by Keyword: Age
Fonte M, Fontinha D, Moita D, Caño-Prades O, Avalos-Padilla Y, Fernàndez-Busquets X, Prudêncio M, Gomes P, Teixeira C, (2023). New 4-(N-cinnamoylbutyl)aminoacridines as potential multi-stage antiplasmodial leads European Journal Of Medicinal Chemistry 258, 115575
A novel family of 4-aminoacridine derivatives was obtained by linking this heteroaromatic core to different trans-cinnamic acids. The 4-(N-cinnamoylbutyl)aminoacridines obtained exhibited in vitro activity in the low- or sub-micromolar range against (i) hepatic stages of Plasmodium berghei, (ii) erythrocytic forms of Plasmodium falciparum, and (iii) early and mature gametocytes of Plasmodium falciparum. The most active compound, having a meta-fluorocinnamoyl group linked to the acridine core, was 20- and 120-fold more potent, respectively, against the hepatic and gametocyte stages of Plasmodium infection than the reference drug, primaquine. Moreover, no cytotoxicity towards mammalian and red blood cells at the concentrations tested was observed for any of the compounds under investigation. These novel conjugates represent promising leads for the development of new multi-target antiplasmodials.Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.
JTD Keywords: agents, analogs, antimalarial, artemisinin, blood-stage, cinnamic acid, gametocyte, hybrid, liver-stage, malaria, multi-target, plasmodium-falciparum, primaquine, quinacrine, resistance, Acridine, Antimalarial, Blood-stage, Cinnamic acid, Cinnamic acid-derivatives, Gametocyte, Hybrid, Liver-stage, Multi-target
Costa, RR, Caballero, D, da Costa, DS, Rodriguez-Trujillo, R, Kundu, SC, Reis, RL, Pashkuleva, I, (2023). Microfluidic-Assisted Interfacial Complexation of Extracellular Matrix Components to Mimic the Properties of Neural Tissues Advanced Materials Technologies , 2300983
Anisotropy is an important cue for neural organization during morphogenesis and healing, contributing to the mechanical and functional properties of neural tissues. The ability to replicate such anisotropy in vitro holds great promise for the development of effective regeneration strategies. In this work, interfacial polyelectrolyte complexation (IPC) is applied to fabricate microfibers from charged ECM components without any chemical modification. Using flow-focusing microfluidics, collagen (Col) and glycosaminoglycans (GAGs), such as chondroitin sulfate (CS) or heparin (Hep), form Col/CS and Col/Hep interfacial complexes that coalesce as IPC microfibers. These fibers are flexible and absorb large amounts of water but remain stable under physiological conditions. At these conditions, the tensile strength of the assembled Col/GAG microfibers is similar to the strength of the neural tissue. The fibers are biocompatible and biofunctional; PC12 neural cells adhere and orient longitudinally to the fibers. Moreover, Col/CS microfibers promote the formation of neural processes. The results demonstrate that the microfluidic-assisted IPC complexation enables the assembly of ECM mimics by synergetic integration of anisotropic, chemical, and mechanical cues that boost the development of neural cells.
JTD Keywords: Cells, Chondroitin sulfate, Collagen, Fibers, Glycosaminoglycans, Heparin, Microfibers
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
Loeck M, Placci M, Muro S, (2023). Effect of acid sphingomyelinase deficiency in type A Niemann-Pick disease on the transport of therapeutic nanocarriers across the blood-brain barrier Drug Delivery And Translational Research
ASM deficiency in Niemann-Pick disease type A results in aberrant cellular accumulation of sphingomyelin, neuroinflammation, neurodegeneration, and early death. There is no available treatment because enzyme replacement therapy cannot surmount the blood-brain barrier (BBB). Nanocarriers (NCs) targeted across the BBB via transcytosis might help; yet, whether ASM deficiency alters transcytosis remains poorly characterized. We investigated this using model NCs targeted to intracellular adhesion molecule-1 (ICAM-1), transferrin receptor (TfR), or plasmalemma vesicle-associated protein-1 (PV1) in ASM-normal vs. ASM-deficient BBB models. Disease differentially changed the expression of all three targets, with ICAM-1 becoming the highest. Apical binding and uptake of anti-TfR NCs and anti-PV1 NCs were unaffected by disease, while anti-ICAM-1 NCs had increased apical binding and decreased uptake rate, resulting in unchanged intracellular NCs. Additionally, anti-ICAM-1 NCs underwent basolateral reuptake after transcytosis, whose rate was decreased by disease, as for apical uptake. Consequently, disease increased the effective transcytosis rate for anti-ICAM-1 NCs. Increased transcytosis was also observed for anti-PV1 NCs, while anti-TfR NCs remained unaffected. A fraction of each formulation trafficked to endothelial lysosomes. This was decreased in disease for anti-ICAM-1 NCs and anti-PV1 NCs, agreeing with opposite transcytosis changes, while it increased for anti-TfR NCs. Overall, these variations in receptor expression and NC transport resulted in anti-ICAM-1 NCs displaying the highest absolute transcytosis in the disease condition. Furthermore, these results revealed that ASM deficiency can differently alter these processes depending on the particular target, for which this type of study is key to guide the design of therapeutic NCs.© 2023. Controlled Release Society.
JTD Keywords: Asm deficiency, Blood–brain barrier, Drug nanocarriers, Icam-1, Lysosomal storage disease, Niemann-pick disease type a, Pv-1, Receptor-mediated transcytosis, Transferrin receptor
Bouras, Abdelwahhab, Gutierrez-Galvez, Agustin, Burgués, Javier, Bouzid, Yasser, Pardo, Antonio, Guiatni, Mohamed, Marco, Santiago, (2023). Concentration map reconstruction for gas source location using nano quadcopters: Metal oxide semiconductor sensor implementation and indoor experiments validation Measurement 213, 112638
Rodríguez-Contreras, Alejandra, Torres, Diego, Piñera-Avellaneda, David, Pérez-Palou, Lluís, Ortiz-Hernández, Mònica, Ginebra, María Pau, Calero, José Antonio, Manero, José María, Rupérez, Elisa, (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
Heras‐Parets, Aina, Ginebra, Maria‐Pau, Manero, Jose Maria, Guillem‐Marti, Jordi, (2023). Guiding Fibroblast Activation Using an RGD‐Mutated Heparin Binding II Fragment of Fibronectin for Gingival Titanium Integration Advanced Healthcare Materials , 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
Almici, E, Arshakyan, M, Carrasco, JL, Martinez, A, Ramirez, J, Enguita, AB, Monso, E, Montero, J, Samitier, J, Alcaraz, J, (2023). Quantitative Image Analysis of Fibrillar Collagens Reveals Novel Diagnostic and Prognostic Biomarkers and Histotype-Dependent Aberrant Mechanobiology in Lung Cancer Modern Pathology 36, 100155
Fibrillar collagens are the most abundant extracellular matrix components in non-small cell lung cancer (NSCLC). However, the potential of collagen fiber descriptors as a source of clinically relevant biomarkers in NSCLC is largely unknown. Similarly, our understanding of the aberrant collagen organization and associated tumor-promoting effects is very scarce. To address these limitations, we identified a digital pathology approach that can be easily implemented in pa-thology units based on CT-FIRE software (version 2; https://loci.wisc.edu/software/ctfire) analysis of Picrosirius red (PSR) stains of fibrillar collagens imaged with polarized light (PL). CT-FIRE set-tings were pre-optimized to assess a panel of collagen fiber descriptors in PSR-PL images of tissue microarrays from surgical NSCLC patients (106 adenocarcinomas [ADC] and 89 squamous cell carcinomas [SCC]). Using this approach, we identified straightness as the single high-accuracy diagnostic collagen fiber descriptor (average area under the curve 1/4 0.92) and fiber density as the single descriptor consistently associated with a poor prognosis in both ADC and SCC inde-pendently of the gold standard based on the TNM staging (hazard ratio, 2.69; 95% CI, 1.55-4.66; P < .001). Moreover, we found that collagen fibers were markedly straighter, longer, and more aligned in tumor samples compared to paired samples from uninvolved pulmonary tissue, particularly in ADC, which is indicative of increased tumor stiffening. Consistently, we observed an increase in a panel of stiffness-associated processes in the high collagen fiber density patient group selectively in ADC, including venous/lymphatic invasion, fibroblast activation (a-smooth muscle actin), and immune evasion (programmed death-ligand 1). Similarly, a transcriptional correlation analysis supported the potential involvement of the major YAP/TAZ pathway in ADC. Our results provide a proof-of-principle to use CT-FIRE analysis of PSR-PL images to assess new collagen fiber-based diagnostic and prognostic biomarkers in pathology units, which may improve the clinical management of patients with surgical NSCLC. Our findings also unveil an aberrant stiff micro -environment in lung ADC that may foster immune evasion and dissemination, encouraging future work to identify therapeutic opportunities. (c) 2023 THE AUTHORS. Published by Elsevier Inc. on behalf of the United States & Canadian Academy of Pathology. This is an open access article under the CC BY-NC-ND license (http://creativecommo ns.org/licenses/by-nc-nd/4.0/).
JTD Keywords: biomarkers, collagen, ct-fire, lung cancer, mechanobiology, Adenocarcinoma, Association, Biomarkers, Collagen, Ct-fire, Differentiation, Expression, Extracellular-matrix, I collagen, Invasion, Lung cancer, Mechanobiology, Microenvironment, Signature, Survival, Tumor microenvironment
Placci, M, Giannotti, MI, Muro, S, (2023). Polymer-based drug delivery systems under investigation for enzyme replacement and other therapies of lysosomal storage disorders Advanced Drug Delivery Reviews 197, 114683
Lysosomes play a central role in cellular homeostasis and alterations in this compartment associate with many diseases. The most studied example is that of lysosomal storage disorders (LSDs), a group of 60 + maladies due to genetic mutations affecting lysosomal components, mostly enzymes. This leads to aberrant intracellular storage of macromolecules, altering normal cell function and causing multiorgan syndromes, often fatal within the first years of life. Several treatment modalities are available for a dozen LSDs, mostly consisting of enzyme replacement therapy (ERT) strategies. Yet, poor biodistribution to main targets such as the central nervous system, musculoskeletal tissue, and others, as well as generation of blocking antibodies and adverse effects hinder effective LSD treatment. Drug delivery systems are being studied to surmount these obstacles, including polymeric constructs and nanoparticles that consti-tute the focus of this article. We provide an overview of the formulations being tested, the diseases they aim to treat, and the results observed from respective in vitro and in vivo studies. We also discuss the advantages and disadvantages of these strategies, the remaining gaps of knowledge regarding their per-formance, and important items to consider for their clinical translation. Overall, polymeric nanocon-structs hold considerable promise to advance treatment for LSDs.(c) 2023 Elsevier B.V. All rights reserved.
JTD Keywords: cellular and animal models, enzyme replacement therapy, lysosomal storage disorders, nanoemulsions, nanoparticles, Beta-glucuronidase deficiency, Blood-brain-barrier, Cellular and animal models, Central-nervous-system, Enzyme replacement therapy, Feline gm1 gangliosidosis, Human acid sphingomyelinase, Human alpha-galactosidase, Lysosomal storage disorders, Mucopolysaccharidosis type-ii, Nanoemulsions, Nanoparticles, Neuronal ceroid-lipofuscinosis, Niemann-pick-disease, Pluripotent stem-cells, Polymer-based drug delivery systems
Román-Álamo, Lucía, Allaw, Mohamad, Avalos-Padilla, Yunuen, Manca, Maria Letizia, Manconi, Maria, Fulgheri, Federica, Fernández-Lajo, Jorge, Rivas, Luis, Vázquez, José Antonio, Peris, José Esteban, Roca-Geronès, Xavier, Poonlaphdecha, Srisupaph, Alcover, Maria Magdalena, Fisa, Roser, Riera, Cristina, Fernàndez-Busquets, Xavier, (2023). In Vitro Evaluation of Aerosol Therapy with Pentamidine-Loaded Liposomes Coated with Chondroitin Sulfate or Heparin for the Treatment of Leishmaniasis Pharmaceutics 15, 1163
The second-line antileishmanial compound pentamidine is administered intramuscularly or, preferably, by intravenous infusion, with its use limited by severe adverse effects, including diabetes, severe hypoglycemia, myocarditis and renal toxicity. We sought to test the potential of phospholipid vesicles to improve the patient compliance and efficacy of this drug for the treatment of leishmaniasis by means of aerosol therapy. The targeting to macrophages of pentamidine-loaded liposomes coated with chondroitin sulfate or heparin increased about twofold (up to ca. 90%) relative to noncoated liposomes. The encapsulation of pentamidine in liposomes ameliorated its activity on the amastigote and promastigote forms of Leishmania infantum and Leishmania pifanoi, and it significantly reduced cytotoxicity on human umbilical endothelial cells, for which the concentration inhibiting 50% of cell viability was 144.2 ± 12.7 µM for pentamidine-containing heparin-coated liposomes vs. 59.3 ± 4.9 µM for free pentamidine. The deposition of liposome dispersions after nebulization was evaluated with the Next Generation Impactor, which mimics human airways. Approximately 53% of total initial pentamidine in solution reached the deeper stages of the impactor, with a median aerodynamic diameter of ~2.8 µm, supporting a partial deposition on the lung alveoli. Upon loading pentamidine in phospholipid vesicles, its deposition in the deeper stages significantly increased up to ~68%, and the median aerodynamic diameter decreased to a range between 1.4 and 1.8 µm, suggesting a better aptitude to reach the deeper lung airways in higher amounts. In all, nebulization of liposome-encapsulated pentamidine improved the bioavailability of this neglected drug by a patient-friendly delivery route amenable to self-administration, paving the way for the treatment of leishmaniasis and other infections where pentamidine is active.
JTD Keywords: aerosol therapy, delivery-systems, drug encapsulation, drugs, ex-vivo models, formulation, leishmania infantum, leishmania pifanoi, leishmaniasis, liposomes, macrophages, miltefosine, pentamidine, pharmacology, pulmonary absorption, visceral leishmaniasis, Amphotericin-b treatment, Leishmania infantum, Pentamidine
Huetter, Larissa, Kyndiah, Adrica, Gomila, Gabriel, (2023). Analytical Physical Model for Electrolyte Gated Organic Field Effect Transistors in the Helmholtz Approximation Advanced Theory And Simulations 6, 2200696
Pizarek, John A., Fischer, Nicholas G., Aparicio, Conrado, (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
Sanmukh, Swapnil Ganesh, Admella, Joana, Moya-Andérico, Laura, Fehér, Tamás, Arévalo-Jaimes, Betsy Verónica, Blanco-Cabra, Núria, Torrents, Eduard, (2023). Accessing the In Vivo Efficiency of Clinically Isolated Phages against Uropathogenic and Invasive Biofilm-Forming Escherichia coli Strains for Phage Therapy Cells 12, 344
Escherichia coli is one of the most common members of the intestinal microbiota. Many of its strains are associated with various inflammatory infections, including urinary or gut infections, especially when displaying antibiotic resistance or in patients with suppressed immune systems. According to recent reports, the biofilm-forming potential of E. coli is a crucial factor for its increased resistance against antibiotics. To overcome the limitations of using antibiotics against resistant E. coli strains, the world is turning once more towards bacteriophage therapy, which is becoming a promising candidate amongst the current personalized approaches to target different bacterial infections. Although matured and persistent biofilms pose a serious challenge to phage therapy, they can still become an effective alternative to antibiotic treatment. Here, we assess the efficiency of clinically isolated phages in phage therapy against representative clinical uropathogenic and invasive biofilm-forming E. coli strains. Our results demonstrate that irrespective of host specificity, bacteriophages producing clear plaques with a high burst size, and exhibiting depolymerizing activity, are good candidates against biofilm-producing E. coli pathogens as verified from our in vitro and in vivo experiments using Galleria mellonella where survival was significantly increased for phage-therapy-treated larvae.
JTD Keywords: antibiotic resistance, assay, bacteriophage, bacteriophages, biofilm-forming potential, infection, inflammatory infections, mechanisms, Galleria-mellonella, Intestinal microflora
Wang, ZH, Klingner, A, Magdanz, V, Hoppenreijs, MW, Misra, S, Khalil, ISM, (2023). Flagellar Propulsion of Sperm Cells Against a Time-Periodic Interaction Force Advanced Biology 7, 2200210
Sperm cells undergo complex interactions with external environments, such as a solid-boundary, fluid flow, as well as other cells before arriving at the fertilization site. The interaction with the oviductal epithelium, as a site of sperm storage, is one type of cell-to-cell interaction that serves as a selection mechanism. Abnormal sperm cells with poor swimming performance, the major cause of male infertility, are filtered out by this selection mechanism. In this study, collinear bundles, consisting of two sperm cells, generate propulsive thrusts along opposite directions and allow to observe the influence of cell-to-cell interaction on flagellar wave-patterns. The developed elasto-hydrodynamic model demonstrates that steric and adhesive forces lead to highly symmetrical wave-pattern and reduce the bending amplitude of the propagating wave. It is measured that the free cells exhibit a mean flagellar curvature of 6.4 +/- 3.5 rad mm(-1) and a bending amplitude of 13.8 +/- 2.8 rad mm(-1). After forming the collinear bundle, the mean flagellar curvature and bending amplitude are decreased to 1.8 +/- 1.1 and 9.6 +/- 1.4 rad mm(-1), respectively. This study presents consistent theoretical and experimental results important for understanding the adaptive behavior of sperm cells to the external time-periodic force encountered during sperm-egg interaction.
