearable device and a standard wired laboratory acquisition system, respectively. The subjects were asked to perform an incremental inspiratory threshold loading protocol during the measurements. The load values were selected to increase progressively until the 60% of the subject's maximal inspiratory pressure. The linear relation of the signals was assessed by Pearson correlation (r ) and the waveform agreement by the mean absolute percentage error (MAPE), both computed cycle by cycle. The results showed a median greater than 0.965 in r coefficients and lower than 11 % in the MAPE values for the entire population in all loads and configurations. Thus, a strong linear relation was found during all loaded breathing and configurations. However, one out of the four electrode configurations showed robust results in terms of agreement with volume during the highest load. In conclusion, bioimpedance measurement using a wearable device is a noninvasive and a comfortable alternative to classical methods for monitoring respiratory diseases in normal and restrictive breathing.
JTD Keywords: Bioimpedance, Chronic respiratory diseases, Electrode configurations, Inspiratory threshold protocol, Wearable
Tozzi, C., Walani, N., Arroyo, M., (2019). Out-of-equilibrium mechanochemistry and self-organization of fluid membranes interacting with curved proteins New Journal of Physics 21, (9), 093004
The function of biological membranes is controlled by the interaction of the fluid lipid bilayer with various proteins, some of which induce or react to curvature. These proteins can preferentially bind or diffuse towards curved regions of the membrane, induce or stabilize membrane curvature and sequester membrane area into protein-rich curved domains. The resulting tight interplay between mechanics and chemistry is thought to control organelle morphogenesis and dynamics, including traffic, membrane mechanotransduction, or membrane area regulation and tension buffering. Despite all these processes are fundamentally dynamical, previous work has largely focused on equilibrium and a self-consistent theoretical treatment of the dynamics of curvature sensing and generation has been lacking. Here, we develop a general theoretical and computational framework based on a nonlinear Onsager's formalism of irreversible thermodynamics for the dynamics of curved proteins and membranes. We develop variants of the model, one of which accounts for membrane curving by asymmetric crowding of bulky off-membrane protein domains. As illustrated by a selection of test cases, the resulting governing equations and numerical simulations provide a foundation to understand the dynamics of curvature sensing, curvature generation, and more generally membrane curvature mechano-chemistry.
JTD Keywords: Curvature generation, Curvature sensing, Lipid bilayers, Membrane proteins
Rodríguez, J., Schulz, S., Giraldo, B. F., Voss, A., (2019). Risk stratification in idiopathic dilated cardiomyopathy patients using cardiovascular coupling analysis Frontiers in Physiology 10, 841
Cardiovascular diseases are one of the most common causes of death; however, the early detection of patients at high risk of sudden cardiac death (SCD) remains an issue. The aim of this study was to analyze the cardio-vascular couplings based on heart rate variability (HRV) and blood pressure variability (BPV) analyses in order to introduce new indices for noninvasive risk stratification in idiopathic dilated cardiomyopathy patients (IDC). High-resolution electrocardiogram (ECG) and continuous noninvasive blood pressure (BP) signals were recorded in 91 IDC patients and 49 healthy subjects (CON). The patients were stratified by their SCD risk as high risk (IDCHR) when after two years the subject either died or suffered life-threatening complications, and as low risk (IDCLR) when the subject remained stable during this period. Values were extracted from ECG and BP signals, the beat-to-beat interval, and systolic and diastolic blood pressure, and analyzed using the segmented Poincaré plot analysis (SPPA), the high-resolution joint symbolic dynamics (HRJSD) and the normalized short time partial directed coherence methods. Support vector machine (SVM) models were built to classify these patients according to SCD risk. IDCHR patients presented lowered HRV and increased BPV compared to both IDCLR patients and the control subjects, suggesting a decrease in their vagal activity and a compensation of sympathetic activity. Both, the cardio -systolic and -diastolic coupling strength was stronger in high-risk patients when comparing with low-risk patients. The cardio-systolic coupling analysis revealed that the systolic influence on heart rate gets weaker as the risk increases. The SVM IDCLR vs. IDCHR model achieved 98.9% accuracy with an area under the curve (AUC) of 0.96. The IDC and the CON groups obtained 93.6% and 0.94 accuracy and AUC, respectively. To simulate a circumstance in which the original status of the subject is unknown, a cascade model was built fusing the aforementioned models, and achieved 94.4% accuracy. In conclusion, this study introduced a novel method for SCD risk stratification for IDC patients based on new indices from coupling analysis and non-linear HRV and BPV. We have uncovered some of the complex interactions within the autonomic regulation in this type of patient.
JTD Keywords: Idiopathic dilated cardiomyopathy, Heart rate variability, Blood pressure variability, Coupling analysis, Sudden cardiac death, Risk stratification
Aguiar, L., Biosca, A., Lantero, E., Gut, J., Vale, N., Rosenthal, P. J., Nogueira, F., Andreu, D., Fernàndez-Busquets, X., Gomes, P., (2019). Coupling the antimalarial cell penetrating peptide TP10 to classical antimalarial drugs primaquine and chloroquine produces strongly hemolytic conjugates Molecules 24, (24), 4559
Recently, we disclosed primaquine cell penetrating peptide conjugates that were more potent than parent primaquine against liver stage Plasmodium parasites and non-toxic to hepatocytes. The same strategy was now applied to the blood-stage antimalarial chloroquine, using a wide set of peptides, including TP10, a cell penetrating peptide with intrinsic antiplasmodial activity. Chloroquine-TP10 conjugates displaying higher antiplasmodial activity than the parent TP10 peptide were identified, at the cost of an increased hemolytic activity, which was further confirmed for their primaquine analogues. Fluorescence microscopy and flow cytometry suggest that these drug-peptide conjugates strongly bind, and likely destroy, erythrocyte membranes. Taken together, the results herein reported put forward that coupling antimalarial aminoquinolines to cell penetrating peptides delivers hemolytic conjugates. Hence, despite their widely reported advantages as carriers for many different types of cargo, from small drugs to biomacromolecules, cell penetrating peptides seem unsuitable for safe intracellular delivery of antimalarial aminoquinolines due to hemolysis issues. This highlights the relevance of paying attention to hemolytic effects of cell penetrating peptide-drug conjugates.
JTD Keywords: Antimalarial, Cell penetrating peptide, Chloroquine, Erythrocyte fluorescence, Flow cytometry, Hemolysis, Microscopy, Plasmodium, Primaquine, Red blood cell
Grechuta, Klaudia, Ulysse, Laura, Rubio Ballester, Belén, Verschure, Paul, (2019). Self beyond the body: Action-driven and task-relevant purely distal cues modulate performance and body ownership Frontiers in Human Neuroscience 13, Article 91
Our understanding of body ownership largely relies on the so-called Rubber Hand Illusion (RHI). In this paradigm, synchronous stroking of the real and the rubber hands leads to an illusion of ownership of the rubber hand provided that it is physically, anatomically, and spatially plausible. Self-attribution of an artificial hand also occurs during visuomotor synchrony. In particular, participants experience ownership over a virtual or a rubber hand when the visual feedback of self-initiated movements follows the trajectory of the instantiated motor commands, such as in the Virtual Hand Illusion (VHI) or the moving Rubber Hand Illusion (mRHI). Evidence yields that both when the cues are triggered externally (RHI) and when they result from voluntary actions (VHI and mRHI), the experience of ownership is established through bottom-up integration and top-down prediction of proximodistal cues (visuotactile or visuomotor) within the peripersonal space. It seems, however, that depending on whether the sensory signals are externally (RHI) or self-generated (VHI and mRHI), the top-down expectation signals are qualitatively different. On the one hand, in the RHI the sensory correlations are modulated by top-down influences which constitute empirically induced priors related to the internal (generative) model of the body. On the other hand, in the VHI and mRHI body ownership is actively shaped by processes which allow for continuous comparison between the expected and the actual sensory consequences of the actions. Ample research demonstrates that the differential processing of the predicted and the reafferent information is addressed by the central nervous system via an internal (forward) model or corollary discharge. Indeed, results from the VHI and mRHI suggest that, in action-contexts, the mechanism underlying body ownership could be similar to the forward model. Crucially, forward models integrate across all self-generated sensory signals including not only proximodistal (i.e., visuotactile or visuomotor) but also purely distal sensory cues (i.e., visuoauditory). Thus, if body ownership results from a consistency of a forward model, it will be affected by the (in)congruency of purely distal cues provided that they inform about action-consequences and are relevant to a goal-oriented task. Specifically, they constitute a corrective error signal. Here, we explicitly addressed this question. To test our hypothesis, we devised an embodied virtual reality-based motor task where action outcomes were signaled by distinct auditory cues. By manipulating the cues with respect to their spatial, temporal and semantic congruency, we show that purely distal (visuoauditory) feedback which violates predictions about action outcomes compromises both performance and body ownership. These results demonstrate, for the first time, that body ownership is influenced by not only externally and self-generated cues which pertain to the body within the peripersonal space but also those arising outside of the body. Hence, during goal-oriented tasks body ownership may result from the consistency of forward models.
JTD Keywords: Body ownership, Internal forward model, Goal-oriented behavior, Multisensory integration, Top-down prediction
Lozano-García, M., Estrada, L., Jané, R., (2019). Performance evaluation of fixed sample entropy in myographic signals for inspiratory muscle activity estimation Entropy 21, (2), 183
Fixed sample entropy (fSampEn) has been successfully applied to myographic signals for inspiratory muscle activity estimation, attenuating interference from cardiac activity. However, several values have been suggested for fSampEn parameters depending on the application, and there is no consensus standard for optimum values. This study aimed to perform a thorough evaluation of the performance of the most relevant fSampEn parameters in myographic respiratory signals, and to propose, for the first time, a set of optimal general fSampEn parameters for a proper estimation of inspiratory muscle activity. Different combinations of fSampEn parameters were used to calculate fSampEn in both non-invasive and the gold standard invasive myographic respiratory signals. All signals were recorded in a heterogeneous population of healthy subjects and chronic obstructive pulmonary disease patients during loaded breathing, thus allowing the performance of fSampEn to be evaluated for a variety of inspiratory muscle activation levels. The performance of fSampEn was assessed by means of the cross-covariance of fSampEn time-series and both mouth and transdiaphragmatic pressures generated by inspiratory muscles. A set of optimal general fSampEn parameters was proposed, allowing fSampEn of different subjects to be compared and contributing to improving the assessment of inspiratory muscle activity in health and disease.
JTD Keywords: Electromyography, Fixed sample entropy, Mechanomyography, Non-invasive physiological measurements, Oesophageal electromyography, Respiratory muscle
Oliveira, V. R., Uriarte, J. J., Falcones, B., Zin, W. A., Navajas, D., Farré, R., Almendros, I., (2019). Escherichia coli lipopolysaccharide induces alveolar epithelial cell stiffening Journal of Biomechanics 83, 315-318
Introduction: Application of lipopolysaccharide (LPS) is a widely employed model to mimic acute respiratory distress syndrome (ARDS). Available data regarding LPS-induced biomechanical changes on pulmonary epithelial cells are limited only to P. aeruginosa LPS. Considering that LPS from different bacteria could promote a specific mechanical response in epithelial cells, we aim to assess the effect of E. coli LPS, widely employed as a model of ARDS, in the biomechanics of alveolar epithelial cells.
Methods: Young’s modulus (E) of alveolar epithelial cells (A549) was measured by atomic force microscopy every 5 min throughout 60 min of experiment after treatment with LPS from E. coli (100 μg/mL). The percentage of cells presenting actin stress fibers (F-actin staining) was also evaluated. Control cells were treated with culture medium and the values obtained were compared with LPS-treated cells for each time-point.
Results: Application of LPS induced significant increase in E after 20 min (77%) till 60 min (104%) in comparison to controls. Increase in lung epithelial cell stiffness induced by LPS was associated with a higher number of cells presenting cytoskeletal remodeling.
Conclusions:
The observed effects of E. coli LPS on alveolar epithelial cells suggest that this widely-used LPS is able to promote a quick formation of actin stress fibers and stiffening cells, thereby facilitating the disruption of the pulmonary epithelial barrier.
JTD Keywords: Acute respiratory distress syndrome model, Alveolar epithelium, Biomechanics, E. coli, Lipopolysaccharide
Ruiz, A. D., Mejía, J. S., López, J. M., Giraldo, B. F., (2019). Characterization of cardiac and respiratory system of healthy subjects in supine and sitting position Pattern Recognition and Image Analysis
ibPRIA 2019: Iberian Conference on Pattern Recognition and Image Analysis (Lecture Notes in Computer Science) , Springer, Cham (Madrid, Spain) 11867, 367-377
Studies based on the cardiac and respiratory system have allowed a better knowledge of their behavior to contribute with the diagnosis and treatment of diseases associated with them. The main goal of this project was to analyze the behavior of the cardiorespiratory system in healthy subjects, depending on the body position. The electrocardiography and respiratory flow signals were recorded in two positions, supine and sitting. Each signal was analyzed considering sliding windows of 30 s, with and overlapping of 50%. Temporal and spectral features were extracted from each signal. A total of 187 features were extracted for each window. According to statistical analysis, 148 features showed significant differences when comparing the position of the subject. Afterwards, the classifications methods based on decision trees, k-nearest neighbor and support vector machines were applied to identify the best classification model. The most advantageous performance model was obtained with a linear support vector machine method, with an accuracy of 99.5%, a sensitivity of 99.2% and a specificity of 99.6%. In conclusion, we have observed that the position of the body (supine or sitting) could modulate the cardiac and respiratory system response. New statistical models might provide new tools to analyze the behavior of these systems and the cardiorespiratory interaction complexity.
JTD Keywords: Cardiac dynamics, Respiratory dynamics, Statistical models, Supine and sitting posture
Romero, D., Jané, R., (2019). Non-linear HRV analysis to quantify the effects of intermittent hypoxia using an OSA rat model Engineering in Medicine and Biology Society (EMBC)
41st Annual International Conference of the IEEE , IEEE (Berlín, Germany) , 4994-4997
In this paper, a non-linear HRV analysis was performed to assess fragmentation signatures observed in heartbeat time series after intermittent hypoxia (IH). Three markers quantifying short-term fragmentation levels, PIP, IALS and PSS, were evaluated on R-R interval series obtained in a rat model of recurrent apnea. Through airway obstructions, apnea episodes were periodically simulated in six anesthetized Sprague-Dawley rats. The number of apnea events per hour (AHI index) was varied during the first half of the experiment while apnea episodes lasted 15 s. For the second part, apnea episodes lasted 5, 10 or 15 s, but the AHI index was fixed. Recurrent apnea was repeated for 15-min time intervals in all cases, alternating with basal periods of the same duration. The fragmentation markers were evaluated in segments of 5 minutes, selected at the beginning and end of the experiment. The impact of the heart and breathing rates (HR and BR, respectively) on the parameter estimates was also investigated. The results obtained show a significant increase (from 5 to 10%, p <; 0.05) in fragmentation measures of heartbeat time series after IH, indicating a clear deterioration of the initial conditions. Moreover, there was a strong linear relationship (r > 0.9) between these markers and BR, as well as with the ratio given by HR/BR. Although fragmentation may be impacted by IH, we found that it is highly dependent on HR and BR values and thus, they should be considered during its calculation or used to normalize the fragmentation estimates.
JTD Keywords: Rats, Time series analysis, Radio access technologies, Protocols, Heart beat
Castillo-Escario, Y., Rodríguez-Cañón, M., García-Alías, G., Jané, R., (2019). Onset detection to study muscle activity in reaching and grasping movements in rats Engineering in Medicine and Biology Society (EMBC)
41st Annual International Conference of the IEEE , IEEE (Berlín, Germany) , 5113-5116
EMG signals reflect the neuromuscular activation patterns related to the execution of a certain movement or task. In this work, we focus on reaching and grasping (R&G) movements in rats. Our objective is to develop an automatic algorithm to detect the onsets and offsets of muscle activity and use it to study muscle latencies in R&G maneuvers. We had a dataset of intramuscular EMG signals containing 51 R&G attempts from 2 different animals. Simultaneous video recordings were used for segmentation and comparison. We developed an automatic onset/offset detector based on the ratio of local maxima of Teager-Kaiser Energy (TKE). Then, we applied it to compute muscle latencies and other features related to the muscle activation pattern during R&G cycles. The automatic onsets that we found were consistent with visual inspection and video labels. Despite the variability between attempts and animals, the two rats shared a sequential pattern of muscle activations. Statistical tests confirmed the differences between the latencies of the studied muscles during R&G tasks. This work provides an automatic tool to detect EMG onsets and offsets and conducts a preliminary characterization of muscle activation during R&G movements in rats. This kind of approaches and data processing algorithms can facilitate the studies on upper limb motor control and motor impairment after spinal cord injury or stroke.
JTD Keywords: Muscles, Electromyography, Rats, Low pass filters, Microsoft Windows, Band-pass filters
Calvo, M., Jané, R., (2019). Sleep stage influence on the autonomic modulation of sleep apnea syndrome
2019 Computing in Cardiology (CinC) , IEEE (Singapore, Singapore) , 1-4
Hypoxia induced by obstructive sleep apnea (OSA) leads to the deregulation of the autonomic nervous system (ANS), resulting in an abnormally increased sympathetic activity. Since ANS modulation varies throughout the night, notably for each sleep stage, the hypno-gram and heart rate signals of 81 OSA patients were collected during a polysomnography. They were classified as mild-moderate (n=44) or severe (n=37) based on their apnea-hypopnea index (AHI). Spectral heart rate variability (HRV) series were extracted by a time-frequency approach. These series were then averaged for each sleep stage, in order to compare the sympathetic modulation of mild-moderate and severe patients at the following phases: rapid eye movement (REM), S1, S2 and SWS (slow wave sleep). According to normalized power at the low-frequency band (LFnu) values, severe OSA seems to be associated with an increased sympathetic modulation at non-REM sleep. Moreover, a decreased autonomic variability throughout the night may be related to a reduced adaptability of the cardiovascular system, characterizing a more advanced stage of the disease. These results provide further evidence for the role of autonomic alterations induced by hypoxia, suggesting the use of HRV analysis, together with AHI, for the study of OSA severity.
JTD Keywords: Sleep apnea, Heart rate variability, Modulation, Indexes, Standards
Fuentes-Mera, L., Camacho, A., Engel, E., Pérez-Silos, V., Lara-Arias, J., Marino-Martínez, I., Peña-Martínez, V., (2019). Therapeutic potential of articular cartilage regeneration using tissue engineering based on multiphase designs
Cartilage Tissue Engineering and Regeneration Techniques (ed. Nikolopoulos, Dimitrios D., Safos, George K., Dimitrios, Kalpaxis), IntechOpen (Budapest, Hungary) , 331-359
Articular cartilage tissue possesses poor ability to regenerate; as the lesion progresses, it extends to the underlying subchondral bone and an osteochondral (OC) defect appears complicating the therapeutic approaches. Cartilage tissue engineering has become a very active research area capable of contributing to medical technology innovation. In this regard, the development of new biomaterials in combination with cells represents one of the best alternatives for the treatment of OC injuries. In the last decades, the strategies have been designed without considering the cartilage as a complex tissue with a functionally stratified three-dimensional structure. Today, efforts are focused on creating a starting point in the process of cartilage formation with the development of a multiphase implants that recapitulates the cartilage as an OC unit, which improves its integration. This chapter will focus on a review of tissue engineering based on multiphase designs for cartilage and OC injuries, highlighting the importance of the biomaterial selection, and also the relevance of a biomimetic approach to reach a suitable microenvironment for the differentiation and maturation of the chondral tissue.
JTD Keywords: Osteochondral regeneration, Cartilage tissue engineering, Multiphasic designs, Biofunctionalization, Vascularization
Samitier, Josep, Correia, A., (2019). Biomimetic Nanotechnology for Biomedical Applications (NanoBio&Med 2018) Biomimetics MDPI
Emerging nanobiotechnologies can offer solutions to the current and future challenges in medicine. By covering topics from regenerative medicine, tissue engineering, drug delivery, bionanofabrication, and molecular biorecognition, this Special Issue aims to provide an update on the trends in nanomedicine and drug delivery using biomimetic approaches, and the development of novel biologically inspired devices for the safe and effective diagnosis, prevention, and treatment of disease.
JTD Keywords: Bioinspired nanotechnologies, Bionanofabrication, Bio-nano measurement and microscopy, Nanomaterials for biological and medical applications, Nanoassemblies, Nanostructured surfaces, Drug delivery, Nanobioelectronics, Integrated systems/nanobiosensors, Nanotoxicology, Graphene-based applications
Castaño, O., Pérez-Amodio, S., Navarro, C., Mateos-Timoneda, M.A., Engel, E., (2018). Instructive microenvironments in skin wound healing: Biomaterials as signal releasing platforms Advanced Drug Delivery Reviews 129, 95-117
Skin wound healing aims to repair and restore tissue through a multistage process that involves different cells and signalling molecules that regulate the cellular response and the dynamic remodelling of the extracellular matrix. Nowadays, several therapies that combine biomolecule signals (growth factors and cytokines) and cells are being proposed. However, a lack of reliable evidence of their efficacy, together with associated issues such as high costs, a lack of standardization, no scalable processes, and storage and regulatory issues, are hampering their application. In situ tissue regeneration appears to be a feasible strategy that uses the body's own capacity for regeneration by mobilizing host endogenous stem cells or tissue-specific progenitor cells to the wound site to promote repair and regeneration. The aim is to engineer instructive systems to regulate the spatio-temporal delivery of proper signalling based on the biological mechanisms of the different events that occur in the host microenvironment. This review describes the current state of the different signal cues used in wound healing and skin regeneration, and their combination with biomaterial supports to create instructive microenvironments for wound healing.
JTD Keywords: Instructive biomaterials, Skin regeneration, Wound healing, Signalling release, In situ tissue engineering
García-Díaz, María, Birch, Ditlev, Wan, Feng, Mørck Nielsen, Hanne, (2018). The role of mucus as an invisible cloak to transepithelial drug delivery by nanoparticles Advanced Drug Delivery Reviews 124, 107-124
Mucosal administration of drugs and drug delivery systems has gained increasing interest. However, nanoparticles intended to protect and deliver drugs to epithelial surfaces require transport through the surface-lining mucus. Translation from bench to bedside is particularly challenging for mucosal administration since a variety of parameters will influence the specific barrier properties of the mucus including the luminal fluids, the microbiota, the mucus composition and clearance rate, and the condition of the underlying epithelia. Besides, after administration, nanoparticles interact with the mucosal components, forming a biomolecular corona that modulates their behavior and fate after mucosal administration. These interactions are greatly influenced by the nanoparticle properties, and therefore different designs and surface-engineering strategies have been proposed. Overall, it is essential to evaluate these biomolecule-nanoparticle interactions by complementary techniques using complex and relevant mucus barrier matrices.
JTD Keywords: Nanoparticle formulation strategies, Corona formation, Digestive tract, Respiratory tract, Luminal content, Methodologies, Analysis
Matera, Carlo, Gomila-Juaneda, Alexandre, Camarero, Núria, Libergoli, Michela, Soler, Concepció, Gorostiza, Pau, (2018). A photoswitchable antimetabolite for targeted photoactivated chemotherapy Journal of the American Chemical Society 140, (46), 15764-15773
The efficacy and tolerability of systemically administered anticancer agents are limited by their off-target effects. Precise spatiotemporal control over their cytotoxic activity would allow improving chemotherapy treatments, and light-regulated drugs are well suited to this purpose. We have developed phototrexate, the first photoswitchable inhibitor of the human dihydrofolate reductase (DHFR), as a photochromic analog of methotrexate, a widely prescribed chemotherapeutic drug to treat cancer and psoriasis. Quantification of the light-regulated DHFR enzymatic activity, cell proliferation, and in vivo effects in zebrafish show that phototrexate behaves as a potent antifolate in its photoactivated cis configuration, and that it is nearly inactive in its dark-relaxed trans form. Thus, phototrexate constitutes a proof-of-concept to design light-regulated cytotoxic small molecules, and a step forward to develop targeted anticancer photochemotherapies with localized efficacy and reduced adverse effects.
JTD Keywords: Photopharmacology, Photodynamic therapy, Antiproliferative, Arthritis, Psoriasis, Nanomedicine
Del Río, J. A., Ferrer, Isidre, Gavín, R., (2018). Role of cellular prion protein in interneuronal amyloid transmission Progress in Neurobiology 165-167, 87-102
Several studies have indicated that certain misfolded amyloids composed of tau, β-amyloid or α-synuclein can be transferred from cell to cell, suggesting the contribution of mechanisms reminiscent of those by which infective prions spread through the brain. This process of a ‘prion-like’ spreading between cells is also relevant as a novel putative therapeutic target that could block the spreading of proteinaceous aggregates throughout the brain which may underlie the progressive nature of neurodegenerative diseases. The relevance of β-amyloid oligomers and cellular prion protein (PrPC) binding has been a focus of interest in Alzheimer’s disease (AD). At the molecular level, β-amyloid/PrPC interaction takes place in two differently charged clusters of PrPC. In addition to β-amyloid, participation of PrPC in α-synuclein binding and brain spreading also appears to be relevant in α-synucleopathies. This review summarizes current knowledge about PrPC as a putative receptor for amyloid proteins and the physiological consequences of these interactions..
JTD Keywords: Cellular prion protein, Amyloid, Proteinaceous species, ‘prion-like’ spreading, Spreading, Neurodegeneration
Pérez, Judit, Dulay, Samuel, Mir, M., Samitier, Josep, (2018). Molecular architecture for DNA wiring Biosensors and Bioelectronics 121, 54-61
Detection of the hybridisation events is of great importance in many different biotechnology applications such as diagnosis, computing, molecular bioelectronics, and among others. However, one important drawback is the low current of some redox reporters that limits their application. This paper demonstrates the powerful features of molecular wires, in particular the case of S-[4-[2-[4-(2-Phenylethynyl)phenyl]ethynyl]phenyl] thiol molecule and the key role that play the nanometric design of the capture probe linkers to achieve an efficient couple of the DNA complementary ferrocene label with the molecular wire for an effective electron transfer in co-immobilised self-assembled monolayers (SAMs) for DNA hybridisation detection. In this article, the length of the linker capture probe was studied for electron transfer enhancement from the ferrocene-motifs of immobilised molecules towards the electrode surface to obtain higher kinetics in the presence of thiolated molecular wires. The use of the right couple of capture probe linker and molecular wire has found to be beneficial as it helps to amplify eightfold the signal obtained.
JTD Keywords: DNA hybridisation, Bioelectronics, Electron transfer rate constant, Molecular wires, Electrochemistry, Ferrocene, Biosensor
Raymond, Santiago, Maazouz, Yassine, Montufar, Edgar B., Perez, Roman A., González, Borja, Konka, Joanna, Kaiser, Jozef, Ginebra, Maria-Pau, (2018). Accelerated hardening of nanotextured 3D-plotted self-setting calcium phosphate inks Acta Biomaterialia 75, 451-462
Direct ink writing (DIW) techniques open up new possibilities for the fabrication of patient-specific bone grafts. Self-setting calcium phosphate inks, which harden at low temperature, allow obtaining nanostructured scaffolds with biomimetic properties and enhanced bioactivity. However, the slow hardening kinetics hampers the translation to the clinics. Different hydrothermal treatments for the consolidation of DIW scaffolds fabricated with an α-tricalcium phosphate /pluronic F127 ink were explored, comparing them with a biomimetic treatment. Three different scaffold architectures were analysed. The hardening process, associated to the conversion of α-tricalcium phosphate to hydroxyapatite was drastically accelerated by the hydrothermal treatments, reducing the time for complete reaction from 7 days to 30 minutes, while preserving the scaffold architectural integrity and retaining the nanostructured features. β-tricalcium phosphate was formed as a secondary phase, and a change of morphology from plate-like to needle-like crystals in the hydroxyapatite phase was observed. The binder was largely released during the treatment. The hydrothermal treatment resulted in a 30% reduction of the compressive strength, associated to the residual presence of β-tricalcium phosphate. Biomimetic and hydrothermally treated scaffolds supported the adhesion and proliferation of rat mesenchymal stem cells, indicating a good suitability for bone tissue engineering applications.
Statement of Significance: 3D plotting has opened up new perspectives in the bone regeneration field allowing the customisation of synthetic bone grafts able to fit patient-specific bone defects. Moreover, this technique allows the control of the scaffolds’ architecture and porosity. The present work introduces a new method to harden biomimetic hydroxyapatite 3D-plotted scaffolds which avoids high-temperature sintering. It has two main advantages: i) it is fast and simple, reducing the whole fabrication process from the several days required for the biomimetic processing to a few hours; and ii) it retains the nanostructured character of biomimetic hydroxyapatite and allows controlling the porosity from the nano- to the macroscale. Moreover, the good in vitro cytocompatibility results support its suitability for cell-based bone regeneration therapies.
JTD Keywords: Calcium phosphate, Hydroxyapatite, Biomimetic, Bone regeneration, 3D plotting, Direct ink writing, Bone graft
Solórzano, A., Rodríguez-Pérez, R., Padilla, M., Graunke, T., Fernandez, L., Marco, S., Fonollosa, J., (2018). Multi-unit calibration rejects inherent device variability of chemical sensor arrays Sensors and Actuators B: Chemical 265, 142-154
Inherent sensor variability limits mass-production applications for metal oxide (MOX) gas sensor arrays because calibration for replicas of a sensor array needs to be performed individually. Recently, calibration transfer strategies have been proposed to alleviate calibration costs of new replicas, but they still require the acquisition of transfer samples. In this work, we present calibration models that can be extended to uncalibrated replicas of sensor arrays without acquiring new samples, i.e., general or global calibration models. The developed methodology consists in including multiple replicas of a sensor array in the calibration process such that sensor variability is rejected by the general model. Our approach was tested using replicas of a MOX sensor array in the classification task of six gases and synthetic air, presented at different background humidity and concentration levels. Results showed that direct transfer of individual calibration models provides poor classification accuracy. However, we also found that general calibration models kept predictive performance when were applied directly to new copies of the sensor array. Moreover, we explored, through feature selection, whether particular combinations of sensors and operating temperatures can provide predictive performances equivalent to the calibration model with the complete array, favoring thereby the existence of more robust calibration models.
JTD Keywords: Gas sensor array, MOX sensor, Robust calibration, Calibration transfer, Machine olfaction
Garcia-Esparcia, P., Koneti, A., Rodríguez-Oroz, M. C., Gago, B., del Rio, J. A., Ferrer, Isidro, (2018). Mitochondrial activity in the frontal cortex area 8 and angular gyrus in Parkinson's disease and Parkinson's disease with dementia Brain Pathology 28, (1), 43-57
Altered mitochondrial function is characteristic in the substantia nigra in Parkinson's disease (PD). Information about mitochondria in other brain regions such as the cerebral cortex is conflicting mainly because most studies have not contemplated the possibility of variable involvement depending on the region, stage of disease progression and clinical symptoms such as the presence or absence of dementia. RT-qPCR of 18 nuclear mRNAs encoding subunits of mitochondrial complexes and 12 mRNAs encoding energy metabolism-related enzymes; western blotting of mitochondrial proteins; and analysis of enzymatic activities of complexes I, II, II, IV and V of the respiratory chain were assessed in frontal cortex area 8 and the angular gyrus of middle-aged individuals (MA), and those with incidental PD (iPD), long-lasting PD with parkinsonism without dementia (PD) and long-lasting PD with dementia (PDD). Up-regulation of several genes was found in frontal cortex area 8 in PD when compared with MA and in the angular gyrus in iPD when compared with MA. Marked down-regulation of genes encoding mitochondrial subunits and energy metabolism-related enzymes occurs in frontal cortex but only of genes coding for energy metabolism-related enzymes in the angular gyrus in PDD. Significant decrease in the protein expression levels of several mitochondrial subunits encoded by these genes occurs in frontal cortex area 8 and angular gyrus in PDD. Moreover, expression of MT-ND1 which is encoded by mitochondrial DNA is also reduced in PDD. Reduced enzymatic activity of complex III in frontal cortex area 8 and angular gyrus is observed in PD, but dramatic reduction in the activity of complexes I, II, II and IV in both regions characterizes PDD. Dementia in the context of PD is linked to region-specific deregulation of genomic genes encoding subunits of mitochondrial complexes and to marked reduction in the activity of mitochondrial complexes I, II, III and IV.
JTD Keywords: Cerebral cortex, Dementia, Energy metabolism, Incidental PD, Mitochondria, Oxidative phosphorylation, Parkinson disease, PDD, Respiratory chain
Burgués, J., Jiménez-Soto, J. M., Marco, S., (2018). Estimation of the limit of detection in semiconductor gas sensors through linearized calibration models Analytica Chimica Acta 1013, 13-25
The limit of detection (LOD) is a key figure of merit in chemical sensing. However, the estimation of this figure of merit is hindered by the non-linear calibration curve characteristic of semiconductor gas sensor technologies such as, metal oxide (MOX), gasFETs or thermoelectric sensors. Additionally, chemical sensors suffer from cross-sensitivities and temporal stability problems. The application of the International Union of Pure and Applied Chemistry (IUPAC) recommendations for univariate LOD estimation in non-linear semiconductor gas sensors is not straightforward due to the strong statistical requirements of the IUPAC methodology (linearity, homoscedasticity, normality). Here, we propose a methodological approach to LOD estimation through linearized calibration models. As an example, the methodology is applied to the detection of low concentrations of carbon monoxide using MOX gas sensors in a scenario where the main source of error is the presence of uncontrolled levels of humidity.
JTD Keywords: Semiconductor gas sensors, Metal-oxide sensors, Limit of detection, Non-linear, Humidity interference, Temperature modulation
Burgués, Javier, Marco, Santiago, (2018). Multivariate estimation of the limit of detection by orthogonal partial least squares in temperature-modulated MOX sensors Analytica Chimica Acta 1019, 49-64
Metal oxide semiconductor (MOX) sensors are usually temperature-modulated and calibrated with multivariate models such as Partial Least Squares (PLS) to increase the inherent low selectivity of this technology. The multivariate sensor response patterns exhibit heteroscedastic and correlated noise, which suggests that maximum likelihood methods should outperform PLS. One contribution of this paper is the comparison between PLS and maximum likelihood principal components regression (MLPCR) in MOX sensors. PLS is often criticized by the lack of interpretability when the model complexity increases beyond the chemical rank of the problem. This happens in MOX sensors due to cross-sensitivities to interferences, such as temperature or humidity and non-linearity. Additionally, the estimation of fundamental figures of merit, such as the limit of detection (LOD), is still not standardized in multivariate models. Orthogonalization methods, such as Orthogonal Projection to Latent Structures (O-PLS), have been successfully applied in other fields to reduce the complexity of PLS models. In this work, we propose a LOD estimation method based on applying the well-accepted univariate LOD formulas to the scores of the first component of an orthogonal PLS model. The resulting LOD is compared to the multivariate LOD range derived from error-propagation. The methodology is applied to data extracted from temperature-modulated MOX sensors (FIS SB-500-12 and Figaro TGS 3870-A04), aiming at the detection of low concentrations of carbon monoxide in the presence of uncontrolled humidity (chemical noise). We found that PLS models were simpler and more accurate than MLPCR models. Average LOD values of 0.79 ppm (FIS) and 1.06 ppm (Figaro) were found using the approach described in this paper. These values were contained within the LOD ranges obtained with the error-propagation approach. The mean LOD increased to 1.13 ppm (FIS) and 1.59 ppm (Figaro) when considering validation samples collected two weeks after calibration, which represents a 43% and 46% degradation, respectively. The orthogonal score-plot was a very convenient tool to visualize MOX sensor data and to validate the LOD estimates.
JTD Keywords: Metal oxide sensors, Partial least squares, Orthogonal projection to latent structures, Maximum likelihood principal component regression, Limit of detection, Temperature modulation
Casanellas, Ignasi, García-Lizarribar, Andrea, Lagunas, Anna, Samitier, Josep, (2018). Producing 3D biomimetic nanomaterials for musculoskeletal system regeneration Frontiers in Bioengineering and Biotechnology 6, Article 128
The human musculoskeletal system is comprised mainly of connective tissues such as cartilage, tendon, ligaments, skeletal muscle and skeletal bone. These tissues support the structure of the body, hold and protect the organs, and are responsible of movement. Since it is subjected to continuous strain, the musculoskeletal system is prone to injury by excessive loading forces or aging, whereas currently available treatments are usually invasive and not always effective. Most of the musculoskeletal injuries require surgical intervention facing a limited post-surgery tissue regeneration, especially for widespread lesions. Therefore, many tissue engineering approaches have been developed tackling musculoskeletal tissue regeneration. Materials are designed to meet the chemical and mechanical requirements of the native tissue three-dimensional (3D) environment, thus facilitating implant integration while providing a good reabsorption rate. With biological systems operating at the nanoscale, nanoengineered materials have been developed to support and promote regeneration at the interprotein communication level. Such materials call for a great precision and architectural control in the production process fostering the development of new fabrication techniques. In this mini review, we would like to summarize the most recent advances in 3D nanoengineered biomaterials for musculoskeletal tissue regeneration, with especial emphasis on the different techniques used to produce them.
JTD Keywords: Nanofiber, 3D printing, Musculoskeletal, Regeneration, Scaffold, Tissue Engineering, Stimuli-responsive
Quiliano, Miguel, Pabón, Adriana, Moles, Ernest, Bonilla-Ramirez, Leonardo, Fabing, Isabelle, Fong, Kim Y., Nieto-Aco, Diego A., Wright, David W., Pizarro, Juan C., Vettorazzi, Ariane, López de Cerain, Adela, Deharo, Eric, Fernàndez-Busquets, Xavier, Garavito, Giovanny, Aldana, Ignacio, Galiano, Silvia, (2018). Structure-activity relationship of new antimalarial 1-aryl-3-susbtituted propanol derivatives: Synthesis, preliminary toxicity profiling, parasite life cycle stage studies, target exploration, and targeted delivery European Journal of Medicinal Chemistry 152, 489-514
Design, synthesis, structure-activity relationship, cytotoxicity studies, in silico drug-likeness, genotoxicity screening, and in vivo studies of new 1-aryl-3-substituted propanol derivatives led to the identification of nine compounds with promising in vitro (55, 56, 61, 64, 66, and 70–73) and in vivo (66 and 72) antimalarial profiles against Plasmodium falciparum and Plasmodium berghei. Compounds 55, 56, 61, 64, 66 and 70–73 exhibited potent antiplasmodial activity against chloroquine-resistant strain FCR-3 (IC50s < 0.28 μM), and compounds 55, 56, 64, 70, 71, and 72 showed potent biological activity in chloroquine-sensitive and multidrug-resistant strains (IC50s < 0.7 μM for 3D7, D6, FCR-3 and C235). All of these compounds share appropriate drug-likeness profiles and adequate selectivity indexes (77 < SI < 184) as well as lack genotoxicity. In vivo efficacy tests in a mouse model showed compounds 66 and 72 to be promising candidates as they exhibited significant parasitemia reductions of 96.4% and 80.4%, respectively. Additional studies such as liver stage and sporogony inhibition, target exploration of heat shock protein 90 of P. falciparum, targeted delivery by immunoliposomes, and enantiomer characterization were performed and strongly reinforce the hypothesis of 1-aryl-3-substituted propanol derivatives as promising antimalarial compounds.
JTD Keywords: Antiplasmodial, Antimalarial, Arylamino alcohol, Multi-stage activity, Hsp90, Enantiomer separation
Guillem-Marti, J., Boix-Lemonche, G., Gugutkov, D., Ginebra, M.-P., Altankov, G., Manero, J.M., (2018). Recombinant fibronectin fragment III8-10/polylactic acid hybrid nanofibers enhance the bioactivity of titanium surface Nanomedicine 13, (8), 899-912
Aim: To develop a nanofiber (NF)-based biomimetic coating on titanium (Ti) that mimics the complex spatiotemporal organization of the extracellular matrix (ECM). Materials & methods: Recombinant cell attachment site (CAS) of fibronectin type III8-10 domain was co-electrospun with polylactic acid (PLA) and covalently bound on polished Ti discs. Osteoblast-like SaOS-2 cells were used to evaluate their complex bioactivity. Results: A significant increase of cell spreading was found on CAS/PLA hybrid NFs, followed by control pure PLA NFs and bare Ti discs. Cell proliferation showed similar trend being about twice higher on CAS/PLA NFs. The significantly increased ALP activity at day 21 indicated an enhanced differentiation of SaOS-2 cells. Conclusion: Coating of Ti implants with hybrid CAS/PLA NFs may improve significantly their osseointegration potential.
JTD Keywords: Electrospinning, Fibronectin, Hybrid nanofibers, Osseointegration, PLA, Recombinant protein
Estrada, L., Torres, A., Sarlabous, L., Jané, R., (2018). Onset and offset estimation of the neural inspiratory time in surface diaphragm electromyography: A pilot study in healthy subjects IEEE Journal of Biomedical and Health Informatics 22, (1), 67-76
This study evaluates the onset and offset of neural inspiratory time estimated from surface diaphragm electromyographic (EMGdi) recordings. EMGdi and airflow signals were recorded in ten healthy subjects according to two respiratory protocols based on respiratory rate (RR) increments, from 15 to 40 breaths per minute (bpm), and fractional inspiratory time (Ti/Ttot) decrements, from 0.54 to 0.18. The analysis of diaphragm electromyographic (EMGdi) signal amplitude is an alternative approach for the quantification of neural respiratory drive (NRD). The EMGdi amplitude was estimated using the fixed sample entropy computed over a 250 ms moving window of the EMGdi signal (EMGdifse). The neural onset was detected through a dynamic threshold over the EMGdifse using the kernel density estimation method, while neural offset was detected by finding when the EMGdifse had decreased to 70 % of the peak value reached during inspiration. The Bland-Altman analysis between airflow and neural onsets showed a global bias of 46 ms in the RR protocol and 22 ms in the Ti/Ttot protocol. The Bland-Altman analysis between airflow and neural offsets reveals a global bias of 11 ms in the RR protocol and -2 ms in the Ti/Ttot protocol. The relationship between pairs of RR values (Pearson’s correlation coefficient of 0.99, Bland- Altman limits of -2.39 to 2.41 bpm, and mean bias of 0.01 bpm) and between pairs of Ti/Ttot values (Pearson’s correlation coefficient of 0.86, Bland-Altman limits of -0.11 to 0.10, and mean bias of -0.01) showed a good agreement. In conclusion, we propose a method for determining neural onset and neural offset based on non-invasive recordings of the electrical activity of the diaphragm that requires no filtering of cardiac muscle interference.
JTD Keywords: Kernel density estimation (KDE),, Surface diaphragm electromyographic,, (EMGdi) signal,, Inspiratory time,, Neural respiratory drive (NRD),, Neural inspiratory time,, Fixed sample entropy (fSampEn)
Farré, Ramon, Otero, Jordi, Almendros, Isaac, Navajas, Daniel, (2018). Bioengineered lungs: A challenge and an opportunity Archivos de Bronconeumología 54, (1), 31-38
Lung biofabrication is a new tissue engineering and regenerative development aimed at providing organs for potential use in transplantation. Lung biofabrication is based on seeding cells into an acellular organ scaffold and on culturing them in an especial purpose bioreactor. The acellular lung scaffold is obtained by decellularizing a non-transplantable donor lung by means of conventional procedures based on application of physical, enzymatic and detergent agents. To avoid immune recipient's rejection of the transplanted bioengineered lung, autologous bone marrow/adipose tissue-derived mesenchymal stem cells, lung progenitor cells or induced pluripotent stem cells are used for biofabricating the bioengineered lung. The bioreactor applies circulatory perfusion and mechanical ventilation with physiological parameters to the lung during biofabrication. These physical stimuli to the organ are translated into the stem cell local microenvironment - e.g. shear stress and cyclic stretch - so that cells sense the physiological conditions in normally functioning mature lungs. After seminal proof of concept in a rodent model was published in 2010, the hypothesis that lungs can be biofabricated is accepted and intense research efforts are being devoted to the topic. The current experimental evidence obtained so far in animal tests and in ex vivo human bioengineered lungs suggests that the date of first clinical tests, although not immediate, is coming. Lung bioengineering is a disrupting concept that poses a challenge for improving our basic science knowledge and is also an opportunity for facilitating lung transplantation in future clinical translation.
JTD Keywords: Tissue engineering, Regenerative medicine, Lung transplantation, Lung repair, Lung regeneration
Caddeo, Carla, Pucci, Laura, Gabriele, Morena, Carbone, Claudia, Fernàndez-Busquets, Xavier, Valenti, Donatella, Pons, Ramon, Vassallo, Antonio, Fadda, Anna Maria, Manconi, Maria, (2018). Stability, biocompatibility and antioxidant activity of PEG-modified liposomes containing resveratrol International Journal of Pharmaceutics 538, (1), 40-47
The present investigation reports the development of PEG-modified liposomes for the delivery of naturally occurring resveratrol. PEG-modified liposomes were prepared by direct sonication of the phospholipid aqueous dispersion, in the presence of two PEG-surfactants. Small, spherical, unilamellar vesicles were produced, as demonstrated by light scattering, cryo-TEM, and SAXS. The aging of the vesicles was assessed by using the Turbiscan® technology, and their physical stability was evaluated in vitro in simulated body fluids, results showing that the key features of the liposomes were preserved. The biocompatibility of the formulations was demonstrated in an ex vivo model of hemolysis in human erythrocytes. Further, the incorporation of resveratrol in PEG-modified liposomes did not affect its intrinsic antioxidant activity, as DPPH radical was almost completely inhibited, and the vesicles were also able to ensure an optimal protection against oxidative stress in an ex vivo human erythrocytes-based model. Therefore, the proposed PEG-modified liposomes, which were prepared by a simple and reliable method, represent an interesting approach to safely deliver resveratrol, ensuring the preservation of the carrier structural integrity in the biological fluids, and the antioxidant efficacy of the polyphenol to be exploited against oxidative stress associated with cancer.
JTD Keywords: Resveratrol, Antioxidant, PEG-surfactants, PEG-modified liposomes, Human erythrocytes
Martí Coma-Cros, Elisabet, Biosca, Arnau, Lantero, Elena, Manca, Maria, Caddeo, Carla, Gutiérrez, Lucía, Ramírez, Miriam, Borgheti-Cardoso, Livia, Manconi, Maria, Fernàndez-Busquets, Xavier, (2018). Antimalarial activity of orally administered curcumin incorporated in Eudragit®-containing liposomes International Journal of Molecular Sciences 19, (5), 1361
Curcumin is an antimalarial compound easy to obtain and inexpensive, having shown little toxicity across a diverse population. However, the clinical use of this interesting polyphenol has been hampered by its poor oral absorption, extremely low aqueous solubility and rapid metabolism. In this study, we have used the anionic copolymer Eudragit® S100 to assemble liposomes incorporating curcumin and containing either hyaluronan (Eudragit-hyaluronan liposomes) or the water-soluble dextrin Nutriose® FM06 (Eudragit-nutriosomes). Upon oral administration of the rehydrated freeze-dried nanosystems administered at 25/75 mg curcumin·kg−1·day−1, only Eudragit-nutriosomes improved the in vivo antimalarial activity of curcumin in a dose-dependent manner, by enhancing the survival of all Plasmodium yoelii-infected mice up to 11/11 days, as compared to 6/7 days upon administration of an equal dose of the free compound. On the other hand, animals treated with curcumin incorporated in Eudragit-hyaluronan liposomes did not live longer than the controls, a result consistent with the lower stability of this formulation after reconstitution. Polymer-lipid nanovesicles hold promise for their development into systems for the oral delivery of curcumin-based antimalarial therapies.
JTD Keywords: Malaria, Curcumin, Nanomedicine, Oral administration, Lipid nanovesicles, Eudragit, Nutriose, Hyaluronan, Plasmodium yoelii
Hoyos-Nogués, Mireia, Buxadera-Palomero, Judit, Ginebra, Maria-Pau, Manero, José María, Gil, F. J., Mas-Moruno, Carlos, (2018). All-in-one trifunctional strategy: A cell adhesive, bacteriostatic and bactericidal coating for titanium implants Colloids and Surfaces B: Biointerfaces 169, 30-40
Strategies to inhibit initial bacterial adhesion are extremely important to prevent infection on biomaterial surfaces. However, the simultaneous attraction of desired eukaryotic cells remains a challenge for successful biomaterial-host tissue integration. Here we describe a method for the development of a trifunctional coating that repels contaminating bacteria, kills those that adhere, and promotes osteoblast adhesion. To this end, titanium surfaces were functionalized by electrodeposition of an antifouling polyethylene glycol (PEG) layer and subsequent binding of a peptidic platform with cell-adhesive and bactericidal properties. The physicochemical characterization of the samples via SEM, contact angle, FTIR and XPS analysis verified the successful binding of the PEG layer and the biomolecules, without altering the morphology and topography of the samples. PEG coatings inhibited protein adsorption and osteoblast-like (SaOS-2) attachment; however, the presence of cell adhesive domains rescued osteoblast adhesion, yielding higher values of cell attachment and spreading compared to controls (p < 0.05). Finally, the antibacterial potential of the coating was measured by live/dead assays and SEM using S. sanguinis as a model of early colonizer in oral biofilms. The presence of PEG layers significantly reduced bacterial attachment on the surfaces (p < 0.05). This antibacterial potential was further increased by the bactericidal peptide, yielding values of bacterial adhesion below 0.2% (p < 0.05). The balance between the risk of infection and the optimal osteointegration of a biomaterial is often described as “the race for the surface”, in which contaminating bacteria and host tissue cells compete to colonize the implant. In the present work, we have developed a multifunctional coating for a titanium surface that promotes the attachment and spreading of osteoblasts, while very efficiently inhibits bacterial colonization, thus holding promise for application in bone replacing applications.
JTD Keywords: Polyethylene glycol, Antibacterial, Osteointegration, Multifunctionality, Peptides, Titanium
Crespo-Villanueva, Adrián, Gumí-Audenis, Berta, Sanz, Fausto, Artzner, Franck, Mériadec, Cristelle, Rousseau, Florence, Lopez, Christelle, Giannotti, M. I., Guyomarc'h, Fanny, (2018). Casein interaction with lipid membranes: Are the phase state or charge density of the phospholipids affecting protein adsorption? Biochimica et Biophysica Acta (BBA) - Biomembranes 1860, (12), 2588-2598
Casein micelles are ~200 nm electronegative particles that constitute 80 wt% of the milk proteins. During synthesis in the lactating mammary cells, caseins are thought to interact in the form of ~20 nm assemblies, directly with the biological membranes of the endoplasmic reticulum and/or the Golgi apparatus. However, conditions that drive this interaction are not yet known. Atomic force microscopy imaging and force spectroscopy were used to directly observe the adsorption of casein particles on supported phospholipid bilayers with controlled compositions to vary their phase state and surface charge density, as verified by X-ray diffraction and zetametry. At pH 6.7, the casein particles adsorbed onto bilayer phases with zwitterionic and liquid-disordered phospholipid molecules, but not on phases with anionic or ordered phospholipids. Furthermore, the presence of adsorbed caseins altered the stability of the yet exposed bilayer. Considering their respective compositions and symmetry/asymmetry, these results cast light on the possible interactions of casein assemblies with the organelles’ membranes of the lactating mammary cells.
JTD Keywords: Casein proteins, Phospholipid membrane, Supported lipid bilayer, Atomic force microscopy
Burgués, J., Marco, S., (2018). Low power operation of temperature-modulated metal oxide semiconductor gas sensors Sensors 18, (2), 339
Mobile applications based on gas sensing present new opportunities for low-cost air quality monitoring, safety, and healthcare. Metal oxide semiconductor (MOX) gas sensors represent the most prominent technology for integration into portable devices, such as smartphones and wearables. Traditionally, MOX sensors have been continuously powered to increase the stability of the sensing layer. However, continuous power is not feasible in many battery-operated applications due to power consumption limitations or the intended intermittent device operation. This work benchmarks two low-power, duty-cycling, and on-demand modes against the continuous power one. The duty-cycling mode periodically turns the sensors on and off and represents a trade-off between power consumption and stability. On-demand operation achieves the lowest power consumption by powering the sensors only while taking a measurement. Twelve thermally modulated SB-500-12 (FIS Inc. Jacksonville, FL, USA) sensors were exposed to low concentrations of carbon monoxide (0–9 ppm) with environmental conditions, such as ambient humidity (15–75% relative humidity) and temperature (21–27 ◦C), varying within the indicated ranges. Partial Least Squares (PLS) models were built using calibration data, and the prediction error in external validation samples was evaluated during the two weeks following calibration. We found that on-demand operation produced a deformation of the sensor conductance patterns, which led to an increase in the prediction error by almost a factor of 5 as compared to continuous operation (2.2 versus 0.45 ppm). Applying a 10% duty-cycling operation of 10-min periods reduced this prediction error to a factor of 2 (0.9 versus 0.45 ppm). The proposed duty-cycling powering scheme saved up to 90% energy as compared to the continuous operating mode. This low-power mode may be advantageous for applications that do not require continuous and periodic measurements, and which can tolerate slightly higher prediction errors.
JTD Keywords: Smartphone, Metal-oxide semiconductor, Gas sensor, Low power, Temperature-modulation, Interferences
Menal, M. J., Jorba, I., Torres, M., Montserrat, J. M., Gozal, D., Colell, A., Piñol-Ripoll, G., Navajas, D., Almendros, I., Farré, R., (2018). Alzheimer's disease mutant mice exhibit reduced brain tissue stiffness compared to wild-type mice in both normoxia and following intermittent hypoxia mimicking sleep apnea Frontiers in Neurology 9, Article 1
Background: Evidence from patients and animal models suggests that obstructive sleep apnea (OSA) may increase the risk of Alzheimer’s disease (AD) and that AD is associated with reduced brain tissue stiffness.
Aim: To investigate whether intermittent hypoxia (IH) alters brain cortex tissue stiffness in AD mutant mice exposed to IH mimicking OSA.
Methods: Six-eight month old (B6C3-Tg(APPswe,PSEN1dE9)85Dbo/J) AD mutant mice and wild-type (WT) littermates were subjected to IH (21% O2 40 s to 5% O2 20 s; 6 h/day) or normoxia for 8 weeks. After euthanasia, the stiffness (E) of 200-μm brain cortex slices was measured by atomic force microscopy.
Results: Two-way ANOVA indicated significant cortical softening and weight increase in AD mice compared to WT littermates, but no significant effects of IH on cortical stiffness and weight were detected. In addition, reduced myelin was apparent in AD (vs. WT), but no significant differences emerged in the cortex extracellular matrix components laminin and glycosaminoglycans when comparing baseline AD and WT mice.
Conclusion: AD mutant mice exhibit reduced brain tissue stiffness following both normoxia and IH mimicking sleep apnea, and such differences are commensurate with increased edema and demyelination in AD.
JTD Keywords: Animal model, Atomic force microscopy, Brain mechanics, Cortex stiffness, Neurodegenerative disease
Santos-Pata, D., Verschure, P., (2018). Human vicarious trial and error is predictive of spatial navigation performance Frontiers in Behavioral Neuroscience 12, Article 237
When learning new environments, rats often pause at decision points and look back and forth over their possible trajectories as if they were imagining the future outcome of their actions, a behavior termed “Vicarious trial and error” (VTE). As the animal learns the environmental configuration, rats change from deliberative to habitual behavior, and VTE tends to disappear, suggesting a functional relevance in the early stages of learning. Despite the extensive research on spatial navigation, learning and VTE in the rat model, fewer studies have focused on humans. Here, we tested whether head-scanning behaviors that humans typically exhibit during spatial navigation are as predictive of spatial learning as in the rat. Subjects performed a goal-oriented virtual navigation task in a symmetric environment. Spatial learning was assessed through the analysis of trajectories, timings, and head orientations, under habitual and deliberative spatial navigation conditions. As expected, we found that trajectory length and duration decreased with the trial number, implying that subjects learned the spatial configuration of the environment over trials. Interestingly, IdPhi (a standard metric of VTE) also decreased with the trial number, suggesting that humans benefit from the same head-orientation scanning behavior as rats at spatial decision-points. Moreover, IdPhi captured exclusively at the first decision-point of each trial, was correlated with trial trajectory duration and length. Our findings demonstrate that in VTE is a signature of the stage of spatial learning in humans, and can be used to predict performance in navigation tasks with high accuracy.
JTD Keywords: Deliberation, Habitual, Hippocampus, Navigation, Spatial decision-making
Páez-Avilés, C., Juanola-Feliu, E., Samitier, J., (2018). Cross-fertilization of Key Enabling Technologies: An empirical study of nanotechnology-related projects based on innovation management strategies Journal of Engineering and Technology Management 49, 22-45
In this empirical study, we have analysed three innovation management strategies that could be influencing the process of cross-fertilization of KETs (Key Enabling Technologies), currently being fostered by European initiatives. To do so, we have interviewed Nanotechnology-related project leaders participating in Horizon 2020. Results from a MCA (Multiple Correspondence Analysis) have shown that higher levels of cross-fertilization of KETs are associated with customer/market-oriented projects developed in informal networks characterized by a moderately heterogeneous knowledge, with a high level of involvement in nanotechnologies. With these outcomes, we argue that absorptive capacities and dynamic capabilities of organizations are decisive in a technologically convergent approach, lead by open innovation strategies.
JTD Keywords: Cross-fertilization, Innovation management strategies, Innovation projects, KETs, Nanotechnology
Lepora, Nathan, Verschure, P., Prescott, T. J., (2018). A roadmap for Living Machines research
Living machines: A handbook of research in biomimetics and biohybrid systems (ed. Prescott, T. J., Lepora, Nathan, Verschure, P.), Oxford Scholarship (Oxford, UK) , 26-50
This roadmap identifies current trends in biomimetic and biohybrid systems together with their implications for future research and innovation. Important questions include the scale at which these systems are defined, the types of biological systems addressed, the kind of principles sought, the differences between biologically based and biologically inspired approaches, the role in the understanding of living systems, relevant application domains, common benchmarks, the relation to other fields, and developments on the horizon. We interviewed and collated answers from experts who have been involved a series of events organized by the Convergent Science Network. These answers were then collated into themes of research. Overall, we see a field rapidly expanding in influence and impact. As such, this report will provide information to researchers and scientific policy makers on contemporary biomimetics and its future, together with pointers to further reading on relevant topics within this handbook.
JTD Keywords: Biomimetics, Biohybrid, Bio-inspiration, Biologically inspired, Roadmap, Living machines, policy
Caballero, D., Palacios, L., Freitas, P. P., Samitier, J., (2017). An interplay between matrix anisotropy and actomyosin contractility regulates 3D-directed cell migration Advanced Functional Materials 27, (35), 1702322
Directed cell migration is essential for many biological processes, such as embryonic development or cancer progression. Cell contractility and adhesion to the extracellular matrix are known to regulate cell locomotion machinery. However, the cross-talk between extrinsic and intrinsic factors at the molecular level on the biophysical mechanism of three dimensional (3D)-directed cell migration is still unclear. In this work, a novel physiologically relevant in vitro model of the extracellular microenvironment is used to reveal how the topological anisotropy of the extracellular matrix synergizes with actomyosin contractility to modulate directional cell migration morphodynamics. This study shows that cells seeded on polarized 3D matrices display asymmetric protrusion morphodynamics and in-vivo-like phenotypes. It is found that matrix anisotropy significantly enhances cell directionality, but strikingly, not the invasion distance of cells. In Rho-inhibited cells, matrix anisotropy counteracts the lack of actomyosin-driven forces to stabilize cell directionality suggesting a myosin-II-independent mechanism for cell guidance. Finally, this study shows that on isotropic 3D environments, cell directionality is independent of actomyosin contractility. Altogether, this study provides novel quantitative data on the biomechanical regulation of directional cell motion and shows the important regulatory role of matrix anisotropy and actomyosin forces to guide cell migration in 3D microenvironments.
JTD Keywords: Anisotropy, Directed cell migration, Extracellular matrices, Migration modes, Three dimensional microenvironments
Hoyos-Nogués, M., Velasco, F., Ginebra, M. P., Manero, J. M., Gil, F. J., Mas-Moruno, C., (2017). Regenerating bone via multifunctional coatings: The blending of cell integration and bacterial inhibition properties on the surface of biomaterials ACS Applied Materials & Interfaces 9, (26), 21618-21630
In dentistry and orthopedics, it is well accepted that implant fixation is a major goal. However, an emerging concern is bacterial infection. Infection of metallic implants can be catastrophic and significantly reduce patient quality of life. Accordingly, in this work, we focus on multifunctional coatings to simultaneously address and mitigate both these problems. We have developed a tailor-made peptide-based chemical platform that integrates the well-known RGD cell adhesive sequence and the lactoferrin-derived LF1-11 antimicrobial peptide. The platform was covalently grafted on titanium via silanization and the functionalization process characterized by contact angle, XPS, and QCM-D. The presence of the platform statistically improved the adhesion, proliferation and mineralization of osteoblast-like cells compared to control surfaces. At the same time, colonization by representative bacterial strains was significantly reduced on the surfaces. Furthermore, the biological potency of the multifunctional platform was verified in a co-culture in vitro model. Our findings demonstrate that this multifunctional approach can be useful to functionalize biomaterials to both improve cell integration and reduce the risk of bacterial infection.
JTD Keywords: Antimicrobial peptides, Cell adhesive peptides, Multifunctionality, Osseointegration, Surface functionalization
Caballero, D., Samitier, J., (2017). Topological control of extracellular matrix growth: A native-like model for cell morphodynamics studies ACS Applied Materials & Interfaces 9, (4), 4159-4170
The interaction of cells with their natural environment influences a large variety of cellular phenomena, including cell adhesion, proliferation, and migration. The complex extracellular matrix network has challenged the attempts to replicate in vitro the heterogeneity of the cell environment and has threatened, in general, the relevance of in vitro studies. In this work, we describe a new and extremely versatile approach to generate native-like extracellular matrices with controlled morphologies for the in vitro study of cellular processes. This general approach combines the confluent culture of fibroblasts with microfabricated guiding templates to direct the three-dimensional growth of well-defined extracellular networks which recapitulate the structural and biomolecular complexity of features typically found in vivo. To evaluate its performance, we studied fundamental cellular processes, including cell cytoskeleton organization, cell-matrix adhesion, proliferation, and protrusions morphodynamics. In all cases, we found striking differences depending on matrix architecture and, in particular, when compared to standard two-dimensional environments. We also assessed whether the engineered matrix networks influenced cell migration dynamics and locomotion strategy, finding enhanced migration efficiency for cells seeded on aligned matrices. Altogether, our methodology paves the way to the development of high-performance models of the extracellular matrix for potential applications in tissue engineering, diagnosis, or stem-cell biology.
JTD Keywords: Biomimetics, Cell migration, Engineered cell-derived matrices, Extracellular matrix, In vitro model
O'Neill, R., McCarthy, H. O., Montufar, E. B., Ginebra, M. P., Wilson, D. I., Lennon, A., Dunne, N., (2017). Critical review: Injectability of calcium phosphate pastes and cements Acta Biomaterialia 50, 1-19
Calcium phosphate cements (CPC) have seen clinical success in many dental and orthopaedic applications in recent years. The properties of CPC essential for clinical success are reviewed in this article, which includes properties of the set cement (e.g. bioresorbability, biocompatibility, porosity and mechanical properties) and unset cement (e.g. setting time, cohesion, flow properties and ease of delivery to the surgical site). Emphasis is on the delivery of calcium phosphate (CaP) pastes and CPC, in particular the occurrence of separation of the liquid and solid components of the pastes and cements during injection; and established methods to reduce this phase separation. In addition a review of phase separation mechanisms observed during the extrusion of other biphasic paste systems and the theoretical models used to describe these mechanisms are discussed. Statement of Significance Occurrence of phase separation of calcium phosphate pastes and cements during injection limits their full exploitation as a bone substitute in minimally invasive surgical applications. Due to lack of theoretical understanding of the phase separation mechanism(s), optimisation of an injectable CPC that satisfies clinical requirements has proven difficult. However, phase separation of pastes during delivery has been the focus across several research fields. Therefore in addition to a review of methods to reduce phase separation of CPC and the associated constraints, a review of phase separation mechanisms observed during extrusion of other pastes and the theoretical models used to describe these mechanisms is presented. It is anticipated this review will benefit future attempts to develop injectable calcium phosphate based systems.
JTD Keywords: Bone cements, Calcium phosphates, Injectability, Material properties, Phase separation
Oliveira, H., Catros, S., Castano, O., Rey, Sylvie, Siadous, R., Clift, D., Marti-Munoz, J., Batista, M., Bareille, R., Planell, J., Engel, E., Amédée, J., (2017). The proangiogenic potential of a novel calcium releasing composite biomaterial: Orthotopic in vivo evaluation Acta Biomaterialia 54, 377-385
Insufficient angiogenesis remains a major hurdle in current bone tissue engineering strategies. An extensive body of work has focused on the use of angiogenic factors or endothelial progenitor cells. However, these approaches are inherently complex, in terms of regulatory and methodologic implementation, and present a high cost. We have recently demonstrate the potential of electrospun poly(lactic acid) (PLA) fiber-based membranes, containing calcium phosphate (CaP) ormoglass particles, to elicit angiogenesis in vivo, in a subcutaneous model in mice. Here we have devised an injectable composite, containing CaP glass-ceramic particles, dispersed within a (Hydroxypropyl)methyl cellulose (HPMC) matrix, with the capacity to release calcium in a more sustained fashion. We show that by tuning the release of calcium in vivo, in a rat bone defect model, we could improve both bone formation and increase angiogenesis. The bone regeneration kinetics was dependent on the Ca2+ release rate, with the faster Ca2+ release composite gel showing improved bone repair at 3Â weeks, in relation to control. In the same line, improved angiogenesis could be observed for the same gel formulation at 6Â weeks post implantation. This methodology allows to integrate two fundamental processes for bone tissue regeneration while using a simple, cost effective, and safe approach. Statement of Significance In current bone tissue engineering approaches the achievement of sufficient angiogenesis, during tissue regeneration, is a major limitation in order to attain full tissue functionality. Recently, we have shown that calcium ions, released by the degradation of calcium phosphate ormoglasses (CaP), are effective angiogenic promoters, in both in vitro and in a subcutaneous implantation model. Here, we devised an injectable composite, containing CaP glass-ceramic particles, dispersed within a HPMC matrix, enabling the release of calcium in a more sustained fashion. We show that by tuning the release of calcium in vivo, in a rat bone defect model, we could improve both bone formation and increase angiogenesis. This simple and cost effective approach holds great promise to translate to the clinics.
JTD Keywords: Angiogenesis, Bone regeneration, Calcium phosphate ormoglasses
Frau-Méndez, Margalida A., Fernández-Vega, Iván, Ansoleaga, Belén, Blanco, Rosa, Carmona, Margarita, Antonio del Rio, Jose, Zerr, Inga, Llorens, Franc, Zarranz, Juan José, Ferrer, Isidro, (2017). Fatal familial insomnia: Mitochondrial and protein synthesis machinery decline in the mediodorsal thalamus Brain Pathology 27, (1), 95-106
The expression of subunits of mitochondrial respiratory complexes and components of the protein synthesis machinery from the nucleolus to the ribosome was analyzed in the mediodorsal thalamus in seven cases of Fatal Familial Insomnia (FFI) compared with age-matched controls. NDUFB8 (complex I subunit), SDHB (complex II subunit), UQCRC2 (complex III subunit), COX2 (complex IV subunit) and ATP50 (complex V subunit) expression levels, as revealed by western blotting, were reduced in FFI. Voltage-dependent anion channel (VDAC) and ATP5H were also reduced due to the marked depopulation of neurons. In contrast, a marked increase in superoxide dismutase 2 (SOD2) was found in reactive astrocytes thus suggesting that astrocytes are key factors in oxidative stress responses. The histone-binding chaperones nucleolin and nucleoplasmin 3, and histone H3 di-methylated K9 were markedly reduced together with a decrease in the expression of protein transcription elongation factor eEF1A. These findings show severe impairment in the expression of crucial components of mitochondrial function and protein synthesis in parallel with neuron loss in mediodorsal thalamus at terminal stages of FFI. Therapeutic measures must be taken long before the appearance of clinical symptoms to prevent the devastating effects of FFI.
JTD Keywords: Fatal familial insomnia, Mitochondria, Protein synthesis, Mitochondrial respiratory chain, Nucleolus, Ribosome
Caddeo, C., Pons, R., Carbone, C., Fernàndez-Busquets, X., Cardia, M. C., Maccioni, A. M., Fadda, A. M., Manconi, M., (2017). Physico-chemical characterization of succinyl chitosan-stabilized liposomes for the oral co-delivery of quercetin and resveratrol
Carbohydrate Polymers , 157, 1853-1861
In the present work, quercetin and resveratrol, natural polyphenols with strong antioxidant and anti-inflammatory properties, were co-loaded in polymer-associated liposomes conceived for oral delivery, by exploiting the potential of pH-sensitive succinyl-chitosan. Chitosan was succinylated, characterized by Nuclear Magnetic Resonance spectroscopy and Gel Permeation Chromatography, and used to form a protective shell on the surface of liposomes. The physico-chemical properties of the succinyl-chitosan liposomes were assessed by light scattering, zeta potential, cryogenic transmission electron microscopy, and small angle X-ray scattering. Small, spherical, uni- and bilamellar vesicles were produced. The succinyl-chitosan shell increased not only the physical stability of the vesicular system, as demonstrated by accelerated stability tests, but also the release of the polyphenols to a greater extent at pH 7.0, mimicking the intestinal environment. The proposed approach based on polyphenol vesicular formulations may be of value in the treatment of pre-cancerous/cancerous intestinal conditions associated with inflammation and oxidative stress.
JTD Keywords: Antioxidant, Liposome, Oral delivery, Quercetin, Resveratrol, Succinyl-chitosan
Vitonyte, J., Manca, M. L., Caddeo, C., Valenti, D., Peris, J. E., Usach, I., Nacher, A., Matos, M., Gutiérrez, G., Orrù, G., Fernàndez-Busquets, X., Fadda, A. M., Manconi, M., (2017). Bifunctional viscous nanovesicles co-loaded with resveratrol and gallic acid for skin protection against microbial and oxidative injuries European Journal of Pharmaceutics and Biopharmaceutics 114, 278-287
Resveratrol and gallic acid were co-loaded in phospholipid vesicles aiming at protecting the skin from external injuries, such as oxidative stress and microbial infections. Liposomes were prepared using biocompatible phospholipids dispersed in water. To improve vesicle stability and applicability, the phospholipids and the phenols were dispersed in water/propylene glycol or water/glycerol, thus obtaining PEVs and glycerosomes, respectively. The vesicles were characterized by size, morphology, physical stability, and their therapeutic efficacy was investigated in vitro. The vesicles were spherical, unilamellar and small in size: liposomes and glycerosomes were around 70 nm in diameter, while PEVs were larger (∼170 nm). The presence of propylene glycol or glycerol increased the viscosity of the vesicle systems, positively affecting their stability. The ability of the vesicles to promote the accumulation of the phenols (especially gallic acid) in the skin was demonstrated, as well as their low toxicity and great ability to protect keratinocytes and fibroblasts from oxidative damage. Additionally, an improvement of the antimicrobial activity of the phenols was shown against different skin pathogens. The co-loading of resveratrol and gallic acid in modified phospholipid vesicles represents an innovative, bifunctional tool for preventing and treating skin affections.
JTD Keywords: Fibroblasts, Keratinocytes, Phenol, Phospholipid vesicle, Skin pathogens
Castellanos, M. I., Mas-Moruno, C., Grau, A., Serra-Picamal, X., Trepat, X., Albericio, F., Joner, M., Gil, F. J., Ginebra, M. P., Manero, J. M., Pegueroles, M., (2017). Functionalization of CoCr surfaces with cell adhesive peptides to promote HUVECs adhesion and proliferation
Applied Surface Science , 393, 82-92
Biomimetic surface modification with peptides that have specific cell-binding moieties is a promising approach to improve endothelialization of metal-based stents. In this study, we functionalized CoCr surfaces with RGDS, REDV, YIGSR peptides and their combinations to promote endothelial cells (ECs) adhesion and proliferation. An extensive characterization of the functionalized surfaces was performed by XPS analysis, surface charge and quartz crystal microbalance with dissipation monitoring (QCM-D), which demonstrated the successful immobilization of the peptides to the surface. Cell studies demonstrated that the covalent functionalization of CoCr surfaces with an equimolar combination of RGDS and YIGSR represents the most powerful strategy to enhance the early stages of ECs adhesion and proliferation, indicating a positive synergistic effect between the two peptide motifs. Although these peptide sequences slightly increased smooth muscle cells (SMCs) adhesion, these values were ten times lower than those observed for ECs. The combination of RGDS with the REDV sequence did not show synergistic effects in promoting the adhesion or proliferation of ECs. The strategy presented in this study holds great potential to overcome clinical limitations of current metal stents by enhancing their capacity to support surface endothelialization.
JTD Keywords: Cell adhesive peptides, CoCr alloy, Endothelialization, HUVEC proliferation, SMCs adhesion, Surface functionalization
Diez-Escudero, A., Espanol, M., Montufar, E. B., Di Pompo, G., Ciapetti, G., Baldini, N., Ginebra, M. P., (2017). Focus ion beam/scanning electron microscopy characterization of osteoclastic resorption of calcium phosphate substrates
Tissue Engineering Part C: Methods , 23, (2), 118-124
This article presents the application of dual focused ion beam/scanning electron microscopy (FIB-SEM) imaging for preclinical testing of calcium phosphates with osteoclast precursor cells and how this high-resolution imaging technique is able to reveal microstructural changes at a level of detail previously not possible. Calcium phosphate substrates, having similar compositions but different microstructures, were produced using low-and high-Temperature processes (biomimetic calcium-deficient hydroxyapatite [CDHA] and stoichiometric sintered hydroxyapatite, respectively). Human osteoclast precursor cells were cultured for 21 days before evaluating their resorptive potential on varying microstructural features. Alternative to classical morphological evaluation of osteoclasts (OC), FIB-SEM was used to observe the subjacent microstructure by transversally sectioning cells and observing both the cells and the substrates. Resorption pits, indicating OC activity, were visible on the smoother surface of high-Temperature sintered hydroxyapatite. FIB-SEM analysis revealed signs of acidic degradation on the grain surface under the cells, as well as intergranular dissolution. No resorption pits were evident on the surface of the rough CDHA substrates. However, whereas no degradation was detected by FIB sections in the material underlying some of the cells, early stages of OC-mediated acidic degradation were observed under cells with more spread morphology. Collectively, these results highlight the potential of FIB to evaluate the resorptive activity of OC, even in rough, irregular, or coarse surfaces where degradation pits are otherwise difficult to visualize.
JTD Keywords: Bone Regeneration, Calcium Phosphate, Focus Ion Beam, Osteoclast, Resorption, Scanning Electron Microscopy
Estrada, L., Torres, A., Sarlabous, L., Jané, R., (2017). Influence of parameter selection in fixed sample entropy of surface diaphragm electromyography for estimating respiratory activity Entropy 19, (9), 460
Fixed sample entropy (fSampEn) is a robust technique that allows the evaluation of inspiratory effort in diaphragm electromyography (EMGdi) signals, and has potential utility in sleep studies. To appropriately estimate respiratory effort, fSampEn requires the adjustment of several parameters. The aims of the present study were to evaluate the influence of the embedding dimension m, the tolerance value r, the size of the moving window, and the sampling frequency, and to establish recommendations for estimating the respiratory activity when using the fSampEn on surface EMGdi recorded for different inspiratory efforts. Values of m equal to 1 and r ranging from 0.1 to 0.64, and m equal to 2 and r ranging from 0.13 to 0.45, were found to be suitable for evaluating respiratory activity. fSampEn was less affected by window size than classical amplitude parameters. Finally, variations in sampling frequency could influence fSampEn results. In conclusion, the findings suggest the potential utility of fSampEn for estimating muscle respiratory effort in further sleep studies.
JTD Keywords: Fixed sample entropy (fSampEn), Non-invasive respiratory monitoring, Respiratory activity, Respiratory effort, Surface diaphragm electromyography
Santos-Pata, D., Zucca, R., Low, S. C., Verschure, P. F. M. J., (2017). Size matters: How scaling affects the interaction between grid and border cells
Frontiers in Computational Neuroscience , 11, Article 65
Many hippocampal cell types are characterized by a progressive increase in scale along the dorsal-to-ventral axis, such as in the cases of head-direction, grid and place cells. Also located in the medial entorhinal cortex (MEC), border cells would be expected to benefit from such scale modulations. However, this phenomenon has not been experimentally observed. Grid cells in the MEC of mammals integrate velocity related signals to map the environment with characteristic hexagonal tessellation patterns. Due to the noisy nature of these input signals, path integration processes tend to accumulate errors as animals explore the environment, leading to a loss of grid-like activity. It has been suggested that border-to-grid cells' associations minimize the accumulated grid cells' error when rodents explore enclosures. Thus, the border-grid interaction for error minimization is a suitable scenario to study the effects of border cell scaling within the context of spatial representation. In this study, we computationally address the question of (i) border cells' scale from the perspective of their role in maintaining the regularity of grid cells' firing fields, as well as (ii) what are the underlying mechanisms of grid-border associations relative to the scales of both grid and border cells. Our results suggest that for optimal contribution to grid cells' error minimization, border cells should express smaller firing fields relative to those of the associated grid cells, which is consistent with the hypothesis of border cells functioning as spatial anchoring signals.
JTD Keywords: Border cells, Error minimization, Grid cells, Navigation, Path integration
Urrea, Laura, Ferrer, Isidro, Gavín, Rosalina, del Río, José Antonio, (2017). The cellular prion protein (PrPC) as neuronal receptor for α-synuclein
Prion , 11, (4), 226-233
The term ‘prion-like’ is used to define some misfolded protein species that propagate intercellularly, triggering protein aggregation in recipient cells. For cell binding, both direct plasma membrane interaction and membrane receptors have been described for particular amyloids. In this respect, emerging evidence demonstrates that several β-sheet enriched proteins can bind to the cellular prion protein (PrPC). Among other interactions, the physiological relevance of the binding between β-amyloid and PrPC has been a relevant focus of numerous studies. At the molecular level, published data point to the second charged cluster domain of the PrPC molecule as the relevant binding domain of the β-amyloid/PrPC interaction. In addition to β-amyloid, participation of PrPC in binding α-synuclein, responsible for neurodegenerative synucleopathies, has been reported. Although results indicate relevant participation of PrPC in the spreading of α-synuclein in living mice, the physiological relevance of the interaction remains elusive. In this comment, we focus our attention on summarizing current knowledge of PrPC as a receptor for amyloid proteins and its physiological significance, with particular focus on α-synuclein.
JTD Keywords: α-synuclein, Charged cluster domain, Interneuronal transport, LAG3, Neurodegeneration, PrPC, Parkinson disease
Garde, A., Sörnmo, L., Laguna, P., Jané, R., Benito, S., Bayés-Genís, A., Giraldo, B. F., (2017). Assessment of respiratory flow cycle morphology in patients with chronic heart failure
Medical and Biological Engineering and Computing , 55, (2), 245-255
Breathing pattern as periodic breathing (PB) in chronic heart failure (CHF) is associated with poor prognosis and high mortality risk. This work investigates the significance of a number of time domain parameters for characterizing respiratory flow cycle morphology in patients with CHF. Thus, our primary goal is to detect PB pattern and identify patients at higher risk. In addition, differences in respiratory flow cycle morphology between CHF patients (with and without PB) and healthy subjects are studied. Differences between these parameters are assessed by investigating the following three classification issues: CHF patients with PB versus with non-periodic breathing (nPB), CHF patients (both PB and nPB) versus healthy subjects, and nPB patients versus healthy subjects. Twenty-six CHF patients (8/18 with PB/nPB) and 35 healthy subjects are studied. The results show that the maximal expiratory flow interval is shorter and with lower dispersion in CHF patients than in healthy subjects. The flow slopes are much steeper in CHF patients, especially for PB. Both inspiration and expiration durations are reduced in CHF patients, mostly for PB. Using the classification and regression tree technique, the most discriminant parameters are selected. For signals shorter than 1 min, the time domain parameters produce better results than the spectral parameters, with accuracies for each classification of 82/78, 89/85, and 91/89 %, respectively. It is concluded that morphologic analysis in the time domain is useful, especially when short signals are analyzed.
JTD Keywords: Chronic heart failure, Ensemble average, Periodic and non-periodic breathing, Respiratory pattern
Castillo, Y., Blanco, D., Whitney, J., Mersky, B., Jané, R., (2017). Characterization of a tooth microphone coupled to an oral appliance device: A new system for monitoring OSA patients Engineering in Medicine and Biology Society (EMBC)
39th Annual International Conference of the IEEE , IEEE (Seogwipo, South Korea) , 1543-1546
Obstructive sleep apnea (OSA) is a highly prevalent chronic disease, especially in elderly and obese populations. Despite constituting a serious health, social and economic problem, most patients remain undiagnosed and untreated due to limitations in current equipment. In this work, we propose a novel method to diagnose OSA and monitor therapy adherence and effectiveness at home in a non-invasive and inexpensive way: combining acoustic analysis of breathing and snoring sounds with oral appliance therapy (OA). Audiodontics has introduced a new sensor, a tooth microphone coupled to an OA device, which is the main pillar of this system. The objective of this work is to characterize the response of this sensor, comparing it with a commercial tracheal microphone (Biopac transducer). Signals containing OSA-related sounds were acquired simultaneously with the two microphones for that purpose. They were processed and analyzed in time, frequency and time-frequency domains, in a custom MATLAB interface. We carried out a single-event approach focused on breaths, snores and apnea episodes. We found that the quality of the signals obtained by both microphones was quite similar, although the tooth microphone spectrum concentrated more energy at the high-frequency band. This opens a new field of study about high-frequency components of snores and breathing sounds. These characteristics, together with its intraoral position, wireless option and combination with customizable OAs, give the tooth microphone a great potential to reduce the impact of sleep disorders, by enabling prompt detection and continuous monitoring of patients at home.
JTD Keywords: Microphones, Teeth, Sleep apnea, Time-frequency analysis, Signal to noise ratio, Monitoring, Acoustics
Burgues, J., Fonollosa, J., Marco, S., (2017). Discontinuously operated MOX sensors for low power applications IEEE Conference Publications
ISOCS/IEEE International Symposium on Olfaction and Electronic Nose (ISOEN) , IEEE (Montreal, Canada) , 1-3
Metal oxide semiconductor sensors are limited by their low selectivity, high power consumption and temporal drift. This paper proposes a novel discontinuous temperature modulation operation mode characterized by on-demand measurements and periodic warm-up cycles. The performance of two sets of FIS SB-500-12 sensors, one group continuously operated and the other group discontinuously operated, was compared in a scenario of carbon monoxide detection at low concentrations for five consecutive days. Results showed that the discontinuous operating mode moderately increased the prediction error and the limit of detection but was advantageous in terms of energy savings (up to 60% with respect to the continuous temperature modulation mode).
JTD Keywords: Discontinuous operation, Duty-cycling, Low power, MOX sensors, Temperature modulation
Sola-Soler, J., Giraldo, B. F., Fiz, J. A., Jane, R., (2017). Relationship between heart rate excursion and apnea duration in patients with Obstructive Sleep Apnea Engineering in Medicine and Biology Society (EMBC)
39th Annual International Conference of the IEEE , IEEE (Seogwipo, South Korea) , 1539-1542
Obstructive Sleep Apnea (OSA) is a sleep disorder with a high prevalence in the general population. It is a risk factor for many cardiovascular diseases, and an independent risk factor for cerebrovascular diseases such as stroke. After an apnea episode, both arterial blood pressure and cerebral blood flow velocity change in function of the apnea duration (AD). We hypothesized that the relative excursion in heart rate (AHR), defined as the percentage difference between the maximum and the minimum heart rate values associated to an obstructive apnea event, is also related to AD. In this work we studied the relationship between apnea-related AHR and AD in a population of eight patients with severe OSA. AHR and AD showed a moderate but statistically significant correlation (p <; 0.0001) in a total of 1454 obstructive apneas analyzed. The average heart rate excursion for apneas with AD ≥ 30s (ΔHR = 31.29 ± 6.64%) was significantly greater (p = 0.0002) than for apneas with AD ∈ [10,20)s (ΔHR = 18.14±3.08%). We also observed that patients with similar Apnea-Hypopnea Index (AHI) may exhibit remarkably different distributions of AHR and AD, and that patients with a high AHI need not have a higher average AHR than others with a lower severity index. We conclude that the overall apnea-induced heart rate excursion is partially explained by the duration of apnoeic episodes, and it may be a simple measure of the cardiovascular stress associated with OSA that is not directly reflected in the AHI.
JTD Keywords: Heart rate, Sleep apnea, Correlation, Indexes, Sociology, Blood vessels
Planell, J. A., Navarro, M., Engel, E., (2017). Developing targeted biocomposites in tissue engineering and regenerative medicine
Biomedical Composites (ed. Ambrosio, L.), Woodhead Publishing (Duxfor, UK) Biomaterials, 569-587
Regenerative medicine is a relatively new field with new requirements for smart materials, where composites will have a strong role to play. The new paradigm of regenerative medicine and tissue engineering requires biomaterials with high specificity, where physical and chemical properties are duly tailored and combined with appropriate mechanical and degradation features in order to trigger specific cell events and functions involved in the regenerative process. In this chapter, the chemical, physical, and biological elements that have to be targeted by biocomposites in regenerative medicine are described.