JTD Keywords: bovine sperm cells, cell-to-cell interaction, flagellar propulsion, Bovine sperm cells, Cell-to-cell interaction, Cilia, Filaments, Flagellar propulsion, Hydrodynamic models, Mechanism, Micro-video, Model, Motility, Thermotaxis, Transformations, Transition
Zhang K, 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: Collective locomotion, Flagellar propulsion, Spermatozoa bundle
Martinez A, Hériché JK, Calvo M, Tischer C, Otxoa-de-Amezaga A, Pedragosa J, Bosch A, Planas AM, Petegnief V, (2023). Characterization of microglia behaviour in healthy and pathological conditions with image analysis tools Open Biology 13, 220200
Microglia are very sensitive to changes in the environment and respond through morphological, functional and metabolic adaptations. To depict the modifications microglia undergo under healthy and pathological conditions, we developed free access image analysis scripts to quantify microglia morphologies and phagocytosis. Neuron-glia cultures, in which microglia express the reporter tdTomato, were exposed to excitotoxicity or excitotoxicity + inflammation and analysed 8 h later. Neuronal death was assessed by SYTOX staining of nucleus debris and phagocytosis was measured through the engulfment of SYTOX+ particles in microglia. We identified seven morphologies: round, hypertrophic, fried egg, bipolar and three 'inflamed' morphologies. We generated a classifier able to separate them and assign one of the seven classes to each microglia in sample images. In control cultures, round and hypertrophic morphologies were predominant. Excitotoxicity had a limited effect on the composition of the populations. By contrast, excitotoxicity + inflammation promoted an enrichment in inflamed morphologies and increased the percentage of phagocytosing microglia. Our data suggest that inflammation is critical to promote phenotypical changes in microglia. We also validated our tools for the segmentation of microglia in brain slices and performed morphometry with the obtained mask. Our method is versatile and useful to correlate microglia sub-populations and behaviour with environmental changes.
JTD Keywords: classification, identification, image analysis, injury, morphometry, neuroinflammation, neurotoxicity, phagocytosis, Classification, Image analysis, Microglia, Morphometry, Neuroinflammation, Nitric-oxide, Phagocytosis
Blanco-Fernandez, B, Ibanez-Fonesca, A, Orbanic, D, Ximenes-Carballo, C, Perez-Amodio, S, Rodriguez-Cabello, JC, Engel, E, (2023). Elastin-like Recombinamer Hydrogels as Platforms for Breast Cancer Modeling Biomacromolecules ,
The involvement of the extracellular matrix (ECM) in tumor progression has motivated the development of biomaterials mimicking the tumor ECM to develop more predictive cancer models. Particularly, polypeptides based on elastin could be an interesting approach to mimic the ECM due to their tunable properties. Here, we demonstrated that elastin-like recombinamer (ELR) hydrogels can be suitable biomaterials to develop breast cancer models. This hydrogel was formed by two ELR polypeptides, one containing sequences biodegradable by matrix metalloproteinase and cyclooctyne and the other carrying arginylglycylaspartic acid and azide groups to allow cell adhesion, biodegradability, and suitable stiffness through "click-chemistry" cross-linking. Our findings show that breast cancer or nontumorigenic breast cells showed high viability and cell proliferation for up to 7 days. MCF7 and MCF10A formed spheroids whereas MDA-MB-231 formed cell networks, with the expression of ECM and high drug resistance in all cases, evidencing that ELR hydrogels are a promising biomaterial for breast cancer modeling.
JTD Keywords: clinical-trials, collagen i, discovery, mcf-7 cells, phenotype, progression, spheroids, translation, tumor microenvironment, Extracellular-matrix
Lagunas, Anna, Belloir, Christine, Briand, Loïc, Gorostiza, Pau, Samitier, Josep, (2022). Determination of the nanoscale electrical properties of olfactory receptor hOR1A1 and their dependence on ligand binding: Towards the development of capacitance-operated odorant biosensors Biosensors & Bioelectronics 218, 114755
The transduction of odorant binding into cellular signaling by olfactory receptors (ORs) is not understood and knowing its mechanism would enable developing new pharmacology and biohybrid electronic detectors of volatile organic compounds bearing high sensitivity and selectivity. The electrical characterization of ORs in bulk experiments is subject to microscopic models and assumptions. We have directly determined the nanoscale electrical properties of ORs immobilized in a fixed orientation, and their change upon odorant binding, using electrochemical scanning tunneling microscopy (EC-STM) in near-physiological conditions. Recordings of current versus time, distance, and electrochemical potential allows determining the OR impedance parameters and their dependence with odorant binding. Our results allow validating OR structural-electrostatic models and their functional activation processes, and anticipating a novel macroscopic biosensor based on ORs.Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.
JTD Keywords: electrochemical scanning tunneling, electrochemical scanning tunneling microscopy (ec-stm), microscopy (ec-stm), neurons, odorant binding, olfactory receptors (ors), open-circuit voltage(voc), Olfactory receptors (ors), Open-circuit voltage (v(oc)), Transport
Bertran, Oscar, Martí, Didac, Torras, Juan, Turon, Pau, Alemán, Carlos, (2022). Computer simulations on oxidative stress-induced reactions in SARS-CoV-2 spike glycoprotein: a multi-scale approach Molecular Diversity 26, 3143-3155
Abstract Oxidative stress, which occurs when an organism is exposed to an adverse stimulus that results in a misbalance of antioxidant and pro-oxidants species, is the common denominator of diseases considered as a risk factor for SARS-CoV-2 lethality. Indeed, reactive oxygen species caused by oxidative stress have been related to many virus pathogenicity. In this work, simulations have been performed on the receptor binding domain of SARS-CoV-2 spike glycoprotein to study what residues are more susceptible to be attacked by ·OH, which is one of the most reactive radicals associated to oxidative stress. The results indicate that isoleucine (ILE) probably plays a crucial role in modification processes driven by radicals. Accordingly, QM/MM-MD simulations have been conducted to study both the ·OH-mediated hydrogen abstraction of ILE residues and the induced modification of the resulting ILE radical through hydroxylation or nitrosylation reactions. All in all, in silico studies show the importance of the chemical environment triggered by oxidative stress on the modifications of the virus, which is expected to help for foreseeing the identification or development of antioxidants as therapeutic drugs. Graphic abstract
JTD Keywords: atom abstraction, damage, density functionals, hydrogen abstraction, isoleucine, molecular dynamics, pathogenesis, protein, reactive oxygen species, receptor binding domain, residues, spike protein, Amino-acids, Hydrogen abstraction, Isoleucine, Molecular dynamics, Reactive oxygen species, Receptor binding domain, Spike protein
Carter SD, Atif AR, Diez-Escudero A, Grape M, Ginebra MP, Tenje M, Mestres G, (2022). A microfluidic-based approach to investigate the inflammatory response of macrophages to pristine and drug-loaded nanostructured hydroxyapatite Materials Today Bio 16, 100351
The in vitro biological characterization of biomaterials is largely based on static cell cultures. However, for highly reactive biomaterials such as calcium-deficient hydroxyapatite (CDHA), this static environment has limitations. Drastic alterations in the ionic composition of the cell culture medium can negatively affect cell behavior, which can lead to misleading results or data that is difficult to interpret. This challenge could be addressed by a microfluidics-based approach (i.e. on-chip), which offers the opportunity to provide a continuous flow of cell culture medium and a potentially more physiologically relevant microenvironment. The aim of this work was to explore microfluidic technology for its potential to characterize CDHA, particularly in the context of inflammation. Two different CDHA substrates (chemically identical, but varying in microstructure) were integrated on-chip and subsequently evaluated. We demonstrated that the on-chip environment can avoid drastic ionic alterations and increase protein sorption, which was reflected in cell studies with RAW 264.7 macrophages. The cells grown on-chip showed a high cell viability and enhanced proliferation compared to cells maintained under static conditions. Whereas no clear differences in the secretion of tumor necrosis factor alpha (TNF-α) were found, variations in cell morphology suggested a more anti-inflammatory environment on-chip. In the second part of this study, the CDHA substrates were loaded with the drug Trolox. We showed that it is possible to characterize drug release on-chip and moreover demonstrated that Trolox affects the TNF-α secretion and morphology of RAW 264.7 cells. Overall, these results highlight the potential of microfluidics to evaluate (bioactive) biomaterials, both in pristine form and when drug-loaded. This is of particular interest for the latter case, as it allows the biological characterization and assessment of drug release to take place under the same dynamic in vitro environment.© 2022 The Authors.
JTD Keywords: alpha-tocopherol, antioxidant, biomaterials, calcium phosphate cement, culture, delivery, drug release, in vitro, in-vitro, ion, macrophage, on-chip, release, tool, Biomaterial, Calcium phosphate cement, Calcium-phosphate cements, Drug release, In vitro, Macrophage, On-chip
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
Barbacena P, Dominguez-Cejudo M, Fonseca CG, Gómez-González M, Faure LM, Zarkada G, Pena A, Pezzarossa A, Ramalho D, Giarratano Y, Ouarné M, Barata D, Fortunato IC, Misikova LH, Mauldin I, Carvalho Y, Trepat X, Roca-Cusachs P, Eichmann A, Bernabeu MO, Franco CA, (2022). Competition for endothelial cell polarity drives vascular morphogenesis in the mouse retina Developmental Cell 57, 2321-2333
Blood-vessel formation generates unique vascular patterns in each individual. The principles governing the apparent stochasticity of this process remain to be elucidated. Using mathematical methods, we find that the transition between two fundamental vascular morphogenetic programs-sprouting angiogenesis and vascular remodeling-is established by a shift of collective front-to-rear polarity of endothelial cells in the mouse retina. We demonstrate that the competition between biochemical (VEGFA) and mechanical (blood-flow-induced shear stress) cues controls this collective polarity shift. Shear stress increases tension at focal adhesions overriding VEGFA-driven collective polarization, which relies on tension at adherens junctions. We propose that vascular morphogenetic cues compete to regulate individual cell polarity and migration through tension shifts that translates into tissue-level emergent behaviors, ultimately leading to uniquely organized vascular patterns.Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.
JTD Keywords: activation, angiogenesis, dynamics, flow, forces, image, mechanisms, vinculin, Angiogenesis, Cell polarity, Fluid shear, Mechanobiology, Morphogenesis, Shear stress
Fernández-Garibay, Xiomara, Gomez-Florit, Manuel, Domingues, Rui M A, Gomes, Manuela, Fernandez-Costa, Juan M., Ramon, Javier, (2022). Xeno-free bioengineered human skeletal muscle tissue using human platelet lysate-based hydrogels Biofabrication 14, 045015
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, Platform, Skeletal muscle, Xeno-free
Solomon M, Loeck M, Silva-Abreu M, Moscoso R, Bautista R, Vigo M, Muro S, (2022). Altered blood-brain barrier transport of nanotherapeutics in lysosomal storage diseases Journal Of Controlled Release 349, 1031-1044
Treatment of neurological lysosomal storage disorders (LSDs) are limited because of impermeability of the blood-brain barrier (BBB) to macromolecules. Nanoformulations targeting BBB transcytosis are being explored, but the status of these routes in LSDs is unknown. We studied nanocarriers (NCs) targeted to the transferrin receptor (TfR), ganglioside GM1 or ICAM1, associated to the clathrin, caveolar or cell adhesion molecule (CAM) routes, respectively. We used brain endothelial cells and mouse models of acid sphingomyelinase-deficient Niemann Pick disease (NPD), and postmortem LSD patients' brains, all compared to respective controls. NC transcytosis across brain endothelial cells and brain distribution in mice were affected, yet through different mechanisms. Reduced TfR and clathrin expression were found, along with decreased transcytosis in cells and mouse brain distribution. Caveolin-1 expression and GM1 transcytosis were also reduced, yet increased GM1 levels seemed to compensate, providing similar NC brain distribution in NPD vs. control mice. A tendency to lower NHE-1 levels was seen, but highly increased ICAM1 expression in cells and human brains correlated with increased transcytosis and brain distribution in mice. Thus, transcytosis-related alterations in NPD and likely other LSDs may impact therapeutic access to the brain, illustrating the need for these mechanistic studies.Copyright © 2022 Elsevier B.V. All rights reserved.
JTD Keywords: acid sphingomyelinase, antibody-affinity, blood -brain barrier, drug-delivery, icam-1-targeted nanocarriers, in-vivo, mediated endocytosis, model, neurological diseases, niemann-pick, targeted nanocarriers, trafficking, transcytosis pathways, Blood-brain barrier, Central-nervous-system, Lysosomal storage disorders, Neurological diseases, Targeted nanocarriers, Transcytosis pathways
Caballeria E, Maier M, Balcells-Oliveró M, López-Pelayo H, Oliveras C, Rubio Ballester B, Verschure PFMJ, Gual A, (2022). Rehabilitation Gaming System for Alcohol-Related Cognitive Impairment: A Pilot Usability Study Alcohol And Alcoholism 57, 595-601
Aims: Cognitive impairment in patients with alcohol use disorder (AUD) is highly prevalent, and it negatively impacts treatment outcome. However, this condition is neither systematically assessed nor treated. Thus, we aimed to explore the usability of a virtual reality-based protocol ('Rehabilitation Gaming System', RGS) for patients with AUD. Methods: Twenty AUD patients (50% also cognitive impairment) underwent a single session of the RGS protocol (four cognitive training tasks, 10 minutes each). System Usability Scale (SUS) and Post-Study System Usability Questionnaire (PSSUQ) were applied to assess the RGS usability and patients' satisfaction with it. Also, the Perceived Competence Scale was administered to assess the patients' feelings of competence when using the training protocol. Comparisons of the responses to these questionnaires were performed between AUD patients with cognitive impairment and those without cognitive impairment. Results: RGS usability was very positively rated (median SUS score = 80, Interquartile Range, IQR = 68.13-86-88). No significant differences were found in the median SUS scores for any of the sociodemographic or clinical variables, excepting for gender (women median score = 85; IQR = 80-94.38 vs. men median score = 71.25; IQR = 61.25-89.25; P-value = 0.035). The quality of the information provided by the RGS training scenarios and the usability were positively rated (PSSUQ), and patients experienced high feelings of competence. Conclusions: The RGS has been found to be usable in the short term and patients with AUD stated to be satisfied with it. Future larger, randomized trials are needed to explore the effectiveness of this tool to help overcome the cognitive deficits in AUD patients. Short Summary: Although cognitive impairments are highly prevalent in alcohol use disorder (AUD), no long-term gold standard intervention has yet been identified. The Rehabilitation Gaming System (virtual reality-based cognitive training protocol) has shown short-term high usability in AUD. Its effectiveness in providing engaging, long-term cognitive rehabilitation in AUD should be further assessed.
JTD Keywords: Addiction, Brain-damage, Deficits, Impact, Neurocognitive impairment, Therapy
F Amil A, Rubio Ballester B, Maier M, FMJ Verschure P, (2022). Chronic use of cannabis might impair sensory error processing in the cerebellum through endocannabinoid dysregulation Addictive Behaviors 131, 107297
Chronic use of cannabis leads to both motor deficits and the downregulation of CB1 receptors (CB1R) in the cerebellum. In turn, cerebellar damage is often related to impairments in motor learning and control. Further, a recent motor learning task that measures cerebellar-dependent adaptation has been shown to distinguish well between healthy subjects and chronic cannabis users. Thus, the deteriorating effects of chronic cannabis use in motor performance point to cerebellar adaptation as a key process to explain such deficits. We review the literature relating chronic cannabis use, the endocannabinoid system in the cerebellum, and different forms of cerebellar-dependent motor learning, to suggest that CB1R downregulation leads to a generalized underestimation and misprocessing of the sensory errors driving synaptic updates in the cerebellar cortex. Further, we test our hypothesis with a computational model performing a motor adaptation task and reproduce the behavioral effect of decreased implicit adaptation that appears to be a sign of chronic cannabis use. Finally, we discuss the potential of our hypothesis to explain similar phenomena related to motor impairments following chronic alcohol dependency. © 2022
JTD Keywords: adaptation, addiction, alcohol-abuse, cerebellum, chronic cannabis use, cognition, deficits, endocannabinoid system, error processing, explicit, modulation, motor learning, release, synaptic plasticity, Adaptation, Adaptation, physiological, Alcoholism, Article, Behavioral science, Cannabinoid 1 receptor, Cannabis, Cannabis addiction, Cerebellum, Cerebellum cortex, Cerebellum disease, Chronic cannabis use, Computer model, Down regulation, Endocannabinoid, Endocannabinoid system, Endocannabinoids, Error processing, Hallucinogens, Human, Humans, Motor dysfunction, Motor learning, Nerve cell plasticity, Nonhuman, Physiology, Psychedelic agent, Purkinje-cells, Regulatory mechanism, Sensation, Sensory dysfunction, Sensory error processing impairment, Synaptic transmission, Task performance
Clua-Ferre, L, De Chiara, F, Rodriguez-Comas, J, Comelles, J, Martinez, E, Godeau, AL, Garcia-Alaman, A, Gasa, R, Ramon-Azcon, J, (2022). Collagen-Tannic Acid Spheroids for beta-Cell Encapsulation Fabricated Using a 3D Bioprinter Advanced Materials Technologies 7, 2101696
Type 1 Diabetes results from autoimmune response elicited against β-cell antigens. Nowadays, insulin injections remain the leading therapeutic option. However, injection treatment fails to emulate the highly dynamic insulin release that β-cells provide. 3D cell-laden microspheres have been proposed during the last years as a major platform for bioengineering insulin-secreting constructs for tissue graft implantation and a model for in vitro drug screening platforms. Current microsphere fabrication technologies have several drawbacks: the need for an oil phase containing surfactants, diameter inconsistency of the microspheres, and high time-consuming processes. These technologies have widely used alginate for its rapid gelation, high processability, and low cost. However, its low biocompatible properties do not provide effective cell attachment. This study proposes a high-throughput methodology using a 3D bioprinter that employs an ECM-like microenvironment for effective cell-laden microsphere production to overcome these limitations. Crosslinking the resulting microspheres with tannic acid prevents collagenase degradation and enhances spherical structural consistency while allowing the diffusion of nutrients and oxygen. The approach allows customization of microsphere diameter with extremely low variability. In conclusion, a novel bio-printing procedure is developed to fabricate large amounts of reproducible microspheres capable of secreting insulin in response to extracellular glucose stimuli.© 2022 The Authors. Advanced Materials Technologies published by Wiley‐VCH GmbH.