JTD Keywords: Biocomposite, Regenerative medicine, Tissue engineering, Scaffolds, Cell/material interactions
Xia, Yun, Montserrat, Nuria, Campistol, Josep M., Izpisua Belmonte, Juan Carlos, Remuzzi, Giuseppe, Williams, David F., (2017). Lineage reprogramming toward kidney regeneration
Kidney Transplantation, Bioengineering and Regeneration (ed. Orlando, G., Remuzzi, Giuseppe, Williams, David F.), Academic Press (London, UK) , 1167-1175
We have known for decades that it is possible to switch the phenotype of one somatic cell type into another. Such epigenetic rewiring processes can be artificially managed and even reversed by using a defined set of transcription factors. Lineage reprogramming is very often defined as a process of converting one cell type into another without going through a pluripotent state, providing great promise for regenerative medicine. However, the identification of key transcription factors for lineage reprogramming is limited, due to the exhaustive and expensive experimental processes. Accumulating knowledge of genetic and epigenetic regulatory networks that are critical for defining a specific lineage provides unprecedented opportunities to model and predict pioneering factors that may drive directional lineage reprogramming to obtain the desired cell type.
JTD Keywords: Reprogramming, Pluripotency, Differentiation, Lineage specification, Epigenetic regulatory network, Regeneration
Ladoux, B., Mège, R. M., Trepat, X., (2016). Front-rear polarization by mechanical cues: From single cells to tissues Trends in Cell Biology 26, (6), 420-433
Directed cell migration is a complex process that involves front-rear polarization, characterized by cell adhesion and cytoskeleton-based protrusion, retraction, and contraction of either a single cell or a cell collective. Single cell polarization depends on a variety of mechanochemical signals including external adhesive cues, substrate stiffness, and confinement. In cell ensembles, coordinated polarization of migrating tissues results not only from the application of traction forces on the extracellular matrix but also from the transmission of mechanical stress through intercellular junctions. We focus here on the impact of mechanical cues on the establishment and maintenance of front-rear polarization from single cell to collective cell behaviors through local or large-scale mechanisms.
JTD Keywords: Cell forces, Cell polarity, Collective cell migration, Mechanobiology, Micropatterning, Substrate stiffness
Oliveira, Hugo, Catros, Sylvain, Boiziau, Claudine, Siadous, Robin, Marti-Munoz, Joan, Bareille, Reine, Rey, Sylvie, Castano, Oscar, Planell, Josep, Amédée, Joëlle, Engel, Elisabeth, (2016). The proangiogenic potential of a novel calcium releasing biomaterial: Impact on cell recruitment Acta Biomaterialia 29, 435-445
Abstract In current bone tissue engineering strategies the achievement of sufficient angiogenesis during tissue regeneration is still a major limitation in order to attain full functionality. Several strategies have been described to tackle this problem, mainly by the use of angiogenic factors or endothelial progenitor cells. However, when facing a clinical scenario these approaches are inherently complex and present a high cost. As such, more cost effective alternatives are awaited. Here, we demonstrate the potential of electrospun poly(lactic acid) (PLA) fiber-based membranes, containing calcium phosphate ormoglass (CaP) particles, to elicit angiogenesis in vivo, in a subcutaneous model in mice. We show that the current approach elicited the local expression of angiogenic factors, associated to a chemotactic effect on macrophages, and sustained angiogenesis into the biomaterial. As both PLA and CaP are currently accepted for clinical application these off-the-shelf novel membranes have great potential for guided bone regeneration applications. Statement of significance In current bone tissue engineering approaches the achievement of sufficient angiogenesis, during tissue regeneration, is a major limitation in order to attain full tissue functionality. Recently, our group has found that calcium ions released by the degradation of calcium phosphate ormoglasses (CaP) are effective angiogenic promoters. Based on this, in this work we successfully produced hybrid fibrous mats with different contents of CaP nanoparticles and thus with different calcium ion release rates, using an ormoglass – poly(lactic acid) blend approach. We show that these matrices, upon implantation in a subcutaneous site, could elicit the local expression of angiogenic factors, associated to a chemotactic effect on macrophages, and sustained angiogenesis into the biomaterial, in a CaP dose dependent manner. This off-the-shelf cost effective approach presents great potential to translate to the clinics.
JTD Keywords: Angiogenesis, Bone regeneration, Calcium phosphate ormoglass
Fraioli, R., Dashnyam, K., Kim, J. H., Perez, R. A., Kim, H. W., Gil, J., Ginebra, M. P., Manero, J. M., Mas-Moruno, C., (2016). Surface guidance of stem cell behavior: Chemically tailored co-presentation of integrin-binding peptides stimulates osteogenic differentiation in vitro and bone formation in vivo Acta Biomaterialia 43, 269-281
Surface modification stands out as a versatile technique to create instructive biomaterials that are able to actively direct stem cell fate. Chemical functionalization of titanium has been used in this work to stimulate the differentiation of human mesenchymal stem cells (hMSCs) into the osteoblastic lineage, by covalently anchoring a synthetic double-branched molecule (PTF) to the metal that allows a finely controlled presentation of peptidic motifs. In detail, the effect of the RGD adhesive peptide and its synergy motif PHSRN is studied, comparing a random distribution of the two peptides with the chemically-tailored disposition within the custom made synthetic platform, which mimics the interspacing between the motifs observed in fibronectin. Contact angle measurement and XPS analysis are used to prove the efficiency of functionalization. We demonstrate that, by rationally designing ligands, stem cell response can be efficiently guided towards the osteogenic phenotype: In vitro, PTF-functionalized surfaces support hMSCs adhesion, with higher cell area and formation of focal contacts, expression of the integrin receptor α5β1 and the osteogenic marker Runx2, and deposition a highly mineralized matrix, reaching values of mineralization comparable to fibronectin. Our strategy is also demonstrated to be efficient in promoting new bone growth in vivo in a rat calvarial defect. These results highlight the efficacy of chemical control over the presentation of bioactive peptides; such systems may be used to engineer bioactive surfaces with improved osseointegrative properties, or can be easily tuned to generate multi-functional coatings requiring a tailored disposition of the peptidic motifs. Statement of significance Organic coatings have been proposed as a solution to foster osseointegration of orthopedic implants. Among them, extracellular matrix-derived peptide motifs are an interesting biomimetic strategy to harness cell-surface interactions. Nonetheless, the combination of multiple peptide motifs in a controlled manner is essential to achieve receptor specificity and fully exploit the potentiality of synthetic peptides. Herein, we covalently graft to titanium a double branched molecule to guide stem cell fate in vitro and generate an osseoinductive titanium surface in vivo. Such synthetic ligand allows for the simultaneous presentation of two bioactive motifs, thus is ideal to test the effect of synergic sequences, such as RGD and PHSRN, and is a clear example of the versatility and feasibility of rationally designed biomolecules.
JTD Keywords: hMSCs, Integrin-binding peptides, Osseointegration, RGD-PHSRN, Titanium
Fonollosa, J., Fernández, L., Gutiérrez-Gálvez, A., Huerta, R., Marco, S., (2016). Calibration transfer and drift counteraction in chemical sensor arrays using Direct Standardization Sensors and Actuators B: Chemical 236, 1044-1053
Inherent variability of chemical sensors makes it necessary to calibrate chemical detection systems individually. This shortcoming has traditionally limited usability of systems based on metal oxide gas sensor arrays and prevented mass-production for some applications. Here, aiming at exploring calibration transfer between chemical sensor arrays, we exposed five twin 8-sensor detection units to different concentration levels of ethanol, ethylene, carbon monoxide, or methane. First, we built calibration models using data acquired with a master unit. Second, to explore the transferability of the calibration models, we used Direct Standardization to map the signals of a slave unit to the space of the master unit in calibration. In particular, we evaluated the transferability of the calibration models to other detection units, and within the same unit measuring days apart. Our results show that signals acquired with one unit can be successfully mapped to the space of a reference unit. Hence, calibration models trained with a master unit can be extended to slave units using a reduced number of transfer samples, diminishing thereby calibration costs. Similarly, signals of a sensing unit can be transformed to match sensor behavior in the past to mitigate drift effects. Therefore, the proposed methodology can reduce calibration costs in mass-production and delay recalibrations due to sensor aging. Acquired dataset is made publicly available.
JTD Keywords: Calibration transfer, Chemical sensors, Direct Standardization, Electronic nose, MOX sensors, Public dataset
Fernandez, L., Guney, S., Gutierrez-Galvez, A., Marco, S., (2016). Calibration transfer in temperature modulated gas sensor arrays Sensors and Actuators B: Chemical 231, 276-284
Abstract Shifts in working temperature are an important issue that prevents the successful transfer of calibration models from one chemical instrument to another. This effect is of special relevance when working with gas sensor arrays modulated in temperature. In this paper, we study the use of multivariate techniques to transfer the calibration model from a temperature modulated gas sensor array to another when a global change of temperature occurs. To do so, we built 12 identical master sensor arrays composed of three different types of commercial Figaro sensors and acquired a dataset of sensor responses to three pure substances (ethanol, acetone and butanone) dosed at 7 concentrations. The master arrays are then shifted in temperature (from −50 to 50 °C, ΔT = 10 °C) and considered as slave arrays. Data correction is performed for an increasing number of transfer samples with 4 different calibration transfer techniques: Direct Standardization, Piece-wise Direct Standardization, Orthogonal Signal Correction and Generalized Least Squares Weighting. In order to evaluate the performance of the calibration transfer, we compare the Root Mean Square Error of Prediction (RMSEP) of master and slave arrays, for each instrument correction. Best results are obtained from Piece-wise Direct standardization, which exhibits the lower RMSEP values after correction for the smaller number of transfer samples.
JTD Keywords: Calibration transfer, Gas sensor array, MOX, Temperature modulation
Garcia-Calero, Elena, Botella-Lopez, Arancha, Bahamonde, Olga, Perez-Balaguer, Ariadna, Martinez, Salvador, (2016). FoxP2 protein levels regulate cell morphology changes and migration patterns in the vertebrate developing telencephalon
Brain Structure and Function , 221, (6), 2905-2917
In the mammalian telencephalon, part of the progenitor cells transition from multipolar to bipolar morphology as they invade the mantle zone. This associates with changing patterns of radial migration. However, the molecules implicated in these morphology transitions are not well known. In the present work, we analyzed the function of FoxP2 protein in this process during telencephalic development in vertebrates. We analyzed the expression of FoxP2 protein and its relation with cell morphology and migratory patterns in mouse and chicken developing striatum. We observed FoxP2 protein expressed in a gradient from the subventricular zone to the mantle layer in mice embryos. In the FoxP2 low domain cells showed multipolar migration. In the striatal mantle layer where FoxP2 protein expression is higher, cells showed locomoting migration and bipolar morphology. In contrast, FoxP2 showed a high and homogenous expression pattern in chicken striatum, thus bipolar morphology predominated. Elevation of FoxP2 in the striatal subventricular zone by in utero electroporation promoted bipolar morphology and impaired multipolar radial migration. In mouse cerebral cortex we obtained similar results. FoxP2 promotes transition from multipolar to bipolar morphology by means of gradiental expression in mouse striatum and cortex. Together these results indicate a role of FoxP2 differential expression in cell morphology control of the vertebrate telencephalon.
JTD Keywords: Radial migration, Bipolar morphology, Striatum, Cortex
Wills, C. R., Malandrino, A., Van Rijsbergen, M., Lacroix, D., Ito, K., Noailly, J., (2016). Simulating the sensitivity of cell nutritive environment to composition changes within the intervertebral disc Journal of the Mechanics and Physics of Solids 90, 108-123
Altered nutrition in the intervertebral disc affects cell viability and can generate catabolic cascades contributing to extracellular matrix (ECM) degradation. Such degradation is expected to affect couplings between disc mechanics and nutrition, contributing to accelerate degenerative processes. However, the relation of ECM changes to major biophysical events within the loaded disc remains unclear. A L4-L5 disc finite element model including the nucleus (NP), annulus (AF) and endplates was used and coupled to a transport-cell viability model. Solute concentrations and cell viability were evaluated along the mid-sagittal plane path. A design of experiment (DOE) was performed. DOE parameters corresponded to AF and NP biochemical tissue measurements in discs with different degeneration grades. Cell viability was not affected by any parameter combinations defined. Nonetheless, the initial water content was the parameter that affected the most the solute contents, especially glucose. Calculations showed that altered NP composition could negatively affect AF cell nutrition. Results suggested that AF and NP tissue degeneration are not critical to nutrition-related cell viability at early-stage of disc degeneration. However, small ECM degenerative changes may alter significantly disc nutrition under mechanical loads. Coupling disc mechano-transport simulations and enzyme expression studies could allow identifying spatiotemporal sequences related to tissue catabolism.
JTD Keywords: Cell nutrition, Finite element analysis, Intervertebral disc degeneration, Multiphysics, Tissue composition
Caddeo, C., Nacher, A., Vassallo, A., Armentano, M. F., Pons, R., Fernàndez-Busquets, X., Carbone, C., Valenti, D., Fadda, A. M., Manconi, M., (2016). Effect of quercetin and resveratrol co-incorporated in liposomes against inflammatory/oxidative response associated with skin cancer International Journal of Pharmaceutics 513, (1-2), 153-163
The present investigation reports the development of liposomes for the co-delivery of naturally occurring polyphenols, namely quercetin and resveratrol. Small, spherical, uni/bilamellar vesicles were produced, as demonstrated by light scattering, cryo-TEM, SAXS. The incorporation of quercetin and resveratrol in liposomes did not affect their intrinsic antioxidant activity, as DPPH radical was almost completely inhibited. The cellular uptake of the polyphenols was higher when they were formulated in liposomes, and especially when co-loaded rather than as single agents, which resulted in a superior ability to scavenge ROS in fibroblasts. The in vivo efficacy of the polyphenols in liposomes was assessed in a mouse model of skin lesion. The topical administration of liposomes led to a remarkable amelioration of the tissue damage, with a significant reduction of oedema and leukocyte infiltration. Therefore, the proposed approach based on polyphenol vesicular formulation may be of value in the treatment of inflammation/oxidative stress associated with pre-cancerous/cancerous skin lesions.
JTD Keywords: Antioxidant, Fibroblast, Liposome, Quercetin, Resveratrol, Skin lesion
Estrada, L., Torres, A., Sarlabous, L., Jané, R., (2016). Improvement in neural respiratory drive estimation from diaphragm electromyographic signals using fixed sample entropy IEEE Journal of Biomedical and Health Informatics 20, (2), 476-485
Diaphragm electromyography is a valuable technique for the recording of electrical activity of the diaphragm. The analysis of diaphragm electromyographic (EMGdi) signal amplitude is an alternative approach for the quantification of neural respiratory drive (NRD). The EMGdi signal is, however, corrupted by electrocardiographic (ECG) activity, and this presence of cardiac activity can make the EMGdi interpretation more difficult. Traditionally, the EMGdi amplitude has been estimated using the average rectified value (ARV) and the root mean square (RMS). In this work, surface EMGdi signals were analyzed using the fixed sample entropy (fSampEn) algorithm, and compared to traditional ARV and RMS methods. The fSampEn is calculated using a tolerance value fixed and independent of the standard deviation of the analysis window. Thus, this method quantifies the amplitude of the complex components of stochastic signals (such as EMGdi), and being less affected by changes in amplitude due to less complex components (such as ECG). The proposed method was tested in synthetic and recorded EMGdi signals. fSampEn was less sensitive to the effect of cardiac activity on EMGdi signals with different levels of NRD than ARV and RMS amplitude parameters. The mean and standard deviation of the Pearson’s correlation values between inspiratory mouth pressure (an indirect measure of the respiratory muscle activity) and fSampEn, ARV and RMS parameters, estimated in the recorded EMGdi signal at tidal volume (without inspiratory load), were 0.38???0.12, 0.27???0.11 and 0.11???0.13, respectively. Whereas at 33 cmH2O (maximum inspiratory load) were 0.83???0.02, 0.76???0.07 and 0.61???0.19, respectively. Our findings suggest that the proposed method may improve the evaluation of NRD.
JTD Keywords: Electromyography, diaphragm muscle, neural respiratory drive
Tahirbegi, I.B., Pardo, W.A., Alvira, M., Mir, M., Samitier, J., (2016). Amyloid Aβ 42, a promoter of magnetite nanoparticle formation in Alzheimer's disease Nanotechnology 27, (46), 465102
The accumulation of iron oxides - mainly magnetite - with amyloid peptide is a key process in the development of Alzheimer's disease (AD). However, the mechanism for biogeneration of magnetite inside the brain of someone with AD is still unclear. The iron-storing protein ferritin has been identified as the main magnetite-storing molecule. However, accumulations of magnetite in AD are not correlated with an increase in ferritin, leaving this question unresolved. Here we demonstrate the key role of amyloid peptide Aβ 42, one of the main hallmarks of AD, in the generation of magnetite nanoparticles in the absence of ferritin. The capacity of amyloid peptide to bind and concentrate iron hydroxides, the basis for the formation of magnetite, benefits the spontaneous synthesis of these nanoparticles, even under unfavorable conditions for their formation. Using scanning and transmission electron microscopy, electron energy loss spectroscopy and magnetic force microscopy we characterized the capacity of amyloid peptide Aβ 42 to promote magnetite formation.
JTD Keywords: Alzheimer disease (AD), amyloid peptide Ab42, magnetite nanoparticle, metallobiomolecule, iron oxide, neurodegenerative brain diseases
Farré, R., Navajas, D., (2016). Forced oscillation: A poorly exploited tool for simply assessing respiratory function in children
Respirology , 21, (6), 982-983
Lozano-Garcia, M., Fiz, J. A., Jané, R., (2016). Performance evaluation of the Hilbert–Huang transform for respiratory sound analysis and its application to continuous adventitious sound characterization
Signal Processing , 120, 99-116
Abstract The use of the Hilbert–Huang transform in the analysis of biomedical signals has increased during the past few years, but its use for respiratory sound (RS) analysis is still limited. The technique includes two steps: empirical mode decomposition (EMD) and instantaneous frequency (IF) estimation. Although the mode mixing (MM) problem of EMD has been widely discussed, this technique continues to be used in many RS analysis algorithms. In this study, we analyzed the MM effect in RS signals recorded from 30 asthmatic patients, and studied the performance of ensemble EMD (EEMD) and noise-assisted multivariate EMD (NA-MEMD) as means for preventing this effect. We propose quantitative parameters for measuring the size, reduction of MM, and residual noise level of each method. These parameters showed that EEMD is a good solution for MM, thus outperforming NA-MEMD. After testing different IF estimators, we propose Kay׳s method to calculate an EEMD-Kay-based Hilbert spectrum that offers high energy concentrations and high time and high frequency resolutions. We also propose an algorithm for the automatic characterization of continuous adventitious sounds (CAS). The tests performed showed that the proposed EEMD-Kay-based Hilbert spectrum makes it possible to determine CAS more precisely than other conventional time-frequency techniques.
JTD Keywords: Hilbert–Huang transform, Ensemble empirical mode decomposition, Instantaneous frequency, Respiratory sounds, Continuous adventitious sounds
Silva, N., Muñoz, C., Diaz-Marcos, J., Samitier, J., Yutronic, N., Kogan, M. J., Jara, P., (2016). In situ visualization of the local photothermal effect produced on α-cyclodextrin inclusion compound associated with gold nanoparticles Nanoscale Research Letters 11, 180
Evidence of guest migration in α-cyclodextrin-octylamine (α-CD-OA) inclusion compound (IC) generated via plasmonic heating of gold nanoparticles (AuNPs) has been studied. In this report, we demonstrate local effects generated by laser-mediated irradiation of a sample of AuNPs covered with inclusion compounds on surface-derivatized glass under liquid conditions by atomic force microscopy (AFM). Functionalized AuNPs on the glass and covered by the ICs were monitored by recording images by AFM during 5 h of irradiation, and images showed that after irradiation, a drastic decrease in the height of the AuNPs occurred. The absorption spectrum of the irradiated sample showed a hypsochromic shift from 542 to 536 nm, evidence suggesting that much of the population of nanoparticles lost all of the parts of the overlay of ICs due to the plasmonic heat generated by the irradiation. Mass spectrometry matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) performed on a sample containing a collection of drops obtained from the surface of the functionalized glass provided evidence that the irradiation lead to disintegration of the ICs and therefore exit of the octylamine molecule (the guest) from the cyclodextrin cavity (the matrix).
JTD Keywords: Cyclodextrin inclusion compound, Gold nanoparticles, Guest migration, Plasmonic heating
del Río, J. A., Gavín, R., (2016). Functions of the cellular prion protein, the end of Moore's law, and Ockham's razor theory
Prion , 10, (1), 25-40
Since its discovery the cellular prion protein (encoded by the Prnp gene) has been associated with a large number of functions. The proposed functions rank from basic cellular processes such as cell cycle and survival to neural functions such as behavior and neuroprotection, following a pattern similar to that of Moore's law for electronics. In addition, particular interest is increasing in the participation of Prnp in neurodegeneration. However, in recent years a redefinition of these functions has begun, since examples of previously attributed functions were increasingly re-associated with other proteins. Most of these functions are linked to so-called “Prnp-flanking genes” that are close to the genomic locus of Prnp and which are present in the genome of some Prnp mouse models. In addition, their role in neuroprotection against convulsive insults has been confirmed in recent studies. Lastly, in recent years a large number of models indicating the participation of different domains of the protein in apoptosis have been uncovered. However, after more than 10 years of molecular dissection our view is that the simplest mechanistic model in PrPC-mediated cell death should be considered, as Ockham's razor theory suggested.
JTD Keywords: Neurodegeneration, Prion, PrP
Huerta, R., Mosqueiro, T., Fonollosa, J., Rulkov, N.F., Rodríguez-Lujan, I., (2016). Online decorrelation of humidity and temperature in chemical sensors for continuous monitoring
Chemometrics and Intelligent Laboratory Systems , 157, 169-176
A method for online decorrelation of chemical sensor signals from the effects of environmental humidity and temperature variations is proposed. The goal is to improve the accuracy of electronic nose measurements for continuous monitoring by processing data from simultaneous readings of environmental humidity and temperature. The electronic nose setup built for this study included eight metal-oxide sensors, temperature and humidity sensors with a wireless communication link to external computer. This wireless electronic nose was used to monitor the air for two years in the residence of one of the authors and it collected data continuously during 537 days with a sampling rate of 1 sample per second. To estimate the effects of variations in air humidity and temperature on the chemical sensors' signals, we used a standard energy band model for an n-type metal-oxide (MOX) gas sensor. The main assumption of the model is that variations in sensor conductivity can be expressed as a nonlinear function of changes in the semiconductor energy bands in the presence of external humidity and temperature variations. Fitting this model to the collected data, we confirmed that the most statistically significant factors are humidity changes and correlated changes of temperature and humidity. This simple model achieves excellent accuracy with a coefficient of determination R2 close to 1. To show how the humidity–temperature correction model works for gas discrimination, we constructed a model for online discrimination among banana, wine and baseline response. This shows that pattern recognition algorithms improve performance and reliability by including the filtered signal of the chemical sensors.
JTD Keywords: Electronic nose, Chemical sensors, Humidity, Temperature, Decorrelation, Wireless e-nose, MOX sensors, Energy band model, Home monitoring
Arcentales, A., Rivera, P., Caminal, P., Voss, A., Bayés-Genís, A., Giraldo, B. F., (2016). Analysis of blood pressure signal in patients with different ventricular ejection fraction using linear and non-linear methods Engineering in Medicine and Biology Society (EMBC)
38th Annual International Conference of the IEEE , IEEE (Orlando, USA) , 2700-2703
Changes in the left ventricle function produce alternans in the hemodynamic and electric behavior of the cardiovascular system. A total of 49 cardiomyopathy patients have been studied based on the blood pressure signal (BP), and were classified according to the left ventricular ejection fraction (LVEF) in low risk (LR: LVEF>35%, 17 patients) and high risk (HR: LVEF≤35, 32 patients) groups. We propose to characterize these patients using a linear and a nonlinear methods, based on the spectral estimation and the recurrence plot, respectively. From BP signal, we extracted each systolic time interval (STI), upward systolic slope (BPsl), and the difference between systolic and diastolic BP, defined as pulse pressure (PP). After, the best subset of parameters were obtained through the sequential feature selection (SFS) method. According to the results, the best classification was obtained using a combination of linear and nonlinear features from STI and PP parameters. For STI, the best combination was obtained considering the frequency peak and the diagonal structures of RP, with an area under the curve (AUC) of 79%. The same results were obtained when comparing PP values. Consequently, the use of combined linear and nonlinear parameters could improve the risk stratification of cardiomyopathy patients.
JTD Keywords: Feature extraction, Blood pressure, Heart rate, Estimation, Data mining, Covariance matrices, Hospitals
Coelho, N. M., Llopis-Hernández, V., Salmerón-Sánchez, M., Altankov, G., (2016). Dynamic reorganization and enzymatic remodeling of type IV collagen at cell–biomaterial interface
Advances in Protein Chemistry and Structural Biology (ed. Christo, Z. Christov), Academic Press (San Diego, USA) 105, 81-104
Abstract Vascular basement membrane remodeling involves assembly and degradation of its main constituents, type IV collagen (Col IV) and laminin, which is critical during development, angiogenesis, and tissue repair. Remodeling can also occur at cell–biomaterials interface altering significantly the biocompatibility of implants. Here we describe the fate of adsorbed Col IV in contact with endothelial cells adhering on positively charged NH2 or hydrophobic CH3 substrata, both based on self-assembly monolayers (SAMs) and studied alone or mixed in different proportions. AFM studies revealed distinct pattern of adsorbed Col IV, varying from single molecular deposition on pure NH2 to network-like assembly on mixed SAMs, turning to big globular aggregates on bare CH3. Human umbilical endothelial cells (HUVECs) interact better with Col IV adsorbed as single molecules on NH2 surface and readily rearrange it in fibril-like pattern that coincide with secreted fibronectin fibrils. The cells show flattened morphology and well-developed focal adhesion complexes that are rich on phosphorylated FAK while expressing markedly low pericellular proteolytic activity. Conversely, on hydrophobic CH3 substrata HUVECs showed abrogated spreading and FAK phosphorylation, combined with less reorganization of the aggregated Col IV and significantly increased proteolytic activity. The later involves both MMP-2 and MMP-9, as measured by zymography and FITC-Col IV release. The mixed SAMs support intermediate remodeling activity. Taken together these results show that chemical functionalization combined with Col IV preadsorption provides a tool for guiding the endothelial cells behavior and pericellular proteolytic activity, events that strongly affect the fate of cardiovascular implants.
JTD Keywords: Type IV collagen, Adsorption, Remodeling, Pericellular proteolysis, Reorganization, Substratum chemistry, CH3 and NH2 groups, Self-assembly monolayers
Ziyatdinov, Andrey, Fonollosa, Jordi, Fernández, Luis, Gutiérrez-Gálvez, Agustín, Marco, Santiago, Perera, Alexandre, (2015). Data set from gas sensor array under flow modulation Data in Brief 3, 131-136
Abstract Recent studies in neuroscience suggest that sniffing, namely sampling odors actively, plays an important role in olfactory system, especially in certain scenarios such as novel odorant detection. While the computational advantages of high frequency sampling have not been yet elucidated, here, in order to motivate further investigation in active sampling strategies, we share the data from an artificial olfactory system made of 16 MOX gas sensors under gas flow modulation. The data were acquired on a custom set up featured by an external mechanical ventilator that emulates the biological respiration cycle. 58 samples were recorded in response to a relatively broad set of 12 gas classes, defined from different binary mixtures of acetone and ethanol in air. The acquired time series show two dominant frequency bands: the low-frequency signal corresponds to a conventional response curve of a sensor in response to a gas pulse, and the high-frequency signal has a clear principal harmonic at the respiration frequency. The data are related to the study in [1], and the data analysis results reported there should be considered as a reference point.
JTD Keywords: Gas sensor array, MOX sensor, Flow modulation, Early detection, Biomimetics, Respiration, Sniffing
Malandrino, Andrea, Pozo, Jose Maria, Castro-Mateos, Isaac, Frangi, Alejandro F., van Rijsbergen, Marc M., Ito, Keita, Wilke, Hans-Joachim, Dao, Tien Tuan, Ho Ba Tho, Marie-Christine, Noailly, Jerome, (2015). On the relative relevance of subject-specific geometries and degeneration-specific mechanical properties for the study of cell death in human intervertebral disc models Frontiers in Bioengineering and Biotechnology 3, (Article 5), 1-15
Capturing patient- or condition-specific intervertebral disk (IVD) properties in finite element models is outmost important in order to explore how biomechanical and biophysical processes may interact in spine diseases. However, disk degenerative changes are often modeled through equations similar to those employed for healthy organs, which might not be valid. As for the simulated effects of degenerative changes, they likely depend on specific disk geometries. Accordingly, we explored the ability of continuum tissue models to simulate disk degenerative changes. We further used the results in order to assess the interplay between these simulated changes and particular IVD morphologies, in relation to disk cell nutrition, a potentially important factor in disk tissue regulation. A protocol to derive patient-specific computational models from clinical images was applied to different spine specimens. In vitro, IVD creep tests were used to optimize poro-hyperelastic input material parameters in these models, in function of the IVD degeneration grade. The use of condition-specific tissue model parameters in the specimen-specific geometrical models was validated against independent kinematic measurements in vitro. Then, models were coupled to a transport-cell viability model in order to assess the respective effects of tissue degeneration and disk geometry on cell viability. While classic disk poro-mechanical models failed in representing known degenerative changes, additional simulation of tissue damage allowed model validation and gave degeneration-dependent material properties related to osmotic pressure and water loss, and to increased fibrosis. Surprisingly, nutrition-induced cell death was independent of the grade-dependent material properties, but was favored by increased diffusion distances in large IVDs. Our results suggest that in situ geometrical screening of IVD morphology might help to anticipate particular mechanisms of disk degeneration.
JTD Keywords: Intervertebral Disc Degeneration, Finite element modelling, Lumbar spine, Poroelasticity, Damage model, Subject-specific modelling, Disc cell nutrition
Kovtun, A., Goeckelmann, M. J., Niclas, A. A., Montufar, E. B., Ginebra, M. P., Planell, J. A., Santin, M., Ignatius, A., (2015). In vivo performance of novel soybean/gelatin-based bioactive and injectable hydroxyapatite foams Acta Biomaterialia Elsevier Ltd 12, (1), 242-249
Major limitations of calcium phosphate cements (CPCs) are their relatively slow degradation rate and the lack of macropores allowing the ingrowth of bone tissue. The development of self-setting cement foams has been proposed as a suitable strategy to overcome these limitations. In previous work we developed a gelatine-based hydroxyapatite foam (G-foam), which exhibited good injectability and cohesion, interconnected porosity and good biocompatibility in vitro. In the present study we evaluated the in vivo performance of the G-foam. Furthermore, we investigated whether enrichment of the foam with soybean extract (SG-foam) increased its bioactivity. G-foam, SG-foam and non-foamed CPC were implanted in a critical-size bone defect in the distal femoral condyle of New Zealand white rabbits. Bone formation and degradation of the materials were investigated after 4, 12 and 20 weeks using histological and biomechanical methods. The foams maintained their macroporosity after injection and setting in vivo. Compared to non-foamed CPC, cellular degradation of the foams was considerably increased and accompanied by new bone formation. The additional functionalization with soybean extract in the SG-foam slightly reduced the degradation rate and positively influenced bone formation in the defect. Furthermore, both foams exhibited excellent biocompatibility, implying that these novel materials may be promising for clinical application in non-loaded bone defects.
JTD Keywords: Bone regeneration, Calcium phosphate cement, Gelatine, Rabbit model, Soybean
Castangia, I., Nácher, A., Caddeo, C., Merino, V., Díez-Sales, O., Catalán-Latorre, A., Fernàndez-Busquets, X., Fadda, A. M., Manconi, M., (2015). Therapeutic efficacy of quercetin enzyme-responsive nanovesicles for the treatment of experimental colitis in rats Acta Biomaterialia 13, 216-227
Biocompatible quercetin nanovesicles were developed by coating polyethylene glycol-containing vesicles with chitosan and nutriose, aimed at targeting the colon. Uncoated and coated vesicles were prepared using hydrogenated soy phosphatidylcholine and quercetin, a potent natural anti-inflammatory and antioxidant drug. Physicochemical characterization was carried out by light scattering, cryogenic microscopy and X-ray scattering, the results showing that vesicles were predominantly multilamellar and around 130 nm in size. The in vitro release of quercetin was investigated under different pH conditions simulating the environment of the gastrointestinal tract, and confirmed that the chitosan/nutriose coating improved the gastric resistance of vesicles, making them a potential carrier system for colon delivery. The preferential localization of fluorescent vesicles in the intestine was demonstrated using the In Vivo FX PRO Imaging System. Above all, a marked amelioration of symptoms of 2,4,6-trinitrobenzenesulfonic acid-induced colitis was observed in animals treated with quercetin-loaded coated vesicles, favoring the restoration of physiological conditions. Therefore, quercetin-loaded chitosan/nutriose-coated vesicles can represent a valuable therapeutic tool for the treatment of chronic intestinal inflammatory diseases, and presumably a preventive system, due to the synergic action of antioxidant quercetin and beneficial prebiotic effects of the chitosan/nutriose complex.
JTD Keywords: Chitosan/nutriose complex, Colon targeting, Phospholipid vesicles, Quercetin, Rat colitis
Reginensi, Diego, Carulla, Patricia, Nocentini, Sara, Seira, Oscar, Serra-Picamal, Xavier, Torres-Espín, Abel, Matamoros-Angles, Andreu, Gavín, Rosalina, Moreno-Flores, María Teresa, Wandosell, Francisco, Samitier, Josep, Trepat, Xavier, Navarro, Xavier, del Río, José Antonio, (2015). Increased migration of olfactory ensheathing cells secreting the Nogo receptor ectodomain over inhibitory substrates and lesioned spinal cord
Cellular and Molecular Life Sciences , 72, (14), 2719-2737
Olfactory ensheathing cell (OEC) transplantation emerged some years ago as a promising therapeutic strategy to repair injured spinal cord. However, inhibitory molecules are present for long periods of time in lesioned spinal cord, inhibiting both OEC migration and axonal regrowth. Two families of these molecules, chondroitin sulphate proteoglycans (CSPG) and myelin-derived inhibitors (MAIs), are able to trigger inhibitory responses in lesioned axons. Mounting evidence suggests that OEC migration is inhibited by myelin. Here we demonstrate that OEC migration is largely inhibited by CSPGs and that inhibition can be overcome by the bacterial enzyme Chondroitinase ABC. In parallel, we have generated a stable OEC cell line overexpressing the Nogo receptor (NgR) ectodomain to reduce MAI-associated inhibition in vitro and in vivo. Results indicate that engineered cells migrate longer distances than unmodified OECs over myelin or oligodendrocyte-myelin glycoprotein (OMgp)-coated substrates. In addition, they also show improved migration in lesioned spinal cord. Our results provide new insights toward the improvement of the mechanisms of action and optimization of OEC-based cell therapy for spinal cord lesion.
JTD Keywords: Olfactory ensheathing cells, Traction force microscopy, Chondroitin sulphate proteoglycans, Cell migration, Nogo receptor ectodomain
Mrkonji, Garcia-Elias, A., Pardo-Pastor, C., Bazellières, E., Trepat, X., Vriens, J., Ghosh, D., Voets, T., Vicente, R., Valverde, M. A., (2015). TRPV4 participates in the establishment of trailing adhesions and directional persistence of migrating cells
Pflugers Archiv European Journal of Physiology , 467, (10), 2107-2119
Calcium signaling participates in different cellular processes leading to cell migration. TRPV4, a non-selective cation channel that responds to mechano-osmotic stimulation and heat, is also involved in cell migration. However, the mechanistic involvement of TRPV4 in cell migration is currently unknown. We now report that expression of the mutant channel TRPV4-121AAWAA (lacking the phosphoinositide-binding site 121KRWRK125 and the response to physiological stimuli) altered HEK293 cell migration. Altered migration patterns included periods of fast and persistent motion followed by periods of stalling and turning, and the extension of multiple long cellular protrusions. TRPV4-WT overexpressing cells showed almost complete loss of directionality with frequent turns, no progression, and absence of long protrusions. Traction microscopy revealed higher tractions forces in the tail of TRPV4-121AAWAA than in TRPV4-WT expressing cells. These results are consistent with a defective and augmented tail retraction in TRPV4-121AAWAA- and TRPV4-WT-expressing cells, respectively. The activity of calpain, a protease implicated in focal adhesion (FA) disassembly, was decreased in TRPV4-121AAWAA compared with TRPV4-WT-expressing cells. Consistently, larger focal adhesions were seen in TRPV4-121AAWAA compared with TRPV4-WT-expressing HEK293 cells, a result that was also reproduced in T47D and U87 cells. Similarly, overexpression of the pore-dead mutant TRPV4-M680D resumed the TRPV4-121AAWAA phenotype presenting larger FA. The migratory phenotype obtained in HEK293 cells overexpressing TRPV4-121AAWAA was mimicked by knocking-down TRPC1, a cationic channel that participates in cell migration. Together, our results point to the participation of TRPV4 in the dynamics of trailing adhesions, a function that may require the interplay of TRPV4 with other cation channels or proteins present at the FA sites.
JTD Keywords: Calcium, Calpain, Focal adhesion, Migration, Traction forces, TRPV4
Estévez, M., Martínez, Elena, Yarwood, S. J., Dalby, M. J., Samitier, J., (2015). Adhesion and migration of cells responding to microtopography
Journal of Biomedical Materials Research - Part A , 103, (5), 1659-1668
It is known that cells respond strongly to microtopography. However, cellular mechanisms of response are unclear. Here, we study wild-type fibroblasts responding to 25 μm2 posts and compare their response to that of FAK-/- fibroblasts and fibroblasts with PMA treatment to stimulate protein kinase C (PKC) and the small g-protein Rac. FAK knockout cells modulated adhesion number and size in a similar way to cells on topography; that is, they used more, smaller adhesions, but migration was almost completely stalled demonstrating the importance of FAK signaling in contact guidance and adhesion turnover. Little similarity, however, was observed to PKC stimulated cells and cells on the topography. Interestingly, with PKC stimulation the cell nuclei became highly deformable bringing focus on these surfaces to the study of metastasis. Surfaces that aid the study of cellular migration are important in developing understanding of mechanisms of wound healing and repair in aligned tissues such as ligament and tendon.
JTD Keywords: Adhesion, Cell migration, Cell morphology, Focal adhesion kinase, Microstructures
Barniol-Xicota, M., Escandell, A., Valverde, E., Julián, E., Torrents, E., Vázquez, S., (2015). Antibacterial activity of novel benzopolycyclic amines
Bioorganic and Medicinal Chemistry , 23, (2), 290-296
Staphylococcus aureus, especially strains resistant to multiple antibiotics, is a major pathogen for humans and animals. In this paper we have synthesized and evaluated the antibacterial activity of a new series of benzopolycyclic amines. Some of them exhibited μM MIC values against Staphylococcus aureus and other bacteria, including methicillin-resistant S. aureus MRSA. Compound 8 that displayed a good selectivity index, showed to be active in eliminating bacterial cells forming a preexisting biofilm.
JTD Keywords: Antibacterials, Minimal biofilm inhibitory concentration, Polycyclic compounds, Staphylococcus aureus
del Moral-Zamora, Beatriz, Punter-Villagrassa, Jaime, Oliva-Brañas, Ana M., Álvarez-Azpeitia, Juan Manuel, Colomer-Farrarons, Jordi, Samitier, Josep, Homs-Corbera, Antoni, Miribel-Català, Pere Ll, (2015). Combined dielectrophoretic and impedance system for on-chip controlled bacteria concentration: application to Escherichia coli
Electrophoresis , 36, (9-10), 1130-1141
The present paper reports a bacteria autonomous controlled concentrator prototype with a user-friendly interface for bench-top applications. It is based on a micro-fluidic lab-on-a-chip and its associated custom instrumentation, which consists in a dielectrophoretic actuator, to pre-concentrate the sample, and an impedance analyser, to measure concentrated bacteria levels. The system is composed by a single micro-fluidic chamber with interdigitated electrodes and a instrumentation with custom electronics. The prototype is supported by a real-time platform connected to a remote computer, which automatically controls the system and displays impedance data used to monitor the status of bacteria accumulation on-chip. The system automates the whole concentrating operation. Performance has been studied for controlled volumes of Escherichia coli (E. coli) samples injected into the micro-fluidic chip at constant flow rate of 10 μL/min. A media conductivity correcting protocol has been developed, as the preliminary results showed distortion of the impedance analyser measurement produced by bacterial media conductivity variations through time. With the correcting protocol, the measured impedance values were related to the quantity of bacteria concentrated with a correlation of 0.988 and a coefficient of variation of 3.1%. Feasibility of E. coli on-chip automated concentration, using the miniaturized system, has been demonstrated. Furthermore, the impedance monitoring protocol had been adjusted and optimized, to handle changes in the electrical properties of the bacteria media over time.
JTD Keywords: Autonomous Device, Bacteria Concentrator, Dielectrophoresis, Escherichia coli, Impedance Analysis
del Moral Zamora, Beatriz, Manuel Álvarez Azpeitia, Juan, Brañas, Ana Ma Oliva, Colomer-Farrarons, Jordi, Castellarnau, Marc, Miribel-Català, Pere Ll, Homs-Corbera, Antoni, Juárez, Antonio, Samitier, Josep, (2015). Dielectrophoretic concentrator enhancement based on dielectric poles for continuously flowing samples
Electrophoresis , 36, (13), 1405-1413
We describe a novel continuous-flow cell concentrator micro-device based on dielectrophoresis (DEP), and its associated custom-made control unit. The performances of a classical interdigitated metal electrode-based DEP microfluidic device and this enhanced version, that includes insulator-based pole structures, were compared using the same setup. Escherichia coli (E. coli) samples were concentrated at several continuous flows and the device's trapping efficiencies were evaluated by exhaustive cell counts. Our results show that pole structures enhance the retention up to 12.6%, obtaining significant differences for flow rates up to 20 μl/min, when compared to an equivalent classical interdigitated electrodes setup. In addition, we performed a subsequent proteomic analysis to evaluate the viability of the biological samples after the long exposure to the actuating electrical field. No E. coli protein alteration in any of the two systems was observed.
JTD Keywords: Concentrator, Dielectrophoresis, Escherichia coli, Lab- on- a- chip
Garde, A., Giraldo, B. F., Jané, R., Latshang, T. D., Turk, A. J., Hess, T., Bosch, M-.M., Barthelmes, D., Merz, T. M., Hefti, J. Pichler, Schoch, O. D., Bloch, K. E., (2015). Time-varying signal analysis to detect high-altitude periodic breathing in climbers ascending to extreme altitude
Medical & Biological Engineering & Computing , 53, (8), 699-712
This work investigates the performance of cardiorespiratory analysis detecting periodic breathing (PB) in chest wall recordings in mountaineers climbing to extreme altitude. The breathing patterns of 34 mountaineers were monitored unobtrusively by inductance plethysmography, ECG and pulse oximetry using a portable recorder during climbs at altitudes between 4497 and 7546 m on Mt. Muztagh Ata. The minute ventilation (VE) and heart rate (HR) signals were studied, to identify visually scored PB, applying time-varying spectral, coherence and entropy analysis. In 411 climbing periods, 30–120 min in duration, high values of mean power (MPVE) and slope (MSlopeVE) of the modulation frequency band of VE, accurately identified PB, with an area under the ROC curve of 88 and 89 %, respectively. Prolonged stay at altitude was associated with an increase in PB. During PB episodes, higher peak power of ventilatory (MPVE) and cardiac (MP LF HR ) oscillations and cardiorespiratory coherence (MP LF Coher ), but reduced ventilation entropy (SampEnVE), was observed. Therefore, the characterization of cardiorespiratory dynamics by the analysis of VE and HR signals accurately identifies PB and effects of altitude acclimatization, providing promising tools for investigating physiologic effects of environmental exposures and diseases.
JTD Keywords: High-altitude periodic breathing, Cardiorespiratory characterization, Time-varying spectral analysis, Acclimatization, Hypoxia
Won, J. E., Mateos-Timoneda, M. A., Castaño, O., Planell, J. A., Seo, S. J., Lee, E. J., Han, C. M., Kim, H. W., (2015). Fibronectin immobilization on to robotic-dispensed nanobioactive glass/polycaprolactone scaffolds for bone tissue engineering
Biotechnology Letters , 37, (4), 935-342
Bioactive nanocomposite scaffolds with cell-adhesive surface have excellent bone regeneration capacities. Fibronectin (FN)-immobilized nanobioactive glass (nBG)/polycaprolactone (PCL) (FN-nBG/PCL) scaffolds with an open pore architecture were generated by a robotic-dispensing technique. The surface immobilization level of FN was significantly higher on the nBG/PCL scaffolds than on the PCL scaffolds, mainly due to the incorporated nBG that provided hydrophilic chemical-linking sites. FN-nBG/PCL scaffolds significantly improved cell responses, including initial anchorage and subsequent cell proliferation. Although further in-depth studies on cell differentiation and the in vivo animal responses are required, bioactive nanocomposite scaffolds with cell-favoring surface are considered to provide promising three-dimensional substrate for bone regeneration.
JTD Keywords: Bone scaffolds, Cell response, Fibronectin, Nanobioactive glass, Nanocomposites, Polycaprolactone, Bone, Cell proliferation, Cells, Cytology, Glass, Nanocomposites, Polycaprolactone, Robotics, Bone scaffolds, Bone tissue engineering, Cell response, Fibronectin, Fibronectin immobilizations, Nano bioactive glass, Nanocomposite scaffolds, Three-dimensional substrates, Scaffolds (biology)
Hernansanz, A., Casals, A., Amat, J., (2015). A multi-robot cooperation strategy for dexterous task oriented teleoperation
Robotics and Autonomous Systems , 68, 156-172
The use of multiple robots working cooperatively in a redundant way offers new possibilities in the execution of complex tasks in dynamic workspaces. The aim of this work is to increase the range of applicability of teleoperated systems by means of the automatic cooperation of multiple slave robots which, controlled by a human operator, act as if they were a unique robot: a Multi-Robot Cooperation Platform for Task-Oriented Teleoperation, MRCP. From the human operator commands, this robotic platform, the MRCP, dynamically selects the most suitable slave robot and manages, when necessary, a task transfer from one robot to another in order to achieve a smooth execution of teleoperated tasks. The result of the proposed methodology is an improved teleoperated system in terms of reachable workspace (volume, manoeuvrability and accessibility) and dexterity, thus widening its range of applicability. This approach allows human operators to focus their attention on the ongoing task more than on the teleoperated robots.
JTD Keywords: Multi-robot cooperation, Single-operator-multiple-robot, Task-oriented teleoperation
Fonollosa, J., Neftci, E., Huerta, R., Marco, S., (2015). Evaluation of calibration transfer strategies between Metal Oxide gas sensor arrays Procedia Engineering
EUROSENSORS 2015 , Elsevier (Freiburg, Germany) 120, 261-264
Abstract Inherent variability of chemical sensors makes necessary individual calibration of chemical detection systems. This shortcoming has traditionally limited usability of systems based on Metal Oxide (MOX) sensor arrays and prevented mass-production for some applications. Here, aiming at exploring transfer calibration between electronic nose systems, we exposed five identical 8-sensor detection units to controlled gas conditions. Our results show that a calibration model provides more accurate predictions when the tested board is included in the calibration dataset. However, we show that previously built calibration models can be extended to other units using a reduced number of measurements. While baseline correction seems imperative for successful baseline correction, among the different tested strategies, piecewise direct standardization provides more accurate predictions.
JTD Keywords: Electronic nose, Calibration, MOX sensor, Machine Olfaction
Estrada, L., Torres, A., Sarlabous, L., Jané, R., (2015). Respiratory signal derived from the smartphone built-in accelerometer during a Respiratory Load Protocol Engineering in Medicine and Biology Society (EMBC)
37th Annual International Conference of the IEEE , IEEE (Milan, Italy) , 6768-6771
The scope of our work focuses on investigating the potential use of the built-in accelerometer of the smartphones for the recording of the respiratory activity and deriving the respiratory rate. Five healthy subjects performed an inspiratory load protocol. The excursion of the right chest was recorded using the built-in triaxial accelerometer of a smartphone along the x, y and z axes and with an external uniaxial accelerometer. Simultaneously, the respiratory airflow and the inspiratory mouth pressure were recorded, as reference respiratory signals. The chest acceleration signal recorded in the z axis with the smartphone was denoised using a scheme based on the ensemble empirical mode decomposition, a noise data assisted method which decomposes nonstationary and nonlinear signals into intrinsic mode functions. To distinguish noisy oscillatory modes from the relevant modes we use the detrended fluctuation analysis. We reported a very strong correlation between the acceleration of the z axis of the smartphone and the reference accelerometer across the inspiratory load protocol (from 0.80 to 0.97). Furthermore, the evaluation of the respiratory rate showed a very strong correlation (0.98). A good agreement was observed between the respiratory rate estimated with the chest acceleration signal from the z axis of the smartphone and with the respiratory airflow signal: Bland-Altman limits of agreement between -1.44 and 1.46 breaths per minute with a mean bias of -0.01 breaths per minute. This preliminary study provides a valuable insight into the use of the smartphone and its built-in accelerometer for respiratory monitoring.
JTD Keywords: Acceleration, Accelerometers, Correlation, Empirical mode decomposition, Fluctuations, Protocols, Time series analysis
Oller-Moreno, S., Singla-Buxarrais, G., Jiménez-Soto, J. M., Pardo, Antonio, Garrido-Delgado, R., Arce, L., Marco, Santiago, (2015). Sliding window multi-curve resolution: Application to gas chromatography - Ion Mobility Spectrometry Sensors and Actuators B: Chemical
15th International Meeting on Chemical Sensors , Elsevier (Buenos Aires, Argentina) 217, 13-21
Abstract Blind Source Separation (BSS) techniques aim to extract a set of source signals from a measured mixture in an unsupervised manner. In the chemical instrumentation domain source signals typically refer to time-varying analyte concentrations, while the measured mixture is the set of observed spectra. Several techniques exist to perform BSS on Ion Mobility Spectrometry, being Simple-to-use interactive self-modeling mixture analysis (SIMPLISMA) and Multivariate Curve Resolution (MCR) the most commonly used. The addition of a multi-capillary gas chromatography column using the ion mobility spectrometer as detector has been proposed in the past to increase chemical resolution. Short chromatography times lead to high levels of co-elution, and ion mobility spectra are key to resolve them. For the first time, BSS techniques are used to deconvolve samples of the gas chromatography - ion mobility spectrometry tandem. We propose a method to extract spectra and concentration profiles based on the application of MCR in a sliding window. Our results provide clear concentration profiles and pure spectra, resolving peaks that were not detected by the conventional use of MCR. The proposed technique could also be applied to other hyphenated instruments with similar strong co-elutions.
JTD Keywords: Blind Source Separation, Multivariate Curve Resolution, Ion Mobility Spectrometry, Gas Chromatography, Hyphenated instrumentation, SIMPLISMA, co-elution
Serra-Picamal, Xavier, Conte, Vito, Sunyer, Raimon, Muñoz, José J., Trepat, Xavier, (2015). Mapping forces and kinematics during collective cell migration
Methods in Cell Biology - Biophysical Methods in Cell Biology (ed. Wilson, L., Tran, P.), Academic Press (Santa Barbara, USA) 125, 309-330
Abstract Fundamental biological processes including morphogenesis and tissue repair require cells to migrate collectively. In these processes, epithelial or endothelial cells move in a cooperative manner coupled by intercellular junctions. Ultimately, the movement of these multicellular systems occurs through the generation of cellular forces, exerted either on the substrate via focal adhesions (cell–substrate forces) or on neighboring cells through cell–cell junctions (cell–cell forces). Quantitative measurements of multicellular forces and kinematics with cellular or subcellular resolution have become possible only in recent years. In this chapter, we describe some of these techniques, which include particle image velocimetry to map cell velocities, traction force microscopy to map forces exerted by cells on the substrate, and monolayer stress microscopy to map forces within and between cells. We also describe experimental protocols to perform these measurements. The combination of these techniques with high-resolution imaging tools and molecular perturbations will lead to a better understanding of the mechanisms underlying collective cell migration in health and disease.
JTD Keywords: Collective cell migration, Monolayer stress microscopy, Traction force microscopy
Comelles, J., Hortigüela, V., Martínez, Elena, Riveline, D., (2015). Methods for rectifying cell motions in vitro: Breaking symmetry using microfabrication and microfluidics
Methods in Cell Biology - Biophysical Methods in Cell Biology (ed. Wilson, L., Tran, P.), Academic Press (Santa Barbara, USA) 125, 437-452
Cell motility is an important phenomenon in cell biology, developmental biology, and cancer. Here we report methods that we designed to identify and characterize external factors which direct cell motions by breaking locally the symmetry. We used microfabrication and microfluidics techniques to impose and combine mechanical and chemical cues to moving fibroblasts. Gradients can thereby be engineered at the cellular scale and this approach has allowed to disentangle roles of the nucleus and protrusion activity in setting cell directions.
JTD Keywords: Adhesion, Biological physics, Cell motility, Gradient, Ratchet
Oliva, A. M., Homs-Corbera, A., Torrents, E., Juarez, A., Samitier, J., (2014). Synergystic effect of temperature and electric field intensity in Escherichia coli inactivation
Micro and Nanosystems , 6, (2), 79-86
Electric Fields are increasingly used to manipulate bacteria. However, there is no systematic and definitive study on how the different electric parameters change bacteria viability. Here we present a study on the effects of electric field intensity and temperature to bacterial cultures. Escherichia coli colonies have been exposed to different electric field intensities at 1MHz during 5 minutes by means of a microfluidic device specially designed for the experiment. From the analysis of the results it is possible to see that Escherichia coli survival rate diminishes when applying field intensities as low as 220V during 5 minutes. Death rates also increase when stronger fields are applied. However, viability of survived bacteria is maintained. Additionally, temperature shows a synergistic effect with voltage. When temperature was increased, results showed a stronger sensitivity of cells to the electric field. Moreover, the expression patterns of Outer Membrane Protein A and Ribosomal Proteins differ in control and treated samples, suggesting changes in bacterial metabolism and structure.
JTD Keywords: E. coli, Electric field, Temperature, Viability
del Moral Zamora, B., Azpeitia, J. M. Á, Farrarons, J. C., Català, P. L. M., Corbera, A. H., Juárez, A., Samitier, J., (2014). Towards point-of-use dielectrophoretic methods: A new portable multiphase generator for bacteria concentration
Micro and Nanosystems , 6, (2), 71-78
This manuscript presents a portable and low cost electronic system for specific point-of-use dielectrophoresis applications. The system is composed of two main modules: a) a multiphase generator based on a Class E amplifier, which provides 4 sinusoidal signals (0°, 90°, 180°, 270°) at 1 MHz with variable output voltage up to 10 Vpp (Vm) and an output driving current of 1 A; and b) a dielectrophoresis-based microfluidic chip containing two interdigitated electrodes. The system has been validated by concentrating Escherichia coli (E. coli) at 1 MHz while applying a continuous flow of 5 µL/min. The device functionalities were verified under different conditions, achieving an 83% trapping efficiency when counter-phased signals are used.
JTD Keywords: Cell Concentrator, Class E amplifier, Dielectrophoresis, Electronics, Lab-on-a-chip (LOC), Low cost, Portable device
Álvarez, Z., Castaño, O., Castells, A. A., Mateos-Timoneda, M. A., Planell, J. A., Engel, E., Alcántara, S., (2014). Neurogenesis and vascularization of the damaged brain using a lactate-releasing biomimetic scaffold Biomaterials 35, (17), 4769-4781
Regenerative medicine strategies to promote recovery following traumatic brain injuries are currently focused on the use of biomaterials as delivery systems for cells or bioactive molecules. This study shows that cell-free biomimetic scaffolds consisting of radially aligned electrospun poly-l/dl lactic acid (PLA70/30) nanofibers release l-lactate and reproduce the 3D organization and supportive function of radial glia embryonic neural stem cells. The topology of PLA nanofibers supports neuronal migration while l-lactate released during PLA degradation acts as an alternative fuel for neurons and is required for progenitor maintenance. Radial scaffolds implanted into cavities made in the postnatal mouse brain fostered complete implant vascularization, sustained neurogenesis, and allowed the long-term survival and integration of the newly generated neurons. Our results suggest that the endogenous central nervous system is capable of regeneration through the invivo dedifferentiation induced by biophysical and metabolic cues, with no need for exogenous cells, growth factors, or genetic manipulation.
JTD Keywords: Lactate, Nanofibers, Neural stem cells, Neurogenesis, Regeneration, Vascularization
Pérez-Madrigal, M. M., Giannotti, M. I., Del Valle, L. J., Franco, L., Armelin, E., Puiggalí, J., Sanz, F., Alemán, C., (2014). Thermoplastic polyurethane:polythiophene nanomembranes for biomedical and biotechnological applications ACS Applied Materials & Interfaces 6, (12), 9719-9732
Nanomembranes have been prepared by spin-coating mixtures of a polythiophene (P3TMA) derivative and thermoplastic polyurethane (TPU) using 20:80, 40:60, and 60:40 TPU:P3TMA weight ratios. After structural, topographical, electrochemical, and thermal characterization, properties typically related with biomedical applications have been investigated: swelling, resistance to both hydrolytic and enzymatic degradation, biocompatibility, and adsorption of type I collagen, which is an extra cellular matrix protein that binds fibronectin favoring cell adhesion processes. The swelling ability and the hydrolytic and enzymatic degradability of TPU:P3TMA membranes increases with the concentration of P3TMA. Moreover, the degradation of the blends is considerably promoted by the presence of enzymes in the hydrolytic medium, TPU:P3TMA blends behaving as biodegradable materials. On the other hand, TPU:P3TMA nanomembranes behave as bioactive platforms stimulating cell adhesion and, especially, cell viability. Type I collagen adsorption largely depends on the substrate employed to support the nanomembrane, whereas it is practically independent of the chemical nature of the polymeric material used to fabricate the nanomembrane. However, detailed microscopy study of the morphology and topography of adsorbed collagen evidence the formation of different organizations, which range from fibrils to pseudoregular honeycomb networks depending on the composition of the nanomembrane that is in contact with the protein. Scaffolds made of electroactive TPU:P3TMA nanomembranes are potential candidates for tissue engineering biomedical applications.
JTD Keywords: Bioactive platform, Biodegradable blend, Collaged adsorption, Scaffolds, Tissue engineering, Ultrathin films
Vila, O. F., Martino, M. M., Nebuloni, L., Kuhn, G., Pérez-Amodio, S., Müller, R., Hubbell, J. A., Rubio, N., Blanco, J., (2014). Bioluminescent and micro-computed tomography imaging of bone repair induced by fibrin-binding growth factors Acta Biomaterialia 10, (10), 4377-4389
In this work we have evaluated the capacity of bone morphogenetic protein-2 (BMP-2) and fibrin-binding platelet-derived growth factor-BB (PDGF-BB) to support cell growth and induce bone regeneration using two different imaging technologies to improve the understanding of structural and organizational processes participating in tissue repair. Human mesenchymal stem cells from adipose tissue (hAMSCs) expressing two luciferase genes, one under the control of the cytomegalovirus (CMV) promoter and the other under the control of a tissue-specific promoter (osteocalcin or platelet endothelial cell adhesion molecule), were seeded in fibrin matrices containing BMP-2 and fibrin-binding PDGF-BB, and further implanted intramuscularly or in a mouse calvarial defect. Then, cell growth and bone regeneration were monitored by bioluminescence imaging (BLI) to analyze the evolution of target gene expression, indicative of cell differentiation towards the osteoblastic and endothelial lineages. Non-invasive imaging was supplemented with micro-computed tomography (μCT) to evaluate bone regeneration and high-resolution μCT of vascular casts. Results from BLI showed hAMSC growth during the first week in all cases, followed by a rapid decrease in cell number; as well as an increment of osteocalcin but not PECAM-1 expression 3 weeks after implantation. Results from μCT show that the delivery of BMP-2 and PDGF-BB by fibrin induced the formation of more bone and improves vascularization, resulting in more abundant and thicker vessels, in comparison with controls. Although the inclusion of hAMSCs in the fibrin matrices made no significant difference in any of these parameters, there was a significant increment in the connectivity of the vascular network in defects treated with hAMSCs.
JTD Keywords: Angiogenesis, Bioluminescence imaging, Bone regeneration, Fibrin, Mesenchymal stem cell
González-Vázquez, A., Planell, J. A., Engel, E., (2014). Extracellular calcium and CaSR drive osteoinduction in mesenchymal stromal cells Acta Biomaterialia 10, (6), 2824–2833
Bone is the main store of calcium and progenitor cells in the body. During the resorption process, the local calcium concentration reaches 8-40 mM, and the surrounding cells are exposed to these fluctuations in calcium. This stimulus is a signal that is detected through the calcium sensing receptor (CaSR), which modulates chemotactic and proliferative G protein-dependent signaling pathways. The objective of the present work is to evaluate the roles of extracellular calcium ([Ca2+]o) and the CaSR in osteoinduction. Rat bone marrow mesenchymal stromal cells (rBMSCs) were stimulated with 10 mM of Ca2+. Several experiments were conducted to demonstrate the effect of [Ca2+]o on chemotaxis, proliferation and differentiation on the osteoblastic lineage. It was found that [Ca2+]o induces rBMSCs to migrate and proliferate in a concentration-dependent manner. Real-time polymerase chain reaction and immunofluorescence also revealed that 10 mM Ca2+ stimulates overexpression of osteogenic markers in rBMSCs, including alkaline phosphatase (ALP), bone sialoprotein, collagen Ia1 and osteocalcin. Functional assays determining ALP activity and mineralization tests both corroborate the increased expression of these markers in rBMSCs stimulated with Ca2+. Moreover, CaSR blockage inhibited the cellular response to stimulation with high concentrations of [Ca2+]o, revealing that the CaSR is a key modulator of these cellular responses.
JTD Keywords: Calcium sensing receptor (CaSR), Extracellular calcium, Mesenchymal stromal cells (MSCs), Osteoinduction, Regenerative medicine
Dalmases, M., Torres, M., Márquez-Kisinousky, L., Almendros, I., Planas, A. M., Embid, C., Martínez-Garcia, M. A., Navajas, D., Farré, R., Montserrat, J. M., (2014). Brain tissue hypoxia and oxidative stress induced by obstructive apneas is different in young and aged rats
Sleep , 37, (7), 1249-1256
Study Objectives: To test the hypotheses that brain oxygen partial pressure (PtO2) in response to obstructive apneas changes with age and that it might lead to different levels of cerebral tissue oxidative stress. Design: Prospective controlled animal study. Setting: University laboratory. Participants: Sixty-four male Wistar rats: 32 young (3 mo old) and 32 aged (18 mo). Interventions: Protocol 1: Twenty-four animals were subjected to obstructive apneas (50 apneas/h, lasting 15 sec each) or to sham procedure for 50 min. Protocol 2: Forty rats were subjected to obstructive apneas or sham procedure for 4 h. Measurements and Results: Protocol 1: Real-time PtO2 measurements were performed using a fast-response oxygen microelectrode. During successive apneas cerebral cortex PtO2 presented a different pattern in the two age groups; there was a fast increase in young rats, whereas it remained without significant changes between the beginning and the end of the protocol in the aged group. Protocol 2: Brain oxidative stress assessed by lipid peroxidation increased after apneas in young rats (1.34 ± 0.17 nmol/mg of protein) compared to old ones (0.63 ± 0.03 nmol/mg), where a higher expression of antioxidant enzymes was observed. Conclusions: The results suggest that brain oxidative stress in aged rats is lower than in young rats in response to recurrent apneas, mimicking obstructive sleep apnea. This could be due to the different PtO2 response observed between age groups and the increased antioxidant expression in aged rats.
JTD Keywords: Aging, Animal model, Obstructive apnea, Oxidative stress, Tissue oxygenation, antioxidant, glutathione disulfide, aged, animal experiment, animal model, animal tissue, apnea, arterial oxygen saturation, article, brain cortex, brain oxygen tension, brain tissue, controlled study, groups by age, hypoxia, lipid peroxidation, male, nonhuman, oxidative stress, pressure, priority journal, rat
Manca, M. L., Castangia, I., Matricardi, P., Lampis, S., Fernàndez-Busquets, X., Fadda, A. M., Manconi, M., (2014). Molecular arrangements and interconnected bilayer formation induced by alcohol or polyalcohol in phospholipid vesicles Colloids and Surfaces B: Biointerfaces 117, 360-367
A self-assembled hybrid phospholipid vesicular system containing various penetration enhancers - ethanol, Transcutol and propylenglycol - was prepared and characterized. The effects of the different alcohol or polyalcohols structure and their concentration on the features of the assembled vesicles were evaluated using a combination of different techniques, including cryo-transmission electron microscopy, laser light scattering, differential scanning calorimetry, small- and wide-angle X-ray scattering and rheological analysis. These techniques allow explaining the structural rearrangements of the bilayer assembly due to the alcohol or polyalcohol addition. X-ray scattering studies showed that such addition at the highest concentration (20%) allowed structure modification to oligolamellar vesicles and a bilayer transition to interdigitated phase. Rheological studies confirmed the importance of alcohol or polyalcohol in the structuring dispersions probably due to a partial tilting of phosphatidylcholine acyl chains forming interdigitated and interconnected bilayer vesicles.
JTD Keywords: (Poly)alcohols, Cryo-TEM, DSC, Liposomes, Penetration Enhancer containing Vesicle (PEVs), Rheology, SAXS
Gramse, G., Kasper, M., Fumagalli, L., Gomila, G., Hinterdorfer, P., Kienberger, F., (2014). Calibrated complex impedance and permittivity measurements with scanning microwave microscopy Nanotechnology 25, (14), 145703 (8)
We present a procedure for calibrated complex impedance measurements and dielectric quantification with scanning microwave microscopy. The calibration procedure works in situ directly on the substrate with the specimen of interest and does not require any specific calibration sample. In the workflow tip-sample approach curves are used to extract calibrated complex impedance values and to convert measured S11 reflection signals into sample capacitance and resistance images. The dielectric constant of thin dielectric SiO2 films were determined from the capacitance images and approach curves using appropriate electrical tip-sample models and the εr value extracted at f = 19.81 GHz is in good agreement with the nominal value of εr ∼ 4. The capacitive and resistive material properties of a doped Si semiconductor sample were studied at different doping densities and tip-sample bias voltages. Following a simple serial model the capacitance-voltage spectroscopy curves are clearly related to the semiconductor depletion zone while the resistivity is rising with falling dopant density from 20 Ω to 20 kΩ. The proposed procedure of calibrated complex impedance measurements is simple and fast and the accuracy of the results is not affected by varying stray capacitances. It works for nanoscale samples on either fully dielectric or highly conductive substrates at frequencies between 1 and 20 GHz.
JTD Keywords: Complex impedance, Dielectric constant, Nanotechnology: calibration, Resistivity, Scanning microwave microscopy
Gomila, G., Gramse, G., Fumagalli, L., (2014). Finite-size effects and analytical modeling of electrostatic force microscopy applied to dielectric films Nanotechnology 25, (25), 255702 (11)
A numerical analysis of the polarization force between a sharp conducting probe and a dielectric film of finite lateral dimensions on a metallic substrate is presented with the double objective of (i) determining the conditions under which the film can be approximated by a laterally infinite film and (ii) proposing an analytical model valid in this limit. We show that, for a given dielectric film, the critical diameter above which the film can be modeled as laterally infinite depends not only on the probe geometry, as expected, but mainly on the film thickness. In particular, for films with intermediate to large thicknesses (>100 nm), the critical diameter is nearly independent from the probe geometry and essentially depends on the film thickness and dielectric constant following a relatively simple phenomenological expression. For films that can be considered as laterally infinite, we propose a generalized analytical model valid in the thin-ultrathin limit (<20-50 nm) that reproduces the numerical calculations and the experimental data. Present results provide a general framework under which accurate quantification of electrostatic force microscopy measurements on dielectric films on metallic substrates can be achieved.
JTD Keywords: Dielectric constant, Dielectric films, Electrostatic force microscopy, Quantification, Analytical models, Electric force microscopy, Electrostatic force, Film thickness, Permittivity, Probes, Substrates, Ultrathin films, Accurate quantifications, Electrostatic force microscopy, Finite size effect, Lateral dimension, Metallic substrate, Numerical calculation, Polarization forces, Quantification, Dielectric films
Uriarte, J. J., Nonaka, P. N., Campillo, N., Palma, R. K., Melo, E., de Oliveira, L. V. F., Navajas, D., Farré, R., (2014). Mechanical properties of acellular mouse lungs after sterilization by gamma irradiation
Journal of the Mechanical Behavior of Biomedical Materials , 40, 168-177
Lung bioengineering using decellularized organ scaffolds is a potential alternative for lung transplantation. Clinical application will require donor scaffold sterilization. As gamma-irradiation is a conventional method for sterilizing tissue preparations for clinical application, the aim of this study was to evaluate the effects of lung scaffold sterilization by gamma irradiation on the mechanical properties of the acellular lung when subjected to the artificial ventilation maneuvers typical within bioreactors. Twenty-six mouse lungs were decellularized by a sodium dodecyl sulfate detergent protocol. Eight lungs were used as controls and 18 of them were submitted to a 31kGy gamma irradiation sterilization process (9 kept frozen in dry ice and 9 at room temperature). Mechanical properties of acellular lungs were measured before and after irradiation. Lung resistance (RL) and elastance (EL) were computed by linear regression fitting of recorded signals during mechanical ventilation (tracheal pressure, flow and volume). Static (Est) and dynamic (Edyn) elastances were obtained by the end-inspiratory occlusion method. After irradiation lungs presented higher values of resistance and elastance than before irradiation: RL increased by 41.1% (room temperature irradiation) and 32.8% (frozen irradiation) and EL increased by 41.8% (room temperature irradiation) and 31.8% (frozen irradiation). Similar increases were induced by irradiation in Est and Edyn. Scanning electron microscopy showed slight structural changes after irradiation, particularly those kept frozen. Sterilization by gamma irradiation at a conventional dose to ensure sterilization modifies acellular lung mechanics, with potential implications for lung bioengineering.
JTD Keywords: Gamma irradiation, Lung bioengineering, Lung decellularization, Organ scaffold, Pulmonary mechanics, Decellularization, Gamma irradiation, Mouse lung, Pulmonary mechanics, dodecyl sulfate sodium, animal tissue, Article, artificial ventilation, bioengineering, bioreactor, compliance (physical), controlled study, freezing, gamma irradiation, lung, lung mechanics, lung resistance, male, mouse, nonhuman, room temperature, scanning electron microscopy, tissue scaffold, trachea pressure
Martinez, Dani, Teixidó, Mercè, Font, Davinia, Moreno, Javier, Tresanchez, Marcel, Marco, Santiago, Palacín, Jordi, (2014). Ambient intelligence application based on environmental measurements performed with an assistant mobile robot Sensors 14, (4), 6045-6055
This paper proposes the use of an autonomous assistant mobile robot in order to monitor the environmental conditions of a large indoor area and develop an ambient intelligence application. The mobile robot uses single high performance embedded sensors in order to collect and geo-reference environmental information such as ambient temperature, air velocity and orientation and gas concentration. The data collected with the assistant mobile robot is analyzed in order to detect unusual measurements or discrepancies and develop focused corrective ambient actions. This paper shows an example of the measurements performed in a research facility which have enabled the detection and location of an uncomfortable temperature profile inside an office of the research facility. The ambient intelligent application has been developed by performing some localized ambient measurements that have been analyzed in order to propose some ambient actuations to correct the uncomfortable temperature profile.
JTD Keywords: Ambient intelligence, Human thermal comfort, Robotic exploration
Tahirbegi, I. B., Alvira, M., Mir, M., Samitier, J., (2014). Simple and fast method for fabrication of endoscopic implantable sensor arrays Sensors 14, (7), 11416-11426
Here we have developed a simple method for the fabrication of disposable implantable all-solid-state ion-selective electrodes (ISE) in an array format without using complex fabrication equipment or clean room facilities. The electrodes were designed in a needle shape instead of planar electrodes for a full contact with the tissue. The needle-shape platform comprises 12 metallic pins which were functionalized with conductive inks and ISE membranes. The modified microelectrodes were characterized with cyclic voltammetry, scanning electron microscope (SEM), and optical interferometry. The surface area and roughness factor of each microelectrode were determined and reproducible values were obtained for all the microelectrodes on the array. In this work, the microelectrodes were modified with membranes for the detection of pH and nitrate ions to prove the reliability of the fabricated sensor array platform adapted to an endoscope.
JTD Keywords: Chemical sensors, Cyclic voltammetry, Electrochemistry, Endoscopy, Fabrication, Implants (surgical), Microelectrodes, Needles, Nitrates, Scanning electron microscopy, Biomedicine, Fabricated sensors, Fabrication equipment, Implantable devices, Implantable sensors, Optical interferometry, Planar electrode, Roughness factor, Ion selective electrodes
Nonaka, P. N., Uriarte, J. J., Campillo, N., Melo, E., Navajas, D., Farré, R., Oliveira, L. V. F., (2014). Mechanical properties of mouse lungs along organ decellularization by sodium dodecyl sulfate
Respiratory Physiology & Neurobiology , 200, 1-5
Lung decellularization is based on the use of physical, chemical, or enzymatic methods to break down the integrity of the cells followed by a treatment to extract the cellular material from the lung scaffold. The aim of this study was to characterize the mechanical changes throughout the different steps of lung decellularization process. Four lungs from mice (C57BL/6) were decellularized by using a conventional protocol based on sodium dodecyl sulfate. Lungs resistance (RL) and elastance (EL) were measured along decellularization steps and were computed by linear regression fitting of tracheal pressure, flow, and volume during mechanical ventilation. Transients differences found were more distinct in an intermediate step after the lungs were rinsed with deionized water and treated with 1% SDS, whereupon the percentage of variation reached approximately 80% for resistance values and 30% for elastance values. In conclusion, although a variation in extracellular matrix stiffness was observed during the decellularization process, this variation can be considered negligible overall because the resistance and elastance returned to basal values at the final decellularization step.
JTD Keywords: Lung bioengineering, Lung decellularization, Organ scaffold, dodecyl sulfate sodium, animal tissue, article, artificial ventilation, compliance (physical), controlled study, enzyme chemistry, extracellular matrix, female, flow, lung, lung decellularization, lung pressure, lung resistance, mouse, nonhuman, positive end expiratory pressure, priority journal, rigidity, tissue engineering, trachea pressure
Oller-Moreno, S., Pardo, A., Jimenez-Soto, J. M., Samitier, J., Marco, S., (2014). Adaptive Asymmetric Least Squares baseline estimation for analytical instruments SSD 2014 Proceedings
11th International Multi-Conference on Systems, Signals & Devices (SSD) , IEEE (Castelldefels-Barcelona, Spain) , 1569846703
Automated signal processing in analytical instrumentation is today required for the analysis of highly complex biomedical samples. Baseline estimation techniques are often used to correct long term instrument contamination or degradation. They are essential for accurate peak area integration. Some methods approach the baseline estimation iteratively, trying to ignore peaks which do not belong to the baseline. The proposed method in this work consists of a modification of the Asymmetric Least Squares (ALS) baseline removal technique developed by Eilers and Boelens. The ALS technique suffers from bias in the presence of intense peaks (in relation to the noise level). This is typical of diverse instrumental techniques such as Gas Chromatography-Mass Spectrometry (GC-MS) or Gas Chromatography-Ion Mobility Spectrometry (GC-IMS). In this work, we propose a modification (named psalsa) to the asymmetry weights of the original ALS method in order to better reject large peaks above the baseline. Our method will be compared to several versions of the ALS algorithm using synthetic and real GC signals. Results show that our proposal improves previous versions being more robust to parameter variations and providing more accurate peak areas.
JTD Keywords: Gas chromatography, Instruments, Radioactivity measurement, Signal processing, Analytical instrument, Analytical Instrumentation, Asymmetric least squares, Baseline estimation, Baseline removal, Gas chromatography-mass spectrometries (GC-MS), Instrumental techniques, Noise levels, Iterative methods
Fernandez, L., Marco, S., (2014). Calibration transfer between e-noses Signal Processing and Communications Applications Conference (SIU)
Signal Processing and Communications Applications Conference (SIU), 2014 22nd , IEEE (Trabzon, Turkey) , 650-653
Electronic nose is an instrument which is composed of gas sensor array and pattern recognition unit. It is generally used for classifying, identifying or quantifying the odors or volatile organic components for these commonly used devices, calibration transfer is an important issue because of differences in each instrument, sensor drift, changes in environmental conditions or background changes. Calibration transfer is a transfer of model between different instruments which have different conditions. In this study, calibration transfer is applied to the e-noses which have different temperature conditions. Also the results of the direct standardization, piecewise direct standardization and orthogonal signal correction which are different calibration methods were compared. The results of the piecewise direct standardization method are more successful than the other methods for the dataset which is used in this study.
JTD Keywords: Calibration, Conferences, Electronic noses, Ethanol, Instruments, Signal processing, Standardization
Correa, L.S., Giraldo, B., Correa, R., Arini, P.D., Laciar, E., (2014). Estudio de la pausa espiratoria en pacientes con enfermedades obstructivas en proceso de desconexión de la ventilación mecánica IFMBE Proceedings
VI Latin American Congress on Biomedical Engineering (CLAIB 2014) , Springer (Paraná, Argentina) 49, 705-708
In this work, the flow signal Expiratory Pause (EP) temporal analysis is used in 18 patients with obstructive lung diseases going through spontaneous breathing trial at weaning process. The main objective was to identify the patients who were successfully disconnected (success group: 9 patients), and those who were not (failure and reintubated group: 9 patients). A variable selection stage was done by mean group comparison and step wise variable inclusion, leading to a 3 parameters set: EP time median; cycle time mean; and median absolute deviation of the EP maxima local number. Next, this set was used in a classifier based on linear discriminant analysis, which results in 17 patients (94.4%) correctly classified, with 88.9% of specificity (Sp) and 100% of sensitivity (Se). Finally, applying the leave-one-out cross validation method, results were 88.9% of correctly classified patients (Sp=77.8% and Se=100%). In conclusion, the proposed parameters showed a good performance and could be used to help therapists to wean patients with obstructive diseases.
JTD Keywords: Chronic Obstructive Pulmonary Disease (COPD), Weaning, Mechanical ventilation, Expiratory pause
Vaca, R., Aranda, J., (2014). Triangular-fan-based algorithm for computing the closure conditions of planar linkages Advanced Numerical Methods IV
11th World Congress on Computational Mechanics (WCCM XI) 5th European Conference on Computational Mechanics (ECCM V) 6th European Conference on Computational Fluid Dynamics (ECFD VI) , CIMNE (Barcelona, Spain) , 1-2
The position analysis of a planar mechanism is based on obtaining the roots of its characteristic polynomial. In general, this polynomial is the result of a system of kinematic equations which they are derived from closure condition of the mechanism, widely known as independent kinematic loop equations or loop closure equations . This way of solving the position analysis of kinematic chains introduces complex variable eliminations, and in general trigonometric substitutions. Recently, the use of methods based on bilateration to solve the position analysis, has been shown to avoid these variable eliminations and trigonometric substitutions in planar mechanism. In this work it is shown how this method based on bilateration can be use to automatically generate closure conditions of a planar mechanism.
JTD Keywords: Position analysis, Bilateration, Rigidity, Isomorphism, Kinematic
Lozano-Garcia, M., Fiz, J. A., Jané, R., (2014). Analysis of normal and continuous adventitious sounds for the assessment of asthma IFMBE Proceedings
XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013 (ed. Roa Romero, Laura M.), Springer International Publishing (London, UK) 41, 981-984
Assessment of asthma is a difficult procedure which is based on the correlation of multiple factors. A major component in the diagnosis of asthma is the assessment of BD response, which is performed by traditional spirometry. In this context, the analysis of respiratory sounds (RS) provides relevant and complementary information about the function of the respiratory system. In particular, continuous adventitious sounds (CAS), such as wheezes, contribute to assess the severity of patients with obstructive diseases. On the other hand, the intensity of normal RS is dependent on airflow level and, therefore, it changes depending on the level of obstruction. This study proposes a new approach to RS analysis for the assessment of asthmatic patients, by combining the quantification of CAS and the analysis of the changes in the normal sound intensity-airflow relationship. According to results obtained from three patients with different characteristics, the proposed technique seems more sensitive and promising for the assessment of asthma.
JTD Keywords: Asthma, Bronchodilator response, Continuous adventitious sound, Respiratory sound intensity, Wheezes
Pérez-Amodio, Soledad, Engel, Elisabeth, (2014). Bone biology and Regeneration
Bio-Ceramics with Clinical Applications (ed. Vallet-Regí, M.), John Wiley & Sons, Ltd (Chichester, UK) , 315-342
Each bone of the skeleton constantly undergoes modeling during life to help it to adapt to changing biomechanical forces as well as remodeling to remove old bone and replace it with new, mechanically stronger bone to help preserve bone strength. Bone remodeling involves the removal of mineralized bone by osteoclasts, followed by the formation of bone matrix through the osteoblasts that subsequently become mineralized. All these assets make bone a suitable model for regeneration. Bone tissue can be grossly divided into inorganic mineral material (mostly HA), and organic material from cells and the extracellular matrix. This chapter outlines some of the bone diseases such as osteoporosis and Paget's disease. Bone can be considered as a biphasic composite material, with two phases: one the mineral and the other collagen. This combination confers better mechanical properties on the tissue than each component itself.
JTD Keywords: Bone biology, Bone cells, Bone diseases, Bone extracellular matrix, Bone mechanics, Bone remodeling, Bone tissue regeneration, Skeleton
Castaño, Oscar, Planell, Josep A., (2014). Cements
Bio-Ceramics with Clinical Applications (ed. Vallet-Regí, M.), John Wiley & Sons, Ltd (Chichester, UK) , 193-247
Calcium phosphate cements (CPCs) were meant to produce hydroxyapatite (HA), which is the calcium phosphate that usually results when the cements are mixed with or immersed in aqueous media. The golden age of CPCs was in the late 1990s and the beginning of the 21st century, when they were presented as promising bone substitutes and drug delivery systems. The different reactions that take part in the cement self-setting process depend on many experimental factors – the composition of the cement, the stability of the different components, pH, liquid-to-powder ratio (LPR), and temperature, among others. CPCs have demonstrated fair efficiency for bone regeneration. Cements have gradually been embraced in the wider field of composites by hybridizing their compositions in order that they may adapt to the new trends.
JTD Keywords: Calcium phosphate cements (CPCs), Cements, Hydroxyapatite (HA), Liquid-to-powder ratio (LPR)
Oliva, A. M., Homs, A., Torrents, E., Juarez, A., Samitier, J., (2014). Effect of electric field and temperature in E.Coli viability IFMBE Proceedings
XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013 (ed. Roa Romero, Laura M.), Springer (Seville, Spain) 41, 1833-1836
Electromagnetic Fields are increasingly used to manipulate bacteria. However, there is no systematic and definitive study on how the different electric parameters change bacteria viability. Here we present preliminary data on the effect of electric field intensity and temperature applica- tion. E. Coli colonies have been exposed to different voltages at 1MHz during 5 minutes by means of a custom-made micro- fluidic device. Results show that E.Coli survival rate is already reduced by applying field intensities as low as 220V/cm during 5 minutes. The use of stronger fields resulted in death rates increase also. Viability of survived bacteria was maintained. On the other hand, temperature has shown a synergistic effect with voltage. When temperature is increased results seem to indicate stronger sensitivity of cells to the electric field. It is necessary to continue studying the contribution of other para- meters as intensity, time, frequency or concentration, to study further synergies.
JTD Keywords: E. Coli, Electromagnetic Field, Temperature, Viability
Vedula, Sri Ram Krishna, Ravasio, Andrea, Anon, Ester, Chen, Tianchi, Peyret, G., Ashraf, Mohammed, Ladoux, Benoit, (2014). Microfabricated environments to study collective cell behaviors
Methods in Cell Biology (ed. Piel, M., Théry, M.), Academic Press 120, 235-252
Abstract Coordinated cell movements in epithelial layers are essential for proper tissue morphogenesis and homeostasis. Microfabrication techniques have proven to be very useful for studies of collective cell migration in vitro. In this chapter, we briefly review the use of microfabricated substrates in providing new insights into collective cell behaviors. We first describe the development of micropatterned substrates to study the influence of geometrical constraints on cell migration and coordinated movements. Then, we present an alternative method based on microfabricated pillar substrates to create well-defined gaps within cell sheets and study gap closure. We also provide a discussion that presents possible pitfalls and sheds light onto the important parameters that allow the study of long-term cell culture on substrates of well-defined geometries.