JTD Keywords: 3d bioprinter, beta-cell, biomaterial, collagen, encapsulation, mechanics, microspheres, survival, 3d bioprinter, ?-cell, Advanced material technologies, Biocompatibility, Cell encapsulations, Cells, Collagen, Cross-linking, Cytology, Drug delivery, Encapsulation, Fabrication, Flavonoids, Gelation, In-vitro, Insulin injections, Insulin release, Microspheres, Tannic acid, Tannins, Throughput, Tissue grafts, Type 1 diabetes, Β‐cell
Almici E, Chiappini V, López-Márquez A, Badosa C, Blázquez B, Caballero D, Montero J, Natera-de Benito D, Nascimento A, Roldán M, Lagunas A, Jiménez-Mallebrera C, Samitier J, (2022). Personalized in vitro Extracellular Matrix Models of Collagen VI-Related Muscular Dystrophies Frontiers In Bioengineering And Biotechnology 10, 851825
Collagen VI-related dystrophies (COL6-RDs) are a group of rare congenital neuromuscular dystrophies that represent a continuum of overlapping clinical phenotypes that go from the milder Bethlem myopathy (BM) to the severe Ullrich congenital muscular dystrophy, for which there is no effective treatment. Mutations in one of the three Collagen VI genes alter the incorporation of this protein into the extracellular matrix (ECM), affecting the assembly and the structural integrity of the whole fibrillar network. Clinical hallmarks of COL6-RDs are secondary to the ECM disruption and include muscle weakness, proximal joint contractures, and distal hyperlaxity. Although some traits have been identified in patients’ ECMs, a correlation between the ECM features and the clinical phenotype has not been established, mainly due to the lack of predictive and reliable models of the pathology. Herein, we engineered a new personalized pre-clinical model of COL6-RDs using cell-derived matrices (CDMs) technology to better recapitulate the complexity of the native scenario. We found that CDMs from COL6-RD patients presented alterations in ECM structure and composition, showing a significantly decreased Collagen VI secretion, especially in the more severe phenotypes, and a decrease in Fibrillin-1 inclusion. Next, we examined the Collagen VI-mediated deposition of Fibronectin in the ECM, finding a higher alignment, length, width, and straightness than in patients with COL6-RDs. Overall, these results indicate that CDMs models are promising tools to explore the alterations that arise in the composition and fibrillar architecture due to mutations in Collagen VI genes, especially in early stages of matrix organization. Ultimately, CDMs derived from COL6-RD patients may become relevant pre-clinical models, which may help identifying novel biomarkers to be employed in the clinics and to investigate novel therapeutic targets and treatments. Copyright © 2022 Almici, Chiappini, López-Márquez, Badosa, Blázquez, Caballero, Montero, Natera-de Benito, Nascimento, Roldán, Lagunas, Jiménez-Mallebrera and Samitier.
JTD Keywords: alpha-3 chain, binding, collagen vi related muscular dystrophy, decellularisation, decellularized matrices, deficiency, expression, extracellular matrix, fibroblasts, fibronectin, in vitro model, patient-derived ecms, skeletal-muscle, ullrich, Cell-derived matrices, Collagen, Collagen vi related muscular dystrophy, Decellularisation, Decellularization, Extracellular matrices, Extracellular matrix, Genes, In vitro model, In-vitro, In-vitro models, Matrix, Matrix model, Muscular dystrophy, Pathology, Patient-derived ecm, Patient-derived ecms, Pre-clinical
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, 867-882
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, Collagen-iv, Contraction, Forces, Gene, Glial-cells, Migration, Morphogenesis, Quantification, System, Tissue, Viscolelastic model
Ferrer, I, Andres-Benito, P, Sala-Jarque, J, Gil, V, del Rio, JA, (2022). Corrigendum: Capacity for Seeding and Spreading of Argyrophilic Grain Disease in a Wild-Type Murine Model; Comparisons With Primary Age-Related Tauopathy (vol 13, 101, 2020) Frontiers In Molecular Neuroscience 15, 870475
[This corrects the article DOI: 10.3389/fnmol.2020.00101.].Copyright © 2022 Ferrer, Andrés-Benito, Sala-Jarque, Gil and del Rio.
JTD Keywords: argyrophilic grain disease, coiled bodies, primary age-related tauopathy, progression, seeding, tau, Argyrophilic grain disease, Coiled bodies, Primary age-related tauopathy, Progression, Seeding, Tau, Tauopathies
Narciso M, Ulldemolins A, Júnior C, Otero J, Navajas D, Farré R, Gavara N, Almendros I, (2022). Novel Decellularization Method for Tissue Slices Frontiers In Bioengineering And Biotechnology 10, 832178
Decellularization procedures have been developed and optimized for the entire organ or tissue blocks, by either perfusion of decellularizing agents through the tissue’s vasculature or submerging large sections in decellularizing solutions. However, some research aims require the analysis of native as well as decellularized tissue slices side by side, but an optimal protocol has not yet been established to address this need. Thus, the main goal of this work was to develop a fast and efficient decellularization method for tissue slices—with an emphasis on lung—while attached to a glass slide. To this end, different decellularizing agents were compared for their effectiveness in cellular removal while preserving the extracellular matrix. The intensity of DNA staining was taken as an indicator of remaining cells and compared to untreated sections. The presence of collagen, elastin and laminin were quantified using immunostaining and signal quantification. Scaffolds resulting from the optimized protocol were mechanically characterized using atomic force microscopy. Lung scaffolds were recellularized with mesenchymal stromal cells to assess their biocompatibility. Some decellularization agents (CHAPS, triton, and ammonia hydroxide) did not achieve sufficient cell removal. Sodium dodecyl sulfate (SDS) was effective in cell removal (1% remaining DNA signal), but its sharp reduction of elastin signal (only 6% remained) plus lower attachment ratio (32%) singled out sodium deoxycholate (SD) as the optimal treatment for this application (6.5% remaining DNA signal), due to its higher elastin retention (34%) and higher attachment ratio (60%). Laminin and collagen were fully preserved in all treatments. The SD decellularization protocol was also successful for porcine and murine (mice and rat) lungs as well as for other tissues such as the heart, kidney, and bladder. No significant mechanical differences were found before and after sample decellularization. The resulting acellular lung scaffolds were shown to be biocompatible (98% cell survival after 72 h of culture). This novel method to decellularize tissue slices opens up new methodological possibilities to better understand the role of the extracellular matrix in the context of several diseases as well as tissue engineering research and can be easily adapted for scarce samples like clinical biopsies. Copyright © 2022 Narciso, Ulldemolins, Júnior, Otero, Navajas, Farré, Gavara and Almendros.
JTD Keywords: biocompatibility, bioscaffold recellularization, decellularization, extracellular matrix, flow, impact, lung, scaffolds, tissue slices, Ammonia, Bio-scaffolds, Biocompatibility, Biological organs, Bioscaffold recellularization, Cell removal, Cells, Collagen, Cytology, Decellularization, Dna, Dna signals, Elastin, Extracellular matrices, Extracellular matrix, Extracellular-matrix, Glycoproteins, Laminin, Lung, Mammals, Recellularization, Scaffolds (biology), Sodium deoxycholate, Sulfur compounds, Tissue, Tissue slice, Tissue slices
Gouveia, Virgínia M., Rizzello, Loris, Vidal, Bruno, Nunes, Claudia, Poma, Alessandro, Lopez-Vasquez, Ciro, Scarpa, Edoardo, Brandner, Sebastian, Oliveira, António, Fonseca, João E., Reis, Salette, Battaglia, Giuseppe, (2022). Targeting Macrophages and Synoviocytes Intracellular Milieu to Augment Anti-Inflammatory Drug Potency Advanced Therapeutics 5,
0
JTD Keywords: cancer, cells, cellular basis, delivery, encapsulation, in-vitro, inflammation, macrophage, methotrexate, pathogenesis, polymersome, polymersomes, synoviocyte, Arthritis, Rheumatoid-arthritis
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,
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
Bonamigo Moreira, Vitor, Rintjema, Jeroen, Bravo, Fernando, Kleij, Arjan W., Franco, Lourdes, Puiggalí, Jordi, Alemán, Carlos, Armelin, Elaine, (2022). Novel Biobased Epoxy Thermosets and Coatings from Poly(limonene carbonate) Oxide and Synthetic Hardeners Acs Sustainable Chemistry & Engineering 10, 2708-2719
In the area of coating development, it is extremely difficult to find a substitute for bisphenol A diglycidyl ether (DGEBA), the classical petroleum-based raw material used for the formulation of epoxy thermosets. This epoxy resin offers fast curing reaction with several hardeners and the best thermal and chemical resistance properties for applications in coatings and adhesive technologies. In this work, a new biobased epoxy, derived from poly(limonene carbonate) oxide (PLCO), was combined with polyetheramine and polyamineamide curing agents, offering a spectrum of thermal and mechanical properties, superior to DGEBA-based thermosets. The best formulation was found to be a combination of PLCO and a commercial curing agent (Jeffamine) in a stoichiometric 1:1 ratio. Although PLCO is a solid due to its high molecular weight, it was possible to create a two-component partially biobased epoxy paint without the need of volatile organic compounds (i.e., solvent-free formulation), intended for use in coating technology to partially replace DGEBA-based thermosets.
JTD Keywords: acid, adhesion, epoxy thermoset, mechanical properties, monomer, polycarbonates, polymers, protection, resins, solvent-free paint, thermal properties, Adhesives, Biobased epoxy, Bisphenol-a-diglycidyl ethers, Carbonation, Coating development, Coating technologies, Curing, Curing agents, Epoxy coatings, Epoxy resins, Epoxy thermoset, Epoxy thermosets, Limonene oxide, Mechanical properties, Monoterpenes, Paint, Poly(limonene carbonate) oxide, Solvent free, Solvent-free paint, Thermal properties, Thermosets, Volatile organic compounds
Dhiman, Shikha, Andrian, Teodora, Gonzalez, Beatriz Santiago, Tholen, Marrit ME., Wang, Yuyang, Albertazzi, Lorenzo, (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
Sans, Jordi, Arnau, Marc, Sanz, Vanesa, Turon, Pau, Alemán, Carlos, (2022). Polarized Hydroxyapatite: New Insights and Future Perspectives Through Systematic Electrical Characterization at the Interface Advanced Materials Interfaces 9,
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
Murar M, Albertazzi L, Pujals S, (2022). Advanced Optical Imaging-Guided Nanotheranostics toward Personalized Cancer Drug Delivery Nanomaterials 12, 399
Nanomedicine involves the use of nanotechnology for clinical applications and holds promise to improve treatments. Recent developments offer new hope for cancer detection, prevention and treatment; however, being a heterogenous disorder, cancer calls for a more targeted treatment approach. Personalized Medicine (PM) aims to revolutionize cancer therapy by matching the most effective treatment to individual patients. Nanotheranostics comprise a combination of therapy and diagnostic imaging incorporated in a nanosystem and are developed to fulfill the promise of PM by helping in the selection of treatments, the objective monitoring of response and the planning of follow-up therapy. Although well-established imaging techniques, such as Magnetic Resonance Imaging (MRI), Computed Tomography (CT), Positron Emission Tomography (PET) and Single-Photon Emission Computed Tomography (SPECT), are primarily used in the development of theranostics, Optical Imaging (OI) offers some advantages, such as high sensitivity, spatial and temporal resolution and less invasiveness. Additionally, it allows for multiplexing, using multi-color imaging and DNA barcoding, which further aids in the development of personalized treatments. Recent advances have also given rise to techniques permitting better penetration, opening new doors for OI-guided nanotheranostics. In this review, we describe in detail these recent advances that may be used to design and develop efficient and specific nanotheranostics for personalized cancer drug delivery. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
JTD Keywords: 5-aminolevulinic acid, cancer, contrast agents, in-vivo, malignant gliomas, multifunctional nanoparticles, nanomedicine, optical imaging, ovarian-cancer, personalized medicine, quantum dots, silica nanoparticles, targeted probes, theranostics, Cancer, Nanomedicine, Optical imaging, Personalized medicine, Superparamagnetic iron-oxide, Theranostics
Cascione M, Rizzello L, Manno D, Serra A, De Matteis V, (2022). Green Silver Nanoparticles Promote Inflammation Shutdown in Human Leukemic Monocytes Materials (Basel) 15,
The use of silver nanoparticles (Ag NPs) in the biomedical field deserves a mindful analysis of the possible inflammatory response which could limit their use in the clinic. Despite the anti-cancer properties of Ag NPs having been widely demonstrated, there are still few studies concerning their involvement in the activation of specific inflammatory pathways. The inflammatory outcome depends on the synthetic route used in the NPs production, in which toxic reagents are employed. In this work, we compared two types of Ag NPs, obtained by two different chemical routes: conventional synthesis using sodium citrate and a green protocol based on leaf extracts as a source of reduction and capping agents. A careful physicochemical characterization was carried out showing spherical and stable Ag NPs with an average size between 20 nm and 35 nm for conventional and green Ag NPs respectively. Then, we evaluated their ability to induce the activation of inflammation in Human Leukemic Monocytes (THP-1) differentiated into M0 macrophages using 1 µM and 2 µM NPs concentrations (corresponded to 0.1 µg/mL and 0.2 µg/mL respectively) and two-time points (24 h and 48 h). Our results showed a clear difference in Nuclear Factor ?B (NF-?b) activation, Interleukins 6–8 (IL-6, IL-8) secretion, Tumor Necrosis Factor-? (TNF-?) and Cyclooxygenase-2 (COX-2) expression exerted by the two kinds of Ag NPs. Green Ag NPs were definitely tolerated by macrophages compared to conventional Ag NPs which induced the activation of all the factors mentioned above. Subsequently, the exposure of breast cancer cell line (MCF-7) to the green Ag NPs showed that they exhibited antitumor activity like the conventional ones, but surprisingly, using the MCF-10A line (not tumoral breast cells) the green Ag NPs did not cause a significant decrease in cell viability. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
JTD Keywords: activation, biosynthesis, gold nanoparticles, green route, inflammation response, mechanism, metal, nanotechnology, physico-chemical properties, raman-spectroscopy, resonance, silver nanoparticles, surface, Biomedical fields, Cell culture, Cell death, Chemical activation, Chemical routes, Conventional synthesis, Diseases, Green route, Inflammation response, Inflammatory response, Macrophages, Metal nanoparticles, Nf-kappa-b, Pathology, Physico-chemical properties, Physicochemical property, Property, Silver nanoparticles, Sodium compounds, Synthetic routes, Toxic reagents
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,
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
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
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. © 2021 Informa UK Limited, trading as Taylor & Francis Group.
JTD Keywords: Augmented reality, Commemoration, Digital heritage, Future memory, Post-wtiness era, Virtual reality
Macedo, MH, Barros, AS, Martinez, E, Barrias, CC, Sarmento, B, (2022). All layers matter: Innovative three-dimensional epithelium-stroma-endothelium intestinal model for reliable permeability outcomes Journal Of Controlled Release 341, 414-430
Drug development is an ever-growing field, increasingly requesting reliable in vitro tools to speed up early screening phases, reducing the need for animal experiments. In oral delivery, understanding the absorption pattern of a new drug in the small intestine is paramount. Classical two-dimensional (2D) in vitro models are generally too simplistic and do not accurately represent native tissues. The main goal of this work was to develop an advanced three-dimensional (3D) in vitro intestinal model to test absorption in a more reliable manner, by better mimicking the native environment. The 3D model is composed of a collagen-based stromal layer with embedded fibroblasts mimicking the intestinal lamina propria and providing support for the epithelium, composed of enterocytes and mucus-secreting cells. An endothelial layer, surrogating the absorptive capillary network, is also present. The cellular crosstalk between the different cells present in the model is unveiled, disclosing key players, namely those involved in the contraction of collagen by fibroblasts. The developed 3D model presents lower levels of P-glycoprotein (P-gp) and Multidrug Resistance Protein 2 (MRP2) efflux transporters, which are normally overexpressed in traditional Caco-2 models, and are paramount in the absorption of many compounds. This, allied with transepithelial electrical resistance (TEER) values closer to physiological ranges, leads to improved and more reliable permeability outcomes, which are observed when comparing our results with in vivo data.