JTD Keywords: Microfabricated substrates, Microcontact printing, Collective cell behavior, Geometrical constraints, Epithelial gap closure
del Moral Zamora, B., Azpeitia, J. M. Á, Farrarons, J. C., Català, P. L. M., Corbera, A. H., Juárez, A., Samitier, J., (2014). Towards point-of-use dielectrophoretic methods: A new portable multiphase generator for bacteria concentration IFMBE Proceedings
XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013 (ed. Roa Romero, Laura M.), Springer International Publishing (London, UK) 41, 856-859
This manuscript presents portable and low cost electronic system for specific point-of-use dielectrophoresis applications. The system is composed of two main modules: a) a multiphase generator based on a Class E amplifier, which provides 4 sinusoidal signals (0º, 90º, 180º, 270º) at 1 MHz with variable output voltage up to 10 Vpp (Vm) and an output driving current of 1 A; and b) a dielectrophoresis-based microfluidic chip containing two interdigitated electrodes. The system has been validated by concentrating Escherichia Coli at 1 MHz while applying a continuous flow of 5 μL/min. Device functionalities were verified under different conditions achieving a 83% trapping efficiency in the best case.
JTD Keywords: Cell Concentrator, Class E amplifier, Dielectrophoresis, Electronics, Lab-on-a-chip (LOC), Low cost, Portable device
Izquierdo-Serra, Mercè, Trauner, Dirk, Llobet, Artur, Gorostiza, Pau, (2013). Optical modulation of neurotransmission using calcium photocurrents through the ion channel LiGluR Frontiers in Molecular Neuroscience 6, (Article 3), 1-6
A wide range of light-activated molecules (photoswitches and phototriggers) have been used to the study of computational properties of an isolated neuron by acting pre and postsynaptically. However, new tools are being pursued to elicit a presynaptic calcium influx that triggers the release of neurotransmitters, most of them based in calcium-permeable Channelrhodopsin-2 mutants. Here we describe a method to control exocytosis of synaptic vesicles through the use of a light-gated glutamate receptor (LiGluR), which has recently been demonstrated that supports secretion by means of calcium influx in chromaffin cells. Expression of LiGluR in hippocampal neurons enables reversible control of neurotransmission with light, and allows modulating the firing rate of the postsynaptic neuron with the wavelength of illumination. This method may be useful for the determination of the complex transfer function of individual synapses.
JTD Keywords: Calcium, Neurotransmission, Optogenetics, Neural coding, Firing rate, Optical control, Synaptic transfer function
Ordoñez-Gutiérrez, L., Torres, J. M., Gavín, R., Antón, M., Arroba-Espinosa, A. I., Espinosa, J. C., Vergara, C., del Río, J. A., Wandosell, F., (2013). Cellular prion protein modulates β-amyloid deposition in aged APP/PS1 transgenic mice
Neurobiology of Aging , 34, (12), 2793-2804
Alzheimer's disease and prion diseases are neuropathological disorders that are caused by abnormal processing and aggregation of amyloid and prion proteins. Interactions between amyloid precursor protein (APP) and PrPc proteins have been described at the neuron level. Accordingly to this putative interaction, we investigated whether β-amyloid accumulation may affect prion infectivity and, conversely, whether different amounts of PrP may affect β-amyloid accumulation. For this purpose, we used the APPswe/PS1dE9 mouse line, a common model of Alzheimer's disease, crossed with mice that either overexpress (Tga20) or that lack prion protein (knock-out) to generate mice that express varying amounts of prion protein and deposit β-amyloid. On these mouse lines, we investigated the influence of each protein on the evolution of both diseases. Our results indicated that although the presence of APP/PS1 and β-amyloid accumulation had no effect on prion infectivity, the accumulation of β-amyloid deposits was dependent on PrPc, whereby increasing levels of prion protein were accompanied by a significant increase in β-amyloid aggregation associated with aging.
JTD Keywords: Aging, Amyloid, Neurodegeneration, Prion, Signaling
Karpas, Z., Guamán, A. V., Pardo, A., Marco, S., (2013). Comparison of the performance of three ion mobility spectrometers for measurement of biogenic amines Analytica Chimica Acta 758, (3), 122-129
The performance of three different types of ion mobility spectrometer (IMS) devices: GDA2 with a radioactive ion source (Airsense, Germany), UV-IMS with a photo-ionization source (G.A.S. Germany) and VG-Test with a corona discharge source (3QBD, Israel) was studied. The gas-phase ion chemistry in the IMS devices affected the species formed and their measured reduced mobility values. The sensitivity and limit of detection for trimethylamine (TMA), putrescine and cadaverine were compared by continuous monitoring of a stream of air with a given concentration of the analyte and by measurement of headspace vapors of TMA in a sealed vial. Preprocessing of the mobility spectra and the effectiveness of multivariate curve resolution techniques (MCR-LASSO) improved the accuracy of the measurements by correcting baseline effects and adjusting for variations in drift time as well as enhancing the signal to noise ratio and deconvolution of the complex data matrix to their pure components. The limit of detection for measurement of the biogenic amines by the three IMS devices was between 0.1 and 1.2 ppm (for TMA with the VG-Test and GDA, respectively) and between 0.2 and 0.7 ppm for putrescine and cadaverine with all three devices. Considering the uncertainty in the LOD determination there is almost no statistically significant difference between the three devices although they differ in their operating temperature, ionization method, drift tube design and dopant chemistry. This finding may have general implications on the achievable performance of classic IMS devices.
JTD Keywords: Biogenic amines, Comparison of performance, Ion mobility spectrometry, Sensitivity, Signal processing, Vapor concentration
Perez, R. A., Altankov, G., Jorge-Herrero, E., Ginebra, M. P., (2013). Micro- and nanostructured hydroxyapatite-collagen microcarriers for bone tissue-engineering applications Journal of Tissue Engineering and Regenerative Medicine 7, (5), 353-361
Novel hydroxyapatite (HA)-collagen microcarriers (MCs) with different micro/nanostructures were developed for bone tissue-engineering applications. The MCs were fabricated via calcium phosphate cement (CPC) emulsion in oil. Collagen incorporation in the liquid phase of the CPC resulted in higher MC sphericity. The MCs consisted of a porous network of entangled hydroxyapatite crystals, formed as a result of the CPC setting reaction. The addition of collagen to the MCs, even in an amount as small as 0.8wt%, resulted in an improved interaction with osteoblast-like Saos-2 cells. The micro/nanostructure and the surface texture of the MCs were further tailored by modifying the initial particle size of the CPC. A synergistic effect between the presence of collagen and the nanosized HA crystals was found, resulting in significantly enhanced alkaline phosphatase activity on the collagen-containing nanosized HA MCs.
JTD Keywords: Bone regeneration, Calcium phosphate cement, Cell response, Collagen, Hydroxyapatite, Microcarrier
Llorens, F., Carulla, P., Villa, A., Torres, J. M., Fortes, P., Ferrer, Isidro, Del Río, J. A., (2013). PrPC regulates epidermal growth factor receptor function and cell shape dynamics in Neuro2a cells
Journal of Neurochemistry , 127, (1), 124-138
The prion protein (PrP) plays a key role in prion disease pathogenesis. Although the misfolded and pathologic variant of this protein (PrPSC) has been studied in depth, the physiological role of PrPC remains elusive and controversial. PrPC is a cell-surface glycoprotein involved in multiple cellular functions at the plasma membrane, where it interacts with a myriad of partners and regulates several intracellular signal transduction cascades. However, little is known about the gene expression changes modulated by PrPC in animals and in cellular models. In this article, we present PrPC-dependent gene expression signature in N2a cells and its implication in the most overrepresented functions: cell cycle, cell growth and proliferation, and maintenance of cell shape. PrPC over-expression enhances cell proliferation and cell cycle re-entrance after serum stimulation, while PrPC silencing slows down cell cycle progression. In addition, MAP kinase and protein kinase B (AKT) pathway activation are under the regulation of PrPC in asynchronous cells and following mitogenic stimulation. These effects are due in part to the modulation of epidermal growth factor receptor (EGFR) by PrPC in the plasma membrane, where the two proteins interact in a multimeric complex. We also describe how PrPC over-expression modulates filopodia formation by Rho GTPase regulation mainly in an AKT-Cdc42-N-WASP-dependent pathway.
JTD Keywords: Cell signaling, Cellular prion protein, Filopodia, Gene expression, Microarray, Proliferation
Fonollosa, Jordi, Fernérndez, Luis, Huerta, Ramón, Gutiérrez-Gálvez, Agustín, Marco, Santiago, (2013). Temperature optimization of metal oxide sensor arrays using Mutual Information Sensors and Actuators B: Chemical Elsevier 187, (0), 331-339
The sensitivity and selectivity of metal oxide (MOX) gas sensors change significantly when the sensors operate at different temperatures. While previous investigations have presented systematic approaches to optimize the operating temperature of a single MOX sensor, in this paper we present a methodology to select the optimal operating temperature of all the MOX sensors constituent of a gas sensor array based on the multivariate response of all the sensing elements. Our approach estimates a widely used Information Theory measure, the so-called Mutual Information (MI), which quantifies the amount of information that the state of one random variable (response of the gas sensor array) can provide from the state of another random variable representing the gas quality. More specifically, our methodology builds sensor models from experimental data to solve the technical problem of populating the joint probability distribution for the MI estimation. We demonstrate the relevance of our approach by maximizing the MI and selecting the best operating temperatures of a four-sensor array sampled at 94 different temperatures to optimize the discrimination task of ethanol, acetic acid, 2-butanone, and acetone. In addition to being applicable in principle to sensor arrays of any size, our approach gives precise information on the ability of the system to discriminate odors according to the temperature of the MOX sensors, for either the optimal set of temperatures or the temperatures that may render inefficient operation of the system itself.
JTD Keywords: MOX gas sensor, Temperature optimization, Limit of detection, Mutual Information, E-nose, Sensor array, Information Theory, Chemical sensing
Sánchez-Danes, A., Benzoni, P., Memo, M., Dell'Era, P., Raya, A., Consiglio, A., (2013). Induced pluripotent stem cell-based studies of Parkinson's disease: Challenges and promises
CNS and Neurological Disorders - Drug Targets , 12, (8), 1114-1127
A critical step in the development of effective therapeutics to treat Parkinson's disease (PD) is the identification of molecular pathogenic mechanisms underlying this chronically progressive neurodegenerative disease. However, while animal models have provided valuable information about the molecular basis of PD, the lack of faithful cellular and animal models that recapitulate human pathophysiology is delaying the development of new therapeutics. The reprogramming of somatic cells to induced pluripotent stem cells (iPSC) using delivery of defined combinations of transcription factors is a groundbreaking discovery that opens great opportunities for modeling human diseases, including PD, since iPSC can be generated from patients and differentiated into disease-relevant cell types, which would capture the patients' genetic complexity. Furthermore, human iPSC-derived neuronal models offer unprecedented access to early stages of the disease, allowing the investigation of the events that initiate the pathologic process in PD. Recently, human iPSC-derived neurons from patients with familial and sporadic PD have been generated and importantly they recapitulate some PD-related cell phenotypes, including abnormal α-synuclein accumulation in vitro, and alterations in the autophagy machinery. This review highlights the current PD iPSC-based models and discusses the potential future research directions of this field.
JTD Keywords: Human cellular model, Induced pluripotent stem cells, Neurodegenerative disease, Parkinson's disease
Dols-Perez, A., Sisquella, X., Fumagalli, L., Gomila, G., (2013). Optical visualization of ultrathin mica flakes on semitransparent gold substrates Nanoscale Research Letters 8, (1), 1-5
We show that optical visualization of ultrathin mica flakes on metallic substrates is viable using semitransparent gold as substrates. This enables to easily localize mica flakes and rapidly estimate their thickness directly on gold substrates by conventional optical reflection microscopy. We experimentally demonstrate it by comparing optical images with atomic force microscopy images of mica flakes on semitransparent gold. Present results open the possibility for simple and rapid characterization of thin mica flakes as well as other thin sheets directly on metallic substrates.
JTD Keywords: Atomic force, Conductive AFM, Gold substrates, Metallic substrate, Optical image, Optical reflection, Optical visualization, Ultrathin layers, Atomic force microscopy, Geometrical optics, Gold, Mica, Optical microscopy, Substrates
Riggio, C., Nocentini, S., Catalayud, M. P., Goya, G. F., Cuschieri, A., Raffa, V., del Río, J. A., (2013). Generation of magnetized olfactory ensheathing cells for regenerative studies in the central and peripheral nervous tissue International Journal of Molecular Sciences 14, (6), 10852-10868
As olfactory receptor axons grow from the peripheral to the central nervous system (CNS) aided by olfactory ensheathing cells (OECs), the transplantation of OECs has been suggested as a plausible therapy for spinal cord lesions. The problem with this hypothesis is that OECs do not represent a single homogeneous entity, but, instead, a functionally heterogeneous population that exhibits a variety of responses, including adhesion and repulsion during cell-matrix interactions. Some studies report that the migratory properties of OECs are compromised by inhibitory molecules and potentiated by chemical gradients. In this paper, we report a system based on modified OECs carrying magnetic nanoparticles as a proof of concept experiment enabling specific studies aimed at exploring the potential of OECs in the treatment of spinal cord injuries. Our studies have confirmed that magnetized OECs (i) survive well without exhibiting stress-associated cellular responses; (ii) in vitro, their migration can be modulated by magnetic fields; and (iii) their transplantation in organotypic slices of spinal cord and peripheral nerve showed positive integration in the model. Altogether, these findings indicate the therapeutic potential of magnetized OECs for CNS injuries.
JTD Keywords: Magnetic nanoparticle, Nerve regeneration, Olfactory ensheathing cell, Organotypic culture
Malandrino, Andrea, Noailly, J., Lacroix, Damien, (2013). Regional annulus fibre orientations used as a tool for the calibration of lumbar intervertebral disc finite element models
Computer Methods in Biomechanics and Biomedical Engineering , 16, (9), 923-928
The collagen network of the annulus fibrosus largely controls the functional biomechanics of the lumbar intervertebral discs (IVDs). Quantitative anatomical examinations have shown bundle orientation patterns, possibly coming from regional adaptations of the annulus mechanics. This study aimed to show that the regional differences in annulus mechanical behaviour could be reproduced by considering only fibre orientation changes. Using the finite element method, a lumbar annulus was modelled as a poro-hyperelastic material in which fibres were represented by a direction-dependent strain energy density term. Fibre orientations were calibrated to reproduce the annulus tensile behaviours measured for four different regions: posterior outer, anterior outer, posterior inner and anterior inner. The back-calculated fibre angles and regional patterns as well as the global disc behaviour were comparable with anatomical descriptions reported in the literature. It was concluded that annulus fibre variations might be an effective tool to calibrate lumbar spine IVD and segment models.
JTD Keywords: Intervertebral disc, Annulus fibrosus, Model calibration, Fibre orientation
Sarlabous, L., Torres, A., Fiz, J. A., Morera, J., Jané, R., (2013). Index for estimation of muscle force from mechanomyography based on the Lempel-Ziv algorithm
Journal of Electromyography and Kinesiology , 23, (3), 548-557
The study of the amplitude of respiratory muscle mechanomyographic (MMG) signals could be useful in clinical practice as an alternative non-invasive technique to assess respiratory muscle strength. The MMG signal is stochastic in nature, and its amplitude is usually estimated by means of the average rectified value (ARV) or the root mean square (RMS) of the signal. Both parameters can be used to estimate MMG activity, as they correlate well with muscle force. These estimations are, however, greatly affected by the presence of structured impulsive noise that overlaps in frequency with the MMG signal. In this paper, we present a method for assessing muscle activity based on the Lempel-Ziv algorithm: the Multistate Lempel-Ziv (MLZ) index. The behaviour of the MLZ index was tested with synthesised signals, with various amplitude distributions and degrees of complexity, and with recorded diaphragm MMG signals. We found that this index, like the ARV and RMS parameters, is positively correlated with changes in amplitude of the diaphragm MMG components, but is less affected by components that have non-random behaviour (like structured impulsive noise). Therefore, the MLZ index could provide more information to assess the MMG-force relationship.
JTD Keywords: Diaphragm, Electromyography, Lempel-Ziv, Mechanomyography, Muscle force, Respiratory muscles
Garde, Ainara, Voss, Andreas, Caminal, Pere, Benito, Salvador, Giraldo, Beatriz F., (2013). SVM-based feature selection to optimize sensitivity-specificity balance applied to weaning
Computers in Biology and Medicine , 43, (5), 533-540
Classification algorithms with unbalanced datasets tend to produce high predictive accuracy over the majority class, but poor predictive accuracy over the minority class. This problem is very common in biomedical data mining. This paper introduces a Support Vector Machine (SVM)-based optimized feature selection method, to select the most relevant features and maintain an accurate and well-balanced sensitivity–specificity result between unbalanced groups. A new metric called the balance index (B) is defined to implement this optimization. The balance index measures the difference between the misclassified data within each class. The proposed optimized feature selection is applied to the classification of patients' weaning trials from mechanical ventilation: patients with successful trials who were able to maintain spontaneous breathing after 48 h and patients who failed to maintain spontaneous breathing and were reconnected to mechanical ventilation after 30 min. Patients are characterized through cardiac and respiratory signals, applying joint symbolic dynamic (JSD) analysis to cardiac interbeat and breath durations. First, the most suitable parameters (C+,C−,σ) are selected to define the appropriate SVM. Then, the feature selection process is carried out with this SVM, to maintain B lower than 40%. The best result is obtained using 6 features with an accuracy of 80%, a B of 18.64%, a sensitivity of 74.36% and a specificity of 82.42%.
JTD Keywords: Support vector machines, Balance index, Sensitivity-specificity balance, Cardiorespiratory interaction, Joint symbolic dynamics, Feature selection, Weaning procedure
Giraldo, B. F., Tellez, J. P., Herrera, S., Benito, S., (2013). Analysis of heart rate variability in elderly patients with chronic heart failure during periodic breathing CinC 2013
Computing in Cardiology Conference (CinC) , IEEE (Zaragoza, Spain) , 991-994
Assessment of the dynamic interactions between cardiovascular signals can provide valuable information that improves the understanding of cardiovascular control. Heart rate variability (HRV) analysis is known to provide information about the autonomic heart rate modulation mechanism. Using the HRV signal, we aimed to obtain parameters for classifying patients with and without chronic heart failure (CHF), and with periodic breathing (PB), non-periodic breathing (nPB), and Cheyne-Stokes respiration (CSR) patterns. An electrocardiogram (ECG) and a respiratory flow signal were recorded in 36 elderly patients: 18 patients with CHF and 18 patients without CHF. According to the clinical criteria, the patients were classified into the follow groups: 19 patients with nPB pattern, 7 with PB pattern, 4 with Cheyne-Stokes respiration (CSR), and 6 non-classified patients (problems with respiratory signal). From the HRV signal, parameters in the time and frequency domain were calculated. Frequency domain parameters were the most discriminant in comparisons of patients with and without CHF: PTot (p = 0.02), PLF (p = 0.022) and fpHF (p = 0.021). For the comparison of the nPB vs. CSR patients groups, the best parameters were RMSSD (p = 0.028) and SDSD (p = 0.028). Therefore, the parameters appear to be suitable for enhanced diagnosis of decompensated CHF patients and the possibility of developed periodic breathing and a CSR pattern.
JTD Keywords: cardiovascular system, diseases, electrocardiography, frequency-domain analysis, geriatrics, medical signal processing, patient diagnosis, pneumodynamics, signal classification, Cheyne-Stokes respiration patterns, ECG, autonomic heart rate modulation mechanism, cardiovascular control, cardiovascular signals, chronic heart failure, decompensated CHF patients, dynamic interaction assessment, elderly patients, electrocardiogram, enhanced diagnosis, frequency domain parameters, heart rate variability analysis, patient classification, periodic breathing, respiratory flow signal recording, Electrocardiography, Frequency modulation, Frequency-domain analysis, Heart rate variability, Senior citizens, Standards
Giraldo, B. F., Chaparro, J. A., Caminal, P., Benito, S., (2013). Characterization of the respiratory pattern variability of patients with different pressure support levels Engineering in Medicine and Biology Society (EMBC)
35th Annual International Conference of the IEEE , IEEE (Osaka, Japan) , 3849-3852
One of the most challenging problems in intensive care is still the process of discontinuing mechanical ventilation, called weaning process. Both an unnecessary delay in the discontinuation process and a weaning trial that is undertaken too early are undesirable. In this study, we analyzed respiratory pattern variability using the respiratory volume signal of patients submitted to two different levels of pressure support ventilation (PSV), prior to withdrawal of the mechanical ventilation. In order to characterize the respiratory pattern, we analyzed the following time series: inspiratory time, expiratory time, breath duration, tidal volume, fractional inspiratory time, mean inspiratory flow and rapid shallow breathing. Several autoregressive modeling techniques were considered: autoregressive models (AR), autoregressive moving average models (ARMA), and autoregressive models with exogenous input (ARX). The following classification methods were used: logistic regression (LR), linear discriminant analysis (LDA) and support vector machines (SVM). 20 patients on weaning trials from mechanical ventilation were analyzed. The patients, submitted to two different levels of PSV, were classified as low PSV and high PSV. The variability of the respiratory patterns of these patients were analyzed. The most relevant parameters were extracted using the classifiers methods. The best results were obtained with the interquartile range and the final prediction errors of AR, ARMA and ARX models. An accuracy of 95% (93% sensitivity and 90% specificity) was obtained when the interquartile range of the expiratory time and the breath duration time series were used a LDA model. All classifiers showed a good compromise between sensitivity and specificity.
JTD Keywords: autoregressive moving average processes, feature extraction, medical signal processing, patient care, pneumodynamics, signal classification, support vector machines, time series, ARX, autoregressive modeling techniques, autoregressive models with exogenous input, autoregressive moving average model, breath duration time series, classification method, classifier method, discontinuing mechanical ventilation, expiratory time, feature extraction, final prediction errors, fractional inspiratory time, intensive care, interquartile range, linear discriminant analysis, logistic regression analysis, mean inspiratory flow, patient respiratory volume signal, pressure support level, pressure support ventilation, rapid shallow breathing, respiratory pattern variability characterization, support vector machines, tidal volume, weaning trial, Analytical models, Autoregressive processes, Biological system modeling, Estimation, Support vector machines, Time series analysis, Ventilation
Hernando, D., Alcaine, A., Pueyo, E., Laguna, P., Orini, M., Arcentales, A., Giraldo, B., Voss, A., Bayes-Genis, A., Bailon, R., (2013). Influence of respiration in the very low frequency modulation of QRS slopes and heart rate variability in cardiomyopathy patients CinC 2013
Computing in Cardiology Conference (CinC) , IEEE (Zaragoza, Spain) , 117-120
This work investigates the very low frequency (VLF) modulation of QRS slopes and heart rate variability (HRV). Electrocardiogram (ECG) and respiratory flow signal were acquired from patients with dilated cardiomyopathy and ischemic cardiomyopathy. HRV as well as the upward QRS slope (IUS) and downward QRS slope (IDS) were extracted from the ECG. The relation between HRV and QRS slopes in the VLF band was measured using ordinary coherence in 5-minute segments. Partial coherence was then used to remove the influence that respiration simultaneously exerts on HRV and QRS slopes. A statistical threshold was determined, below which coherence values were considered not to represent a linear relation. 7 out of 276 segments belonging to 5 out of 29 patients for IUS and 10 segments belonging to 5 patients for IDS presented a VLF modulation in QRS slopes, HRV and respiration. In these segments spectral coherence was statistically significant, while partial coherence decreased, indicating that the coupling HRV and QRS slopes was related to respiration. 4 segments had a partial coherence value below the threshold for IUS, 3 segments for IDS. The rest of the segments also presented a notable decrease in partial coherence, but still above the threshold, which means that other non-linearly effects may also affect this modulation.
JTD Keywords: diseases, electrocardiography, feature extraction, medical signal processing, pneumodynamics, statistical analysis, ECG, QRS slopes, cardiomyopathy patients, dilated cardiomyopathy, electrocardiogram, feature extraction, heart rate variability, ischemic cardiomyopathy, ordinary coherence, partial coherence value, respiration, respiratory flow signal acquisition, spectral coherence, statistical threshold, time 5 min, very low frequency modulation, Coherence, Educational institutions, Electrocardiography, Frequency modulation, Heart rate variability
Gonzalez, H., Acevedo, H., Arizmendi, C., Giraldo, B. F., (2013). Methodology for determine the moment of disconnection of patients of the mechanical ventilation using discrete wavelet transform Complex Medical Engineering (CME)
2013 ICME International Conference , IEEE (Beijing, China) , 483-486
The process of weaning from mechanical ventilation is one of the challenges in intensive care units. 66 patients under extubation process (T-tube test) were studied: 33 patients with successful trials and 33 patients who failed to maintain spontaneous breathing and were reconnected. Each patient was characterized using 7 time series from respiratory signals, and for each serie was evaluated the discrete wavelet transform. It trains a neural network for discriminating between patients from the two groups.
JTD Keywords: discrete wavelet transforms, neural nets, patient treatment, pneumodynamics, time series, ventilation, T-tube test, discrete wavelet transform, extubation process, intensive care units, mechanical ventilation, moment of disconnection, neural network, patients, respiratory signals, spontaneous breathing, time series, weaning, Mechanical Ventilation, Neural Networks, Time series from respiratory signals, Wavelet Transform
Jané, R., Lazaro, J., Ruiz, P., Gil, E., Navajas, D., Farre, R., Laguna, P., (2013). Obstructive Sleep Apnea in a rat model: Effects of anesthesia on autonomic evaluation from heart rate variability measures CinC 2013
Computing in Cardiology Conference (CinC) , IEEE (Zaragoza, Spain) , 1011-1014
Rat model of Obstructive Sleep Apnea (OSA) is a realistic approach for studying physiological mechanisms involved in sleep. Rats are usually anesthetized and autonomic nervous system (ANS) could be blocked. This study aimed to assess the effect of anesthesia on ANS activity during OSA episodes. Seven male Sprague-Dawley rats were anesthetized intraperitoneally with urethane (1g/kg). The experiments were conducted applying airway obstructions, simulating 15s-apnea episodes for 15 minutes. Five signals were acquired: respiratory pressure and flow, SaO2, ECG and photoplethysmography (PPG). In total, 210 apnea episodes were studied. Normalized power spectrum of Pulse Rate Variability (PRV) was analyzed in the Low Frequency (LF) and High Frequency (HF) bands, for each episode in consecutive 15s intervals (before, during and after the apnea). All episodes showed changes in respiratory flow and SaO2 signal. Conversely, decreases in the amplitude fluctuations of PPG (DAP) were not observed. Normalized LF presented extremely low values during breathing (median=7,67%), suggesting inhibition of sympathetic system due to anesthetic effect. Subtle increases of LF were observed during apnea. HRV and PPG analysis during apnea could be an indirect tool to assess the effect and deep of anesthesia.
JTD Keywords: electrocardiography, fluctuations, medical disorders, medical signal detection, medical signal processing, neurophysiology, photoplethysmography, pneumodynamics, sleep, ECG, SaO2 flow, SaO2 signal, airway obstructions, amplitude fluctuations, anesthesia effects, anesthetized nervous system, autonomic evaluation, autonomic nervous system, breathing, heart rate variability, high-frequency bands, low-frequency bands, male Sprague-Dawley rats, normalized power spectrum, obstructive sleep apnea, photoplethysmography, physiological mechanisms, pulse rate variability, rat model, respiratory flow, respiratory pressure, signal acquisition, sympathetic system inhibition, time 15 min, time 15 s, Abstracts, Atmospheric modeling, Computational modeling, Electrocardiography, Rats, Resonant frequency
Giraldo, B. F., Tellez, J. P., Herrera, S., Benito, S., (2013). Study of the oscillatory breathing pattern in elderly patients Engineering in Medicine and Biology Society (EMBC)
35th Annual International Conference of the IEEE , IEEE (Osaka, Japan) , 5228-5231
Some of the most common clinical problems in elderly patients are related to diseases of the cardiac and respiratory systems. Elderly patients often have altered breathing patterns, such as periodic breathing (PB) and Cheyne-Stokes respiration (CSR), which may coincide with chronic heart failure. In this study, we used the envelope of the respiratory flow signal to characterize respiratory patterns in elderly patients. To study different breathing patterns in the same patient, the signals were segmented into windows of 5 min. In oscillatory breathing patterns, frequency and time-frequency parameters that characterize the discriminant band were evaluated to identify periodic and non-periodic breathing (PB and nPB). In order to evaluate the accuracy of this characterization, we used a feature selection process, followed by linear discriminant analysis. 22 elderly patients (7 patients with PB and 15 with nPB pattern) were studied. The following classification problems were analyzed: patients with either PB (with and without apnea) or nPB patterns, and patients with CSR versus PB, CSR versus nPB and PB versus nPB patterns. The results showed 81.8% accuracy in the comparisons of nPB and PB patients, using the power of the modulation peak. For the segmented signal, the power of the modulation peak, the frequency variability and the interquartile ranges provided the best results with 84.8% accuracy, for classifying nPB and PB patients.
JTD Keywords: cardiovascular system, diseases, feature extraction, geriatrics, medical signal processing, oscillations, pneumodynamics, signal classification, time-frequency analysis, Cheyne-Stokes respiration, apnea, cardiac systems, chronic heart failure, classification problems, discriminant band, diseases, elderly patients, feature selection process, frequency variability, interquartile ranges, linear discriminant analysis, nonperiodic breathing, oscillatory breathing pattern, periodic breathing, respiratory How signal, respiratory systems, signal segmentation, time 5 min, time-frequency parameters, Accuracy, Aging, Frequency modulation, Heart, Senior citizens, Time-frequency analysis
Diéguez, Lorena, Caballero, David, Calderer, Josep, Moreno, Mauricio, Martínez, Elena, Samitier, Josep, (2012). Optical gratings coated with thin Si3N4 layer for efficient immunosensing by optical waveguide lightmode spectroscopy
Biosensors , 2, (2), 114-126
New silicon nitride coated optical gratings were tested by means of Optical Waveguide Lightmode Spectroscopy (OWLS). A thin layer of 10 nm of transparent silicon nitride was deposited on commercial optical gratings by means of sputtering. The quality of the layer was tested by x-ray photoelectron spectroscopy and atomic force microscopy. As a proof of concept, the sensors were successfully tested with OWLS by monitoring the concentration dependence on the detection of an antibody-protein pair. The potential of the Si3N4 as functional layer in a real-time biosensor opens new ways for the integration of optical waveguides with microelectronics.
JTD Keywords: Silicon nitride, Optical gratings, Waveguide, Biosensor
Ginebra, M. P., Canal, C., Espanol, M., Pastorino, D., Montufar, E. B., (2012). Calcium phosphate cements as drug delivery materials Advanced Drug Delivery Reviews 64, (12), 1090-1110
Calcium phosphate cements are used as synthetic bone grafts, with several advantages, such as their osteoconductivity and injectability. Moreover, their low-temperature setting reaction and intrinsic porosity allow for the incorporation of drugs and active principles in the material. It is the aim of the present work to: a) provide an overview of the different approaches taken in the application of calcium phosphate cements for drug delivery in the skeletal system, and b) identify the most significant achievements. The drugs or active principles associated to calcium phosphate cements are classified in three groups, i) low molecular weight drugs; ii) high molecular weight biomolecules; and iii) ions.
JTD Keywords: Antibiotic, Bioceramic, Biomaterial, Bone regeneration, Calcium phosphate cement, Ceramic matrix, Growth factor, Hydroxyapatite, Ions, Protein
Sánchez-Danés, A., Richaud-Patin, Y., Carballo-Carbajal, I., Jiménez-Delgado, S., Caig, C., Mora, S., Di Guglielmo, C., Ezquerra, M., Patel, B., Giralt, A., Canals, J. M., Memo, M., Alberch, J., López-Barneo, J., Vila, M., Cuervo, A. M., Tolosa, E., Consiglio, A., Raya, A., (2012). Disease-specific phenotypes in dopamine neurons from human iPS-based models of genetic and sporadic Parkinson's disease EMBO Molecular Medicine 4, (5), 380-395
Induced pluripotent stem cells (iPSC) offer an unprecedented opportunity to model human disease in relevant cell types, but it is unclear whether they could successfully model age-related diseases such as Parkinson's disease (PD). Here, we generated iPSC lines from seven patients with idiopathic PD (ID-PD), four patients with familial PD associated to the G2019S mutation in the Leucine-Rich Repeat Kinase 2 (LRRK2) gene (LRRK2-PD) and four age- and sex-matched healthy individuals (Ctrl). Over long-time culture, dopaminergic neurons (DAn) differentiated from either ID-PD- or LRRK2-PD-iPSC showed morphological alterations, including reduced numbers of neurites and neurite arborization, as well as accumulation of autophagic vacuoles, which were not evident in DAn differentiated from Ctrl-iPSC. Further induction of autophagy and/or inhibition of lysosomal proteolysis greatly exacerbated the DAn morphological alterations, indicating autophagic compromise in DAn from ID-PD- and LRRK2-PD-iPSC, which we demonstrate occurs at the level of autophagosome clearance. Our study provides an iPSC-based in vitro model that captures the patients' genetic complexity and allows investigation of the pathogenesis of both sporadic and familial PD cases in a disease-relevant cell type.
JTD Keywords: Autophagy, Disease modeling, LRRK2 mutation, Neurodegeneration, Pluripotent stem cells
Nocentini, S., Reginensi, D., Garcia, S., Carulla, P., Moreno-Flores, Wandosell, F., Trepat, X., Bribian, A., Del Rí, (2012). Myelin-associated proteins block the migration of olfactory ensheathing cells: an in vitro study using single-cell tracking and traction force microscopy
Cellular and Molecular Life Sciences , 69, (10), 1689-1703
Newly generated olfactory receptor axons grow from the peripheral to the central nervous system aided by olfactory ensheathing cells (OECs). Thus, OEC transplantation has emerged as a promising therapy for spinal cord injuries and for other neural diseases. However, these cells do not present a uniform population, but instead a functionally heterogeneous population that exhibits a variety of responses including adhesion, repulsion, and crossover during cell–cell and cell–matrix interactions. Some studies report that the migratory properties of OECs are compromised by inhibitory molecules and potentiated by chemical gradients. Here, we demonstrated that rodent OECs express all the components of the Nogo receptor complex and that their migration is blocked by myelin. Next, we used cell tracking and traction force microscopy to analyze OEC migration and its mechanical properties over myelin. Our data relate the decrease of traction force of OEC with lower migratory capacity over myelin, which correlates with changes in the F-actin cytoskeleton and focal adhesion distribution. Lastly, OEC traction force and migratory capacity is enhanced after cell incubation with the Nogo receptor inhibitor NEP1-40.
JTD Keywords: Ensheathing glia, Traction force, microscopy, Migration, Myelin-associated inhibitors
Yang, Cheng, Lates, Vasilica, Prieto-Simón, Beatriz, Marty, Jean-Louis, Yang, Xiurong, (2012). Aptamer-DNAzyme hairpins for biosensing of Ochratoxin A Biosensors and Bioelectronics 32, (1), 208-212
We report an aptasensor for biosensing of Ochratoxin A (OTA) using aptamer-DNAzyme hairpin as biorecognition element. The structure of this engineered nucleic acid includes the horseradish peroxidase (HRP)-mimicking DNAzyme and the OTA specific aptamer sequences. A blocking tail captures a part of these sequences in the stem region of the hairpin. In the presence of OTA, the hairpin is opened due to the formation of the aptamer–analyte complex. As a result, self-assembly of the active HRP-mimicking DNAzyme occurs. The activity of this DNAzyme is linearly correlated with OTA concentration up to 10 nM, showing a limit of detection of 2.5 nM.
JTD Keywords: Ochratoxin A, Aptamer, G-quadruplex, DNAzyme, Hairpin
Gustavsson, J., Ginebra, M. P., Planell, J., Engel, E., (2012). Electrochemical microelectrodes for improved spatial and temporal characterization of aqueous environments around calcium phosphate cements Acta Biomaterialia 8, (1), 386-393
Calcium phosphate compounds can potentially influence cellular fate through ionic substitutions. However, to be able to turn such solution-mediated processes into successful directors of cellular response, a perfect understanding of the material-induced chemical reactions in situ is required. We therefore report on the application of home-made electrochemical microelectrodes, tested as pH and chloride sensors, for precise spatial and temporal characterization of different aqueous environments around calcium phosphate-based biomaterials prepared from α-tricalcium phosphate using clinically relevant liquid to powder ratios. The small size of the electrodes allowed for online measurements in traditionally inaccessible in vitro environments, such as the immediate material-liquid interface and the interior of curing bone cement. The kinetic data obtained has been compared to theoretical sorption models, confirming that the proposed setup can provide key information for improved understanding of the biochemical environment imposed by chemically reactive biomaterials.
JTD Keywords: Calcium phosphate, Hydroxyapatite, Ion sorption, Iridium oxide, Sensors, Animals, Biocompatible Materials, Bone Cements, Calcium Phosphates, Cells, Cultured, Chlorides, Electrochemical Techniques, Gold, Hydrogen-Ion Concentration, Hydroxyapatites, Iridium, Materials Testing, Microelectrodes, Powders, Silver, Silver Compounds, Water
McLenachan, S., Menchon, C., Raya, A., Consiglio, A., Edel, M. J., (2012). Cyclin A(1) is essential for setting the pluripotent state and reducing tumorigenicity of induced pluripotent stem cells
Stem Cells and Development , 21, (15), 2891-2899
The proper differentiation and threat of cancer rising from the application of induced pluripotent stem (iPS) cells are major bottlenecks in the field and are thought to be inherently linked to the pluripotent nature of iPS cells. To address this question, we have compared iPS cells to embryonic stem cells (ESCs), the gold standard of ground state pluripotency, in search for proteins that may improve pluripotency of iPS cells. We have found that when reprogramming somatic cells toward pluripotency, 1%-5% of proteins of 5 important cell functions are not set to the correct expression levels compared to ESCs, including mainly cell cycle proteins. We have shown that resetting cyclin A1 protein expression of early- passage iPS cells closer to the ground state pluripotent state of mouse ESCs improves the pluripotency and reduces the threat of cancer of iPS cells. This work is a proof of principle that reveals that setting expression of certain proteins correctly during reprogramming is essential for achieving ESC- state pluripotency. This finding would be of immediate help to those researchers in different fields of iPS cell work that specializes in cell cycle, apoptosis, cell adhesion, cell signaling, and cytoskeleton.
JTD Keywords: Self-renewal, IPS cells, Ground-state, C-MYC, Generation, Pathway, Disease, Mice, Link, P53
Penon, O., Novo, S., Duran, S., Ibanez, E., Nogues, C., Samitier, J., Duch, M., Plaza, J. A., Perez-Garcia, L., (2012). Efficient biofunctionalization of polysilicon barcodes for adhesion to the zona pellucida of mouse embryos
Bioconjugate Chemistry , 23, (12), 2392-2402
Cell tracking is an emergent area in nano-biotechnology, promising the study of individual cells or the identification of populations of cultured cells. In our approach, microtools designed for extracellular tagging are prepared, because using biofunctionalized polysilicon barcodes to tag cell membranes externally avoids the inconveniences of cell internalization. The crucial covalent biofunctionalization process determining the ultimate functionality was studied in order to find the optimum conditions to link a biomolecule to a polysilicon barcode surface using a self-assembled monolayer (SAM) as the connector. Specifically, a lectin (wheat germ agglutinin, WGA) was used because of its capacity to recognize some specific carbohydrates present on the surface of most mammalian cells. Self-assembled monolayers were prepared on polysilicon surfaces including aldehyde groups as terminal functions to study the suitability of their covalent chemical bonding to WGA. Some parameters, such as the polysilicon surface roughness or the concentration of WGA, proved to be crucial for successful biofunctionalization and bioactivity. The SAMs were characterized by contact angle measurements, time-of-flight secondary ion mass spectrometry (TOF-SIMS), laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS), and atomic force microscopy (AFM). The biofunctionalization step was also characterized by fluorescence microscopy and, in the case of barcodes, by adhesion experiments to the zona pellucida of mouse embryos. These experiments showed high barcode retention rates after 96 h of culture as well as high embryo viability to the blastocyst stage, indicating the robustness of the biofunctionalization and, therefore, the potential of these new microtools to be used for cell tagging.
JTD Keywords: Self-assembled monolayers, Wheat-germ-agglutinin, Protein immobilization strategies, Mass-spectrometry, Cell-surface, Petide, Binding, Identifications, Nanoparticles, Recognition
Caballero, D., Martinez, E., Bausells, J., Errachid, A., Samitier, J., (2012). Impedimetric immunosensor for human serum albumin detection on a direct aldehyde-functionalized silicon nitride surface Analytica Chimica Acta 720, 43-48
In this work we report the fabrication and characterization of a label-free impedimetric immunosensor based on a silicon nitride (Si 3N 4) surface for the specific detection of human serum albumin (HSA) proteins. Silicon nitride provides several advantages compared with other materials commonly used, such as gold, and in particular in solid-state physics for electronic-based biosensors. However, few Si 3N 4-based biosensors have been developed; the lack of an efficient and direct protocol for the integration of biological elements with silicon-based substrates is still one of its the main drawbacks. Here, we use a direct functionalization method for the direct covalent binding of monoclonal anti-HSA antibodies on an aldehyde-functionalized Si-p/SiO 2/Si 3N 4 structure. This methodology, in contrast with most of the protocols reported in literature, requires less chemical reagents, it is less time-consuming and it does not need any chemical activation. The detection capability of the immunosensor was tested by performing non-faradaic electrochemical impedance spectroscopy (EIS) measurements for the specific detection of HSA proteins. Protein concentrations within the linear range of 10 -13-10 -7M were detected, showing a sensitivity of 0.128ΩμM -1 and a limit of detection of 10 -14M. The specificity of the sensor was also addressed by studying the interferences with a similar protein, bovine serum albumin. The results obtained show that the antibodies were efficiently immobilized and the proteins detected specifically, thus, establishing the basis and the potential applicability of the developed silicon nitride-based immunosensor for the detection of proteins in real and more complex samples.
JTD Keywords: Aldehyde, Electrochemical impedance spectroscopy, Human serum albumin, Immunosensor, Silicon nitride, Bovine serum albumins, Chemical reagents, Complex samples, Covalent binding, Detection capability, Electrochemical impedance, Electrochemical impedance spectroscopy measurements, Functionalizations, Human serum albumins, Impedimetric immunosensors, Label free, Limit of detection, Linear range, Protein concentrations, Silicon-based, Specific detection, Aldehydes
Comelles, J., Hortigüela, V., Samitier, J., Martinez, E., (2012). Versatile gradients of covalently bound proteins on microstructured substrates Langmuir 28, (38), 13688-13697
In this work, we propose an easy method to produce highly tunable gradients of covalently bound proteins on topographically modified poly(methyl methacrylate). We used a rnicrofluidic approach to obtain linear gradients with high slope (0.5 pmol.cm(-2).mm(-1)), relevant at the single-cell level. These protein gradients were characterized using fluorescence microscopy and surface plasmon resonance. Both experimental results and theoretical modeling on the protein gradients generated have proved them to be highly reproducible, stable up to 7 days, and easily tunable. This method enables formation of versatile cell culture platforms combining both complex biochemical and physical cues in an attempt to approach in vitro cell culture methods to in vivo cellular microenvironments.