JTD Keywords: 3d intestinal model, drug absorption, drug development, endothelium, hydrogel, 3d intestinal model, 3d modeling, 3d models, 3d-modeling, Alkaline-phosphatase, Animal experiments, Biopharmaceutics classification, Caco-2 cells, Cell culture, Collagen, Collagen gel, Drug absorption, Drug development, Endothelium, Fibroblasts, Glycoproteins, Hydrogel, In-vitro, Matrix metalloproteinases, Membrane-permeability, Paracellular transport, Permeability, Single-pass vs., Speed up
Moreira, VB, Aleman, C, Rintjema, J, Bravo, F, Kleij, AW, Armelin, E, (2022). A Biosourced Epoxy Resin for Adhesive Thermoset Applications Chemsuschem 15, e202102624
Biobased epoxy-derived raw materials will be essential for future coating and adhesive designs in industry. Here, a facile approach is reported towards the incorporation of limonene into an epoxy-functionalized polycarbonate and its crosslinking with a polyamine curing agent to obtain a thermoset material. For the first time, a solvent-borne adhesive with excellent film-forming, mechanical and adhesion strength properties is described.
JTD Keywords: adhesives, biobased epoxies, limonene, polycarbonate, Adhesives, Biobased epoxies, Biobased epoxy, Carbon-dioxide, Curing agents, Design in industries, Epoxides, Epoxy, Epoxy resins, Film adhesion, Film-forming, Functionalized, Limonene, Mechanical, Monomer, Monoterpenes, Oil, Oxide, Performance, Polyamines, Polycarbonate, Polycarbonates, Terpenes, Thermoset materials, Thermosets
Casanellas, I, Lagunas, A, Vida, Y, Perez-Inestrosa, E, Rodriguez-Pereira, C, Magalhaes, J, Andrades, JA, Becerra, J, Samitier, J, (2022). Nanoscale ligand density modulates gap junction intercellular communication of cell condensates during chondrogenesis Nanomedicine 17, 775-791
Aim: To unveil the influence of cell-matrix adhesions in the establishment of gap junction intercellular communication (GJIC) during cell condensation in chondrogenesis. Materials & methods: Previously developed nanopatterns of the cell adhesive ligand arginine-glycine-aspartic acid were used as cell culture substrates to control cell adhesion at the nanoscale. In vitro chondrogenesis of mesenchymal stem cells was conducted on the nanopatterns. Cohesion and GJIC were evaluated in cell condensates. Results: Mechanical stability and GJIC are enhanced by a nanopattern configuration in which 90% of the surface area presents adhesion sites separated less than 70 nm, thus providing an onset for cell signaling. Conclusion: Cell-matrix adhesions regulate GJIC of mesenchymal cell condensates during in vitro chondrogenesis from a threshold configuration at the nanoscale.
JTD Keywords: arginine-glycine-aspartic acid, arginine–glycine–aspartic acid, cell adhesion, condensation, dendrimer-based nanopatterning, gap junction intercellular communication, Actin, Adhesion, Arginine-glycine-aspartic acid, Cell adhesion, Collagen, Condensation, Connexin-43, Dendrimer-based nanopatterning, Dynamics, Extracellular-matrix, Fibronectin, Gap junction intercellular communication, Mesenchymal stem cells, Permeability, Phenotype, Vinculin
Rosales-Rojas, R, Zuniga-Bustos, M, Salas-Sepulveda, F, Galaz-Araya, C, Zamora, RA, Poblete, H, (2022). Self-Organization Dynamics of Collagen-like Peptides Crosslinking Is Driven by Rose-Bengal-Mediated Electrostatic Bridges Pharmaceutics 14,
The present work focuses on the computational study of the structural micro-organization of hydrogels based on collagen-like peptides (CLPs) in complex with Rose Bengal (RB). In previous studies, these hydrogels computationally and experimentally demonstrated that when RB was activated by green light, it could generate forms of stable crosslinked structures capable of regenerating biological tissues such as the skin and cornea. Here, we focus on the structural and atomic interactions of two collagen-like peptides (collagen-like peptide I (CLPI), and collagen-like peptide II, (CLPII)) in the presence and absence of RB, highlighting the acquired three-dimensional organization and going deep into the stabilization effect caused by the dye. Our results suggest that the dye could generate a ternary ground-state complex between collagen-like peptide fibers, specifically with positively charged amino acids (Lys in CLPI and Arg in CLPII), thus stabilizing ordered three-dimensional structures. The discoveries generated in this study provide the structural and atomic bases for the subsequent rational development of new synthetic peptides with improved characteristics for applications in the regeneration of biological tissues during photochemical tissue bonding therapies.
JTD Keywords: collagen-like peptide, crosslinking, molecular dynamics, qm/mm simulations, rose bengal, Anastomosis, Collagen-like peptide, Crosslinking, Green light, Mm simulations, Molecular dynamics, Molecular-dynamics, Photochemical tissue bonding therapies, Qm, Rose bengal
Biosca, A, Ramirez, M, Gomez-Gomez, A, Lafuente, A, Iglesias, V, Pozo, OJ, Imperial, S, Fernandez-Busquets, X, (2022). Characterization of Domiphen Bromide as a New Fast-Acting Antiplasmodial Agent Inhibiting the Apicoplastidic Methyl Erythritol Phosphate Pathway Pharmaceutics 14,
The evolution of resistance by the malaria parasite to artemisinin, the key component of the combination therapy strategies that are at the core of current antimalarial treatments, calls for the urgent identification of new fast-acting antimalarials. The apicoplast organelle is a preferred target of antimalarial drugs because it contains biochemical processes absent from the human host. Fosmidomycin is the only drug in clinical trials targeting the apicoplast, where it inhibits the methyl erythritol phosphate (MEP) pathway. Here, we characterized the antiplasmodial activity of domiphen bromide (DB), another MEP pathway inhibitor with a rapid mode of action that arrests the in vitro growth of Plasmodium falciparum at the early trophozoite stage. Metabolomic analysis of the MEP pathway and Krebs cycle intermediates in 20 mu M DB-treated parasites suggested a rapid activation of glycolysis with a concomitant decrease in mitochondrial activity, consistent with a rapid killing of the pathogen. These results present DB as a model compound for the development of new, potentially interesting drugs for future antimalarial combination therapies.
JTD Keywords: antibiotics, antimalarial drugs, domiphen bromide, malaria, plasmodium falciparum, Antibiotics, Antimalarial drugs, Antimalarial-drug, Artemisinin, Combination therapies, Domiphen bromide, Intraerythrocytic stages, Isoprenoid biosynthesis, Malaria, Methyl erythritol phosphate pathway, Nonmevalonate pathway, Plasmodium falciparum, Plasmodium-falciparum apicoplast, Red-blood-cells, Targeted delivery
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 Transl Sci 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
De Matteis, V, Rizzello, L, Cascione, M, Pellegrino, P, Singh, J, Manno, D, Rinaldi, R, (2022). Sustainable Synthesis of FITC Chitosan-Capped Gold Nanoparticles for Biomedical Applications Clean Technologies 4, 942-953
The quest for novel nanoscale materials for different applications necessitates that they are easy to obtain and have excellent physical properties and low toxicity. Moreover, considering the ongoing environmental impact of noxious chemical waste products, it is important to adopt eco-friendly approaches for nanoparticle synthesis. In this work, a natural polymer (medium molecular weight chitosan) derived from chitin was employed as a reducing agent to obtain gold nanoparticles (AuNPs) with a chitosan shell (AuNPs@CS) by a microwave oven. The chitosan is economically viable and cost-competitive in the market showing also nontoxic behavior in the environment and living organisms. The synthesized AuNPs@CS-FITC NPs were fully characterized by spectroscopic and microscopic characterization techniques. The size distribution of NPs was about 15 nm, which is a suitable dimension to use in biomedical applications due to their high tissue penetration, great circulation in blood, and optimal clearance as well as low toxicity. The prepared polymer-capped NPs were further functionalized with a fluorescent molecule, i.e., Fluorescein-5-isothiocyanate (FITC), to perform imaging in the cell. The results highlighted the goodness of the synthesis procedure, as well as the high internalization rate that resulted in an optimal fluorescence intensity. Thus, this work presents a good sustainable/green approach-mediated polymer nanocomposite for various applications in the field of diagnostic imaging.
JTD Keywords: Agent, Biomedical, Fluorescent, Gold nanoparticles, Green synthesis, Nanomaterials, Silver nanoparticles
Rodriguez J, Schulz S, Voss A, Giraldo BF, (2021). Classification of ischemic and dilated cardiomyopathy patients based on the analysis of the pulse transit time Conference Proceedings : ... Annual International Conference Of The Ieee Engineering In Medicine And Biology Society. Ieee Engineering In Medicine And Biology Society. Conference 2021, 5527-5530
Cardiomyopathies diseases affects a great number of the elderly population. An adequate identification of the etiology of a cardiomyopathy patient is still a challenge. The aim of this study was to classify patients by their etiology in function of indexes extracted from the characterization of the pulse transit time (PTT). This time series represents the time taken by the pulse pressure to propagate through the length of the arterial tree and corresponding to the time between R peak of ECG and the mid-point of the diastolic to systolic slope in the blood pressure signal. For each patient, the PTT time series was extracted. Thirty cardiomyopathy patients (CMP) classified as ischemic (ICM - 15 patients) and dilated (DCM - 15 patients) were analyzed. Forty-three healthy subjects (CON) were used as a reference. The PTT time series was characterized through statistical descriptive indices and the joint symbolic dynamics method. The best indices were used to build support vector machine models. The optimal model to classify ICM versus DCM patients achieved 89.6% accuracy, 78.5% sensitivity, and 100% specificity. When comparing CMP patients and CON subjects, the best model achieved 91.3% accuracy, 91.3% sensitivity, and 88.3% specificity. Our results suggests a significantly lower pulse transit time in ischemic patients.Clinical relevance - This study analyzed the suitability of the pulse transit time for the classification of ICM and DCM patients. © 2021 IEEE.
JTD Keywords: Aged, Blood pressure, Cardiomyopathies, Cardiomyopathy, Cardiomyopathy, dilated, Congestive cardiomyopathy, Human, Humans, Pulse wave, Pulse wave analysis, Support vector machine
Vukomanovic M, Cendra MdM, Baelo A, Torrents E, (2021). Nano-engineering stable contact-based antimicrobials: Chemistry at the interface between nano-gold and bacteria Colloids And Surfaces B-Biointerfaces 208, 112083
Contact-based antimicrobials, as antibiotic-free technologies that use non-specific interactions with bacterial cells to exert antimicrobial activity, are a prospective solution in fighting the global issue of bacterial resistance. A very simplified approach to their design considers the direct bonding of cationic guanidine-containing amino acids to the surface of nano-gold carriers. The structure enables antimicrobial activity due to a high density of cationic surface charges. This opens a set of novel questions that are important for their effective engineering, particularly regarding (i) chemistry and events that take place at the interface between NPs and cells, (ii) the direct influence of a charge (and its change) on interactions with bacterial and mammalian cells, and (iii) the stability of structures (and their antimicrobial activity) in the presence of enzymes, which are addressed in this paper. Because of the ability of amino acid-functionalized nano-gold to retain structural and functional activity, even after exposure to a range of physicochemical stimuli, they provide an excellent nanotechnological platform for designing highly effective contact-based antimicrobials and their applications.
JTD Keywords: agents, antibiotic-free technology, arginine, charged amino acids, contact-based antimicrobials, discovery, enzyme-resistant antimicrobials, functionalized gold, peptides, polymers, resistant, Antibiotic-free technology, Charged amino acids, Contact-based antimicrobials, Enzyme-resistant antimicrobials, Functionalized gold, Nanoparticles
Ferrer I, Andrés-Benito P, Ausín K, Pamplona R, del Rio JA, Fernández-Irigoyen J, Santamaría E, (2021). Dysregulated protein phosphorylation: A determining condition in the continuum of brain aging and Alzheimer's disease Brain Pathology 31, e12996
Tau hyperphosphorylation is the first step of neurofibrillary tangle (NFT) formation. In the present study, samples of the entorhinal cortex (EC) and frontal cortex area 8 (FC) of cases with NFT pathology classified as stages I–II, III–IV, and V–VI without comorbidities, and of middle-aged (MA) individuals with no NFT pathology, were analyzed by conventional label-free 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 214 in the EC, 65 of which were dysregulated at the first stages (I–II) of NFT pathology; 167 phosphoproteins were dysregulated in the FC, 81 of them at stages I–II of NFT pathology. A large percentage of dysregulated phosphoproteins were identified in the two regions and at different stages of NFT progression. The main group of dysregulated phosphoproteins was made up of components of the membranes, cytoskeleton, synapses, proteins linked to membrane transport and ion channels, and kinases. The present results show abnormal phosphorylation of proteins at the first stages of NFT pathology in the elderly (in individuals clinically considered representative of normal aging) and sporadic Alzheimer's disease (sAD). Dysregulated protein phosphorylation in the FC precedes the formation of NFTs and SPs. The most active period of dysregulated phosphorylation is at stages III–IV when a subpopulation of individuals might be clinically categorized as suffering from mild cognitive impairment which is a preceding determinant stage in the progression to dementia. Altered phosphorylation of selected proteins, carried out by activation of several kinases, may alter membrane and cytoskeletal functions, among them synaptic transmission and membrane/cytoskeleton signaling. Besides their implications in sAD, the present observations suggest a molecular substrate for “benign” cognitive deterioration in “normal” brain aging.
JTD Keywords: (phospho)proteomics, alzheimer's disease, amyloid-beta, association guidelines, brain aging, cytoskeleton, frontal-cortex, kinases, lipid rafts, membranes, national institute, neuropathologic assessment, pathological process, protein phosphorylation, synapse pathology, synapses, tau, tau pathology, (phospho)proteomics, Age-related tauopathy, Alzheimer's disease, Brain aging, Cytoskeleton, Kinases, Membranes, Protein phosphorylation, Synapses, Tau
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,
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, Bio-actuator, Drug testing, Human skeletal muscle, Muscle ageing, Necrosis-factor-alpha
Illa M, Pla L, Berdún S, Mir M, Rivas L, Dulay S, Picard-Hagen N, Samitier J, Gratacós E, Eixarch E, (2021). Miniaturized electrochemical sensors to monitor fetal hypoxia and acidosis in a pregnant sheep model Biomedicines 9,
Perinatal asphyxia is a major cause of severe brain damage and death. For its prenatal identification, Doppler ultrasound has been used as a surrogate marker of fetal hypoxia. However, Doppler evaluation cannot be performed continuously. We have evaluated the performance of a miniaturized multiparametric sensor aiming to evaluate tissular oxygen and pH changes continuously in an umbilical cord occlusion (UCO) sheep model. The electrochemical sensors were inserted in fetal hindlimb skeletal muscle and electrochemical signals were recorded. Fetal hemodynamic changes and metabolic status were also monitored during the experiment. Additionally, histological assessment of the tissue surrounding the sensors was performed. Both electrochemical sensors detected the pO2 and pH changes induced by the UCO and these changes were correlated with hemodynamic parameters as well as with pH and oxygen content in the blood. Finally, histological assessment revealed no signs of alteration on the same day of insertion. This study provides the first evidence showing the application of miniaturized multiparametric electrochemical sensors detecting changes in oxygen and pH in skeletal muscular tissue in a fetal sheep model.
JTD Keywords: continuous monitoring of acid-base status, diagnosis, doppler, electrochemical sensors, growth restriction, high-risk pregnancies, human-fetus, management, responses, tissue ph, Continuous monitoring of acid-base status, Electrochemical sensors, High-risk pregnancies, Umbilical cord occlusion, Umbilical-cord occlusion
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). Corrigendum to Level of MFAP4 in ascites independently predicts 1-year transplant-free survival in patients with cirrhosis (Correction of vol 3, 100287, 2021) Jhep Rep 3, 100353
[This corrects the article DOI: 10.1016/j.jhepr.2021.100287.].© 2021 The Author(s).
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, gfr, glomerular filtration rate, hr, hazard ratio, inr, internationalised normal ratio, liver disease, ltx, liver transplantation, meld-na, model for end-stage liver disease, mfap4, microfibrillar associated protein 4, mortality, nash, non-alcoholic steatohepatitis, prognosis, sbp, spontaneous bacterial peritonitis, Biomarker, Decompensated, Egfr, estimated gfr, Erratum, Fibrosis, Liver disease, Mortality, Prognosis
Rubí-Sans G, Nyga A, Rebollo E, Pérez-Amodio S, Otero J, Navajas D, Mateos-Timoneda MA, Engel E, (2021). Development of Cell-Derived Matrices for Three-Dimensional in Vitro Cancer Cell Models Acs Applied Materials & Interfaces 13, 44108-44123
Most morphogenetic and pathological processes are driven by cells responding to the surrounding matrix, such as its composition, architecture, and mechanical properties. Despite increasing evidence for the role of extracellular matrix (ECM) in tissue and disease development, many in vitro substitutes still fail to effectively mimic the native microenvironment. We established a novel method to produce macroscale (>1 cm) mesenchymal cell-derived matrices (CDMs) aimed to mimic the fibrotic tumor microenvironment surrounding epithelial cancer cells. CDMs are produced by human adipose mesenchymal stem cells cultured in sacrificial 3D scaffold templates of fibronectin-coated poly-lactic acid microcarriers (MCs) in the presence of macromolecular crowders. We showed that decellularized CDMs closely mimic the fibrillar protein composition, architecture, and mechanical properties of human fibrotic ECM from cancer masses. CDMs had highly reproducible composition made of collagen types I and III and fibronectin ECM with tunable mechanical properties. Moreover, decellularized and MC-free CDMs were successfully repopulated with cancer cells throughout their 3D structure, and following chemotherapeutic treatment, cancer cells showed greater doxorubicin resistance compared to 3D culture in collagen hydrogels. Collectively, these results support the use of CDMs as a reproducible and tunable tool for developing 3D in vitro cancer models.
JTD Keywords: 3d cell-derived matrices, adipose mesenchymal stem cells, collagen matrix, colorectal adenocarcinoma, cytotoxicity assay, deposition, expansion, extracellular microenvironment, extracellular-matrix, fibronectin, growth, macromolecular crowders, microcarriers, scaffolds, tissue, 3d cell-derived matrices, Adipose mesenchymal stem cells, Cytotoxicity assay, Extracellular microenvironment, Macromolecular crowders, Mesenchymal stem-cells, Microcarriers
Rial-Hermida MI, Rey-Rico A, Blanco-Fernandez B, Carballo-Pedrares N, Byrne EM, Mano JF, (2021). Recent Progress on Polysaccharide-Based Hydrogels for Controlled Delivery of Therapeutic Biomolecules Acs Biomaterials Science & Engineering 7, 4102-4127
A plethora of applications using polysaccharides have been developed in recent years due to their availability as well as their frequent nontoxicity and biodegradability. These polymers are usually obtained from renewable sources or are byproducts of industrial processes, thus, their use is collaborative in waste management and shows promise for an enhanced sustainable circular economy. Regarding the development of novel delivery systems for biotherapeutics, the potential of polysaccharides is attractive for the previously mentioned properties and also for the possibility of chemical modification of their structures, their ability to form matrixes of diverse architectures and mechanical properties, as well as for their ability to maintain bioactivity following incorporation of the biomolecules into the matrix. Biotherapeutics, such as proteins, growth factors, gene vectors, enzymes, hormones, DNA/RNA, and antibodies are currently in use as major therapeutics in a wide range of pathologies. In the present review, we summarize recent progress in the development of polysaccharide-based hydrogels of diverse nature, alone or in combination with other polymers or drug delivery systems, which have been implemented in the delivery of biotherapeutics in the pharmaceutical and biomedical fields. © 2021 American Chemical Society.
JTD Keywords: biodegradable dextran hydrogels, biotherapeutics, bone morphogenetic protein-2, carrageenan-based hydrogels, chitosan-based hydrogels, controlled delivery, controlled-release, cross-linked hydrogels, growth-factor delivery, hydrogels, in-vitro characterization, polysaccharides, self-healing hydrogel, stimuli-responsiveness, tissue engineering, Antibodies, Bioactivity, Biodegradability, Biomedical fields, Biomolecules, Biotherapeutics, Chemical modification, Circular economy, Controlled delivery, Controlled drug delivery, Delivery systems, Drug delivery system, Functional polymers, Hyaluronic-acid hydrogels, Hydrogels, Industrial processs, Polysaccharides, Recent progress, Renewable sources, Stimuli-responsiveness, Targeted drug delivery, Tissue engineering, Waste management
Madsen BS, Thiele M, Detlefsen S, Kjaergaard M, Møller LS, Trebicka J, Nielsen MJ, Gudmann NS, Leeming DJ, Karsdal MA, Krag A, GALAXY consortium, (2021). PRO-C3 and ADAPT algorithm accurately identify patients with advanced fibrosis due to alcohol-related liver disease Alimentary Pharmacology & Therapeutics 54, 699-708
Background: Alcohol is a main cause of preventable deaths and frequently leads to the development of alcohol-related liver disease. Due to the lack of diagnostics, patients are commonly diagnosed after developing clinical manifestations. Recently, the biomarker PRO-C3 was shown to accurately identify fibrosis due to non-alcoholic fatty liver disease. Aim: To assess the diagnostic accuracy of PRO-C3, the ADAPT score and best-performing non-patented serological test to detect advanced alcohol-related liver fibrosis. Methods: We enrolled 426 patients with alcohol overuse in a prospective biopsy-controlled study. We evaluated the accuracy of PRO-C3 and the PRO-C3-based algorithm ADAPT to detect advanced liver fibrosis. Results: The accuracy of PRO-C3 was good with an AUROC of 0.85 (95% CI 0.79-0.90). The best-performing non-patented test was the Forns index with an AUROC of 0.83 (95% CI 0.78-0.89). The ADAPT algorithm performed better as compared to both the Forns index and PRO-C3 alone with an AUROC = 0.88 (95% CI 0.83-0.93). Conclusion: PRO-C3 is a new marker with high accuracy to detect advanced alcohol-related liver fibrosis. The diagnostic accuracy of PRO-C3 can be further improved by using the ADAPT algorithm in which the test outperforms currently available non-patented serological fibrosis markers. The study is registered in the Odense Patient Data Exploratory Network (OPEN) under study identification numbers OP_040 (https://open.rsyd.dk/OpenProjects/da/openProject.jsp?openNo=40) and OP_239 (https://open.rsyd.dk/OpenProjects/openProject.jsp?openNo=239&lang=da).
JTD Keywords: mortality, Collagen
Demirel B, Moulin-Frier C, Arsiwalla XD, Verschure PFMJ, Sánchez-Fibla M, (2021). Distinguishing Self, Other, and Autonomy From Visual Feedback: A Combined Correlation and Acceleration Transfer Analysis Frontiers In Human Neuroscience 15, 560657
In cognitive science, Theory of Mind (ToM) is the mental faculty of assessing intentions and beliefs of others and requires, in part, to distinguish incoming sensorimotor (SM) signals and, accordingly, attribute these to either the self-model, the model of the other, or one pertaining to the external world, including inanimate objects. To gain an understanding of this mechanism, we perform a computational analysis of SM interactions in a dual-arm robotic setup. Our main contribution is that, under the common fate principle, a correlation analysis of the velocities of visual pivots is shown to be sufficient to characterize the self (including proximo-distal arm-joint dependencies) and to assess motor to sensory influences, and the other by computing clusters in the correlation dependency graph. A correlational analysis, however, is not sufficient to assess the non-symmetric/directed dependencies required to infer autonomy, the ability of entities to move by themselves. We subsequently validate 3 measures that can potentially quantify a metric for autonomy: Granger causality (GC), transfer entropy (TE), as well as a novel “Acceleration Transfer” (AT) measure, which is an instantaneous measure that computes the estimated instantaneous transfer of acceleration between visual features, from which one can compute a directed SM graph. Subsequently, autonomy is characterized by the sink nodes in this directed graph. This study results show that although TE can capture the directional dependencies, a rectified subtraction operation denoted, in this study, as AT is both sufficient and computationally cheaper.
JTD Keywords: agency, attention, autonomy, cognitive development, computational cognition, developmental psychology, sensorimotor learning, Agency, Attention, Autonomy, Cognitive development, Computational cognition, Developmental psychology, Model, Sensorimotor learning, Theory of mind
Narciso M, Otero J, Navajas D, Farré R, Almendros I, Gavara N, (2021). Image-based method to quantify decellularization of tissue sections International Journal Of Molecular Sciences 22,
Tissue decellularization is typically assessed through absorbance-based DNA quantification after tissue digestion. This method has several disadvantages, namely its destructive nature and inadequacy in experimental situations where tissue is scarce. Here, we present an image processing algorithm for quantitative analysis of DNA content in (de)cellularized tissues as a faster, simpler and more comprehensive alternative. Our method uses local entropy measurements of a phase contrast image to create a mask, which is then applied to corresponding nuclei labelled (UV) images to extract average fluorescence intensities as an estimate of DNA content. The method can be used on native or decellularized tissue to quantify DNA content, thus allowing quantitative assessment of decellularization procedures. We confirm that our new method yields results in line with those obtained using the standard DNA quantification method and that it is successful for both lung and heart tissues. We are also able to accurately obtain a timeline of decreasing DNA content with increased incubation time with a decellularizing agent. Finally, the identified masks can also be applied to additional fluorescence images of immunostained proteins such as collagen or elastin, thus allowing further image-based tissue characterization.
JTD Keywords: decellularization, differentiation, fluorescence image, image processing, microscopic image, Decellularization, Fluorescence image, Image processing, Matrix, Microscopic image, Segmentation
Xu D, Hu J, Pan X, Sánchez S, Yan X, Ma X, (2021). Enzyme-Powered Liquid Metal Nanobots Endowed with Multiple Biomedical Functions Acs Nano 15, 11543-11554
Catalytically powered micro/nanobots (MNBs) can perform active movement by harnessing energy from in situ chemical reactions and show tremendous potential in biomedical applications. However, the development of imageable MNBs that are driven by bioavailable fuels and possess multiple therapeutic functions remains challenging. To resolve such issues, we herein propose enzyme (urease) powered liquid metal (LM) nanobots that are naturally of multiple therapeutic functions and imaging signals. The main body of the nanobot is composed of a biocompatible LM nanoparticle encapsulated by polydopamine (PDA). Urease enzyme needed for the powering and desired drug molecules, e.g., cefixime trihydrate antibiotic, are grafted on external surfaces of the PDA shell. Such a chemical composition endows the nanobots with dual-mode ultrasonic (US) and photoacoustic (PA) imaging signals and favorable photothermal effect. These LM nanobots exhibit positive chemotaxis and therefore can be collectively guided along a concentration gradient of urea for targeted transportation. When exposed to NIR light, the LM nanobots would deform and complete the function change from active drug carriers to photothermal reagents, to achieve synergetic antibacterial treatment by both photothermal and chemotherapeutic effects. The US and PA properties of the LM nanoparticle can be used to not only track and monitor the active movement of the nanobots in a microfluidic vessel model but also visualize their dynamics in the bladder of a living mouse in vivo. To conclude, the LM nanobots demonstrated herein represent a proof-of-concept therapeutic nanosystem with multiple biomedical functionalities, providing a feasible tool for preclinical studies and clinical trials of MNB-based imaging-guided therapy.
JTD Keywords: cell, chemo-photothermal therapy, chemotaxis, image tracking, liquid metal nanobots, nanomotors, tracking, Chemo-photothermal therapy, Chemotaxis, Image tracking, Liquid metal nanobots, Nanomotors
Ortiz C, Schierwagen R, Schaefer L, Klein S, Trepat X, Trebicka J, (2021). Extracellular Matrix Remodeling in Chronic Liver Disease Current Tissue Microenvironment Reports 2, 41-52
Abstract Purpose of the Review This review aims to summarize the current knowledge of the extracellular matrix remodeling during hepatic fibrosis. We discuss the diverse interactions of the extracellular matrix with hepatic cells and the surrounding matrix in liver fibrosis, with the focus on the molecular pathways and the mechanisms that regulate extracellular matrix remodeling. Recent Findings The extracellular matrix not only provides structure and support for the cells, but also controls cell behavior by providing adhesion signals and by acting as a reservoir of growth factors and cytokines. Summary Hepatic fibrosis is characterized by an excessive accumulation of extracellular matrix. During fibrogenesis, the natural remodeling process of the extracellular matrix varies, resulting in the excessive accumulation of its components, mainly collagens. Signals released by the extracellular matrix induce the activation of hepatic stellate cells, which are the major source of extracellular matrix and most abundant myofibroblasts in the liver. Graphical abstract
JTD Keywords: collagen, extracellular matrix, hepatic stellate cell, liver fibrosis, metalloproteinases, Tgf-?1, Tgf-β1
Falcones B, Sanz-Fraile H, Marhuenda E, Mendizábal I, Cabrera-Aguilera I, Malandain N, Uriarte JJ, Almendros I, Navajas D, Weiss DJ, Farré R, Otero J, (2021). Bioprintable lung extracellular matrix hydrogel scaffolds for 3d culture of mesenchymal stromal cells Polymers 13,
Mesenchymal stromal cell (MSC)-based cell therapy in acute respiratory diseases is based on MSC secretion of paracrine factors. Several strategies have proposed to improve this are being explored including pre-conditioning the MSCs prior to administration. We here propose a strategy for improving the therapeutic efficacy of MSCs based on cell preconditioning by growing them in native extracellular matrix (ECM) derived from the lung. To this end, a bioink with tunable stiffness based on decellularized porcine lung ECM hydrogels was developed and characterized. The bioink was suitable for 3D culturing of lung-resident MSCs without the need for additional chemical or physical crosslinking. MSCs showed good viability, and contraction assays showed the existence of cell–matrix interactions in the bioprinted scaffolds. Adhesion capacity and length of the focal adhesions formed were increased for the cells cultured within the lung hydrogel scaffolds. Also, there was more than a 20-fold increase of the expression of the CXCR4 receptor in the 3D-cultured cells compared to the cells cultured in plastic. Secretion of cytokines when cultured in an in vitro model of lung injury showed a decreased secretion of pro-inflammatory mediators for the cells cultured in the 3D scaffolds. Moreover, the morphology of the harvested cells was markedly different with respect to conventionally (2D) cultured MSCs. In conclusion, the developed bioink can be used to bioprint structures aimed to improve preconditioning MSCs for therapeutic purposes.
JTD Keywords: 3d bioprinting, acute lung injury, adhesion, collagen, differentiation, dimension, elastic properties, extracellular matrix, hydrogels, in-vitro, mechanical-properties, mesenchymal stromal cells, microenvironment, potentiate, tissue engineering, 3d bioprinting, Acute lung injury, Extracellular matrix, Hydrogels, Mesenchymal stromal cells, Stem-cells, Tissue engineering
Ferrer-Lluis I, Castillo-Escario Y, Montserrat JM, Jané R, (2021). SleepPos app: An automated smartphone application for angle based high resolution sleep position monitoring and treatment Sensors 21,
Poor sleep quality or disturbed sleep is associated with multiple health conditions. Sleep position affects the severity and occurrence of these complications, and positional therapy is one of the less invasive treatments to deal with them. Sleep positions can be self-reported, which is unreliable, or determined by using specific devices, such as polysomnography, polygraphy or cameras, that can be expensive and difficult to employ at home. The aim of this study is to determine how smartphones could be used to monitor and treat sleep position at home. We divided our research into three tasks: (1) develop an Android smartphone application (‘SleepPos’ app) which monitors angle-based high-resolution sleep position and allows to simultaneously apply positional treatment; (2) test the smartphone application at home coupled with a pulse oximeter; and (3) explore the potential of this tool to detect the positional occurrence of desaturation events. The results show how the ‘SleepPos’ app successfully determined the sleep position and revealed positional patterns of occurrence of desaturation events. The ‘SleepPos’ app also succeeded in applying positional therapy and preventing the subjects from sleeping in the supine sleep position. This study demonstrates how smartphones are capable of reliably monitoring high-resolution sleep position and provide useful clinical information about the positional occurrence of desaturation events.
JTD Keywords: accelerometry, android, apnea patients, app, association, biomedical signal processing, management, mhealth, monitoring, pathophysiology, pilot mhealth, questionnaire, sleep position, smartphone, supine position, time, Accelerometry, Android, App, Biomedical signal processing, Mhealth, Monitoring, Sleep position, Smart-phone, Smartphone, Tennis ball technique
Mallafré‐muro C, Llambrich M, Cumeras R, Pardo A, Brezmes J, Marco S, Gumà J, (2021). Comprehensive volatilome and metabolome signatures of colorectal cancer in urine: A systematic review and meta‐analysis Cancers 13, 2534
To increase compliance with colorectal cancer screening programs and to reduce the recommended screening age, cheaper and easy non‐invasiveness alternatives to the fecal immunochemical test should be provided. Following the PRISMA procedure of studies that evaluated the metabolome and volatilome signatures of colorectal cancer in human urine samples, an exhaustive search in PubMed, Web of Science, and Scopus found 28 studies that met the required criteria. There were no restrictions on the query for the type of study, leading to not only colorectal cancer samples versus control comparison but also polyps versus control and prospective studies of surgical effects, CRC staging and comparisons of CRC with other cancers. With this systematic review, we identified up to 244 compounds in urine samples (3 shared compounds between the volatilome and metabolome), and 10 of them were relevant in more than three articles. In the meta-analysis, nine studies met the criteria for inclusion, and the results combining the case‐control and the pre‐/post‐surgery groups, eleven compounds were found to be relevant. Four upregulated metabolites were identified, 3‐hydroxybutyric acid, L‐dopa, L‐histidinol, and N1, N12‐ diacetylspermine and seven downregulated compounds were identified, pyruvic acid, hydroquinone, tartaric acid, and hippuric acid as metabolites and butyraldehyde, ether, and 1,1,6‐ trimethyl‐1,2‐dihydronaphthalene as volatiles.