JTD Keywords: Cell-migration, Microfluidic channel, Surface, Streptavidin, Molecules, Topography, Mechanisms, Generation, Responses, Guidance
Valle-Delgado, J. J., Liepina, I., Lapidus, D., Sabaté, R., Ventura, S., Samitier, J., Fernàndez-Busquets, X., (2012). Self-assembly of human amylin-derived peptides studied by atomic force microscopy and single molecule force spectroscopy Soft Matter 8, (4), 1234-1242
The self-assembly of peptides and proteins into amyloid fibrils of nanometric thickness and up to several micrometres in length, a phenomenon widely observed in biological systems, has recently aroused a growing interest in nanotechnology and nanomedicine. Here we have applied atomic force microscopy and single molecule force spectroscopy to study the amyloidogenesis of a peptide derived from human amylin and of its reverse sequence. The spontaneous formation of protofibrils and their orientation along well-defined directions on graphite and DMSO-coated graphite substrates make the studied peptides interesting candidates for nanotechnological applications. The measured binding forces between peptides correlate with the number of hydrogen bonds between individual peptides inside the fibril structure according to molecular dynamics simulations.
JTD Keywords: Amyloid fibril, Amyloidogenesis, Binding forces, Fibril structure, Graphite substrate, Molecular dynamics simulations, Nanometrics, Protofibrils, Single molecule force spectroscopy, Spontaneous formation, Atomic force microscopy, Atomic spectroscopy, Graphite, Hydrogen bonds, Medical nanotechnology, Molecular dynamics, Molecular physics, Self assembly, Thickness measurement, Peptides
Juanola-Feliu, E., Colomer-Farrarons, J., Miribel-Català , P., Samitier, J., Valls-Pasola, J., (2012). Market challenges facing academic research in commercializing nano-enabled implantable devices for in-vivo biomedical analysis
Technovation , 32, (3-4), 193-204
This article reports on the research and development of a cutting-edge biomedical device for continuous in-vivo glucose monitoring. This entirely public-funded process of technological innovation has been conducted at the University of Barcelona within a context of converging technologies involving the fields of medicine, physics, chemistry, biology, telecommunications, electronics and energy. The authors examine the value chain and the market challenges faced by in-vivo implantable biomedical devices based on nanotechnologies. In so doing, they trace the process from the point of applied research to the final integration and commercialization of the product, when the social rate of return from academic research can be estimated. Using a case-study approach, the paper also examines the high-tech activities involved in the development of this nano-enabled device and describes the technology and innovation management process within the value chain conducted in a University-Hospital-Industry-Administration-Citizens framework. Here, nanotechnology is seen to represent a new industrial revolution, boosting the biomedical devices market. Nanosensors may well provide the tools required for investigating biological processes at the cellular level in vivo when embedded into medical devices of small dimensions, using biocompatible materials, and requiring reliable and targeted biosensors, high speed data transfer, safely stored data, and even energy autonomy.
JTD Keywords: Biomedical device, Diabetes, Innovation management, Nanobiosensor, Nanotechnology, Research commercialization, Technology transfer, Academic research, Applied research, Barcelona, Biocompatible materials, Biological process, Biomedical analysis, Biomedical devices, Cellular levels, Converging technologies, Glucose monitoring, High-speed data transfer, Implantable biomedical devices, Implantable devices, In-vivo, Industrial revolutions, Innovation management, Medical Devices, Nanobiosensor, Rate of return, Research and development, Technological innovation, Value chains, Biological materials, Biomedical engineering, Biosensors, Commerce, Data transfer, Earnings, Engineering education, Glucose, Implants (surgical), Industrial research, Innovation, Medical problems, Nanosensors, Nanotechnology, Technology transfer, Equipment
Guamán, Ana V., Carreras, Alba, Calvo, Daniel, Agudo, Idoya, Navajas, Daniel, Pardo, Antonio, Marco, Santiago, Farré, Ramon, (2012). Rapid detection of sepsis in rats through volatile organic compounds in breath
Journal of Chromatography B , 881-882, 76-82
Background: Sepsis is one of the main causes of death in adult intensive care units. The major drawbacks of the different methods used for its diagnosis and monitoring are their inability to provide fast responses and unsuitability for bedside use. In this study, performed using a rat sepsis model, we evaluate breath
analysis with Ion Mobility Spectrometry (IMS) as a fast, portable and non-invasive strategy. Methods: This study was carried out on 20 Sprague-Dawley rats. Ten rats were injected with lipopolysaccharide from Escherichia coli and ten rats were IP injected with regular saline. After a 24-h period, the rats were anaesthetized and their exhaled breaths were collected and measured with IMS and SPME-gas chromatography/mass spectrometry (SPME-GC/MS) and the data were analyzed with multivariate data processing techniques. Results: The SPME-GC/MS dataset processing showed 92% accuracy in the discrimination between the two groups, with a confidence interval of between 90.9% and 92.9%. Percentages for sensitivity and specificity were 98% (97.5–98.5%) and 85% (84.6–87.6%), respectively. The IMS database processing generated an accuracy of 99.8% (99.7–99.9%), a specificity of 99.6% (99.5–99.7%) and a sensitivity of 99.9% (99.8–100%). Conclusions: IMS involving fast analysis times, minimum sample handling and portable instrumentation can be an alternative for continuous bedside monitoring. IMS spectra require data processing with proper statistical models for the technique to be used as an alternative to other methods. These animal model results suggest that exhaled breath can be used as a point-of-care tool for the diagnosis and monitoring of sepsis.
JTD Keywords: Sepsis, Volatile organic compounds, Ion mobility spectrometer, Rat model, Bedside patient systems, Non-invasive detection
Gustavsson, J., Ginebra, M. P., Planell, J., Engel, E., (2012). Osteoblast-like cellular response to dynamic changes in the ionic extracellular environment produced by calcium-deficient hydroxyapatite
Journal of Materials Science-Materials in Medicine , 23, (10), 2509-2520
Solution-mediated reactions due to ionic substitutions are increasingly explored as a strategy to improve the biological performance of calcium phosphate-based materials. Yet, cellular response to well-defined dynamic changes of the ionic extracellular environment has so far not been carefully studied in a biomaterials context. In this work, we present kinetic data on how osteoblast-like SAOS-2 cellular activity and calcium-deficient hydroxyapatite (CDHA) influenced extracellular pH as well as extracellular concentrations of calcium and phosphate in standard in vitro conditions. Since cells were grown on membranes permeable to ions and proteins, they could share the same aqueous environment with CDHA, but still be physically separated from the material. In such culture conditions, it was observed that gradual material-induced adsorption of calcium and phosphate from the medium had only minor influence on cellular proliferation and alkaline phosphatase activity, but that competition for calcium and phosphate between cells and the biomaterial delayed and reduced significantly the cellular capacity to deposit calcium in the extracellular matrix. The presented work thus gives insights into how and to what extent solution-mediated reactions can influence cellular response, and this will be necessary to take into account when interpreting CDHA performance both in vitro and in vivo.
JTD Keywords: Alkaline-phosphatase activity, Saos-2 cells, In-vitro, bone mineralization, Biological basis, Differentiation, Culture, Matrix, Proliferation, Topography
Pomareda, Víctor, Guamán, Ana V., Mohammadnejad, Masoumeh, Calvo, Daniel, Pardo, Antonio, Marco, Santiago, (2012). Multivariate curve resolution of nonlinear ion mobility spectra followed by multivariate nonlinear calibration for quantitative prediction
Chemometrics and Intelligent Laboratory Systems , 118, 219-229
In this work, a new methodology to analyze spectra time-series obtained from ion mobility spectrometry (IMS) has been investigated. The proposed method combines the advantages of multivariate curve resolution-alternating least squares (MCR-ALS) for an optimal physical and chemical interpretation of the system (qualitative information) and a multivariate calibration technique such as polynomial partial least squares (poly-PLS) for an improved quantification (quantitative information) of new samples. Ten different concentrations of 2-butanone and ethanol were generated using a volatile generator based on permeation tubes. The different concentrations were measured with IMS. These data present a non-linear behaviour as substance concentration increases. Although MCR-ALS is based on a bilinear decomposition, non-linear behaviour can be modelled adding new components to the model. After spectral pre-processing, MCR-ALS was applied aiming to get information about the ionic species that appear in the drift tube and their evolution with the analyte concentration. By resolving the IMS data matrix, concentration profiles and pure spectra of the different ionic species have been obtained for both analytes. Finally, poly-PLS was used in order to build a calibration model using concentration profiles obtained from MCR-ALS for ethanol and 2-butanone. The results, with more than 99% of explained variance for both substances, show the feasibility of using MCR-ALS to resolve IMS datasets. Furthermore, similar or better prediction accuracy is achieved when concentration profiles from MCR-ALS are used to build a calibration model (using poly-PLS) compared to other standard univariate and multivariate calibration methodologies.
JTD Keywords: Ion Mobility Spectrometry, Multivariate Curve Resolution, Gas phase ion chemistry, Multivariate calibration
Azevedo, S., Diéguez, L., Carvalho, P., Carneiro, J. O., Teixeira, V., Martínez, Elena, Samitier, J., (2012). Deposition of ITO thin films onto PMMA substrates for waveguide based biosensing devices
Journal of Nano Research , 17, 75-83
Biosensors' research filed has clearly been changing towards the production of multifunctional and innovative design concepts to address the needs related with sensitivity and selectivity of the devices. More recently, waveguide biosensors, that do not require any label procedure to detect biomolecules adsorbed on its surface, have been pointed out as one of the most promising technologies for the production of biosensing devices with enhanced performance. Moreover the combination of optical and electrochemical measurements through the integration of transparent and conducting oxides in the multilayer structures can greatly enhance the biosensors' sensitivity. Furthermore, the integration of polymeric substrates may bring powerful advantages in comparison with silicon based ones. The biosensors will have a lower production costs being possible to disposable them after use ("one use sensor chip"). This research work represents a preliminary study about the influence of substrate temperature on the overall properties of ITO thin films deposited by DC magnetron sputtering onto 0,5 mm thick PMMA sheets.
JTD Keywords: ITO thin films, PMMA sheets, Waveguide biosensing devices, Biosensing devices, Conducting oxides, Dc magnetron sputtering, Electrochemical measurements, Enhanced performance, Innovative design, ITO thin films, Multilayer structures, Overall properties, PMMA sheets, Polymeric substrate, Production cost, Sensor chips, Silicon-based, Substrate temperature, Biosensors, Deposition, Design, Film preparation, Optical multilayers, Thin films, Vapor deposition, Waveguides, Substrates
Giraldo, B.F., Gaspar, B.W., Caminal, P., Benito, S., (2012). Analysis of roots in ARMA model for the classification of patients on weaning trials Engineering in Medicine and Biology Society (EMBC)
34th Annual International Conference of the IEEE , IEEE (San Diego, USA) , 698-701
One objective of mechanical ventilation is the recovery of spontaneous breathing as soon as possible. Remove the mechanical ventilation is sometimes more difficult that maintain it. This paper proposes the study of respiratory flow signal of patients on weaning trials process by autoregressive moving average model (ARMA), through the location of poles and zeros of the model. A total of 151 patients under extubation process (T-tube test) were analyzed: 91 patients with successful weaning (GS), 39 patients that failed to maintain spontaneous breathing and were reconnected (GF), and 21 patients extubated after the test but before 48 hours were reintubated (GR). The optimal model was obtained with order 8, and statistical significant differences were obtained considering the values of angles of the first four poles and the first zero. The best classification was obtained between GF and GR, with an accuracy of 75.3% on the mean value of the angle of the first pole.
JTD Keywords: Analytical models, Biological system modeling, Computational modeling, Estimation, Hospitals, Poles and zeros, Ventilation, Autoregressive moving average processes, Patient care, Patient monitoring, Pneumodynamics, Poles and zeros, Ventilation, ARMA model, T-tube test, Autoregressive moving average model, Extubation process, Mechanical ventilation, Optimal model, Patient classification, Respiratory flow signal, Roots, Spontaneous breathing, Weaning trials
Sarlabous, L., Torres, A., Fiz, J. A., Morera, J., Jané, R., (2012). Evaluation and adaptive attenuation of the cardiac vibration interference in mechanomyographic signals Engineering in Medicine and Biology Society (EMBC)
34th Annual International Conference of the IEEE , IEEE (San Diego, USA) , 3400-3403
The study of the mechanomyographic signal of the diaphragm muscle (MMGdi) is a promising technique in order to evaluate the respiratory muscles effort. The relationship between amplitude and frequency parameters of this signal with the respiratory effort performed during respiration is of great interest for researchers and physicians due to its diagnostic potentials. However, MMGdi signals are frequently contaminated by a cardiac vibration or mechanocardiographic (MCG) signal. An adaptive noise cancellation (ANC) can be used to reduce the MCG interference in the recorded MMGdi activity. In this paper, it is evaluated the proposed ANC scheme by means of a synthetic MMGdi signal with a controlled MCG interference. The Pearson's correlation coefficient (PCC) between both root mean square (RMS) and mean frequency (fm) of the synthetic MMGdi signal are considerably reduced with the presence of cardiac vibration noise (from 0.95 to 0.87, and from 0.97 to 0.76, respectively). With the ANC algorithm proposed the effect of the MCG noise on the amplitude and frequency of MMG parameters is reduced considerably (PCC of 0.93 and 0.97 for the RMS and fm, respectively). The ANC method proposed in this work is an interesting technique to attenuate the cardiac interference in respiratory MMG signals. Further investigation should be carried out to evaluate the performance of the ANC algorithm in real MMGdi signals.
JTD Keywords: Adaptive filters, Frequency modulation, Interference, Muscles, Noise cancellation, Vibrations, Cardiology, Medical signal processing, Muscle, Signal denoising, ANC algorithm, MCG interference, Pearson correlation coefficient, Adaptive noise cancellation, Cardiac vibration interference, Cardiac vibration noise, Diaphragm muscle, Mechanocardiographic signal, Mechanomyographic signals, Respiratory muscles effort
Chaparro, J.A., Giraldo, B.F., Caminal, P., Benito, S., (2012). Performance of respiratory pattern parameters in classifiers for predict weaning process Engineering in Medicine and Biology Society (EMBC)
34th Annual International Conference of the IEEE , IEEE (San Diego, USA) , 4349-4352
Weaning trials process of patients in intensive care units is a complex clinical procedure. 153 patients under extubation process (T-tube test) were studied: 94 patients with successful trials (group S), 38 patients who failed to maintain spontaneous breathing and were reconnected (group F), and 21 patients with successful test but that had to be reintubated before 48 hours (group R). The respiratory pattern of each patient was characterized through the following time series: inspiratory time (TI), expiratory time (TE), breathing cycle duration (TTot), tidal volume (VT), inspiratory fraction (TI/TTot), half inspired flow (VT/TI), and rapid shallow index (f/VT), where f is respiratory rate. Using techniques as autoregressive models (AR), autoregressive moving average models (ARMA) and autoregressive models with exogenous input (ARX), the most relevant parameters of the respiratory pattern were obtained. We proposed the evaluation of these parameters using classifiers as logistic regression (LR), linear discriminant analysis (LDA), support vector machines (SVM) and classification and regression tree (CART) to discriminate between patients from groups S, F and R. An accuracy of 93% (98% sensitivity and 82% specificity) has been obtained using CART classification.
JTD Keywords: Accuracy, Indexes, Logistics, Regression tree analysis, Support vector machines, Time series analysis, Autoregressive moving average processes, Medical signal processing, Pattern classification, Pneumodynamics, Regression analysis, Sensitivity, Signal classification, Support vector machines, Time series, SVM, T-tube testing, Autoregressive models-with-exogenous input, Autoregressive moving average models, Breathing cycle duration, Classification-and-regression tree, Expiratory time, Extubation process, Half inspired flow, Inspiratory fraction, Inspiratory time, Intensive care units, Linear discriminant analysis, Logistic regression, Rapid shallow index, Respiratory pattern parameter performance, Sensitivity, Spontaneous breathing, Support vector machines, Tidal volume, Time 48 hr, Time series, Weaning process classifiers
Garde, A., Giraldo, B.F., Jané, R., Latshang, T.D., Turk, A.J., Hess, T., Bosch, M-.M., Barthelmes, D., Hefti, J.P., Maggiorini, M., Hefti, U., Merz, T.M., Schoch, O.D., Bloch, K.E., (2012). Periodic breathing during ascent to extreme altitude quantified by spectral analysis of the respiratory volume signal Engineering in Medicine and Biology Society (EMBC)
34th Annual International Conference of the IEEE , IEEE (San Diego, USA) , 707-710
High altitude periodic breathing (PB) shares some common pathophysiologic aspects with sleep apnea, Cheyne-Stokes respiration and PB in heart failure patients. Methods that allow quantifying instabilities of respiratory control provide valuable insights in physiologic mechanisms and help to identify therapeutic targets. Under the hypothesis that high altitude PB appears even during physical activity and can be identified in comparison to visual analysis in conditions of low SNR, this study aims to identify PB by characterizing the respiratory pattern through the respiratory volume signal. A number of spectral parameters are extracted from the power spectral density (PSD) of the volume signal, derived from respiratory inductive plethysmography and evaluated through a linear discriminant analysis. A dataset of 34 healthy mountaineers ascending to Mt. Muztagh Ata, China (7,546 m) visually labeled as PB and non periodic breathing (nPB) is analyzed. All climbing periods within all the ascents are considered (total climbing periods: 371 nPB and 40 PB). The best crossvalidated result classifying PB and nPB is obtained with Pm (power of the modulation frequency band) and R (ratio between modulation and respiration power) with an accuracy of 80.3% and area under the receiver operating characteristic curve of 84.5%. Comparing the subjects from 1st and 2nd ascents (at the same altitudes but the latter more acclimatized) the effect of acclimatization is evaluated. SaO2 and periodic breathing cycles significantly increased with acclimatization (p-value <; 0.05). Higher Pm and higher respiratory frequencies are observed at lower SaO2, through a significant negative correlation (p-value <; 0.01). Higher Pm is observed at climbing periods visually labeled as PB with >; 5 periodic breathing cycles through a significant positive correlation (p-value <; 0.01). Our data demonstrate that quantification of the respiratory volum- signal using spectral analysis is suitable to identify effects of hypobaric hypoxia on control of breathing.
JTD Keywords: Frequency domain analysis, Frequency modulation, Heart, Sleep apnea, Ventilation, Visualization, Cardiology, Medical disorders, Medical signal processing, Plethysmography, Pneumodynamics, Sensitivity analysis, Sleep, Spectral analysis, Cheyne-Stokes respiration, Climbing periods, Dataset, Heart failure patients, High altitude PB, High altitude periodic breathing, Hypobaric hypoxia, Linear discriminant analysis, Pathophysiologic aspects, Physical activity, Physiologic mechanisms, Power spectral density, Receiver operating characteristic curve, Respiratory control, Respiratory frequency, Respiratory inductive plethysmography, Respiratory pattern, Respiratory volume signal, Sleep apnea, Spectral analysis, Spectral parameters
Colomer-Farrarons, J., Miribel-Català , P., Juanola-Feliu, E., Samitier, J., (2012). A proof-of-concept of a multi-harvesting power source in a low-voltage CMOS technology IEEE Computer Society
2012 IEEE International Conference on Green Computing and Communications, Conference on Internet of Things, and Conference on Cyber, Physical and Social Computing , IEEE (Besancon, France) , 655-659
This paper presents a view of the state of the art in the field of energy harvesting solutions focused on discrete to integrated solutions in the range of low-power generation, from a few microwatts to several nanowatts. A view of commercial solutions to the new trends in new self-powered smart sensors operating without the use of any kind of battery will be presented. A specific solution developed in our laboratory will be used as an example of application.
JTD Keywords: Electric power generation, Energy scavenging, Low-power electronics, Power conditioning
Mesquita, J., Poree, F., Carrault, G., Fiz, J. A., Abad, J., Jané, R., (2012). Respiratory and spontaneous arousals in patients with Sleep Apnea Hypopnea Syndrome Engineering in Medicine and Biology Society (EMBC)
34th Annual International Conference of the IEEE , IEEE (San Diego, USA) , 6337-6340
Sleep in patients with Sleep Apnea-Hypopnea Syndrome (SAHS) is frequently interrupted with arousals. Increased amounts of arousals result in shortening total sleep time and repeated sleep-arousal change can result in sleep fragmentation. According to the American Sleep Disorders Association (ASDA) an arousal is a marker of sleep disruption representing a detrimental and harmful feature for sleep. The nature of arousals and its role on the regulation of the sleep process raises controversy and has sparked the debate in the last years. In this work, we analyzed and compared the EEG spectral content of respiratory and spontaneous arousals on a database of 45 SAHS subjects. A total of 3980 arousals (1996 respiratory and 1984 spontaneous) were analyzed. The results showed no differences between the spectral content of the two kinds of arousals. Our findings raise doubt as to whether these two kinds of arousals are truly triggered by different organic mechanisms. Furthermore, they may also challenge the current beliefs regarding the underestimation of the importance of spontaneous arousals and their contribution to sleep fragmentation in patients suffering from SAHS.
JTD Keywords: Adaptive filters, Correlation, Databases, Electroencephalography, Hospitals, Sleep apnea, Electroencephalography, Medical signal processing, Pneumodynamics, Sleep, EEG spectral content, Organic mechanism, Respiratory, Sleep apnea hypopnea syndrome, Sleep fragmentation, Spectral content, Spontaneous arousal
Hernansanz, A., Amat, J., Casals, A., (2012). Virtual Robot: A new teleoperation paradigm for minimally invasive robotic surgery IEEE Conference Publications
4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob) , IEEE (Roma, Italy) , 749-754
This paper presents a novel teleoperation paradigm, the Virtual Robot (VR), focused on facilitating the surgeon tasks in minimally invasive robotic surgery. The VR has been conceived to increase the range of applicability of traditional master slave teleoperation architectures by means of an automatic cooperative behavior that assigns the execution of the ongoing task to the most suitable robot. From the user's point of view, the VR internal operation must be automatic and transparent. A set of evaluation indexes have been developed to obtain the suitability of each robot as well as an algorithm to determine the optimal instant of time to execute a task transfer. Several experiments demonstrate the usefulness of the VR, as well as indicates the next steps of the research.
JTD Keywords: Cameras, Collision avoidance, Indexes, Joints, Robots, Surgery, Trajectory, Medical robotics, Surgery, Telerobotics, VR internal operation, Automatic cooperative behavior, Evaluation indexes, Master slave teleoperation architectures, Minimally invasive robotic surgery, Task transfer, Virtual robot
Castaño, O., Eltohamy, M., Kim, H. W., (2012). Electrospinning technology in tissue regeneration
Nanotechnology in Regenerative Medicine - Methods and Protocols (Methods in Molecular Biology) (ed. Navarro, M., Planell, J. A.), Springer (New York, USA) 811, 127-140
Electrospinning is one of the most versatile and effective tools to produce nanostructured fibers in the biomedical science fields. The nanofibrous structure with diameters from tens to hundreds of nanometers largely mimics the native extracellular matrix (ECM) of many tissues. Thus far, a range of compositions including polymers and ceramics and their composites/hybrids have been successfully applied for generating electrospun nanofibers. Different processing tools in electrospinning set-ups and assemblies are currently developed to tune the morphology and properties of nanofibers. Herein, we demonstrate the electrospinning process and the electrospun biomaterials for specific use in tissue regeneration with some examples, involving different material combinations and fiber morphologies.
JTD Keywords: Ceramic, Composites, Electrospinning, Nanofi bers, Nanostructured fi bers, Polymer, Tissue regeneration
Navarro, M., Planell, J. A., (2012). Is nanotechnology the key to unravel and engineer biological processes?
Nanotechnology in Regenerative Medicine - Methods and Protocols (Methods in Molecular Biology) (ed. Navarro, M., Planell, J. A.), Springer (New York, USA) 811, 1-16
Regenerative medicine is an emerging field aiming to the development of new reparative strategies to treat degenerative diseases, injury, and trauma through developmental pathways in order to rebuild the architecture of the original injured organ and take over its functionality. Most of the processes and interactions involved in the regenerative process take place at subcellular scale. Nanotechnology provides the tools and technology not only to detect, to measure, or to image the interactions between the different biomolecules and biological entities, but also to control and guide the regenerative process. The relevance of nanotechnology for the development of regenerative medicine as well as an overview of the different tools that contribute to unravel and engineer biological systems are presented in this chapter. In addition, general data about the social impact and global investment in nanotechnology are provided.
JTD Keywords: Nanotechnology, Regenerative medicine, Tissue engineering
Montufar, Edgar B., Traykova, Tania, Planell, Josep A., Ginebra, Maria-Pau, (2011). Comparison of a low molecular weight and a macromolecular surfactant as foaming agents for injectable self setting hydroxyapatite foams: Polysorbate 80 versus gelatine Materials Science and Engineering: C 31, (7), 1498-1504
Hydroxyapatite foams are potential synthetic bone grafting materials or scaffolds for bone tissue engineering. A novel method to obtain injectable hydroxyapatite foams consists in foaming the liquid phase of a calcium phosphate cement. In this process, the cement powder is incorporated into a liquid foam, which acts as a template for macroporosity. After setting, the cement hardens maintaining the macroporous structure of the foam. In this study a low molecular weight surfactant, Polysorbate 80, and a protein, gelatine, were compared as foaming agents of a calcium phosphate cement. The foamability of Polysorbate 80 was greater than that of gelatine, resulting in higher macroporosity in the set hydroxyapatite foam and higher macropore interconnectivity. Gelatine produced less interconnected foams, especially at high concentrations, due to a higher liquid foam stability. However it increased the injectability and cohesion of the foamed paste, and enhanced osteoblastic-like cell adhesion, all of them important properties for bone grafting materials.
JTD Keywords: Hydroxyapatite, Porosity, Calcium phosphate cement, Scaffolds, Foaming, Bone regeneration
Yue, J. J., Morgenstern, R., Morgenstern, C., Lauryssen, C., (2011). Shape memory hydrogels - A novel material for treating age-related degenerative conditions of the Spine
European Musculoskeletal Review , 6, (3), 184-188
Hydrogels are water-insoluble hydrophilic polymers used in a wide range of medical products such as, drug delivery, tissue replacement, heart surgery, gynaecology, ophthalmology, plastic surgery and orthopaedic surgery. These polymers exhibit low toxicity, reduced tissue adherence, and are highly biocompatible. A class of hydrogels, hydrolysed polyacrylonitriles, possess unique shape memory properties, which, when combined with biodurability, mechanical strength and viscoelasticity make them ideal for treating certain degenerative conditions of the spine. Animal and other in vitro studies have shown that the hydrogel is biocompatible and well tolerated by host tissues. This article focuses on two specific indications in spine surgery that demonstrate the potential of hydrogel-based technology to provide significant treatment advantages.
JTD Keywords: Biocompatibility, Degenerative disc disease, Hydrolysed polyacrylonitrile, Minimally invasive surgery, Shape memory hydrogel, Spinal stenosis
Simao, C., Mas-Torrent, M., Crivillers, N., Lloveras, V., Artés, Juan Manuel, Gorostiza, Pau, Veciana, Jaume, Rovira, C., (2011). A robust molecular platform for non-volatile memory devices with optical and magnetic responses
Nature Chemistry , 3, (5), 359-364
Bistable molecules that behave as switches in solution have long been known. Systems that can be reversibly converted between two stable states that differ in their physical properties are particularly attractive in the development of memory devices when immobilized in substrates. Here, we report a highly robust surface-confined switch based on an electroactive, persistent organic radical immobilized on indium tin oxide substrates that can be electrochemically and reversibly converted to the anion form. This molecular bistable system behaves as an extremely robust redox switch in which an electrical input is transduced into optical as well as magnetic outputs under ambient conditions. The fact that this molecular surface switch, operating at very low voltages, can be patterned and addressed locally, and also has exceptionally high long-term stability and excellent reversibility and reproducibility, makes it a very promising platform for non-volatile memory devices.
JTD Keywords: Self-assembled monolayers, Chromophore-based monolayers, Ultrathin platinum films, Carbon free-radicals, Per-million levels, Polychlorotriphenylmethyl radicals, Electron-transfer, Surface, Logic, Quantification
Trepat, X., Fredberg, J. J., (2011). Plithotaxis and emergent dynamics in collective cellular migration Trends in Cell Biology 21, (11), 638-646
For a monolayer sheet to migrate cohesively, it has long been suspected that each constituent cell must exert physical forces not only upon its extracellular matrix but also upon neighboring cells. The first comprehensive maps of these distinct force components reveal an unexpected physical picture. Rather than showing smooth and systematic variation within the monolayer, the distribution of physical forces is dominated by heterogeneity, both in space and in time, which emerges spontaneously, propagates over great distances, and cooperates over the span of many cell bodies. To explain the severe ruggedness of this force landscape and its role in collective cell guidance, the well known mechanisms of chemotaxis, durotaxis, haptotaxis are clearly insufficient. In a broad range of epithelial and endothelial cell sheets, collective cell migration is governed instead by a newly discovered emergent mechanism of innately collective cell guidance - plithotaxis.
JTD Keywords: Positional information, Drosophila embryo, Sheet migration, Dpp gradient, Cells, Force, Morphogenesis, Transition, Identification, Proliferation
Valle-Delgado, J. J., Molina-Bolívar, J. A., Galisteo-González, F., Gálvez-Ruiz, M. J., (2011). Evidence of hydration forces between proteins
Current Opinion in Colloid and Interface Science , 16, (6), 572-578
Proteins are fundamental molecules in biology that are also involved in a wide range of industrial and biotechnological processes. Consequently, many works in the literature have been devoted to the study of protein-protein and protein-surface interactions in aqueous solutions. The results have been usually interpreted within the frame of the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory for colloidal systems. However, against the DLVO predictions, striking evidence of repulsive forces between proteins at high salt concentrations has been observed in different works based on the analysis of the second virial coefficient or on the direct measurement of protein interaction with an atomic force microscope. Hydration forces due to the adsorption of hydrated cations onto the negatively charged protein surfaces have been invoked to rationalize this anomalous repulsion. The hydration forces between proteins provide protein-covered particles with a non-DLVO colloidal stability at high salt concentrations, as different studies in the literature has proven. This review summarizes the most relevant results published so far on the presence of hydration forces between proteins and protein-coated colloidal particles.
JTD Keywords: Colloidal particles, Colloidal stability, Hydrated ions, Hydration forces, Proteins
Ivon Rodriguez-Villarreal, Angeles, Tarn, Mark D., Madden, Leigh A., Lutz, Julia B., Greenman, John, Samitier, Josep, Pamme, Nicole, (2011). Flow focussing of particles and cells based on their intrinsic properties using a simple diamagnetic repulsion setup Lab on a Chip 11, (7), 1240-1248
The continuous flow focussing and manipulation of particles and cells are important factors in microfluidic applications for performing accurate and reproducible procedures downstream. Many particle focussing methods require complex setups or channel designs that can limit the process and its applications. Here, we present diamagnetic repulsion as a simple means of focussing objects in continuous flow, based only on their intrinsic properties without the requirement of any label. Diamagnetic polystyrene particles were suspended in a paramagnetic medium and pumped through a capillary between a pair of permanent magnets, whereupon the particles were repelled by each magnet into the central axis of the capillary, thus achieving focussing. By investigating this effect, we found that the focussing was greatly enhanced with (i) increased magnetic susceptibility of the medium, (ii) reduced flow rate of the suspension, (iii) increased particle size, and (iv) increased residence time in the magnetic field. Furthermore, we applied diamagnetic repulsion to the flow focussing of living, label-free HaCaT cells.
JTD Keywords: Feeble magnetic substances, On-chip, Blood-cells, Microfluidic device, Separation, Field, Levitation, Magnetophoresis, Fractionation, Nanoparticles
Caballero-Briones, F., Palacios-Padrós, A., Sanz, Fausto, (2011). CuInSe2 films prepared by three step pulsed electrodeposition. Deposition mechanisms, optical and photoelectrochemical studies Electrochimica Acta 56, (26), 9556-9567
p-Type semiconducting copper indium diselenide thin films have been prepared onto In2O3:Sn substrates by a recently developed pulse electrodeposition method that consists in repeated cycles of three potential application steps. The Cu–In–Se electrochemical system and the related single component electrolytes were studied by cyclic voltammetry to identify the electrode processes and study the deposition processes. In situ atomic force microscopy measurements during the first 100 deposition cycles denote a continuous nucleation and growth mechanism. Particles removed by film sonication from some of the films were characterized by transmission electron microscopy and determined to consist in nanoscopic and crystalline CuInSe2. The remaining film is still crystalline CuInSe2, as assessed by X-ray diffraction. The chemical characterization by combined X-ray photoelectron spectroscopy, X-ray fluorescence and inductively coupled plasma optical emission spectroscopy, showed that films were Cu-poor and Se-poor. Raman characterization of the as-grown films showed that film composition varies with film thickness; thinner films are Se-rich, while thicker ones have an increased Cu–Se content. Different optical absorption bands were identified by the analysis of the UV–NIR transmittance spectra that were related with the presence of CuInSe2, ordered vacancy compounds, Se, Cu2−xSe and In2Se3. The photoelectrochemical activity confirmed the p-type character and showed a better response for the films prepared with the pulse method.
JTD Keywords: CuInSe2, Solar cells, Electrodeposition, Optical properties, As-deposited films, ITO substrate
Garrido-Delgado, R., Arce, L., Guaman, A. V., Pardo, A., Marco, S., Valcárcel, M., (2011). Direct coupling of a gas-liquid separator to an Ion Mobility Spectrometer for the classification of different white wines using chemometrics tools Talanta 84, (2), 471-479
The potential of a vanguard technique as is the Ion Mobility Spectrometry with Ultraviolet ionization (UV-IMS) coupled to a Continuous Flow System (CFS) have been demonstrated in this work by using a Gas Phase Separator (GPS). This vanguard system (CFS-GPS-UV-IMS) has been used for the analysis of different types of white wines to obtain a characteristic profile for each type of wine and their posterior classification using different chemometric tools. Precision of the method was 3.1% expressed as relative standard deviation. A deep chemometric study was carried out for the classification of the four types of wines selected. The best classification performance was obtained by first reducing the data dimensionality by Principal Component Analysis (PCA) followed by Linear Discriminant Analysis (LDA) and finally using a K-Nearest Neighbour (kNN) classifier. The classification rate in an independent validation set were 92.0% classification rate value with confidence interval [89.0%, 95.0%] at P = 0.05 confidence level. The same white wines analyzed by using CFS-GPS-UV-IMS were analyzed by using Gas Chromatography with a Flame Detector (GC-FID) as conventional technique. The chromatographic method used for the determination of superior alcohols in wine samples shown in the Regulation CEE 1238/1992 was selected to carry out the analysis of the same samples set and later the classification using appropriate chemometric tools. In this case, strategies PCA-LDA and kNN classifier were also used for the correct classification of the wine samples. This combination showed similar results to the ones obtained with the proposed method.
JTD Keywords: Classification, White wines, Ultraviolet-Ion Mobility Spectrometry, Gas Phase Separate, Vanguard method, Continuous Flow System, Chemometric analysis.
Krishnan, Ramaswamy, Klumpers, Darinka D., Park, Chan Y., Rajendran, Kavitha, Trepat, Xavier, van Bezu, Jan, van Hinsbergh, Victor W. M., Carman, Christopher V., Brain, Joseph D., Fredberg, Jeffrey J., Butler, James P., van Nieuw Amerongen, Geerten P., (2011). Substrate stiffening promotes endothelial monolayer disruption through enhanced physical forces
American Journal of Physiology - Cell Physiology , 300, (1), C146-C154
A hallmark of many, sometimes life-threatening, inflammatory diseases and disorders is vascular leakage. The extent and severity of vascular leakage is broadly mediated by the integrity of the endothelial cell (EC) monolayer, which is in turn governed by three major interactions: cell-cell and cell-substrate contacts, soluble mediators, and biomechanical forces. A potentially critical but essentially uninvestigated component mediating these interactions is the stiffness of the substrate to which the endothelial monolayer is adherent. Accordingly, we investigated the extent to which substrate stiffening influences endothelial monolayer disruption and the role of cell-cell and cell-substrate contacts, soluble mediators, and physical forces in that process. Traction force microscopy showed that forces between cell and cell and between cell and substrate were greater on stiffer substrates. On stiffer substrates, these forces were substantially enhanced by a hyperpermeability stimulus (thrombin, 1 U/ml), and gaps formed between cells. On softer substrates, by contrast, these forces were increased far less by thrombin, and gaps did not form between cells. This stiffness-dependent force enhancement was associated with increased Rho kinase activity, whereas inhibition of Rho kinase attenuated baseline forces and lessened thrombin-induced inter-EC gap formation. Our findings demonstrate a central role of physical forces in EC gap formation and highlight a novel physiological mechanism. Integrity of the endothelial monolayer is governed by its physical microenvironment, which in normal circumstances is compliant but during pathology becomes stiffer.
JTD Keywords: Contraction, Human umbilical vein endothelial cells, Permeability, Traction force, Cell-cell contact, Cell-substrate contact, Substrate stiffness, Rho kinase, Vascular endothelial cadherin, Thrombin
Dellaca, Raffaele, Montserrat, Josep M., Govoni, Leonardo, Pedotti, Antonio, Navajas, Daniel, Farre, Ramon, (2011). Telemetric CPAP titration at home in patients with sleep apnea-hypopnea syndrome
Sleep Medicine , 12, (2), 153-157
Background: Home continuous positive airway pressure (CPAP) titration with automatic devices is not possible in a non-negligible percentage of patients with sleep apnea-hypopnea syndrome (SAHS). Objectives: To test the feasibility of a novel telemetric system for home CPAP titration.
Methods: One-night home CPAP titration was carried out on 20 SAHS patients (56 +/- 3 years; BMI = 35 +/- 2 kg/m(2)). A telemetric unit, based on the conventional GPRS mobile phone network and connected to a commercial CPAP device, allowed the hospital technician to monitor flow, pressure and air leaks by remote control and titrate CPAP (elimination of apneas, hypopneas, flow limitation and snoring) in real time. After 1 week, a full hospital polysomnography was performed while the patient was subjected to the value of CPAP that was previously titrated at home via telemetry.
Results: The home-titrated CPAP systematically improved patients' breathing: the apnea-hypopnea index and percentage of sleep time with arterial oxygen saturation below 90% were reduced from 58.1 +/- 5.1 to 3.8 +/- 0.6 events/h and from 19.8 +/- 1.1% to 4.4 +/- 0.7%, respectively. This CPAP value (9.15 +/- 0.47 cmH(2)O) was virtually the same as the pressure that optimized breathing during hospital polysomnography (9.20 +/- 0.41 cmH(2)O; mean difference: 0.02 cmH(2)O, limits of agreement: +/- 1.00 cmH(2)O).
Conclusions: This pilot study shows that a simple telemetric system, requiring neither a special telemedicine network nor any infrastructure in the patient's home, made it possible to perform effective remote CPAP titration on SAHS patients.
JTD Keywords: Home CPAP titration by telemetry, Telecare, Telemedicine, E-health, Obstructive sleep apnea, Point of care
Byrne, Damien P., Lacroix, Damien, Prendergast, Patrick J., (2011). Simulation of fracture healing in the tibia: Mechanoregulation of cell activity using a lattice modeling approach
Journal of Orthopaedic Research , 29, (10), 1496-1503
In this study, a three-dimensional (3D) computational simulation of bone regeneration was performed in a human tibia under realistic muscle loading. The simulation was achieved using a discrete lattice modeling approach combined with a mechanoregulation algorithm to describe the cellular processes involved in the healing process namely proliferation, migration, apoptosis, and differentiation of cells. The main phases of fracture healing were predicted by the simulation, including the bone resorption phase, and there was a qualitative agreement between the temporal changes in interfragmentary strain and bending stiffness by comparison to experimental data and clinical results. Bone healing was simulated beyond the reparative phase by modeling the transition of woven bone into lamellar bone. Because the simulation has been shown to work with realistic anatomical 3D geometry and muscle loading, it demonstrates the potential of simulation tools for patient-specific pre-operative treatment planning.
JTD Keywords: Tissue differentiation, Computational analysis, Mechanical conditions, Bone regeneration, Weight-bearing, Proliferation, Osteoblast, Stiffness, Ingrowth, Scaffold
Barthelmebs, L., Jonca, J., Hayat, A., Prieto-Simon, B., Marty, J. L., (2011). Enzyme-Linked Aptamer Assays (ELAAs), based on a competition format for a rapid and sensitive detection of Ochratoxin A in wine
Food Control , 22, (5), 737-743
Ochratoxin A (OTA) is one of the most important mycotoxins because of its high toxicity to both humans and animals and its occurrence in a number of basic foods and agro-products. The need to develop high-performing methods for OTA analysis able to improve the traditional ones is evident. In this work, through in vitro SELEX (Systematic Evolution of Ligands by EXponential enrichment) two aptamers, designated H8 and H12 were produced that bind with nanomolar affinity with Ochratoxin A (OTA). Two strategies were investigated by using an indirect and a direct competitive Enzyme-Linked Aptamer Assay (ELAA) and were compared to the classical competitive Enzyme-Linked Immunosorbent Assay (ELISA) for the determination of OTA in spiked red wine samples. The limit of detection attained (1 ng/mL), the midpoint value obtained (5 ng/mL) and the analysis time needed (125 min) for the real sample analysis validate the direct competitive ELAA as useful screening tool for routine use in the control of OTA level in wine.
JTD Keywords: Competitive Enzyme-Linked Aptamer Assay (ELAA), DNA aptamer, Ochratoxin A, SELEX, Wine analysis
Rodriguez-Segui, Santiago A., Pons Ximenez, Jose Ignacio, Sevilla, Lidia, Ruiz, Ana, Colpo, Pascal, Rossi, Francois, Martinez, Elena, Samitier, Josep, (2011). Quantification of protein immobilization on substrates for cellular microarray applications
Journal of Biomedical Materials Research - Part A , 98A, (2), 245-256
Cellular microarray developments and its applications are the next step after DNA and protein microarrays. The choice of the surface chemistry of the substrates used for the implementation of this technique, that must favor proper protein immobilization while avoiding cell adhesion on the nonspotted areas, presents a complex challenge. This is a key issue since usually the best nonfouling surfaces are also the ones that retain immobilized the smallest amounts of printed protein. To quantitatively assess the amount of protein immobilization, in this study several combinations of fluorescently labeled fibronectin (Fn*) and streptavidin (SA*) were microspotted, with and without glycerol addition in the printing buffer, on several substrates suitable for cellular microarrays. The substrates assayed included chemically activated surfaces as well as Poly ethylene oxide (PEO) films that are nonfouling in solution but accept adhesion of proteins in dry conditions. The results showed that the spotted Fn* was retained by all the surfaces, although the PEO surface did show smaller amounts of immobilization. The SA*, on the other hand, was only retained by the chemically activated surfaces. The inclusion of glycerol in the printing buffer significantly reduced the immobilization of both proteins. The results presented in this article provide quantitative evidence of the convenience of using a chemically activated surface to immobilize proteins relevant for cellular microarray applications, particularly when ECM proteins are cospotted with smaller factors which are more difficult to be retained by the surfaces.