JTD Keywords: biomarkers, breast, chromatography, colorectal cancer, diagnosis, markers, meta-analysis, metabolomics, metabonomics, n-1,n-12-diacetylspermine, nucleosides, systematic review, urine, validation, volatilomics, Colorectal cancer, Early-stage, Metabolomics, Meta‐analysis, Systematic review, Urine, Volatilomics
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 Rep 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
González-Piñero M, Páez-Avilés C, Juanola-Feliu E, Samitier J, (2021). Cross-fertilization of knowledge and technologies in collaborative research projects Journal Of Knowledge Management 25, 34-59
Purpose: This paper aims to explore how the cross-fertilization of knowledge and technologies in EU-funded research projects, including serious games and gamification, is influenced by the following variables: multidisciplinarity, knowledge base and organizations (number and diversity). The interrelation of actors and projects form a network of innovation. The largest contribution to cross-fertilization comes from the multidisciplinary nature of projects and the previous knowledge and technology of actors. The analysis draws on the understanding of how consortia perform as an innovation network, what their outcomes are and what capabilities are needed to reap value. Design/methodology/approach: All the research projects including serious games and/or gamification, funded by the EU-Horizon 2020 work programme, have been analyzed to test the hypotheses in this paper. The study sample covers the period between 2014 and 2016 (June), selecting the 87 research projects that comprised 519 organizations as coordinators and participants, and 597 observations – because more organizations participate in more than one project. The data were complemented by documentary and external database analysis. Findings: To create cross-fertilization of knowledge and technologies, the following emphasis should be placed on projects: partners concern various disciplines; partners have an extensive knowledge base for generating novel combinations and added-value technologies; there is a diverse typology of partners with unique knowledge and skills; and there is a limited number of organizations not too closely connected to provide cross-fertilization. Research limitations/implications: First, the database sample covers a period of 30 months. The authors’ attention was focused on this period because H2020 prioritized for the first time the serious games and gamification with two specific calls (ICT-21–14 and ICT-24–16) and, second, for the explosion of projects including these technologies in the past years (Adkins, 2017). These facts can be understood as a way to push the research to higher technology readiness levels (TRLs) and introducing the end-user in the co-creation and co-development along the value chain. Second, an additional limitation makes reference to the European focus of the projects, missing strong regional initiatives not identified and studied. Originality/value: This paper has attempted to explore and define theoretically and empirically the characteristics found in the cross-fertilization of collaborative research projects, emphasizing which variables, and how, need to be stimulated to benefit more multidisciplinary consortia and accelerate the process of innovation. © 2021, Manel González-Piñero, Cristina Páez-Avilés, Esteve Juanola-Feliu and Josep Samitier.
JTD Keywords: absorptive-capacity, business model, cross-fertilization of knowledge, diversity, front-end, impact, innovation systems, knowledge management, management research, science, social networks, team, technology, Cross-fertilization of knowledge, Innovation, Knowledge management, Management research, Research-and-development, Technology
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
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
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 Rep 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
Badia M, Bolognesi B, (2021). Assembling the right type of switch: Protein condensation to signal cell death Current Opinion In Cell Biology 69, 55-61
© 2020 Elsevier Ltd Protein phase transitions are particularly amenable for cell signalling as these highly cooperative processes allow cells to make binary decisions in response to relatively small intracellular changes. The different processes of condensate formation and the distinct material properties of the resulting condensates provide a dictionary to modulate a range of decisions on cell fate. We argue that, on the one hand, the reversibility of liquid demixing offers a chance to arrest cell growth under specific circumstances. On the other hand, the transition to amyloids is better suited for terminal decisions such as those leading to apoptosis and necrosis. Here, we review recent examples of both scenarios, highlighting how mutations in signalling proteins affect the formation of biomolecular condensates with drastic effects on cell survival.
JTD Keywords: amyloid, cell death, deep mutagenesis, llps, rna-binding proteins, Amyloid, Cell death, Deep mutagenesis, Llps, Rna-binding proteins
Magdanz V, Vivaldi J, Mohanty S, Klingner A, Vendittelli M, Simmchen J, Misra S, Khalil ISM, (2021). Impact of Segmented Magnetization on the Flagellar Propulsion of Sperm-Templated Microrobots Advanced Science 8, 2004037
© 2021 The Authors. Advanced Science published by Wiley-VCH GmbH Technical design features for improving the way a passive elastic filament produces propulsive thrust can be understood by analyzing the deformation of sperm-templated microrobots with segmented magnetization. Magnetic nanoparticles are electrostatically self-assembled on bovine sperm cells with nonuniform surface charge, producing different categories of sperm-templated microrobots. Depending on the amount and location of the nanoparticles on each cellular segment, magnetoelastic and viscous forces determine the wave pattern of each category during flagellar motion. Passively propagating waves are induced along the length of these microrobots using external rotating magnetic fields and the resultant wave patterns are measured. The response of the microrobots to the external field reveals distinct flow fields, propulsive thrust, and frequency responses during flagellar propulsion. This work allows predictions for optimizing the design and propulsion of flexible magnetic microrobots with segmented magnetization.
JTD Keywords: biohybrid microrobots, flagellar propulsion, magnetic actuation, nanoparticles, sperm cells, Biohybrid microrobots, Flagellar propulsion, Magnetic actuation, Nanoparticles, Sperm cells
Fonte M, Tassi N, Fontinha D, Bouzón-Arnáiz I, Ferraz R, Araújo MJ, Fernàndez-Busquets X, Prudêncio M, Gomes P, Teixeira C, (2021). 4,9-Diaminoacridines and 4-Aminoacridines as Dual-Stage Antiplasmodial Hits Chemmedchem 16, 788-792
© 2020 Wiley-VCH GmbH Multi-stage drugs have been prioritized in antimalarial drug discovery, as targeting more than one process in the Plasmodium life cycle is likely to increase efficiency, while decreasing the chances of emergence of resistance by the parasite. Herein, we disclose two novel acridine-based families of compounds that combine the structural features of primaquine and chloroquine. Compounds prepared and studied thus far retained the in vitro activity displayed by the parent drugs against the erythrocytic stages of chloroquine-sensitive and -resistant Plasmodium falciparum strains, and against the hepatic stages of Plasmodium berghei, hence acting as dual-stage antiplasmodial hits.
JTD Keywords: acridines, antimalarial activity, blood-stage, liver-stage, malaria, plasmodium, Acridines, Antimalarial activity, Blood-stage, Liver-stage, Malaria, Plasmodium, Synthesis
Seras-Franzoso J, Díaz-Riascos ZV, Corchero JL, González P, García-Aranda N, Mandaña M, Riera R, Boullosa A, Mancilla S, Grayston A, Moltó-Abad M, Garcia-Fruitós E, Mendoza R, Pintos-Morell G, Albertazzi L, Rosell A, Casas J, Villaverde A, Schwartz S, Abasolo I, (2021). Extracellular vesicles from recombinant cell factories improve the activity and efficacy of enzymes defective in lysosomal storage disorders Journal Of Extracellular Vesicles 10, e12058
In the present study the use of extracellular vesicles (EVs) as vehicles for therapeutic enzymes in lysosomal storage disorders was explored. EVs were isolated from mammalian cells overexpressing alpha-galactosidase A (GLA) or N-sulfoglucosamine sulfohydrolase (SGSH) enzymes, defective in Fabry and Sanfilippo A diseases, respectively. Direct purification of EVs from cell supernatants was found to be a simple and efficient method to obtain highly active GLA and SGSH proteins, even after EV lyophilization. Likewise, EVs carrying GLA (EV-GLA) were rapidly uptaken and reached the lysosomes in cellular models of Fabry disease, restoring lysosomal functionality much more efficiently than the recombinant enzyme in clinical use. In vivo, EVs were well tolerated and distributed among all main organs, including the brain. DiR-labelled EVs were localized in brain parenchyma 1 h after intra-arterial (internal carotid artery) or intravenous (tail vein) administrations. Moreover, a single intravenous administration of EV-GLA was able to reduce globotriaosylceramide (Gb3) substrate levels in clinically relevant tissues, such kidneys and brain. Overall, our results demonstrate that EVs from cells overexpressing lysosomal enzymes act as natural protein delivery systems, improving the activity and the efficacy of the recombinant proteins and facilitating their access to organs neglected by conventional enzyme replacement therapies.
JTD Keywords: alpha?galactosidase a, alpha‐galactosidase a, drug delivery, enzyme replacement therapy, fabry disease, lysosomal storage disorders, n-sulfoglucosamine sulfohydrolase, n?sulfoglucosamine sulfohydrolase, n‐sulfoglucosamine sulfohydrolase, sanfilippo syndrome, Alpha-galactosidase a, Drug delivery, Enzyme replacement therapy, Fabry disease, Lysosomal storage disorders, N-sulfoglucosamine sulfohydrolase, Sanfilippo syndrome
Puiggalí-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
Abdelrahman F, Easwaran M, Daramola OI, Ragab S, Lynch S, Oduselu TJ, Khan FM, Ayobami A, Adnan F, Torrents E, Sanmukh S, El-Shibiny A, (2021). Phage-Encoded Endolysins Antibiotics 10, 124
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. Due to the global emergence of antibiotic resistance, there has been an increase in research surrounding endolysins as an alternative therapeutic. Endolysins are phage-encoded enzymes, utilized by mature phage virions to hydrolyze the cell wall from within. There is significant evidence that proves the ability of endolysins to degrade the peptidoglycan externally without the assistance of phage. Thus, their incorporation in therapeutic strategies has opened new options for therapeutic application against bacterial infections in the human and veterinary sectors, as well as within the agricultural and biotechnology sectors. While endolysins show promising results within the laboratory, it is important to document their resistance, safety, and immunogenicity for in-vivo application. This review aims to provide new insights into the synergy between endolysins and antibiotics, as well as the formulation of endolysins. Thus, it provides crucial information for clinical trials involving endolysins.
JTD Keywords: antibiotic resistance, bacteriophages, Antibiotic resistance, Bacteriophages, Endolysin
Mateu-Sanz, M, Tornin, J, Ginebra, MP, Canal, C, (2021). Cold Atmospheric Plasma: A New Strategy Based Primarily on Oxidative Stress for Osteosarcoma Therapy Journal Of Clinical Medicine 10, 893
Osteosarcoma is the most common primary bone tumor, and its first line of treatment presents a high failure rate. The 5-year survival for children and teenagers with osteosarcoma is 70% (if diagnosed before it has metastasized) or 20% (if spread at the time of diagnosis), stressing the need for novel therapies. Recently, cold atmospheric plasmas (ionized gases consisting of UV-Vis radiation, electromagnetic fields and a great variety of reactive species) and plasma-treated liquids have been shown to have the potential to selectively eliminate cancer cells in different tumors through an oxidative stress-dependent mechanism. In this work, we review the current state of the art in cold plasma therapy for osteosarcoma. Specifically, we emphasize the mechanisms unveiled thus far regarding the action of plasmas on osteosarcoma. Finally, we review current and potential future approaches, emphasizing the most critical challenges for the development of osteosarcoma therapies based on this emerging technique.
JTD Keywords: cancer stem cells, cold atmospheric plasma, osteosarcoma, oxidative stress, plasma treated liquids, reactive oxygen and nitrogen species, Antineoplastic activity, Antineoplastic agent, Cancer chemotherapy, Cancer stem cell, Cancer stem cells, Cancer surgery, Cancer survival, Cell therapy, Cold atmospheric plasma, Cold atmospheric plasma therapy, Electromagnetism, Human, In vitro study, Intracellular signaling, Oncogene, Osteosarcoma, Oxidative stress, Plasma treated liquids, Reactive nitrogen species, Reactive oxygen and nitrogen species, Reactive oxygen metabolite, Review, Tumor microenvironment
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,
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's, Amyloid, Computational biology, Deep mutagenesis, Genetics, Genomics, Kinetics, Nucleation, Oligomers, Onset, Precursor protein, Rates, S. cerevisiae, State, Systems biology
Abramov A, Maiti B, Keridou I, Puiggalí J, Reiser O, Díaz DD, (2021). A pH-Triggered Polymer Degradation or Drug Delivery System by Light-Mediated Cis/Trans Isomerization of o-Hydroxy Cinnamates Macromolecular Rapid Communications 42, e2100213
A new methodology for the pH-triggered degradation of polymers or for the release of drugs under visible light irradiation based on the cyclization of ortho-hydroxy-cinnamates (oHC) to coumarins is described. The key oHC structural motif can be readily incorporated into the rational design of novel photocleavable polymers via click chemistry. This main-chain moiety undergoes a fast photocleavage when irradiated with 455 nm light provided that a suitable base is added. A series of polyethylene glycol-alt-ortho-hydroxy cinnamate (polyethylene glycol (PEG)(n)-alt-oHC)-based polymers are synthesized and the time-dependent visible-light initiated cleavage of the photoactive monomer and polymer is investigated in solution by a variety of spectroscopic and chromatographic techniques. The photo-degradation behavior of the water-soluble poly(PEG(2000)-alt-oHC) is investigated within a broad pH range (pH = 2.1-11.8), demonstrating fast degradation at pH 11.8, while the stability of the polymer is greatly enhanced at pH 2.1. Moreover, the neat polymer shows long-term stability under daylight conditions, thus allowing its storage without special precautions. In addition, two water-soluble PEG-based drug-carrier molecules (mPEG(2000)-oHC-benzhydrol/phenol) are synthesized and used for drug delivery studies, monitoring the process by UV-vis spectroscopy in an ON/OFF intermittent manner.
JTD Keywords: coumarins, drug delivery, e/z-double bond isomerization, o-hydroxy cinnamates, polymer degradation, Aliphatic compounds, Antioxidant activity, Antitumor, Chromatographic techniques, Chromatography, Cis/trans isomerization, Controlled drug delivery, Coumarin derivatives, Coumarins, Drug delivery, Drug delivery system, E/z-double bond isomerization, Films, Hydrogels, Image enhancement, Light, Long term stability, O-hydroxy cinnamates, Particles, Photoactive monomers, Photodegradation, Polyethylene glycols, Polyethylenes, Polymer degradation, Responsive polymers, Salts, Structural motifs, Synthesis (chemical), Targeted drug delivery, Visible light photocatalysis, Visible-light irradiation
Watt, AC, Cejas, P, DeCristo, MJ, Metzger, O, Lam, EYN, Qiu, XT, BrinJones, H, Kesten, N, Coulson, R, Font-Tello, A, Lim, K, Vadhi, R, Daniels, VW, Montero, J, Taing, L, Meyer, CA, Gilan, O, Bell, CC, Korthauer, KD, Giambartolomei, C, Pasaniuc, B, Seo, JH, Freedman, ML, Ma, CT, Ellis, MJ, Krop, I, Winer, E, Letai, A, Brown, M, Dawson, MA, Long, HW, Zhao, JJ, Goel, S, (2021). CDK4/6 inhibition reprograms the breast cancer enhancer landscape by stimulating AP-1 transcriptional activity Nature Cancer 2, 34-48
Goel and colleagues show that CDK4/6 inhibition induces global chromatin changes mediated by AP-1 factors, which mediate key biological and clinical effects in breast cancer. Pharmacologic inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6) were designed to induce cancer cell cycle arrest. Recent studies have suggested that these agents also exert other effects, influencing cancer cell immunogenicity, apoptotic responses and differentiation. Using cell-based and mouse models of breast cancer together with clinical specimens, we show that CDK4/6 inhibitors induce remodeling of cancer cell chromatin characterized by widespread enhancer activation, and that this explains many of these effects. The newly activated enhancers include classical super-enhancers that drive luminal differentiation and apoptotic evasion, as well as a set of enhancers overlying endogenous retroviral elements that are enriched for proximity to interferon-driven genes. Mechanistically, CDK4/6 inhibition increases the level of several activator protein-1 transcription factor proteins, which are in turn implicated in the activity of many of the new enhancers. Our findings offer insights into CDK4/6 pathway biology and should inform the future development of CDK4/6 inhibitors.
JTD Keywords: Abemaciclib, Androgen receptor, Animal experiment, Animal model, Animal tissue, Apoptosis, Article, Breast cancer, C-jun, Cancer cell, Carcinoembryonic antigen related cell adhesion molecule 1, Caspase 3, Cell cycle arrest, Cells, Chromatin, Chromatin immunoprecipitation, Controlled study, Cyclin dependent kinase 4, Cyclin dependent kinase 6, Dna damage, Epidermal growth factor receptor 2, Estrogen receptor, Female, Flow cytometry, Fulvestrant, Hla drb1 antigen, Human, Human cell, Immunoblotting, Immunogenicity, Immunoprecipitation, Interferon, Luciferase assay, Mcf-7 cell line, Mda-mb-231 cell line, Microarray analysis, Morphogenesis, Mouse, Nonhuman, Palbociclib, Protein, Protein expression, Rb, Resistance, Rna polymerase ii, Rna sequence, Selective-inhibition, Senescence, Short tandem repeat, Signal transduction, Tamoxifen, Transcription elongation, Transcription factor, Transcription factor ap 1, Transcriptome, Tumor biopsy, Tumor differentiation, Tumor spheroid, Tumor xenograft, Vinculin, Whole exome sequencing
Pepe, G, Sfogliarini, C, Rizzello, L, Battaglia, G, Pinna, C, Rovati, G, Ciana, P, Brunialti, E, Mornata, F, Maggi, A, Locati, M, Vegeto, E, (2021). ER alpha-independent NRF2-mediated immunoregulatory activity of tamoxifen Biomedicine & Pharmacotherapy 144, 112274
Sex differences in immune-mediated diseases are linked to the activity of estrogens on innate immunity cells, including macrophages. Tamoxifen (TAM) is a selective estrogen receptor modulator (SERM) used in estrogen receptor-alpha (ER alpha)-dependent breast cancers and off-target indications such as infections, although the immune activity of TAM and its active metabolite, 4-OH tamoxifen (4HT), is poorly characterized. Here, we aimed at investigating the endocrine and immune activity of these SERMs in macrophages. Using primary cultures of female mouse macrophages, we analyzed the expression of immune mediators and activation of effector functions in competition experiments with SERMs and 17 beta-estradiol (E2) or the bacterial endotoxin LPS. We observed that 4HT and TAM induce estrogen antagonist effects when used at nanomolar concentrations, while pharmacological concentrations that are reached by TAM in clinical settings regulate the expression of VEGF alpha and other immune activation genes by ER alpha- and G protein-coupled receptor 1 (GPER1)-independent mechanisms that involve NRF2 through PI3K/Akt-dependent mechanisms. Importantly, we observed that SERMs potentiate cell phagocytosis and modify the effects of LPS on the expression of inflammatory cytokines, such as TNF alpha and IL1 beta, with an overall increase in cell inflammatory phenotype, further sustained by potentiation of IL1 beta secretion through caspase-1 activation.
JTD Keywords: drug repurposing, inflammation, macrophage, nrf2, Apoptosis, Breast-cancer, Drug repurposing, Expression, Inflammation, Macrophage, Nrf2, Resistance, Sex-differences, Tamoxifen, Tumor-associated macrophages
Dulay, S, Rivas, L, Pla, L, Berdun, S, Eixarch, E, Gratacos, E, Illa, M, Mir, M, Samitier, J, (2021). Fetal ischemia monitoring with in vivo implanted electrochemical multiparametric microsensors Journal Of Biological Engineering 15, 28
Under intrauterine growth restriction (IUGR), abnormal attainment of the nutrients and oxygen by the fetus restricts the normal evolution of the prenatal causing in many cases high morbidity being one of the top-ten causes of neonatal death. The current gold standards in hospitals to detect this relevant problem is the clinical observation by echography, cardiotocography and Doppler. These qualitative techniques are not conclusive and requires risky invasive fetal scalp blood testing and/or amniocentesis. We developed micro-implantable multiparametric electrochemical sensors for measuring ischemia in real time in fetal tissue and vascular. This implantable technology is designed to continuous monitoring for an early detection of ischemia to avoid potential fetal injury. Two miniaturized electrochemical sensors were developed based on oxygen and pH detection. The sensors were optimized in vitro under controlled concentration, to assess the selectivity and sensitivity required. The sensors were then validated in vivo in the ewe fetus model, by means of their insertion in the muscle leg and inside the iliac artery of the fetus. Ischemia was achieved by gradually obstructing the umbilical cord to regulate the amount of blood reaching the fetus. An important challenge in fetal monitoring is the detection of low levels of oxygen and pH changes under ischemic conditions, requiring high sensitivity sensors. Significant differences were observed in both; pH and pO(2) sensors under changes from normoxia to hypoxia states in the fetus tissue and vascular with both sensors. Herein, we demonstrate the feasibility of the developed sensors for future fetal monitoring in medical applications.
JTD Keywords: electrochemical biosensor, implantable sensor, in vivo validation, ischemia detection, tissue and vascular monitoring, Animal experiment, Animal model, Animal tissue, Article, Blood-gases, Brain, Classification, Controlled study, Diagnosis, Doppler, Early diagnosis, Electrochemical analysis, Electrochemical biosensor, Ewe, Feasibility study, Female, Fetus, Fetus disease, Fetus monitoring, Gestational age, Hypoxemia, Iliac artery, Implantable sensor, In vivo validation, Intrauterine growth restriction, Intrauterine growth retardation, Ischemia detection, Leg muscle, Management, Nonhuman, Oxygen consumption, Ph, Ph and oxygen detection, Ph measurement, Process optimization, Sheep, Tissue and vascular monitoring, Umbilical-cord occlusion
Ballester, BR, Antenucci, F, Maier, M, Coolen, ACC, Verschure, PFMJ, (2021). Estimating upper-extremity function from kinematics in stroke patients following goal-oriented computer-based training Journal Of Neuroengineering And Rehabilitation 18, 186
Introduction: After a stroke, a wide range of deficits can occur with varying onset latencies. As a result, assessing impairment and recovery are enormous challenges in neurorehabilitation. Although several clinical scales are generally accepted, they are time-consuming, show high inter-rater variability, have low ecological validity, and are vulnerable to biases introduced by compensatory movements and action modifications. Alternative methods need to be developed for efficient and objective assessment. In this study, we explore the potential of computer-based body tracking systems and classification tools to estimate the motor impairment of the more affected arm in stroke patients. Methods: We present a method for estimating clinical scores from movement parameters that are extracted from kinematic data recorded during unsupervised computer-based rehabilitation sessions. We identify a number of kinematic descriptors that characterise the patients' hemiparesis (e.g., movement smoothness, work area), we implement a double-noise model and perform a multivariate regression using clinical data from 98 stroke patients who completed a total of 191 sessions with RGS. Results: Our results reveal a new digital biomarker of arm function, the Total Goal-Directed Movement (TGDM), which relates to the patients work area during the execution of goal-oriented reaching movements. The model's performance to estimate FM-UE scores reaches an accuracy of R-2: 0.38 with an error (sigma: 12.8). Next, we evaluate its reliability (r = 0.89 for test-retest), longitudinal external validity (95% true positive rate), sensitivity, and generalisation to other tasks that involve planar reaching movements (R-2: 0.39). The model achieves comparable accuracy also for the Chedoke Arm and Hand Activity Inventory (R-2: 0.40) and Barthel Index (R-2: 0.35). Conclusions: Our results highlight the clinical value of kinematic data collected during unsupervised goal-oriented motor training with the RGS combined with data science techniques, and provide new insight into factors underlying recovery and its biomarkers.
JTD Keywords: interactive feedback, motion classification, motion sensing, multivariate regression, posture monitoring, rehabilitation, stroke, Adult, Aged, Analytic method, Arm movement, Article, Barthel index, Brain hemorrhage, Cerebrovascular accident, Chedoke arm and hand activity inventory, Clinical protocol, Cognitive defect, Computer analysis, Controlled study, Convergent validity, Correlation coefficient, Disease severity, External validity, Female, Fugl meyer assessment for the upper extremity, Functional assessment, Functional status assessment, General health status assessment, Hemiparesis, Human, Interactive feedback, Ischemic stroke, Kinematics, Major clinical study, Male, Mini mental state examination, Motion classification, Motion sensing, Motor analog scale, Movement, Multivariate regression, Muscle function, Posture monitoring, Probability, Recovery, Rehabilitation, Reliability, Retrospective study, Stroke, Stroke patient, Test retest reliability, Therapy, Total goal directed movement, Upper extremities, Upper limb, Upper-limb, Wolf motor function test
Revilla-López, G., Sans, J., Casanovas, J., Bertran, O., Puiggalí, J., Turon, P., Alemán, C., (2020). Analysis of nitrogen fixation by a catalyst capable of transforming N2, CO2 and CH4 into amino acids under mild reactions conditions Applied Catalysis A: General 596, 117526
The processes related to the fixation of nitrogen in a catalyst able to produce glycine and alanine from a N2, CO2 and CH4 gas mixture at mild reaction conditions have been studied by combining experimental and theoretical investigations. Results have allowed to understand the role of different elements of the catalyst, which is constituted by permanently polarized hydroxyapatite (p-HAp), zirconia, and aminotris(methylenephosphonic acid) (ATMP). ATMP attracts N2 molecules towards the surface, maintaining them close to the zirconia and p-HAp components that are the most active from a catalytic point of view. On the other hand, the associative mechanism is thermodynamically favoured under mild reaction conditions with respect to the dissociative one, which is limited by the barrier associated to the Nsingle bondN bond cleavage. Because this reaction mechanism is similar to that employed in the nitrogen fixation by nitrogenase enzymes, these findings provide an opportunity to design new bioinspired catalysts.
JTD Keywords: Artificial photosynthesis, Carbon fixation, Hydroxyapatite, N[sbnd]N bond cleavage
Ruano, G., Díaz, A., Tononi, J., Torras, J., Puiggalí, J., Alemán, C., (2020). Biohydrogel from unsaturated polyesteramide: Synthesis, properties and utilization as electrolytic medium for electrochemical supercapacitors Polymer Testing 82, 106300
The utilization of hydrogels derived from biopolymers as solid electrolyte (SE) of electrochemical supercapacitors (ESCs) is a topic of increasing interest because of their promising applications in biomedicine (e.g. for energy storage in autonomous implantable devices). In this work an unsaturated polyesteramide that contains phenylalanine, butenediol and fumarate as building blocks has been photo-crosslinked to obtain a hydrogel (UPEA-h). The structure of UPEA-h, which is characterized by a network of open interconnected pores surrounded by regions with compact morphology, favors ion transport, while the biodegradability and biocompatibility conferred by the α-amino acid unit and the ester group are appropriated for its usage in the biomedical field. Voltammetric and galvanostatic assays have been conducted to evaluate the behavior of UPEA-h when used as SE in ESCs with poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes. Hence, PEDOT/UPEA-h devices displayed supercapacitor response of up 179 F/g and capacitance retention higher than 90%. Moreover, the long-term stability, leakage-current, and self-discharging response of PEDOT/UPEA-h ESCs reflect the great potential of UPEA-h as ion-conductive electrolyte. Indeed, the performance of PEDOT/UPEA-h is higher than found in analogous devices constructed using other biohydrogels as SE (e.g. κ-carrageenan, poly-γ-glutamic acid and cellulose hydrogels).
JTD Keywords: Energy storage, Hydrogel electronics, Ion conductivity, Photo-crosslinking, Wearable electronics
Ferrer, Isidro, Andrés-Benito, Pol, Sala-Jarque, Julia, Gil, Vanessa, del Rio, José Antonio, (2020). Capacity for seeding and spreading of argyrophilic grain disease in a wild-type murine model; Comparisons with primary age-related tauopathy Frontiers in Molecular Neuroscience 13, 101
Argyrophilic grain disease (AGD) is a common 4R-tauopathy, causing or contributing to cognitive impairment in the elderly. AGD is characterized neuropathologically by pre-tangles in neurons, dendritic swellings called grains, threads, thorn-shaped astrocytes, and coiled bodies in oligodendrocytes in the limbic system. AGD has a characteristic pattern progressively involving the entorhinal cortex, amygdala, hippocampus, dentate gyrus, presubiculum, subiculum, hypothalamic nuclei, temporal cortex, and neocortex and brainstem, thus suggesting that argyrophilic grain pathology is a natural model of tau propagation. One series of WT mice was unilaterally inoculated in the hippocampus with sarkosyl-insoluble and sarkosyl-soluble fractions from “pure” AGD at the age of 3 or 7/12 months and killed 3 or 7 months later. Abnormal hyper-phosphorylated tau deposits were found in ipsilateral hippocampal neurons, grains (dots) in the hippocampus, and threads, dots and coiled bodies in the fimbria, as well as the ipsilateral and contralateral corpus callosum. The extension of lesions was wider in animals surviving 7 months compared with those surviving 3 months. Astrocytic inclusions were not observed at any time. Tau deposits were mainly composed of 4Rtau, but also 3Rtau. For comparative purposes, another series of WT mice was inoculated with sarkosyl-insoluble fractions from primary age-related tauopathy (PART), a pure neuronal neurofibrillary tangle 3Rtau + 4Rtau tauopathy involving the deep temporal cortex and limbic system. Abnormal hyper-phosphorylated tau deposits were found in neurons in the ipsilateral hippocampus, coiled bodies and threads in the fimbria, and the ipsilateral and contralateral corpus callosum, which extended with time along the anterior-posterior axis and distant regions such as hypothalamic nuclei and nuclei of the septum when comparing mice surviving 7 months with mice surviving 3 months. Astrocytic inclusions were not observed. Tau deposits were mainly composed of 4Rtau and 3Rtau. These results show the capacity for seeding and spreading of AGD tau and PART tau in the brain of WT mouse, and suggest that characteristics of host tau, in addition to those of inoculated tau, are key to identifying commonalities and differences between human tauopathies and corresponding murine models.
JTD Keywords: Argyrophilic grain disease, Tauopathies, Tau, Seeding, Progression, Coiled Bodies, Primary age-related tauopathy
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
Gabasa, M., Arshakyan, M., Llorente, A., Chuliá-Peris, L., Pavelescu, I., Xaubet, A., Pereda, J., Alcaraz, J., (2020). Interleukin-1β modulation of the mechanobiology of primary human pulmonary fibroblasts: Potential implications in lung repair International Journal of Molecular Sciences 21, (22), 8417
Pro-inflammatory cytokines like interleukin-1β (IL-1β) are upregulated during early responses to tissue damage and are expected to transiently compromise the mechanical microenvironment. Fibroblasts are key regulators of tissue mechanics in the lungs and other organs. However, the effects of IL-1β on fibroblast mechanics and functions remain unclear. Here we treated human pulmonary fibroblasts from control donors with IL-1β and used Atomic Force Microscopy to unveil that IL-1β significantly reduces the stiffness of fibroblasts concomitantly with a downregulation of filamentous actin (F-actin) and alpha-smooth muscle (α-SMA). Likewise, COL1A1 mRNA was reduced, whereas that of collagenases MMP1 and MMP2 were upregulated, favoring a reduction of type-I collagen. These mechanobiology changes were functionally associated with reduced proliferation and enhanced migration upon IL-1β stimulation, which could facilitate lung repair by drawing fibroblasts to sites of tissue damage. Our observations reveal that IL-1β may reduce local tissue rigidity by acting both intracellularly and extracellularly through the downregulation of fibroblast contractility and type I collagen deposition, respectively. These IL-1β-dependent mechanical effects may enhance lung repair further by locally increasing pulmonary tissue compliance to preserve normal lung distension and function. Moreover, our results support that IL-1β provides innate anti-fibrotic protection that may be relevant during the early stages of lung repair.
JTD Keywords: Cell mechanics, Collagen, IL-1β, MMPs, Pulmonary fibroblasts, Repair
Raote, Ishier, Chabanon, Morgan, Walani, Nikhil, Arroyo, Marino, Garcia-Parajo, Maria F., Malhotra, Vivek, Campelo, Felix, (2020). A physical mechanism of TANGO1-mediated bulky cargo export eLife 9, e59426
The endoplasmic reticulum (ER)-resident protein TANGO1 assembles into a ring around ER exit sites (ERES), and links procollagens in the ER lumen to COPII machinery, tethers, and ER-Golgi intermediate compartment (ERGIC) in the cytoplasm (Raote et al., 2018). Here, we present a theoretical approach to investigate the physical mechanisms of TANGO1 ring assembly and how COPII polymerization, membrane tension, and force facilitate the formation of a transport intermediate for procollagen export. Our results indicate that a TANGO1 ring, by acting as a linactant, stabilizes the open neck of a nascent COPII bud. Elongation of such a bud into a transport intermediate commensurate with bulky procollagens is then facilitated by two complementary mechanisms: (i) by relieving membrane tension, possibly by TANGO1-mediated fusion of retrograde ERGIC membranes and (ii) by force application. Altogether, our theoretical approach identifies key biophysical events in TANGO1-driven procollagen export.
JTD Keywords: Membrane tension, Procollagen export, Secretory pathway, Membrane curvature, Membrane dynamics, Budding
Ferrer, I., Zelaya, M. V., Aguiló García, M., Carmona, M., López-González, I., Andrés-Benito, P., Lidón, L., Gavín, R., Garcia-Esparcia, P., del Rio, J. A., (2020). Relevance of host tau in tau seeding and spreading in tauopathies Brain Pathology 30, (2), 298-318
Human tau seeding and spreading occur following intracerebral inoculation of brain homogenates obtained from tauopathies in transgenic mice expressing natural or mutant tau, and in wild-type (WT) mice. The present study was geared to learning about the patterns of tau seeding, the cells involved and the characteristics of tau following intracerebral inoculation of homogenates from primary age-related tauopathy (PART: neuronal 4Rtau and 3Rtau), aging-related tau astrogliopathy (ARTAG: astrocytic 4Rtau) and globular glial tauopathy (GGT: 4Rtau with neuronal deposits and specific tau inclusions in astrocytes and oligodendrocytes). For this purpose, young and adult WT mice were inoculated unilaterally in the hippocampus or in the lateral corpus callosum with sarkosyl-insoluble fractions from PART, ARTAG and GGT cases, and were killed at variable periods of three to seven months. Brains were processed for immunohistochemistry in paraffin sections. Tau seeding occurred in the ipsilateral hippocampus and corpus callosum and spread to the septal nuclei, periventricular hypothalamus and contralateral corpus callosum, respectively. Tau deposits were mainly found in neurons, oligodendrocytes and threads; the deposits were diffuse or granular, composed of phosphorylated tau, tau with abnormal conformation and 3Rtau and 4Rtau independently of the type of tauopathy. Truncated tau at the aspartic acid 421 and ubiquitination were absent. Tau deposits had the characteristics of pre-tangles. A percentage of intracellular tau deposits co-localized with active (phosphorylated) tau kinases p38 and ERK 1/2. Present study shows that seeding and spreading of human tau into the brain of WT mice involves neurons and glial cells, mainly oligodendrocytes, thereby supporting the idea of a primary role of oligodendrogliopathy, together with neuronopathy, in the progression of tauopathies. In addition, it suggests that human tau inoculation modifies murine tau metabolism with the production and deposition of 3Rtau and 4Rtau, and by activation of specific tau kinases in affected cells.