JTD Keywords: Protein immobilization, Quantification, Microarray, Substrate, Surface chemistry
Cagido, Viviane Ramos, Zin, Walter Araujo, Ramirez, Jose, Navajas, Daniel, Farre, Ramon, (2011). Alternating ventilation in a rat model of increased abdominal pressure
Respiratory Physiology & Neurobiology , 175, (3), 310-315
During alternating ventilation (AV) one lung is inflating while the other is deflating. Considering the possible respiratory and hemodynamic advantages of AV, we investigated its effects during increased intra-abdominal pressure (IAP = 10 mmHg). In Sprague-Dawley rats (n = 6, 270–375 g) the main bronchi were independently cannulated, and respiratory mechanics determined while animals underwent different ventilatory patterns: synchronic ventilation without increased IAP (SV-0), elevated IAP during SV (SV-10), and AV with elevated IAP (AV-10). Thirty-three other animals (SV-0, n = 10; SV-10, n = 11 and AV-10, n = 12) were ventilated during 3 h. Mean arterial pressure (MAP), and lung histology were assessed. Increased IAP resulted in significantly higher elastances (p < 0.001), being AV-10 lower than SV-10 (p < 0.020). SV-10 showed higher central venous pressure (p < 0.003) than S-0; no change was observed in AV-10. Wet/dry lung weight ratio was lower in AV-10 than SV-10 (p = 0.009). Application of AV reduced hemodynamic and lung impairments induced by increased IAP during SV.
JTD Keywords: Alternating ventilation, Respiratory mechanics, Intra-abdominal pressure, Hemodynamic, Mechanical ventilation, Animal model
Carreras, Alba, Wang, Yang, Gozal, David, Montserrat, Josep M., Navajas, Daniel, Farre, Ramon, (2011). Non-invasive system for applying airway obstructions to model obstructive sleep apnea in mice
Respiratory Physiology & Neurobiology , 175, (1), 164-168
Obstructive sleep apnea (OSA) is characterized by recurrent upper airway obstructions during sleep. The most common animal model of OSA is based on subjecting rodents to intermittent hypoxic exposures and does not mimic important OSA features, such as recurrent hypercapnia and increased inspiratory efforts. To circumvent some of these issues, a novel murine model involving non-invasive application of recurrent airway obstructions was developed. An electronically controlled airbag system is placed in front of the mouse's snout, whereby inflating the airbag leads to obstructed breathing and spontaneous breathing occurs with the airbag deflated. The device was tested on 29 anesthetized mice by measuring inspiratory effort and arterial oxygen saturation (SaO(2)). Application of recurrent obstructive apneas (6s each, 120/h) for 6h resulted in SaO(2) oscillations to values reaching 84.4 +/- 2.5% nadir, with swings mimicking OSA patients. This novel system, capable of applying controlled recurrent airway obstructions in mice, is an easy-to-use tool for investigating pertinent aspects of OSA.
JTD Keywords: Animal model, Upper airway Obstruction, Mouse model, Non-invasive system, Model sleep apnea, Respiratory disease
Punter-Villagrasa, J., Colomer-Farrarons, J., Miribel-Catala, P., Puig-Vidal, M., Samitier, J., (2011). Discrete to full custom ASIC solutions for bioelectronic applications Proceedings of the SPIE - The International Society for Optical Engineering
VLSI Circuits and Systems V , SPIE - The International Society for Optical Engineering (Prague, Czech Republic) 8067, 80670Q
This paper presents a first approach on multi-pathogen detection system for portable point-of-care applications on discrete electronics field. The main interest is focused on the development of custom built electronic solutions for bioelectronics applications, from discrete devices to ASICS solutions.
JTD Keywords: Application specific integrated circuits, Biomedical electronics, Biosensors
Gutierrez-Galvez, Agustin, Fernandez, Luis, Marco, Santiago, (2011). Study of sensory diversity and redundancy to encode for chemical mixtures Olfaction and Electronic Nose: Proceedings of the 14th International Symposium on Olfaction and Electronic Nose
AIP Conference Proceedings (ed. Perena Gouma, SUNY Stony Brook), AIP (New York City, USA) 1362, (1), 147-148
Inspired by sensory diversity and redundancy at the olfactory epithelium, we have built a large chemical sensor array based on commercial MOX sensors. Different sensor families along with temperature modulation accounts for sensory diversity, whereas sensors of the same family combined with different load resistors provide redundancy to the system. To study the encoding of odor mixtures, a data collection consisting on the response of the array to 3 binary mixtures of ethanol, acetone, and butanone with 18 different concentration ratios is obtained.
JTD Keywords: Chemioception, Sensors, Data acquisition, Temperature measurement
del Rio, Jose Antonio, Soriano, Eduardo, (2010). Regenerating cortical connections in a dish: the entorhino-hippocampal organotypic slice co-culture as tool for pharmacological screening of molecules promoting axon regeneration Nature Protocols 5, (2), 217-226
We present a method for using long-term organotypic slice co-cultures of the entorhino-hippocampal formation to analyze the axon-regenerative properties of a determined compound. The culture method is based on the membrane interphase method, which is easy to perform and is generally reproducible. The degree of axonal regeneration after treatment in lesioned cultures can be seen directly using green fluorescent protein (GFP) transgenic mice or by axon tracing and histological methods. Possible changes in cell morphology after pharmacological treatment can be determined easily by focal in vitro electroporation. The well-preserved cytoarchitectonics in the co-culture facilitate the analysis of identified cells or regenerating axons. The protocol takes up to a month.
JTD Keywords: Cajal-retzius cells, Green-fluorescent-protein, In-vitro model, Rat hippocampus, Nervous-tissue, Brain-slices, Dentate gyrus, Gene-transfer, Cultures, Damage
Santoro, R., Olivares, A. L., Brans, G., Wirz, D., Longinotti, C., Lacroix, D., Martin, I., Wendt, D., (2010). Bioreactor based engineering of large-scale human cartilage grafts for joint resurfacing Biomaterials 31, (34), 8946-8952
Apart from partial or total joint replacement, no surgical procedure is currently available to treat large and deep cartilage defects associated with advanced diseases such as osteoarthritis. In this work, we developed a perfusion bioreactor system to engineer human cartilage grafts in a size with clinical relevance for unicompartmental resurfacing of human knee joints (50 mm diameter x 3 mm thick). Computational fluid dynamics models were developed to optimize the flow profile when designing the perfusion chamber. Using the developed system, human chondrocytes could be seeded throughout large 50 mm diameter scaffolds with a uniform distribution. Following two weeks culture, tissues grown in the bioreactor were viable and homogeneously cartilaginous, with biomechanical properties approaching those of native cartilage. In contrast, tissues generated by conventional manual production procedures were highly inhomogeneous and contained large necrotic regions. The unprecedented engineering of human cartilage tissues in this large-scale opens the practical perspective of grafting functional biological substitutes for the clinical treatment for extensive cartilage defects, possibly in combination with surgical or pharmacological therapies to support durability of the implant. Ongoing efforts are aimed at integrating the up-scaled bioreactor based processes within a fully automated and closed manufacturing system for safe, standardized, and GMP compliant production of large-scale cartilage grafts.
JTD Keywords: Bioreactor, Cartilage repair, Computational fluid dynamics, Scale-up, Regenerative medicine, Tissue engineering
Fernàndez-Busquets, X., Ponce, J., Bravo, R., Arimon, M., Martianez, T., Gella, A., Cladera, J., Durany, N., (2010). Modulation of amyloid beta peptide(1-42) cytotoxicity and aggregation in vitro by glucose and chondroitin sulfate
Current Alzheimer Research , 7, (5), 428-438
One mechanism leading to neurodegeneration during Alzheimer's Disease (AD) is amyloid beta peptide (A beta)-induced neurotoxicity. Among the factors proposed to potentiate A beta toxicity is its covalent modification through carbohydrate-derived advanced glycation endproducts (AGEs). Other experimental evidence, though, indicates that certain polymeric carbohydrates like the glycosaminoglycan (GAG) chains found in proteoglycan molecules attenuate the neurotoxic effect of A beta in primary neuronal cultures. Pretreatment of the 42-residue A beta fragment (A beta(1-42)) with the ubiquitous brain carbohydrates, glucose, fructose, and the GAG chondroitin sulfate B (CSB) inhibits A beta beta(1-42)-induced apoptosis and reduces the peptide neurotoxicity on neuroblastoma cells, a cytoprotective effect that is partially reverted by AGE inhibitors such as pyridoxamine and L-carnosine. Thioflavin T fluorescence measurements indicate that at concentrations close to physiological, only CSB promotes the formation of A beta amyloid fibril structure. Atomic force microscopy imaging and Western blot analysis suggest that glucose favours the formation of globular oligomeric structures derived from aggregated species. Our data suggest that at short times carbohydrates reduce A beta(1-42) toxicity through different mechanisms both dependent and independent of AGE formation.
JTD Keywords: Alzheimer's disease, Advanced glycation endproducts, Amyloid fibrils, Amyloid beta peptide, Apoptosis, Carbohydrates, Glycosaminoglycans
Michiardi, A., Helary, G., Nguyen, P. C. T., Gamble, L. J., Anagnostou, F., Castner, D. G., Migonney, V., (2010). Bioactive polymer grafting onto titanium alloy surfaces Acta Biomaterialia 6, (2), 667-675
Bioactive polymers bearing sulfonate (styrene sodium sulfonate, NaSS) and carboxylate (methylacrylic acid, MA) groups were grafted onto Ti6Al4V alloy surfaces by a two-step procedure. The Ti alloy surfaces were first chemically oxidized in a piranha solution and then directly subjected to radical polymerization at 70 °C in the absence of oxygen. The grafted surfaces were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the toluidine blue colorimetric method. Toluidine blue results showed 1-5 μg cm-2 of polymer was grafted onto the oxidized Ti surfaces. Grafting resulted in a decrease in the XPS Ti and O signals from the underlying Ti substrate and a corresponding increase in the XPS C and S signals from the polymer layer. The ToF-SIMS intensities of the S- and SO- ions correlated linearly with the XPS atomic percent S concentrations and the ToF-SIMS intensity of the TiO3H2- ion correlated linearly with the XPS atomic per cent Ti concentration. Thus, the ToF-SIMS S-, SO- and TiO3H2- intensities can be used to quantify the composition and amount of grafted polymer. ToF-SIMS also detected ions that were more characteristic of the polymer molecular structure (C6H4SO3- and C8H7SO3- from NaSS, C4H5O2- from MA), but the intensity of these peaks depended on the polymer thickness and composition. An in vitro cell culture test was carried out with human osteoblast-like cells to assess the influence of the grafted polymers on cell response. Cell adhesion after 30 min of incubation showed significant differences between the grafted and ungrafted surfaces. The NaSS grafted surfaces showed the highest degree of cell adhesion while the MA-NaSS grafted surfaces showed the lowest degree of cell adhesion. After 4 weeks in vivo in rabbit femoral bones, bone was observed to be in direct contact with all implants. The percentage of mineralized tissue around the implants was similar for NaSS grafted and non-grafted implants (59% and 57%). The MA-NaSS grafted implant exhibited a lower amount of mineralized tissue (47%).
JTD Keywords: Bioactive polymers, Osteointegration, Titanium alloy, ToF-SIMS, XPS
Ginebra, M. P., Espanol, M., Montufar, E. B., Perez, R. A., Mestres, G., (2010). New processing approaches in calcium phosphate cements and their applications in regenerative medicine Acta Biomaterialia 6, (8), 2863-2873
The key feature of calcium phosphate cements (CPCs) lies in the setting reaction triggered by mixing one or more solid calcium phosphate salts with an aqueous solution. Upon mixture, the reaction takes place through a dissolution-precipitation process which is macroscopically observed by a gradual hardening of the cement paste. The precipitation of hydroxyapatite nanocrystals at body or room temperature, and the fact that those materials can be used as self-setting pastes, have for many years been the most attractive features of CPCs. However, the need to develop materials able to sustain bone tissue ingrowth and be capable of delivering drugs and bioactive molecules, together with the continuous requirement from surgeons to develop more easily handling cements, has pushed the development of new processing routes that can accommodate all these requirements, taking advantage of the possibility of manipulating the self-setting CPC paste. It is the goal of this paper to provide a brief overview of the new processing developments in the area of CPCs and to identify the most significant achievements.
JTD Keywords: Bone regeneration, Calcium phosphate cements, Granules, Microcarriers, Scaffolds
Madronal, Noelia, Lopez-Aracil, Cristina, Rangel, Alejandra, del Rio, Jose A., Delgado-Garcia, Jose M., Gruart, Agnes, (2010). Effects of Enriched Physical and Social Environments on Motor Performance, Associative Learning, and Hippocampal Neurogenesis in Mice PLoS ONE 5, (6), e11130
We have studied the motor abilities and associative learning capabilities of adult mice placed in different enriched environments. Three-month-old animals were maintained for a month alone (AL), alone in a physically enriched environment (PHY), and, finally, in groups in the absence (SO) or presence (SOPHY) of an enriched environment. The animals' capabilities were subsequently checked in the rotarod test, and for classical and instrumental learning. The PHY and SOPHY groups presented better performances in the rotarod test and in the acquisition of the instrumental learning task. In contrast, no significant differences between groups were observed for classical eyeblink conditioning. The four groups presented similar increases in the strength of field EPSPs (fEPSPs) evoked at the hippocampal CA3-CA1 synapse across classical conditioning sessions, with no significant differences between groups. These trained animals were pulse-injected with bromodeoxyuridine (BrdU) to determine hippocampal neurogenesis. No significant differences were found in the number of NeuN/BrdU double-labeled neurons. We repeated the same BrdU study in one-month-old mice raised for an additional month in the above-mentioned four different environments. These animals were not submitted to rotarod or conditioned tests. Non-trained PHY and SOPHY groups presented more neurogenesis than the other two groups. Thus, neurogenesis seems to be related to physical enrichment at early ages, but not to learning acquisition in adult mice.
JTD Keywords: Long-term potentiation, Adult neurogenesis, Synaptic transmission, Cell proliferation, CA3-CA1 synapse, Granule cells
Jaramillo, M. D., Torrents, E., Martinez-Duarte, R., Madou, M. J., Juarez, A., (2010). On-line separation of bacterial cells by carbon-electrode dielectrophoresis
Electrophoresis , 31, (17), 2921-2928
Dielectrophoresis (DEP) represents a powerful approach to manipulate and study living cells. Hitherto, several approaches have used 2-D DEP chips. With the aim to increase sample volume, in this study we used a 3-D carbon-electrode DEP chip to trap and release bacterial cells. A continuous flow was used to plug an Escherichia coli cell suspension first, to retain cells by positive DEP, and thereafter to recover them by washing with peptone water washing solution. This approach allows one not only to analyze DEP behavior of living cells within the chip, but also to further recover fractions containing DEP-trapped cells. Bacterial concentration and flow rate appeared as critical parameters influencing the separation capacity of the chip. Evidence is presented demonstrating that the setup developed in this study can be used to separate different types of bacterial cells.
JTD Keywords: Bacteria, Carbon electrode, Dielectrophoresis, E. coli, Separation
Perera, A., Pardo, A., Barrettino, D., Hierlermann, A., Marco, S., (2010). Evaluation of fish spoilage by means of a single metal oxide sensor under temperature modulation Sensors and Actuators B: Chemical 146, (2), 477-482
In this paper the feasibility of using metal oxide gas sensor technology for evaluating spoilage process for sea bream (Sparus aurata) is explored. It is shown that a single sensor under temperature modulation is able to find a correlation with the fish spoilage process. Results are obtained in real frigorific storage conditions: that is, at low measurement temperatures with variations of relative humidity.
JTD Keywords: Gas sensors, Electronic nose, Spoilage process, Temperature modulation, Bream sparus-aurata, Electronic nose, Freshness, Quality, Sardines, Storage
Darwish-, N., Caballero, D., Moreno, M., Errachid, A., Samitier, J., (2010). Multi-analytic grating coupler biosensor for differential binding analysis Sensors and Actuators B: Chemical 144, (2), 413-417
In this paper, a multiple-channel extension of a dual-grating Coupler biosensor is presented as a Solution for the problem of resolving different selectivities, Usual when heterogeneous samples are analyzed. Several differently functionalized channels can perform quantitative analysis of competiting recognition events, Suppress shifts due to buffer changes and even monitorize drifts coming from the light Source. Here, the multiple-channel approach is developed and proven for a four-channel configuration, providing a resolution limit of 10(-5) Refractive index Units (RIU) and with an a potentially Unlimited scalability. Finally, a differential HSA recognition event is monitored, at both an IgG functionalized channel and at a blocked one.
JTD Keywords: Optical grating coupler, Multi-channel biorecognition, On-chip reference
Montoliu, I., Tauler, R., Padilla, M., Pardo, A., Marco, S., (2010). Multivariate curve resolution applied to temperature modulated metal oxide gas sensors Sensors and Actuators B: Chemical 145, (1), 464-473
Metal oxide (MOX) gas sensors have been widely used for years. Temperature modulation of gas sensors is as an alternative to increase their sensitivity and selectivity to different gas species. In order to enhance the extraction of useful information from this kind of signals, data processing techniques are needed. In this work, the use of self-modelling curve resolution techniques, in particular multivariate curve resolution-alternating least squares (MCR-ALS), is presented for the analysis of these signals. First, the performance of MCR in a synthetic dataset generated from temperature-modulated gas sensor response models has been evaluated, showing good results both in the resolution of gas mixtures and in the determination of concentration/sensitivity profiles. Secondly, experimental confirmation of previously obtained conclusions is attempted using temperature-modulated MOX sensors together with MCR-ALS for the analysis of carbon monoxide (CO) and methane (CH4) gas mixtures in dry air. Results allow confirming the possibility of using the proposed approach as a quantitative technique for gas mixtures analysis, and also reveal some limitations.
JTD Keywords: Temperature modulation, Multivariate curve resolution, MCR-ALS, Metal oxide sensors
Messeguer, J., Masip, I., Montolio, M., del Rio, J. A., Soriano, E., Messeguer, A., (2010). Peptoids bearing tertiary amino residues in the n-alkyl side chains: synthesis of a potent inhibitor of Semaphorin 3A
Tetrahedron , 66, (13), 2444-2454
A study on the preparation of N-alkylglycines (peptoids) that contain tertiary amino residues on the N-alkyl side chains is reported. The appropriate combination of the submonomer strategy with N-alkylglycine monomer couplings depending upon the structure of the N-alkyl side chain that must be incorporated into the peptoid is determinant for the efficiency of the synthetic pathway. The application of this strategy to the preparation of SICHI, an N-alkyglycine trimer containing tertiary amino residues in the three N-alkyl branches, and that has been identified as a potent Semaphorin 3A inhibitor, is presented.
JTD Keywords: Peptoids, N-Alkylglycine monomers, Solid-phase synthesis, Semaphorin inhibition, Axonal regeneration
Almendros, I., Montserrat, J. M., Torres, M., Gonzalez, C., Navajas, D., Farre, R., (2010). Changes in oxygen partial pressure of brain tissue in an animal model of obstructive apnea
Respiratory Research , 11, (3), 1-6
Cognitive impairment is one of the main consequences of obstructive sleep apnea (OSA) and is usually attributed in part to the oxidative stress caused by intermittent hypoxia in cerebral tissues. The presence of oxygen-reactive species in the brain tissue should be produced by the deoxygenation-reoxygenation cycles which occur at tissue level during recurrent apneic events. However, how changes in arterial blood oxygen saturation (SpO(2)) during repetitive apneas translate into oxygen partial pressure (PtO2) in brain tissue has not been studied. The objective of this study was to assess whether brain tissue is partially protected from intermittently occurring interruption of O-2 supply during recurrent swings in arterial SpO(2) in an animal model of OSA. Methods: Twenty-four male Sprague-Dawley rats (300-350 g) were used. Sixteen rats were anesthetized and noninvasively subjected to recurrent obstructive apneas: 60 apneas/h, 15 s each, for 1 h. A control group of 8 rats was instrumented but not subjected to obstructive apneas. PtO2 in the cerebral cortex was measured using a fast-response oxygen microelectrode. SpO(2) was measured by pulse oximetry. The time dependence of arterial SpO(2) and brain tissue PtO2 was carried out by Friedman repeated measures ANOVA. Results: Arterial SpO(2) showed a stable periodic pattern (no significant changes in maximum [95.5 +/- 0.5%; m +/- SE] and minimum values [83.9 +/- 1.3%]). By contrast, brain tissue PtO2 exhibited a different pattern from that of arterial SpO(2). The minimum cerebral cortex PtO2 computed during the first apnea (29.6 +/- 2.4 mmHg) was significantly lower than baseline PtO2 (39.7 +/- 2.9 mmHg; p = 0.011). In contrast to SpO(2), the minimum and maximum values of PtO2 gradually increased (p < 0.001) over the course of the 60 min studied. After 60 min, the maximum (51.9 +/- 3.9 mmHg) and minimum (43.7 +/- 3.8 mmHg) values of PtO2 were significantly greater relative to baseline and the first apnea dip, respectively. Conclusions: These data suggest that the cerebral cortex is partially protected from intermittently occurring interruption of O-2 supply induced by obstructive apneas mimicking OSA.
JTD Keywords: Near-infrared spectroscopy, Sleep-apnea, Iintermittent hypoxia, Cerebral oxygenation, Oxidative stress, Blood-flow, Rat, Apoptosis, Inflammation, Hypercapnia
Carreras, A., Rojas, M., Tsapikouni, T., Montserrat, J. M., Navajas, D., Farre, R., (2010). Obstructive apneas induce early activation of mesenchymal stem cells and enhancement of endothelial wound healing
Respiratory Research , 11, (91), 1-7
Background: The aim was to test the hypothesis that the blood serum of rats subjected to recurrent airway obstructions mimicking obstructive sleep apnea (OSA) induces early activation of bone marrow-derived mesenchymal stem cells (MSC) and enhancement of endothelial wound healing. Methods: We studied 30 control rats and 30 rats subjected to recurrent obstructive apneas (60 per hour, lasting 15 s each, for 5 h). The migration induced in MSC by apneic serum was measured by transwell assays. MSC-endothelial adhesion induced by apneic serum was assessed by incubating fluorescent-labelled MSC on monolayers of cultured endothelial cells from rat aorta. A wound healing assay was used to investigate the effect of apneic serum on endothelial repair. Results: Apneic serum showed significant increase in chemotaxis in MSC when compared with control serum: the normalized chemotaxis indices were 2.20 +/- 0.58 (m +/- SE) and 1.00 +/- 0.26, respectively (p < 0.05). MSC adhesion to endothelial cells was greater (1.75 +/- 0.14 -fold; p < 0.01) in apneic serum than in control serum. When compared with control serum, apneic serum significantly increased endothelial wound healing (2.01 +/- 0.24 -fold; p < 0.05). Conclusions: The early increases induced by recurrent obstructive apneas in MSC migration, adhesion and endothelial repair suggest that these mechanisms play a role in the physiological response to the challenges associated to OSA.
JTD Keywords: Induced acute lung, Sleep-apnea, Intermitent hypoxia, Cardiovascular-disease, Progenito Cells, Rat model, Inflammation, Mechanisms, Repair, Blood
Garde, A., Sörnmo, L., Jané, R., Giraldo, B., (2010). Breathing pattern characterization in chronic heart failure patients using the respiratory flow signal
Annals of Biomedical Engineering , 38, (12), 3572-3580
This study proposes a method for the characterization of respiratory patterns in chronic heart failure (CHF) patients with periodic breathing (PB) and nonperiodic breathing (nPB), using the flow signal. Autoregressive modeling of the envelope of the respiratory flow signal is the starting point for the pattern characterization. Spectral parameters extracted from the discriminant frequency band (DB) are used to characterize the respiratory patterns. For each classification problem, the most discriminant parameter subset is selected using the leave-one-out cross-validation technique. The power in the right DB provides an accuracy of 84.6% when classifying PB vs. nPB patterns in CHF patients, whereas the power of the DB provides an accuracy of 85.5% when classifying the whole group of CHF patients vs. healthy subjects, and 85.2% when classifying nPB patients vs. healthy subjects.
JTD Keywords: Chronic heart failure, AR modeling, Respiratory pattern, Discriminant band, Periodic and nonperiodic breathing
Caminal, P., Giraldo, B. F., Vallverdu, M., Benito, S., Schroeder, R., Voss, A., (2010). Symbolic dynamic analysis of relations between cardiac and breathing cycles in patients on weaning trials
Annals of Biomedical Engineering , 38, (8), 2542-52
Traditional time-domain techniques of data analysis are often not sufficient to characterize the complex dynamics of the cardiorespiratory interdependencies during the weaning trials. In this paper, the interactions between the heart rate (HR) and the breathing rate (BR) were studied using joint symbolic dynamic analysis. A total of 133 patients on weaning trials from mechanical ventilation were analyzed: 94 patients with successful weaning (group S) and 39 patients that failed to maintain spontaneous breathing (group F). The word distribution matrix enabled a coarse-grained quantitative assessment of short-term nonlinear analysis of the cardiorespiratory interactions. The histogram of the occurrence probability of the cardiorespiratory words presented a higher homogeneity in group F than in group S, measured with a higher number of forbidden words in group S as well as a higher number of words whose probability of occurrence is higher than a probability threshold in group S. The discriminant analysis revealed the best results when applying symbolic dynamic variables. Therefore, we hypothesize that joint symbolic dynamic analysis provides enhanced information about different interactions between HR and BR, when comparing patients with successful weaning and patients that failed to maintain spontaneous breathing in the weaning procedure.
JTD Keywords: Dynamical nonlinearities analysis, Cardiorespiratory interdependencies, Joint symbolic dynamic, Weaning procedure
Rajzer, I., Castano, O., Engel, E., Planell, J. A., (2010). Injectable and fast resorbable calcium phosphate cement for body-setting bone grafts
Journal of Materials Science-Materials in Medicine , 21, (7), 2049-2056
In this work a calcium phosphate (CPC)/polymer blend was developed with the advantage of being moldable and capable of in situ setting to form calcium deficient hydroxyapatite under physiological conditions in an aqueous environment at body temperature. The CPC paste consists in a mix of R cement, glycerol as a liquid phase carrier and a biodegradable hydrogel such as Polyvinyl alcohol, which acts as a binder. Microstructure and mechanical analysis shows that the CPC blend can be used as an injectable implant for low loaded applications and fast adsorption requirements. The storage for commercial distribution was also evaluated and the properties of the materials obtained do not significantly change during storage at -18A degrees C.
JTD Keywords: Clinical-applications, Composites, Regeneration, Behavior, Scaffold, Repair
Pomareda, V., Calvo, D., Pardo, A., Marco, S., (2010). Hard modeling multivariate curve resolution using LASSO: Application to ion mobility spectra
Chemometrics and Intelligent Laboratory Systems , 104, (2), 318-332
Multivariate Curve Resolution (MCR) aims to blindly recover the concentration profile and the source spectra without any prior supervised calibration step. It is well known that imposing additional constraints like positiveness, closure and others may improve the quality of the solution. When a physico-chemical model of the process is known, this can be also introduced constraining even more the solution. In this paper, we apply MCR to Ion Mobility Spectra. Since instrumental models suggest that peaks are of Gaussian shape with a width depending on the instrument resolution, we introduce that each source is characterized by a linear superposition of Gaussian peaks of fixed spread. We also prove that this model is able to fit wider peaks departing from pure Gaussian shape. Instead of introducing a non-linear Gaussian peak fitting, we use a very dense model and rely on a least square solver with L1-norm regularization to obtain a sparse solution. This is accomplished via Least Absolute Shrinkage and Selection Operator (LASSO). Results provide nicely resolved concentration profiles and spectra improving the results of the basic MCR solution.
JTD Keywords: Blind source separation, Ion mobility spectrometry, Multivariate curve resolution, Sparse solution, Non negative matrix factorization
Morgenstern, C., Schwaibold, M., Randerath, W. J., Bolz, A., Jané, R., (2010). An invasive and a noninvasive approach for the automatic differentiation of obstructive and central hypopneas IEEE Transactions on Biomedical Engineering 57, (8), 1927-1936
The automatic differentiation of obstructive and central respiratory events is a major challenge in the diagnosis of sleep-disordered breathing. Esophageal pressure (Pes) measurement is the gold-standard method to identify these events. This study presents a new classifier that automatically differentiates obstructive and central hypopneas with the Pes signal and a new approach for an automatic noninvasive classifier with nasal airflow. An overall of 28 patients underwent night polysomnography with Pes recording, and a total of 769 hypopneas were manually scored by human experts to create a gold-standard annotation set. Features were automatically extracted from the Pes signal to train and test the classifiers (discriminant analysis, support vector machines, and adaboost). After a significantly (p < 0.01) higher incidence of inspiratory flow limitation episodes in obstructive hypopneas was objectively, invasively assessed compared to central hypopneas, the feasibility of an automatic noninvasive classifier with features extracted from the airflow signal was demonstrated. The automatic invasive classifier achieved a mean sensitivity, specificity, and accuracy of 0.90 after a 100-fold cross validation. The automatic noninvasive feasibility study obtained similar hypopnea differentiation results as a manual noninvasive classification algorithm. Hence, both systems seem promising for the automatic differentiation of obstructive and central hypopneas.
JTD Keywords: Automatic differentiation, Central hypopnea, Esophageal pressure (Pes), Inspiratory flow limitation (IFL), Noninvasive classification, Obstructive hypopnea
Caballero, D., Villanueva, G., Plaza, J. A., Mills, C. A., Samitier, J., Errachid, A., (2010). Sharp high-aspect-ratio AFM tips fabricated by a combination of deep reactive ion etching and focused ion beam techniques
Journal of Nanoscience and Nanotechnology , 10, (1), 497-501
The shape and dimensions of an atomic force microscope tip are crucial factors to obtain high resolution images at the nanoscale. When measuring samples with narrow trenches, inclined sidewalls near 90 or nanoscaled structures, standard silicon atomic force microscopy (AFM) tips do not provide satisfactory results. We have combined deep reactive ion etching (DRIE) and focused ion beam (FIB) lithography techniques in order to produce probes with sharp rocket-shaped silicon AFM tips for high resolution imaging. The cantilevers were shaped and the bulk micromachining was performed using the same DRIE equipment. To improve the tip aspect ratio we used FIB nanolithography technique. The tips were tested on narrow silicon trenches and over biological samples showing a better resolution when compared with standard AFM tips, which enables nanocharacterization and nanometrology of high-aspect-ratio structures and nanoscaled biological elements to be completed, and provides an alternative to commercial high aspect ratio AFM tips.
JTD Keywords: Atomic-Force Microscope, Carbon nanotube tips, Probes, Roughness, Cells, Microfabrication, Calibration, Surfaces
Morgenstern, C., Schwaibold, M., Randerath, W., Bolz, A., Jané, R., (2010). Automatic non-invasive differentiation of obstructive and central hypopneas with nasal airflow compared to esophageal pressure Engineering in Medicine and Biology Society (EMBC)
32nd Annual International Conference of the IEEE , IEEE (Buenos Aires, Argentina) , 6142-6145
The differentiation of obstructive and central respiratory events is a major challenge in the diagnosis of sleep disordered breathing. Esophageal pressure (Pes) measurement is the gold-standard method to identify these events but its invasiveness deters its usage in clinical routine. Flattening patterns appear in the airflow signal during episodes of inspiratory flow limitation (IFL) and have been shown with invasive techniques to be useful to differentiate between central and obstructive hypopneas. In this study we present a new method for the automatic non-invasive differentiation of obstructive and central hypopneas solely with nasal airflow. An overall of 36 patients underwent full night polysomnography with systematic Pes recording and a total of 1069 hypopneas were manually scored by human experts to create a gold-standard annotation set. Features were automatically extracted from the nasal airflow signal to train and test our automatic classifier (Discriminant Analysis). Flattening patterns were non-invasively assessed in the airflow signal using spectral and time analysis. The automatic non-invasive classifier obtained a sensitivity of 0.71 and an accuracy of 0.69, similar to the results obtained with a manual non-invasive classification algorithm. Hence, flattening airflow patterns seem promising for the non-invasive differentiation of obstructive and central hypopneas.
JTD Keywords: Practical, Experimental/ biomedical measurement, Feature extraction, Flow measurement, Medical disorders, Medical signal processing, Patient diagnosis, Pneumodynamics, Pressure measurement, Signal classification, Sleep, Spectral analysis/ automatic noninvasive differentiation, Obstructive hypopnea, Central hypopnea, Inspiratory flow limitation, Nasal airflow, Esophageal pressure, Polysomnography, Feature extraction, Discriminant analysis, Spectral analysis
Garde, A., Sörnmo, L., Jané, R., Giraldo, B. F., (2010). Correntropy-based nonlinearity test applied to patients with chronic heart failure Engineering in Medicine and Biology Society (EMBC)
32nd Annual International Conference of the IEEE , IEEE (Buenos Aires, Argentina) , 2399-2402
In this study we propose the correntropy function as a discriminative measure for detecting nonlinearities in the respiratory pattern of chronic heart failure (CHF) patients with periodic or nonperiodic breathing pattern (PB or nPB, respectively). The complexity seems to be reduced in CHF patients with higher risk level. Correntropy reflects information on both, statistical distribution and temporal structure of the underlying dataset. It is a suitable measure due to its capability to preserve nonlinear information. The null hypothesis considered is that the analyzed data is generated by a Gaussian linear stochastic process. Correntropy is used in a statistical test to reject the null hypothesis through surrogate data methods. Various parameters, derived from the correntropy and correntropy spectral density (CSD) to characterize the respiratory pattern, presented no significant differences when extracted from the iteratively refined amplitude adjusted Fourier transform (IAAFT) surrogate data. The ratio between the powers in the modulation and respiratory frequency bands R was significantly different in nPB patients, but not in PB patients, which reflects a higher presence of nonlinearities in nPB patients than in PB patients.
JTD Keywords: Practical, Theoretical or Mathematical, Experimental/cardiology diseases, Fourier transforms, Medical signal processing, Pattern classification, Pneumodynamics, Spectral analysis, Statistical analysis, Stochastic processes/ correntropy based nonlinearity test, Chronic heart failure, Correntropy function, Respiratory pattern nonlinearities, CHF patients, Nonperiodic breathing pattern, Dataset statistical distribution, Dataset temporal structure, Nonlinear information, Null hypothesis, Gaussian linear stochastic process, Statistical test, Correntropy spectral density, Iteratively refined amplitude adjusted Fourier transform, Surrogate data, Periodic breathing pattern
Fernandez, L., Gutierrez-Galvez, A., Marco, S., (2010). Gas sensor array system inspired on the sensory diversity and redundancy of the olfactory epithelium Procedia Engineering
Eurosensor XXIV Conference (ed. Jakoby, B., Vellekoop, M.J.), Elsevier Science BV (Linz, Austria) 5, (0), 25-28
This paper presents a chemical sensing system that takes inspiration from the combination of sensory diversity and redundancy at the olfactory epithelium to enhance the chemical information obtained from the odorants. The system is based on commercial MOS sensors and achieves, first, diversity trough different types of MOS along with modulation of their temperatures, and second redundancy including 12 MOS sensors for each type (12×8) combined with a high-speed multiplexing system that allows connecting 16 load resistors with each and every one of the 96 sensors in about two seconds. Exposition of the system to ethanol, ammonia, and acetone at different concentrations shows how the system is able to capture a large amount of information of the identity and the concentration of the odorant.
JTD Keywords: Gas sensor array, Biologically inspired system, Redundancy, Diversity, MOX sensors, Temperature modulation
Sarlabous, L., Torres, A., Fiz, J. A., Gea, J., Marti nez-Llorens, J. M., Morera, J., Jané, R., (2010). Interpretation of the approximate entropy using fixed tolerance values as a measure of amplitude variations in biomedical signals Engineering in Medicine and Biology Society (EMBC)
32nd Annual International Conference of the IEEE , IEEE (Buenos Aires, Argentina) , 5967-5970
A new method for the quantification of amplitude variations in biomedical signals through moving approximate entropy is presented. Unlike the usual method to calculate the approximate entropy (ApEn), in which the tolerance value (r) varies based on the standard deviation of each moving window, in this work ApEn has been computed using a fixed value of r. We called this method, moving approximate entropy with fixed tolerance values: ApEn/sub f/. The obtained results indicate that ApEn/sub f/ allows determining amplitude variations in biomedical data series. These amplitude variations are better determined when intermediate values of tolerance are used. The study performed in diaphragmatic mechanomyographic signals shows that the ApEn/sub f/ curve is more correlated with the respiratory effort than the standard RMS amplitude parameter. Furthermore, it has been observed that the ApEn/sub f/ parameter is less affected by the existence of impulsive, sinusoidal, constant and Gaussian noises in comparison with the RMS amplitude parameter.
JTD Keywords: Practical, Theoretical or Mathematical/ biomechanics, Entropy, Gaussian noise, Medical signal processing, Muscle, Random processes/ approximate entropy interpretation, Fixed tolerance values, Diaphragmatic mechanomyographic signals, ApEnf curve, Respiratory effort, Gaussian noises
Correa, L. S., Laciar, E., Mut, V., Giraldo, B. F., Torres, A., (2010). Multi-parameter analysis of ECG and Respiratory Flow signals to identify success of patients on weaning trials Engineering in Medicine and Biology Society (EMBC)
32nd Annual International Conference of the IEEE , IEEE (Buenos Aires, Argentina) -----, 6070-6073
Statistical analysis, power spectral density, and Lempel Ziv complexity, are used in a multi-parameter approach to analyze four temporal series obtained from the Electrocardiographic and Respiratory Flow signals of 126 patients on weaning trials. In which, 88 patients belong to successful group (SG), and 38 patients belong to failure group (FG), i.e. failed to maintain spontaneous breathing during trial. It was found that mean values of cardiac inter-beat and breath durations give higher values for SG than for FG; Kurtosis coefficient of the spectrum of the rapid shallow breathing index is higher for FG; also Lempel Ziv complexity mean values associated with the respiratory flow signal are bigger for FG. Patients were then classified with a pattern recognition neural network, obtaining 80% of correct classifications (81.6% for FG and 79.5% for SG).
JTD Keywords: Electrocardiography, Medical signal processing, Neural nets, Pattern recognition, Pneumodynamics, Signal classification, Statistical analysis, ECG, Kurtosis coefficient, Lempel Ziv complexity, Breath durations, Cardiac interbeat durations, Electrocardiography, Multiparameter analysis, Pattern recognition neural network, Power spectral density, Respiratory flow signals, Signal classification, Spontaneous breathing, Statistical analysis, Weaning trials
Leder, R. S., Schlotthauer, G., Penzel, T., Jané, R., (2010). The natural history of the sleep and respiratory engineering track at EMBC 1988 to 2010 Engineering in Medicine and Biology Society (EMBC)
32nd Annual International Conference of the IEEE , IEEE (Buenos Aires, Argentina) , 288-291
Sleep science and respiratory engineering as medical subspecialties and research areas grew up side-by-side with biomedical engineering. The formation of EMBS in the 1950's and the discovery of REM sleep in the 1950's led to parallel development and interaction of sleep and biomedical engineering in diagnostics and therapeutics.
JTD Keywords: Practical/ biomedical equipment, Biomedical measurement, Patient diagnosis, Patient monitoring, Patient treatment, Pneumodynamics, Sleep/ sleep engineering, Respiratory engineering, Automatic sleep analysis, Automatic sleep interpretation systems, Breathing, Biomedical, Engineering, Diagnostics, Therapeutics, REM sleep, Portable, Measurement, Ambulatory measurement, Monitoring
Casamitjana, M., Pérez, M. C., Aranda, J., Montseny, E., Martin, E. X., (2010). Reliable 3D reconstruction extending pixel-level certainty measures IEEE International Conference on Fuzzy
2010 IEEE World Congress on Computational Intelligence , IEEE (Barcelona, Spain) , 1-7
A new method for obtaining a three-dimensional volumetric reconstruction from a set of views improving the classical Shape from Silhouette method (SFS) is presented. SFS approaches can be easily accelerated through hardware and software techniques but they are very sensible to errors arising during calibration and segmentation processes so they present difficulties when dealing with real images. This paper proposes a new algorithm which uses the information about pixel segmentation uncertainty contained in each view in order to get a reliable 3D reconstruction of the scene. Aggregation of the projected uncertainties permits to classify scene's voxels by means of a decision rule but also makes it possible to create a three-dimensional confidence map of the scene. As a consequence, the regions where more information is needed can be foreseen. Sample reconstructions from real image sets are presented and evaluated.
JTD Keywords: Calibration, Image classification, Image reconstruction, Image segmentation, 3D reconstruction, Calibration process, Decision rule, Hardware technique, Pixel segmentation, Pixel-level certainty measures, Scene voxel classification, Segmentation process, Shape from silhouette method, Software technique, Three-dimensional confidence map, Three-dimensional volumetric reconstruction
Arcentales, A., Giraldo, B. F., Caminal, P., Diaz, I., Benito, S., (2010). Spectral analysis of the RR series and the respiratory flow signal on patients in weaning process Engineering in Medicine and Biology Society (EMBC)
32nd Annual International Conference of the IEEE , IEEE (Buenos Aires, Argentina) , 2485-2488
A considerable number of patients in weaning process have problems to keep spontaneous breathing during the trial and after it. This study proposes to extract characteristic parameters of the RR series and respiratory flow signal according to the patients' condition in weaning test. Three groups of patients have been considered: 93 patients with successful trials (group S), 40 patients that failed to maintain spontaneous breathing (group F), and 21 patients who had successful weaning trials, but that had to be reintubated before 48 hours (group R). The characterization was performed using spectral analysis of the signals, through the power spectral density, cross power spectral density and Coherence method. The parameters were extracted on the three frequency bands (VLF, LF and HF), and the principal statistical differences between groups were obtained in bands of VLF and HF. The results show an accuracy of 76.9% in the classification of the groups S and F.
JTD Keywords: Biomedical measurement, Electrocardiography, Medical signal processing, Pneumodynamics, Spectral analysis, RR series, Coherence method, Cross power spectral density, Electrocardiography, Principal statistical differences, Respiratory flow signal, Spectral analysis, Spontaneous breathing, Weaning test
Andonovski, B., Ponsa, P., Casals, A., (2010). Towards the development of a haptics guideline in human-robot systems 3rd International Conference on Human System Interactions (HSI)
3rd International Conference on Human System Interactions (HSI) (ed. Pardela, T.), IEEE (Rzeszow, Poland) , 380-387
The main goal of this work is to propose a haptics guideline in human-robot systems focused on the relationship between the human and robot task, the use of a physical interface and the object to manipulate. With this aim, this guideline presents two main parts: a set of heuristic indicators and a qualitative evaluation. In order to assess its ergonomic validation, an application over a well known haptics interface is presented. The final goal of this work is the study of possible applications in regular laboratory conditions in order to improve the design and use of human-robot haptic interfaces in telerobotics applications.
JTD Keywords: Haptic interface design, Human-robot interaction, Surgical applications, Teleoperation
Fernàndez-Busquets, X., Körnig, A., Bucior, I., Burger, M. M., Anselmetti, D., (2009). Self-recognition and Ca2+-dependent carbohydrate-carbohydrate cell adhesion provide clues to the cambrian explosion
Molecular Biology and Evolution , 26, (11), 2551-2561
The Cambrian explosion of life was a relatively short period approximately 540 Ma that marked a generalized acceleration in the evolution of most animal phyla, but the trigger of this key biological event remains elusive. Sponges are the oldest extant Precambrian metazoan phylum and thus a valid model to study factors that could have unleashed the rise of multicellular animals. One such factor is the advent of self-/non-self-recognition systems, which would be evolutionarily beneficial to organisms to prevent germ-cell parasitism or the introduction of deleterious mutations resulting from fusion with genetically different individuals. However, the molecules responsible for allorecognition probably evolved gradually before the Cambrian period, and some other (external) factor remains to be identified as the missing triggering event. Sponge cells associate through calcium-dependent, multivalent carbohydrate-carbohydrate interactions of the g200 glycan found on extracellular proteoglycans. Single molecule force spectroscopy analysis of g200-g200 binding indicates that calcium affects the lifetime (+Ca/-Ca: 680 s/3 s) and bond reaction length (+Ca/-Ca: 3.47 /2.27). Calculation of mean g200 dissociation times in low and high calcium within the theoretical framework of a cooperative binding model indicates the nonlinear and divergent characteristics leading to either disaggregated cells or stable multicellular assemblies, respectively. This fundamental phenomenon can explain a switch from weak to strong adhesion between primitive metazoan cells caused by the well-documented rise in ocean calcium levels at the end of Precambrian time. We propose that stronger cell adhesion allowed the integrity of genetically uniform animals composed only of "self" cells, facilitating genetic constitutions to remain within the metazoan individual and be passed down inheritance lines. The Cambrian explosion might have been triggered by the coincidence in time of primitive animals endowed with self-/non-self-recognition and of a surge in seawater calcium that increased the binding forces between their calcium-dependent cell adhesion molecules.
JTD Keywords: Calcium, Cambrian explosion, Carbohydrates, Cell adhesion, Origin of Metazoa, Sponges
Nicolas, O., Gavin, R., Del Rio, J. A., (2009). New insights into cellular prion protein (PrPc) functions: The "ying and yang" of a relevant protein
Brain Research Reviews , 61, (2), 170-184
The conversion of cellular prion protein (PrPc) a GPI-anchored protein, into a protease-K-resistant and infective form (generally termed PrPsc) is mainly responsible for Transmissible Spongiform Encephalopathies (TSEs), characterized by neuronal degeneration and progressive loss of basic brain functions. Although PrPc is expressed by a wide range of tissues throughout the body, the complete repertoire of its functions has not been fully deter-mined. Recent studies have confirmed its participation in basic physiological processes such as cell proliferation and the regulation of cellular homeostasis. Other studies indicate that PrPc interacts with several molecules to activate signaling cascades with a high number of cellular effects. To deter-mine PrPc functions, transgenic mouse models have been generated in the last decade. In particular, mice lacking specific domains of the PrPc protein have revealed the contribution of these domains to neurodegenerative processes. A dual role of PrPc has been shown, since most authors report protective roles for this protein while others describe pro-apoptotic functions. in this review, we summarize new findings on PrPc functions, especially those related to neural degeneration and cell signaling.
JTD Keywords: Prion, Doppel, Shadoo, Cell death, Cell proliferation, Cell differentiation
Fernandez, Javier G., Mills, C. A., Samitier, J., (2009). Complex microstructured 3D surfaces using chitosan biopolymer Small 5, (5), 614-620
A technique for producing micrometer-scale structures over large, nonplanar chitosan surfaces is described. The technique makes use of the rheological characteristics (deformability) of the chitosan to create freestanding, three-dimensional scaffolds with controlled shapes, incorporating defined microtopography. The results of an investigation into the technical limits of molding different combinations of shapes and microtopographies are presented, highlighting the versatility of the technique when used irrespectively with inorganic or delicate organic moulds. The final, replicated scaffolds presented here are patterned with arrays of one-micrometer-tall microstructures over large areas. Structural integrity is characterized by the measurement of structural degradation. Human umbilical vein endothelial cells cultured on a tubular scaffold show that early cell growth is conditioned by the microtopography and indicate possible uses for the structures in biomedical applications. For those applications requiring improved chemical and mechanical resistance, the structures can be replicated in poly(dimethyl siloxane).
JTD Keywords: Biocompatible Materials/ chemistry, Cell Adhesion, Cell Culture Techniques/ methods, Cell Proliferation, Cells, Cultured, Chitosan/ chemistry, Crystallization/methods, Endothelial Cells/ cytology/ physiology, Humans, Materials Testing, Nanostructures/ chemistry/ ultrastructure, Nanotechnology/methods, Particle Size, Surface Properties, Tissue Engineering/methods
Carreras, A., Almendros, I., Acerbi, I., Montserrat, J. M., Navajas, D., Farre, R., (2009). Obstructive apneas induce early release of mesenchymal stem cells into circulating blood
Sleep , 32, (1), 117-119
STUDY OBJECTIVES: To investigate whether noninvasive application of recurrent airway obstructions induces early release of mesenchymal stem cells into the circulating blood in a rat model of obstructive sleep apnea. DESIGN: Prospective controlled animal study. SETTING: University laboratory. PATIENTS OR PARTICIPANTS: Twenty male Sprague-Dawley rats (250-300 g). INTERVENTIONS: A specially designed nasal mask was applied to the anesthetized rats. Ten rats were subjected to a pattern of recurrent obstructive apneas (60 per hour, lasting 15 seconds each) for 5 hours. Ten anesthetized rats were used as controls. MEASUREMENTS AND RESULTS: Mesenchymal stem cells from the blood and bone marrow samples were isolated and cultured to count the total number of colony-forming unit fibroblasts (CFU-F) of adherent cells after 9 days in culture. The number of CFU-F from circulating blood was significantly (P = 0.02) higher in the rats subjected to recurrent obstructive apneas (5.00 +/- 1.16; mean +/- SEM) than in controls (1.70 +/- 0.72). No significant (P = 0.54) differences were observed in CFU-F from bone marrow. CONCLUSIONS: Application of a pattern of airway obstructions similar to those experienced by patients with sleep apnea induced an early mobilization of mesenchymal stem cells into circulating blood.
JTD Keywords: Adipocytes/cytology, Animals, Blood Cell Count, Bone Marrow Cells/ cytology, Cell Adhesion/physiology, Cell Count, Cell Differentiation/physiology, Cell Division/physiology, Disease Models, Animal, Fibroblasts/cytology, Male, Mesenchymal Stem Cells/ cytology, Osteocytes/cytology, Rats, Rats, Sprague-Dawley, Sleep Apnea, Obstructive/ blood, Stem Cells/cytology
Sellares, J., Acerbi, I., Loureiro, H., Dellaca, R. L., Ferrer, M., Torres, A., Navajas, D., Farre, R., (2009). Respiratory impedance during weaning from mechanical ventilation in a mixed population of critically ill patients
British Journal of Anaesthesia , 103, (6), 828-832
Worsening of respiratory mechanics during a spontaneous breathing trial (SBT) has been traditionally associated with weaning failure, although this finding is based on studies with chronic obstructive pulmonary disease patients only. The aim of our study was to assess the course of respiratory impedance non-invasively measured by forced oscillation technique (FOT) during a successful and failed SBT in a mixed population. Thirty-four weaning trials were reported in 29 consecutive mechanically ventilated patients with different causes of initiation of ventilation. During the SBT, the patient was breathing through a conventional T-piece connected to the tracheal tube. FOT (5 Hz, +/- 1 cm H2O, 30 s) was applied at 5, 10, 15, 20, 25, and 30 min. Respiratory resistance (Rrs) and reactance (Xrs) were computed from pressure and flow measurements. The frequency to tidal volume ratio f/V-t was obtained from the flow signal. At the end of the trial, patients were divided into two groups: SBT success and failure. Mixed model analysis showed no significant differences in Rrs and Xrs over the course of the SBT, or between the success (n=16) and the failure (n=18) groups. In contrast, f/V-t was significantly (P < 0.001) higher in the failure group. Worsening of respiratory impedance measured by FOT is not a common finding during a failed SBT in a typically heterogeneous intensive care unit population of mechanically ventilated patients.
JTD Keywords: Ventilation, High frequency oscillation, Ventilation, Mechanical, Ventilation, Respiratory impedance
Nussio, M. R., Oncins, G., Ridelis, I., Szili, E., Shapter, J. G., Sanz, F., Voelcker, N. H., (2009). Nanomechanical characterization of phospholipid bilayer islands on flat and porous substrates: A force spectroscopy study
Journal of Physical Chemistry B , 113, (30), 10339-10347
In this study, we compare for the first time the nanomechanical properties of lipid bilayer islands on flat and porous surfaces. 1,2-Dimyzistoyl-sn-glycero-3-phosphatidylcholine (DMPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) bilayers were deposited on flat (silicon and mica) and porous silicon (pSi) substrate surfaces and examined using atomic force spectroscopy and force volume imaging. Force spectroscopy measurements revealed the effects of the underlying substrate and of the lipid phase on the nanomechanical properties of bilayers islands. For mica and silicon, significant differences in breakthrough force between the center and the edges of bilayer islands were observed for both phospolipids. These differences were more pronounced for DMPC than for DPPC, presumably due to melting effects at the edges of DMPC bilayers. In contrast, bilayer islands deposited on pSi yielded similar breakthrough forces in the central region and along the perimeter of the islands, and those values in turn were similar to those measured along the perimeter of bilayer islands deposited on the flat substrates. The study also demonstrates that pSi is suitable solid support for the formation of pore-spanning phospholipid bilayers with potential applications in transmembrane protein studies, drug delivery, and biosensing.
JTD Keywords: Black lipid-membranes, Gold surfaces, Supported bilayers, Channel activity, Micro-BLMS, Silicon, Proteins, Vesicles, AFM, Temperature measurement
Morgenstern, C., Schwaibold, M., Randerath, W. J., Bolz, A., Jané, R., (2009). Assessment of changes in upper airway obstruction by automatic identification of inspiratory flow limitation during sleep IEEE Transactions on Biomedical Engineering 56, (8), 2006-2015
New techniques for automatic invasive and noninvasive identification of inspiratory flow limitation (IFL) are presented. Data were collected from 11 patients with full nocturnal polysomnography and gold-standard esophageal pressure (Pes) measurement. A total of 38,782 breaths were extracted and automatically analyzed. An exponential model is proposed to reproduce the relationship between Pes and airflow of an inspiration and achieve an objective assessment of changes in upper airway obstruction. The characterization performance of the model is appraised with three evaluation parameters: mean-squared error when estimating resistance at peak pressure, coefficient of determination, and assessment of IFL episodes. The model's results are compared to the two best-performing models in the literature. The obtained gold-standard IFL annotations were then employed to train, test, and validate a new noninvasive automatic IFL classification system. Discriminant analysis, support vector machines, and Adaboost algorithms were employed to objectively classify breaths noninvasively with features extracted from the time and frequency domains of the breaths' flowpatterns. The results indicated that the exponential model characterizes IFL and subtle relative changes in upper airway obstruction with the highest accuracy and objectivity. The new noninvasive automatic classification system also succeeded in identifying IFL episodes, achieving a sensitivity of 0.87 and a specificity of 0.85.
JTD Keywords: Esophageal pressure, Exponential model, Inspiratory flow limitation, Noninvasive, Classification, Upper airway obstruction
Munoz, L. M., Casals, A., (2009). Improving the human-robot interface through adaptive multispace transformation
IEEE Transactions on Robotics , 25, (5), 1208-1213
Teleoperation is essential for applications in which, despite the availability of a precise geometrical definition of the working area, a task cannot be explicitly programmed. This paper describes a method of assisted teleoperation that improves the execution of such tasks in terms of ergonomics, precision, and reduction of execution time. The relationships between the operating spaces corresponding to the human-robot interface triangle are analyzed. The proposed teleoperation aid is based on applying adaptive transformations between these spaces.
JTD Keywords: Human factors, Human-robot interaction, Teleoperation
Kirchhof, K., Hristova, K., Krasteva, N., Altankov, G., Groth, T., (2009). Multilayer coatings on biomaterials for control of MG-63 osteoblast adhesion and growth
Journal of Materials Science: Materials in Medicine , 20, (4), 897-907
Here, the layer-by-layer technique (LbL) was used to modify glass as model biomaterial with multilayers of chitosan and heparin to control the interaction with MG-63 osteoblast-like cells. Different pH values during multilayer formation were applied to control their physico-chemical properties. In the absence of adhesive proteins like plasma fibronectin (pFN) both plain layers were rather cytophobic. Hence, the preadsorption of pFN was used to enhance cell adhesion which was strongly dependent on pH. Comparing the adhesion promoting effects of pFN with an engineered repeat of the FN III fragment and collagen I which both lack a heparin binding domain it was found that multilayers could bind pFN specifically because only this protein was capable of promoting cell adhesion. Multilayer surfaces that inhibited MG-63 adhesion did also cause a decreased cell growth in the presence of serum, while an enhanced adhesion of cells was connected to an improved cell growth.
JTD Keywords: Cell-adhesion, Polyelectrolyte multilayers, Substratum chemistry, Surface-properties, Fibroblast-growth, Fibronectin, Polymers, Chitosan, Polysaccharides, Wettability
Puig, F., Gavara, N., Sunyer, R., Carreras, A., Farre, R., Navajas, D., (2009). Stiffening and contraction induced by dexamethasone in alveolar epithelial cells
Experimental Mechanics , 49, (1), 47-55
The structural integrity of the alveolar monolayer, which is compromised during lung inflammation, is determined by the balance between cell-cell and cell-matrix tethering forces and the centripetal forces owing to cell viscoelasticity and contraction. Dexamethasone is an anti-inflammatory glucocorticoid with protective effects in lung injury. To determine the effects of Dexamethasone on the stiffness and contractility of alveolar epithelial cells. Cell stiffness (G') and average traction exerted by the cell (T) were measured by magnetic twisting cytometry and by traction microscopy, respectively. A549 cells were treated 24 h with Dexamethasone (1 mu M) or vehicle (control). G' and T were measured before and 5 min after challenge with the inflammatory mediator Thrombin (0.5 U/ml). Changes induced by Dexamethasone in actin cytoskeleton polymerization were assessed by the fluorescent ratio between F-actin and G-actin obtained by staining cells with phalloidin and DNase I. Dexamethasone significantly increased G' and T by 56% (n = 11; p < 0.01) and by 80% (n = 17; p < 0.05), respectively. Dexamethasone also increased F/G-actin ratio from 2.68 +/- 0.07 to 2.96 +/- 0.09 (n = 10; p < 0.05). The relative increase in stiffness and contraction induced by Thrombin in control cells was significantly (p < 0.05) reduced by Dexamethasone treatment: from 190 to 98% in G' and from 318 to 105% in T. The cytoskeleton remodelling and the increase in cell stiffness and contraction induced by Dexamethasone could account for its protective effect in the alveolar epithelium when subjected to inflammatory challenge.
JTD Keywords: Cell mechanics, Cytoskeleton, Magnetic twisting cytometry, Traction microscopy, Respiratory diseases
Caballero, D., Samitier, J., Errachid, A., (2009). Submerged nanocontact printing (SnCP) of thiols
Journal of Nanoscience and Nanotechnology , 9, (11), 6478-6482
Biological patterned surfaces having sub-micron scale resolution are of great importance in many fields of life science and biomedicine. Different techniques have been proposed for surface patterning at the nanoscale. However, most of them present some limitations regarding the patterned area size or are time-consuming. Micro/nanocontact printing is the most representative soft lithography-based technique for surface patterning at the nanoscale. Unfortunately, conventional micro/nanocontact printing also suffers from problems such as diffusion and stamp collapsing that limit pattern resolution. To overcome these problems, a simple way of patterning thiols under liquid media using submerged nanocontact printing (SnCP) over large areas (similar to cm(2)) achieving nanosize resolution is presented. The technique is also low cost and any special equipment neither laboratory conditions are required. Nanostructured poly(dimethyl siloxane) stamps are replicated from commercially available digital video disks. SnCP is used to stamp patterns of 200 nm 1-octadecanethiol lines in liquid media, avoiding ink diffusion and stamp collapsing, over large areas on gold substrates compared with conventional procedures. Atomic force microscopy measurements reveal that the patterns have been successfully transferred with high fidelity. This is an easy, direct, effective and low cost methodology for molecule patterning immobilization which is of interest in those areas that require nanoscale structures over large areas, such as tissue engineering or biosensor applications.
JTD Keywords: Submerged Nanocontact Printing, Replica Molding, Nanopatterning, Large Area, Dip-pen nanolithography, High-aspect-ratio, Soft lithography, Submicronscale, Nanoimprint lithography, Thin-film, Surfaces, Fabrication, Proteins, Nanofabrication
Casals, A., Frigola, M., Amat, J., (2009). Robotics, a valuable tool in surgery
Revista Iberoamericana de Automatica e Informatica Industrial , 6, (1), 5-19
Continuous advances on diagnostic techniques based on medical images, as well as the incorporation of new techniques in surgical instruments are progressively changing the new surgical procedures. Also, new minimally invasive techniques, which are currently highly consolidated, have produced significant advances, both from the technological and from the surgical treatment perspectives. The limitations that the manual realization of surgical interventions implies, in what refers to precision and accessibility, can be tackled with the help of robotics. In the same way, sensor based robot control techniques are opening new possibilities for the introduction of more improvements in these procedures, either relying on teleoperation, in which the surgeon and the robot establish their best synergy to get the optimal results, or by means of the automation of some specific actions or tasks. In this article the effect of robotics in the evolution of surgical techniques is described. Starting with a review of the robotics application fields, the article continues analyzing the methods and technologies involved in the process of robotizing surgical procedures, as well as the surgeon-robot interaction systems.
JTD Keywords: Robotics, Medical Applications, Teleoperation, Biomedical Systems, Computer Aided Surgery, Human-Machine Interaction
Marco, S., Pomareda, V., Pardo, A., Kessler, M., Goebel, J., Mueller, G., (2009). Blind source separation for ion mobility spectra Olfaction and Electronic Nose: Proceedings of the 13th International Symposium on Olfaction and Electronic Nose
13th International Symposium on Olfaction and the Electronic Nose (ed. Pardo, M., Sberveglieri, G.), Amer Inst Physics (Brescia, Italy) 1137, 551-553
Miniaturization is a powerful trend for smart chemical instrumentation in a diversity of applications.. It is know that miniaturization in IMS leads to a degradation of the system characteristics. For the present work, we are interested in signal processing solutions to mitigate limitations introduced by limited drift tube length that basically involve a loss of chemical selectivity. While blind source separation techniques (BSS) are popular in other domains, their application for smart chemical instrumentation is limited. However, in some conditions, basically linearity, BSS may fully recover the concentration time evolution and the pure spectra with few underlying hypothesis. This is extremely helpful in conditions where non-expected chemical interferents may appear, or unwanted perturbations may pollute the spectra. SIMPLISMA has been advocated by Harrington et al. in several papers. However, more modem methods of BSS for bilinear decomposition with the restriction of positiveness have appeared in the last decade. In order to explore and compare the performances of those methods a series of experiments were performed.
JTD Keywords: Ion Mobility Spectrometry (IMS), Blind Source Separation (BSS), Multivariate Analysis, SIMPLISMA, MCR, Non-Negative Matrix Factorization (NMF)
Colomer-Farrarons, J., Miribel-Catala, P. L., Samitier, J., Arundell, M., Rodriguez, I., (2009). Design of a miniaturized electrochemical instrument for in-situ O/sub 2/ monitoring Sensors and Signal Conditioning
VLSI Circuits and Systems IV , SPIE (Desdren, Germany) 7363, 73630A
The authors are working toward the design of a device for the detection of oxygen, following a discrete and an integrated instrumentation implementation. The discrete electronics are also used for preliminary analysis, to confirm the validity of the conception of system, and its set-up would be used in the characterization of the integrated device, waiting for the chip fabrication. This paper presents the design of a small and portable potentiostat integrated with electrodes, which is cheap and miniaturized, which can be applied for on-site measurements for the simultaneous detection of O/sub 2/ and temperature in water systems. As a first approach a discrete PCB has been designed based on commercial discrete electronics and specific oxygen sensors. Dissolved oxygen concentration (DO) is an important index of water quality and the ability to measure the oxygen concentration and temperature at different positions and depths would be an important attribute to environmental analysis. Especially, the objective is that the sensor and the electronics can be integrated in a single encapsulated device able to be submerged in environmental water systems and be able to make multiple measurements. For our proposed application a small and portable device is developed, where electronics and sensors are miniaturized and placed in close proximity to each other. This system would be based on the sensors and electronics, forming one module, and connected to a portable notebook to save and analyze the measurements on-line. The key electronics is defined by the potentiostat amplifier, used to fix the voltage between the working (WE) and reference (RE) electrodes following an input voltage (Vin). Vin is a triangular signal, programmed by a LabView/sup c / interface, which is also used to represent the CV transfers. To obtain a smaller and compact solution the potentiostat amplifier has also been integrated defining a full custom ASIC amplifier, which is in progress, looking for a point-of-care device. These circuits have been designed with a 0.13 mu m technology from ST Microelectronics through the CMP-TIMA service.
JTD Keywords: Amplifiers, Application specific integrated circuits, Chemical sensors, Electrodes, Portable instruments, Temperature measurement, Water sources
Rodriguez-Segui, S. A., Bucior, I., Burger, M. M., Errachid, A., Fernàndez-Busquets, X., (2009). Application of the quartz crystal microbalance to the study of multivalent carbohydrate-carbohydrate adhesion Sensor Letters
6th Maghreb-Europe Meeting on Materials and Their Applications for Devices and Physical, Chemical and Biological Sensors , AMER SCIENTIFIC PUBLISHERS (Rabat, Morocco) 7, (5), 782-787
Carbohydrate-carbohydrate interactions in cell adhesion are being increasingly explored as important players in cell-cell and cell-extracellular matrix interactions that are characterized by finelytuned on-off rates. The emerging field of glycomics requires the application of new methodologies to the study of the generally weak and multivalent carbohydrate binding sites. Here we use the quartz crystal microbalance (QCM) for the analysis of the self-binding activity of the g200 glycan, a molecule of marine sponge origin that is responsible for Ca2+-dependent species-specific cell adhesion. The QCM has the advantages over other highly sensitive techniques of having only one of the interacting partners bound to a surface, and of lacking microfluidics circuits prone to be clogged by self-aggregating glycans. Our results show that g200 self-interaction is negligible in the absence of Ca2+. Different association kinetics at low and high Ca2+ concentrations suggest the existence of two different Ca2+ binding sites in g200. Finally, the observation of a non-saturable binding indicates that g200 has more than one self-adhesion site per molecule. This work represents the first report to date using the QCM to study carbohydrate-carbohydrate interactions involved in cell adhesion.
JTD Keywords: Ca2+-dependent binding, Carbohydrate-carbohydrate interaction, Cell adhesion, Proteoglycan, Quartz crystal microbalance, Sponges
Engel, E., Michiardi, A., Navarro, M., Lacroix, D., Planell, J. A., (2008). Nanotechnology in regenerative medicine: the materials side
Trends in Biotechnology , 26, (1), 39-47
Regenerative medicine is an emerging multidisciplinary field that aims to restore, maintain or enhance tissues and hence organ functions. Regeneration of tissues can be achieved by the combination of living cells, which will provide biological functionality, and materials, which act as scaffolds to support cell proliferation. Mammalian cells behave in vivo in response to the biological signals they receive from the surrounding environment, which is structured by nanometre-scaled components. Therefore, materials used in repairing the human body have to reproduce the correct signals that guide the cells towards a desirable behaviour. Nanotechnology is not only an excellent tool to produce material structures that mimic the biological ones but also holds the promise of providing efficient delivery systems. The application of nanotechnology to regenerative medicine is a wide issue and this short review will only focus on aspects of nanotechnology relevant to biomaterials science. Specifically, the fabrication of materials, such as nanoparticles and scaffolds for tissue engineering, and the nanopatterning of surfaces aimed at eliciting specific biological responses from the host tissue will be addressed.
JTD Keywords: Animals, Biocompatible Materials/ metabolism, Humans, Nanoparticles, Nanotechnology/ methods, Regenerative Medicine/ methods, Tissue Scaffolds
Bravo, R., Arimon, M., Valle-Delgado, J. J., Garcia, R., Durany, N., Castel, S., Cruz, M., Ventura, S., Fernàndez-Busquets, X., (2008). Sulfated polysaccharides promote the assembly of amyloid beta(1-42) peptide into stable fibrils of reduced cytotoxicity
Journal of Biological Chemistry , 283, (47), 32471-32483
The histopathological hallmarks of Alzheimer disease are the self-aggregation of the amyloid beta peptide (A beta) in extracellular amyloid fibrils and the formation of intraneuronal Tau filaments, but a convincing mechanism connecting both processes has yet to be provided. Here we show that the endogenous polysaccharide chondroitin sulfate B (CSB) promotes the formation of fibrillar structures of the 42-residue fragment, A beta(1-42). Atomic force microscopy visualization, thioflavin T fluorescence, CD measurements, and cell viability assays indicate that CSB-induced fibrils are highly stable entities with abundant beta-sheet structure that have little toxicity for neuroblastoma cells. We propose a wedged cylinder model for A beta(1-42) fibrils that is consistent with the majority of available data, it is an energetically favorable assembly that minimizes the exposure of hydrophobic areas, and it explains why fibrils do not grow in thickness. Fluorescence measurements of the effect of different A beta(1-42) species on Ca2+ homeostasis show that weakly structured nodular fibrils, but not CSB-induced smooth fibrils, trigger a rise in cytosolic Ca2+ that depends on the presence of both extracellular and intracellular stocks. In vitro assays indicate that such transient, local Ca2+ increases can have a direct effect in promoting the formation of Tau filaments similar to those isolated from Alzheimer disease brains.
JTD Keywords: AFM, Alzheimers-disease, Chondroitin sulfate, Heparan-sulfate, Lipid-bilayers, Beta-peptide, In-vitro, Neurodegenerative diseases, Extracellular-matrix, Prion protein
Engel, E., Del Valle, S., Aparicio, C., Altankov, G., Asin, L., Planell, J. A., Ginebra, M. P., (2008). Discerning the role of topography and ion exchange in cell response of bioactive tissue engineering scaffolds
Tissue Engineering Part A , 14, (8), 1341-1351
Surface topography is known to have an influence on osteoblast activity. However, in the case of bioactive materials, topographical changes can affect also ion exchange properties. This makes the problem more complex, since it is often difficult to separate the strictly topographical effects from the effects of ionic fluctuations in the medium. The scope of this paper is to analyze the simultaneous effect of topography and topography-mediated ion exchange on the initial cellular behavior of osteoblastic-like cells cultured on bioactive tissue engineering substrates. Two apatitic substrates with identical chemical composition but different micro/nanostructural features were obtained by low-temperature setting of a calcium phosphate cement. MG63 osteoblastic-like cells were cultured either in direct contact with the substrates or with their extracts. A strong and permanent decrease of calcium concentration in the culture medium, dependent on substrate topography, was detected. A major effect of the substrate microstructure on cell proliferation was observed, explained in part by the topography-mediated ion exchange, but not specifically by the ionic Ca(2+) fluctuations. Cell differentiation was strongly enhanced when cells were cultured on the finer substrate. This effect was not explained by the chemical modification of the medium, but rather suggested a strictly topographical effect.
JTD Keywords: Alkaline Phosphatase/metabolism, Bone Cements/pharmacology, Calcium/metabolism, Calcium Phosphates/pharmacology, Cell Adhesion/drug effects, Cell Differentiation/drug effects, Cell Proliferation/drug effects, Cell Shape/drug effects, Cells, Cultured, Culture Media, Durapatite/pharmacology, Humans, Interferometry, Ion Exchange, Materials Testing, Osteoblasts/ cytology/drug effects/enzymology/ultrastructure, Phosphorus/metabolism, Powders, Tissue Engineering, Tissue Scaffolds
Roca-Cusachs, P., Alcaraz, J., Sunyer, R., Samitier, J., Farre, R., Navajas, D., (2008). Micropatterning of single endothelial cell shape reveals a tight coupling between nuclear volume in G1 and proliferation
Biophysical Journal , 94, (12), 4984-4995
Shape-dependent local differentials in cell proliferation are considered to be a major driving mechanism of structuring processes in vivo, such as embryogenesis, wound healing, and angiogenesis. However, the specific biophysical signaling by which changes in cell shape contribute to cell cycle regulation remains poorly understood. Here, we describe our study of the roles of nuclear volume and cytoskeletal mechanics in mediating shape control of proliferation in single endothelial cells. Micropatterned adhesive islands were used to independently control cell spreading and elongation. We show that, irrespective of elongation, nuclear volume and apparent chromatin decondensation of cells in G1 systematically increased with cell spreading and highly correlated with DNA synthesis (percent of cells in the S phase). In contrast, cell elongation dramatically affected the organization of the actin cytoskeleton, markedly reduced both cytoskeletal stiffness (measured dorsally with atomic force microscopy) and contractility (measured ventrally with traction microscopy), and increased mechanical anisotropy, without affecting either DNA synthesis or nuclear volume. Our results reveal that the nuclear volume in G1 is predictive of the proliferative status of single endothelial cells within a population, whereas cell stiffness and contractility are not. These findings show that the effects of cell mechanics in shape control of proliferation are far more complex than a linear or straightforward relationship. Our data are consistent with a mechanism by which spreading of cells in G1 partially enhances proliferation by inducing nuclear swelling and decreasing chromatin condensation, thereby rendering DNA more accessible to the replication machinery.
JTD Keywords: Cell Line, Cell Nucleus/ physiology, Cell Proliferation, Cell Size, Computer Simulation, Endothelial Cells/ cytology/ physiology, G1 Phase/ physiology, Humans, Mechanotransduction, Cellular/ physiology, Models, Biological, Statistics as Topic
Sanzana, E. S., Navarro, M., Macule, F., Suso, S., Planell, J. A., Ginebra, M. P., (2008). Of the in vivo behavior of calcium phosphate cements and glasses as bone substitutes Acta Biomaterialia 4, (6), 1924-1933
The use of injectable self-setting calcium phosphate cements or soluble glass granules represent two different strategies for bone regeneration, each with distinct advantages and potential applications. This study compares the in vivo behavior of two calcium phosphate cements and two phosphate glasses with different composition, microstructure and solubility, using autologous bone as a control, in a rabbit model. The implanted materials were alpha-tricalcium phosphate cement (cement H), calcium sodium potassium phosphate cement (cement R), and two phosphate glasses in the P2O5-CaO-Na2O and P2O5-CaO-Na2O-TiO2 systems. The four materials were osteoconductive, biocompatible and biodegradable. Radiological and histological studies demonstrated correct osteointegration and substitution of the implants by new bone. The reactivity of the different materials, which depends on their solubility, porosity and specific surface area, affected the resorption rate and bone formation mainly during the early stages of implantation, although this effect was weak. Thus, at 4 weeks the degradation was slightly higher in cements than in glasses, especially for cement R. However, after 12 weeks of implantation all materials showed a similar degradation degree and promoted bone neoformation equivalent to that of the control group.
JTD Keywords: Calcium phosphates, Calcium phosphate cements, Phosphate glasses, Bone grafts, Bone regenerations
Farre, R., Montserrat, J. M., Navajas, D., (2008). Assessment of upper airway mechanics during sleep
Respiratory Physiology & Neurobiology , 163, (1-3), 74-81
Obstructive sleep apnea, which is the most prevalent sleep breathing disorder, is characterized by recurrent episodes of upper airway collapse and reopening. However, the mechanical properties of the upper airway are not directly measured in routine polysomnography because only qualitative sensors (thermistors for flow and thoraco-abdominal bands for pressure) are used. This review focuses on two techniques that quantify upper airway obstruction during sleep. A Starling model of collapsible conduit allows us to interpret the mechanics of the upper airway by means of two parameters: the critical pressure (Pcrit) and the upstream resistance (Rup). A simple technique to measure Pcrit and Rup involves the application of different levels of continuous positive airway pressure (CPAP) during sleep. The forced oscillation technique is another non-invasive procedure for quantifying upper airway impedance during the breathing cycle in sleep studies. The latest developments in these two methods allow them to be easily applied on a routine basis in order to more fully characterize upper airway mechanics in patients with sleep breathing disorders.
JTD Keywords: Obstructive sleep apnea, Upper airway, Airway resistance, Critical pressure, Respiratory impedance
Charles-Harris, M., Koch, M. A., Navarro, M., Lacroix, D., Engel, E., Planell, J. A., (2008). A PLA/calcium phosphate degradable composite material for bone tissue engineering: an in vitro study
Journal of Materials Science-Materials in Medicine , 19, (4), 1503-1513
Biodegradable polymers reinforced with an inorganic phase such as calcium phosphate glasses may be a promising approach to fulfil the challenging requirements presented by 3D porous scaffolds for tissue engineering. Scaffolds' success depends mainly on their biological behaviour. This work is aimed to the in vitro study of polylactic acid (PLA)/CaP glass 3D porous constructs for bone regeneration. The scaffolds were elaborated using two different techniques, namely solvent-casting and phase-separation. The effect of scaffolds' micro and macrostructure on the biological response of these scaffolds was assayed. Cell proliferation, differentiation and morphology within the scaffolds were studied. Furthermore, polymer/glass scaffolds were seeded under dynamic conditions in a custom-made perfusion bioreactor. Results indicate that the final architecture of the solvent-cast or phase separated scaffolds have a significant effect on cells' behaviour. Solvent-cast scaffolds seem to be the best candidates for bone tissue engineering. Besides, dynamic seeding yielded a higher seeding efficiency in comparison with the static method.
JTD Keywords: Biocompatible Materials/ chemistry, Bone and Bones/ metabolism, Calcium Phosphates/ chemistry, Cell Differentiation, Cell Proliferation, Humans, Lactic Acid/ chemistry, Microscopy, Confocal, Microscopy, Electron, Scanning, Osteoblasts/metabolism, Permeability, Polymers/ chemistry, Porosity, Solvents/chemistry, Tissue Engineering/ methods
Gustavsson, J., Altankov, G., Errachid, A., Samitier, J., Planell, J. A., Engel, E., (2008). Surface modifications of silicon nitride for cellular biosensor applications
Journal of Materials Science-Materials in Medicine , 19, (4), 1839-1850
Thin films of silicon nitride (Si3N4) can be used in several kinds of micro-sized biosensors as a material to monitor fine environmental changes related to the process of bone formation in vitro. We found however that Si3N4 does not provide optimal conditions for osseointegration as osteoblast-like MG-63 cells tend to detach from the surface when cultured over confluence. Therefore Si3N4 was modified with self-assembled monolayers bearing functional end groups of primary amine (NH2) and carboxyl (COOH) respectively. Both these modifications enhanced the interaction with confluent cell layers and thus improve osseointegration over Si3N4. Furthermore it was observed that the NH2 functionality increased the adsorption of fibronectin (FN), promoted cell proliferation, but delayed the differentiation. We also studied the fate of pre-adsorbed and secreted FN from cells to learn more about the impact of above functionalities for the development of provisional extracellular matrix on materials interface. Taken together our data supports that Si3N4 has low tissue integration but good cellular biocompatibility and thus is appropriate in cellular biosensor applications such as the ion-sensitive field effect transistor (ISFET). COOH and NH2 chemistries generally improve the interfacial tissue interaction with the sensor and they are therefore suitable substrates for monitoring cellular growth or matrix deposition using electrical impedance spectroscopy.
JTD Keywords: Adsorption, Amines/chemistry, Biocompatible Materials/ chemistry, Biosensing Techniques, Cell Differentiation, Cell Line, Cell Proliferation, Electric Impedance, Extracellular Matrix/metabolism, Fibronectins/chemistry, Humans, Materials Testing, Osteoblasts/ cytology, Silicon Compounds/ chemistry, Surface Properties
Udina, S., Pardo, A., Marco, S., Santander, J., Fonseca, L., (2008). Thermoelectric MEMS sensors for natural gas analysis Electronic Proceedings of the Seventh IEEE Sensors Conference 2008
Sensors, 2008 IEEE (ed. Frech, P., Siciliano, P.), IEEE (Lecce, Italy) , 1364-1367
T Multivariate data analysis techniques have been used for the first time in thermoelectric MEMS sensors in order to determine the composition of natural gas mixtures. Experimental measurements with different thermoelectric devices have been performed, the gathered data have been used to calibrate the sensor responses to four main components of natural gas: CH4, C2H6, N2 and CO2. Presence of the three first components was predicted with good accuracy while CO2 prediction was poor. Presented results indicate that thremoelectric sensors operated at different heater temperatures open the possibility of low-cost natural gas analysis.
JTD Keywords: Natural gas, Multivariate calibration, Thermal conductivity, Thermal sensor
Orini, Michele, Giraldo, Beatriz F., Bailon, Raquel, Vallverdu, Montserrat, Mainardi, Luca, Benito, Salvador, Diaz, Ivan, Caminal, Pere, (2008). Time-frequency analysis of cardiac and respiratory parameters for the prediction of ventilator weaning IEEE Engineering in Medicine and Biology Society Conference Proceedings
30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (ed. IEEE), IEEE (Vancouver, Canada) 1-8, 2793-2796
Mechanical ventilators are used to provide life support in patients with respiratory failure. Assessing autonomic control during the ventilator weaning provides information about physiopathological imbalances. Autonomic parameters can be derived and used to predict success in discontinuing from the mechanical support. Time-frequency analysis is used to derive cardiac and respiratory parameters, as well as their evolution in time, during ventilator weaning in 130 patients. Statistically significant differences have been observed in autonomic parameters between patients who are considered ready for spontaneous breathing and patients who are not. A classification based on respiratory frequency, heart rate and heart rate variability spectral components has been proposed and has been able to correctly classify more than 80% of the cases.
JTD Keywords: Automatic Data Processing, Databases, Factual, Electrocardiography, Humans, Models, Statistical, Respiration, Respiration, Artificial, Respiratory Insufficiency, Respiratory Mechanics, Respiratory Muscles, Signal Processing, Computer-Assisted, Time Factors, Ventilator Weaning, Ventilators, Mechanical, Work of Breathing
Mills, C. A., Pla, M., Martin, C., Lee, M., Kuphal, M., Sisquella, X., Martinez, E., Errachid, A., Samitier, J., (2007). Structured thin organic active layers and their use in electrochemical biosensors
Measurement & Control , 40, (3), 88-91
Rodriguez, Segui, Bucior, I., Burger, M. M., Samitier, J., Errachid, A., Fernàndez-Busquets, X., (2007). Application of a bio-QCM to study carbohydrates self-interaction in presence of calcium Transducers '07 & Eurosensors Xxi, Digest of Technical Papers
14th International Conference on Solid-State Sensors, Actuators and Microsystems , IEEE (Lyon, France) 1-2, 1995-1998
In the past years, the quartz crystal microbalance (QCM) has been successfully applied to follow interfacial physical chemistry phenomena in a label free and real time manner. However, carbohydrate self adhesion has only been addressed partially using this technique. Carbohydrates play an important role in cell adhesion, providing a highly versatile form of attachment, suitable for biologically relevant recognition events in the initial steps of adhesion. Here, we provide a QCM study of carbohydrates' self-recognition in the presence of calcium, based on a species-specific cell recognition model provided by marine sponges. Our results show a difference in adhesion kinetics when varying either the calcium concentration (with a constant carbohydrate concentration) or the carbohydrate concentration (with constant calcium concentration).
JTD Keywords: Biomedical materials, Calcium, Cellular biophysics, Microbalances, Porous materials, Quartz, Surface chemistry/ bio-QCM, Carbohydrates self-interaction, Quartz crystal microbalance, Interfacial physical chemistry phenomena, Carbohydrate self adhesion, Biologically relevant recognition events, Marine sponges, Adhesion kinetics, Calcium concentration, Carbohydrate concentration, Biosensors, Biomedical materials, Surface chemistry, Cellular biophysics
Castellarnau, Marc, Errachid, Abdelhamid, Madrid, Cristina, Juárez, Antonio, Samitier, Josep, (2006). Dielectrophoresis as a tool to characterize and differentiate isogenic mutants of Escherichia coli
Biophysical Journal , 91, (10), 3937-3945
In this study we report on an experimental method based on dielectrophoretic analysis to identify changes in four Escherichia coli isogenic strains that differed exclusively in one mutant allele. The dielectrophoretic properties of wild-type cells were compared to those of hns, hha, and hha hns mutant derivatives. The hns and hha genes code respectively for the global regulators Hha and H-NS. The Hha and H-NS proteins modulate gene expression in Escherichia coli and other Gram negative bacteria. Mutations in either hha or hns genes result in a pleiotropic phenotype. A two-shell prolate ellipsoidal model has been used to fit the experimental data, obtained from dielectrophoresis measurements, and to study the differences in the dielectric properties of the bacterial strains. The experimental results show that the mutant genotype can be predicted from the dielectrophoretic analysis of the corresponding cultures, opening the way to the development of microdevices for specific identification. Therefore, this study shows that dielectrophoresis can be a valuable tool to study bacterial populations which, although apparently homogeneous, may present phenotypic variability.
JTD Keywords: H-NS, Dielectric behaviour, Hemolysin genes, Cells, Separation, Expression, Proteins, HHA, Electrorotation, Polarization
Muñoz, Luis Miguel, Casals, Alícia, Amat, Josep, Puig-Vidal, Manel, Samitier, Josep, (2005). Improved AFM scanning methodology with adaptation to the target shape C3 - Proceedings - IEEE International Conference on Robotics and Automation ICRA 2005
2005 IEEE International Conference on Robotics and Automation , IEEE (Barcelona, Spain) , 1529-1534
This paper presents a manipulation and measurement aid for tasks carried out in micro-nano environments operating with scanning AFM. In teleoperated manipulation or measurement over a given point of the target, where a slow and precise movement is necessary, the developed system increases the accuracy in this point producing a space deformation. In automatic scanning, the adjusted selection of the target, through assisted image segmentation, enables to reduce the working time.
JTD Keywords: Assisted teleoperation, Image segmentation, Micro-nano manipulation, Workspace deformation