JTD Keywords: Aging-related tau astrogliopathy, Globular glial tauopathy, Primary age-related tauopathy, Seeding, Spreading, Tau, Tauopathies
Cremonese, C., Schierwagen, R., Uschner, F. E., Torres, S., Tyc, O., Ortiz, C., Schulz, M., Queck, A., Kristiansen, G., Bader, M., Sauerbruch, T., Weiskirchen, R., Walther, T., Trebicka, J., Klein, S., (2020). Short-term western diet aggravates non-alcoholic fatty liver disease (NAFLD) with portal hypertension in TGR(mREN2)27 rats International Journal of Molecular Sciences 21, (9), 3308
Non-alcoholic fatty liver disease (NAFLD) is gaining in importance and is linked to obesity. Especially, the development of fibrosis and portal hypertension in NAFLD patients requires treatment. Transgenic TGR(mREN2)27 rats overexpressing mouse renin spontaneously develop NAFLD with portal hypertension but without obesity. This study investigated the additional role of obesity in this model on the development of portal hypertension and fibrosis. Obesity was induced in twelve-week old TGR(mREN2)27 rats after receiving Western diet (WD) for two or four weeks. Liver fibrosis was assessed using standard techniques. Hepatic expression of transforming growth factor-β1 (TGF-β1), collagen type Iα1, α-smooth muscle actin, and the macrophage markers Emr1, as well as the chemoattractant Ccl2, interleukin-1β (IL1β) and tumor necrosis factor-α (TNFα) were analyzed. Assessment of portal and systemic hemodynamics was performed using the colored microsphere technique. As expected, WD induced obesity and liver fibrosis as confirmed by Sirius Red and Oil Red O staining. The expression of the monocyte-macrophage markers, Emr1, Ccl2, IL1β and TNFα were increased during feeding of WD, indicating infiltration of macrophages into the liver, even though this increase was statistically not significant for the EGF module-containing mucin-like receptor (Emr1) mRNA expression levels. Of note, portal pressure increased with the duration of WD compared to animals that received a normal chow. Besides obesity, WD feeding increased systemic vascular resistance reflecting systemic endothelial and splanchnic vascular dysfunction. We conclude that transgenic TGR(mREN2)27 rats are a suitable model to investigate NAFLD development with liver fibrosis and portal hypertension. Tendency towards elevated expression of Emr1 is associated with macrophage activity point to a significant role of macrophages in NAFLD pathogenesis, probably due to a shift of the renin–angiotensin system towards a higher activation of the classical pathway. The hepatic injury induced by WD in TGR(mREN2)27 rats is suitable to evaluate different stages of fibrosis and portal hypertension in NAFLD with obesity.
JTD Keywords: ADGRE1, EMR1, F4/80, Immunity, Liver fibrosis, Macrophage, NAFLD, Portal hypertension, TGR(mREN2)27, Western diet
Sanz-Fraile, H., Amoros, S., Mendizabal, I., Galvez-Monton, C., Prat-Vidal, C., Bayes-Genis, A., Navajas, D., Farre, R., Otero, J., (2020). Silk-reinforced collagen hydrogels with raised multiscale stiffness for mesenchymal cells 3D culture Tissue Engineering - Part A 26, (5-6), 358-370
Type I collagen hydrogels are of high interest in tissue engineering. With the evolution of 3D bioprinting technologies, a high number of collagen-based scaffolds have been reported for the development of 3D cell cultures. A recent proposal was to mix collagen with silk fibroin derived from Bombyx mori silkworm. Nevertheless, due to the difficulties in the preparation and the characteristics of the protein, several problems such as phase separation and collagen denaturation appear during the procedure. Therefore, the common solution is to diminish the concentration of collagen although in that way the most biologically relevant component is reduced. In this study, we present a new, simple, and effective method to develop a collagen-silk hybrid hydrogel with high collagen concentration and with increased stiffness approaching that of natural tissues, which could be of high interest for the development of cardiac patches for myocardial regeneration and for preconditioning of mesenchymal stem cells (MSCs) to improve their therapeutic potential. Sericin in the silk was preserved by using a physical solubilizing procedure that results in a preserved fibrous structure of type I collagen, as shown by ultrastructural imaging. The macro- and micromechanical properties of the hybrid hydrogels measured by tensile stretch and atomic force microscopy, respectively, showed a more than twofold stiffening than the collagen-only hydrogels. Rheological measurements showed improved printability properties for the developed biomaterial. The suitability of the hydrogels for 3D cell culture was assessed by 3D bioprinting bone marrow-derived MSCs cultured within the scaffolds. The result was a biomaterial with improved printability characteristics that better resembled the mechanical properties of natural soft tissues while preserving biocompatibility owing to the high concentration of collagen. In this study, we report the development of silk microfiber-reinforced type I collagen hydrogels for 3D bioprinting and cell culture. In contrast with previously reported studies, a novel physical method allowed the preservation of the silk sericin protein. Hydrogels were stable, showed no phase separation between the biomaterials, and they presented improved printability. An increase between two- and threefold of the multiscale stiffness of the scaffolds was achieved with no need of using additional crosslinkers or complex methods, which could be of high relevance for cardiac patches development and for preconditioning mesenchymal stem cells (MSCs) for therapeutic applications. We demonstrate that bone marrow-derived MSCs can be effectively bioprinted and 3D cultured within the stiffened structures.
JTD Keywords: 3D bioprinting, Collagen, Hydrogel, Mesenchymal cells, Multiscale mechanics, Silk
Vouloutsi, Vasiliki, Mura, Anna, Tauber, F., Speck, T., Prescott, T. J., Verschure, P., (2020). Biomimetic and Biohybrid Systems
9th International Conference, Living Machines 2020, Freiburg, Germany, July 28–30, 2020, Proceedings , Springer, Cham (Lausanne, Switzerland) 12413, 1-428
This book constitutes the proceedings of the )th International Conference on Biomimetic and Biohybrid Systems, Living Machines 2020, held in Freiburg, Germany, in July 2020. Due to COVID-19 pandemic the conference was held virtually. The 32 full and 7 short papers presented in this volume were carefully reviewed and selected from 45 submissions. They deal with research on novel life-like technologies inspired by the scientific investigation of biological systems, biomimetics, and research that seeks to interface biological and artificial systems to create biohybrid systems.
JTD Keywords: Artificial intelligence, Soft robotics, Biomimetics, Insect navigation, Synthetic nervous system, Computer vision, Bio-inspired materials, Visual homing, Locomotion+, Image processing, Intelligent robots, Human-robot interaction, Machine learning, Snake robot, Mobile robots, Robotic systems, Drosophila, Robots, Sensors, Signal processing
Mas, S., Torro, A., Bec, N., Fernández, L., Erschov, G., Gongora, C., Larroque, C., Martineau, P., de Juan, A., Marco, S., (2019). Use of physiological information based on grayscale images to improve mass spectrometry imaging data analysis from biological tissues Analytica Chimica Acta 1074, 69-79
The characterization of cancer tissues by matrix-assisted laser desorption ionization-mass spectrometry images (MALDI-MSI) is of great interest because of the power of MALDI-MS to understand the composition of biological samples and the imaging side that allows for setting spatial boundaries among tissues of different nature based on their compositional differences. In tissue-based cancer research, information on the spatial location of necrotic/tumoral cell populations can be approximately known from grayscale images of the scanned tissue slices. This study proposes as a major novelty the introduction of this physiologically-based information to help in the performance of unmixing methods, oriented to extract the MS signatures and distribution maps of the different tissues present in biological samples. Specifically, the information gathered from grayscale images will be used as a local rank constraint in Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) for the analysis of MALDI-MSI of cancer tissues. The use of this constraint, setting absence of certain kind of tissues only in clear zones of the image, will help to improve the performance of MCR-ALS and to provide a more reliable definition of the chemical MS fingerprint and location of the tissues of interest. The general strategy to address the analysis of MALDI-MSI of cancer tissues will involve the study of the MCR-ALS results and the posterior use of MCR-ALS scores as dimensionality reduction for image segmentation based on K-means clustering. The resolution method will provide the MS signatures and their distribution maps for each tissue in the sample. Then, the resolved distribution maps for each biological component (MCR scores) will be submitted as initial information to K-means clustering for image segmentation to obtain information on the boundaries of the different tissular regions in the samples studied. MCR-ALS prior to K-means not only provides the desired dimensionality reduction, but additionally resolved non-biological signal contributions are not used and the weight given to the different biological components in the segmentation process can be modulated by suitable preprocessing methods.
JTD Keywords: MCR-ALS, K-means, Local rank constraints, MALDI-MSI, Grayscale images
Lehmann, J., Praktiknjo, M., Nielsen, M. J., Schierwagen, R., Meyer, C., Thomas, D., Violi, F., Strassburg, C. P., Bendtsen, F., Moller, S., Krag, A., Karsdal, M. A., Leeming, D. J., Trebicka, J., (2019). Collagen type IV remodelling gender-specifically predicts mortality in decompensated cirrhosis Liver International 39, (5), 885-893
Background & Aims: Remodelling of extracellular matrix is crucial in progressive liver fibrosis. Collagen type III desposition has been shown in acute decompensation. Extratracellular matrix is compiled of deposition of various components. The role of basement membrane collagen type IV in advanced cirrhosis and acute decompensation is unclear and investigated in this study. Methods: Patients with decompensated cirrhosis from the prospective NEPTUN cohort (ClinicalTrials.gov Identifier: NCT03628807), who underwent transjugular intrahepatic portosystemic shunt procedure were included. Clinical and laboratory parameters, PRO-C4 and C4M levels were measured in blood samples from portal and hepatic veins just before transjugular intrahepatic portosystemic shunt placement. Results: Levels of C4M and PRO-C4 are significantly lower in patients with massive ascites and impaired renal sodium excretion. C4M and PRO-C4 show gender-specific profiles with significantly lower levels in females compared to males. Females with higher C4M levels show higher mortality. By contrast, males with higher C4M levels show lower mortality. In multivariate Cox regression analysis, C4M is an independent predictor of survival in female patients. Conclusion: This study shows that markers of collagen type IV remodelling do not accumulate in severe renal dysfunction. Although collagen type IV degradation markers derive from the liver, portal venous C4M levels are relevant for survival. Moreover, it demonstrates that circulating C4M shows gender-specific profiles, which can independently predict survival in female patients with decompensated cirrhosis.
JTD Keywords: ACLF, Acute decompensation, Acute-on-chronic liver failure, Cirrhosis, Collagen type IV, Extracellular matrix remodelling, Gender, Liver, Portal hypertension, Transjugular intrahepatic portosystemic shunt
Alcaraz, J., Carrasco, J. L., Millares, L., Luis, I. C., Fernández-Porras, F. J., Martínez-Romero, A., Diaz-Valdivia, N., De Cos, J. S., Rami-Porta, R., Seijo, L., Ramírez, J., Pajares, M. J., Reguart, N., Barreiro, E., Monsó, E., (2019). Stromal markers of activated tumor associated fibroblasts predict poor survival and are associated with necrosis in non-small cell lung cancer Lung Cancer 135, 151-160
Objectives: Tumor associated fibroblasts (TAFs) are essential contributors of the progression of non-small cell lung cancer (NSCLC). Most lung TAFs exhibit an activated phenotype characterized by the expression of α-SMA and fibrillar collagens. However, the prognostic value of these activation markers in NSCLC remains unclear.
Material and Methods: We conducted a quantitative image analysis of α-SMA immunostaining and picrosirius red staining of fibrillar collagens imaged by bright-field and polarized microscopy, respectively, using tissue microarrays with samples from 220 surgical patients, which elicited a percentage of positive staining area for each marker and patient.
Results: Kaplan-Meier curves showed that all TAF activation markers were significantly associated with poor survival, and their prognostic value was independent of TNM staging as revealed by multivariate analysis, which elicited an adjusted increased risk of death after 3 years of 129% and 94% for fibrillar collagens imaged with bright-field (p = 0.004) and polarized light (p = 0.003), respectively, and of 89% for α-SMA (p = 0.009). We also found a significant association between all TAF activation markers and tumor necrosis, which is often indicative of hypoxia, supporting a pathologic link between tumor desmoplasia and necrosis/hypoxia.
Conclusions: Our findings identify patients with large histologic coverage of fibrillar collagens and α-SMA + TAFs to be at higher risk of recurrence and death, supporting that they could be considered for adjuvant therapy.
JTD Keywords: Cancer associated fibroblast, Collagen, Lung cancer, Necrosis, Survival, α-SMA
Malandrino, Andrea, Trepat, Xavier, Kamm, Roger D., Mak, Michael, (2019). Dynamic filopodial forces induce accumulation, damage, and plastic remodeling of 3D extracellular matrices PLoS Computational Biology 15, (4), e1006684
The mechanical properties of the extracellular matrix (ECM)–a complex, 3D, fibrillar scaffold of cells in physiological environments–modulate cell behavior and can drive tissue morphogenesis, regeneration, and disease progression. For simplicity, it is often convenient to assume these properties to be time-invariant. In living systems, however, cells dynamically remodel the ECM and create time-dependent local microenvironments. Here, we show how cell-generated contractile forces produce substantial irreversible changes to the density and architecture of physiologically relevant ECMs–collagen I and fibrin–in a matter of minutes. We measure the 3D deformation profiles of the ECM surrounding cancer and endothelial cells during stages when force generation is active or inactive. We further correlate these ECM measurements to both discrete fiber simulations that incorporate fiber crosslink unbinding kinetics and continuum-scale simulations that account for viscoplastic and damage features. Our findings further confirm that plasticity, as a mechanical law to capture remodeling in these networks, is fundamentally tied to material damage via force-driven unbinding of fiber crosslinks. These results characterize in a multiscale manner the dynamic nature of the mechanical environment of physiologically mimicking cell-in-gel systems.
JTD Keywords: Collagens, Fibrin, Extracellular matrix, Cross-linking, Cell physiology, Deformation, Fluorescence imaging, Cell biology
Gouveia, Virgínia M., Rizzello, Loris, Nunes, Claudia, Poma, Alessandro, Ruiz-Perez, Lorena, Oliveira, António, Reis, Salette, Battaglia, Giuseppe, (2019). Macrophage targeting pH responsive polymersomes for glucocorticoid therapy Pharmaceutics 11, (11), 614
Glucocorticoid (GC) drugs are the cornerstone therapy used in the treatment of inflammatory diseases. Here, we report pH responsive poly(2-methacryloyloxyethyl phosphorylcholine)–poly(2-(diisopropylamino)ethyl methacrylate) (PMPC–PDPA) polymersomes as a suitable nanoscopic carrier to precisely and controllably deliver GCs within inflamed target cells. The in vitro cellular studies revealed that polymersomes ensure the stability, selectivity and bioavailability of the loaded drug within macrophages. At molecular level, we tested key inflammation-related markers, such as the nuclear factor-κB, tumour necrosis factor-α, interleukin-1β, and interleukin-6. With this, we demonstrated that pH responsive polymersomes are able to enhance the anti-inflammatory effect of loaded GC drug. Overall, we prove the potential of PMPC–PDPA polymersomes to efficiently promote the inflammation shutdown, while reducing the well-known therapeutic limitations in GC-based therapy.
JTD Keywords: Inflammation, Macrophages, Glucocorticoid, Polymersomes
de la Mata, Ana, Mateos-Timoneda, Miguel A., Nieto-Miguel, Teresa, Galindo, Sara, López-Paniagua, Marina, Planell, Josep A., Engel, Elisabeth, Calonge, Margarita, (2019). Poly-l/dl-lactic acid films functionalized with collagen IV as carrier substrata for corneal epithelial stem cells Colloids and Surfaces B: Biointerfaces 177, 121-129
Limbal epithelial stem cells (LESCs) are responsible for the renewal of corneal epithelium. Cultivated limbal epithelial transplantation is the current treatment of choice for restoring the loss or dysfunction of LESCs. To perform this procedure, a substratum is necessary for in vitro culturing of limbal epithelial cells and their subsequent transplantation onto the ocular surface. In this work, we evaluated poly-L/DL-lactic acid 70:30 (PLA) films functionalized with type IV collagen (col IV) as potential in vitro carrier substrata for LESCs. We first demonstrated that PLA-col IV films were biocompatible and suitable for the proliferation of human corneal epithelial cells. Subsequently, limbal epithelial cell suspensions, isolated from human limbal rings, were cultivated using culture medium that did not contain animal components. The cells adhered significantly faster to PLA-col IV films than to tissue culture plastic (TCP). The mRNA expression levels for the LESC specific markers, K15, P63α and ABCG2 were similar or greater (significantly in the case of K15) in limbal epithelial cells cultured on PLA-col IV films than limbal epithelial cells cultured on TCP. The percentage of cells expressing the corneal (K3, K12) and the LESC (P63α, ABCG2) specific markers was similar for both substrata. These results suggest that the PLA-col IV films promoted LESC attachment and helped to maintain their undifferentiated stem cell phenotype. Consequently, these substrata offer an alternative for the transplantation of limbal cells onto the ocular surface.
JTD Keywords: Corneal epithelium, Collagen IV, Limbal stem cells, Polylactic acid, Tissue engineering
Saborío, M. G., Svelic, P., Casanovas, J., Ruano, G., Pérez-Madrigal, M. M., Franco, L., Torras, J., Estrany, F., Alemán, C., (2019). Hydrogels for flexible and compressible free standing cellulose supercapacitors European Polymer Journal 118, 347-357
Cellulose-based supercapacitors display important advantages in comparison with devices fabricated with other materials, regarding environmental friendliness, flexibility, cost and versatility. Recent progress in the field has been mainly focused on the utilization of cellulose fibres as: structural mechanical reinforcement of electrodes; precursors of electrically active carbon-based materials; or primary electrolytes that act as reservoirs of secondary electrolytes. In this work, a flexible, lightweight, robust, portable and manageable all-carboxymethyl cellulose symmetric supercapacitor has been obtained by assembling two electrodes based on carboxymethyl cellulose hydrogels to a solid electrolytic medium formulated with the same material. Hydrogels, which were made by cross-linking carboxymethyl cellulose paste with citric acid in water, rendered not only effective solid electrolytic media by simply loading NaCl but also electroactive electrodes. For the latter, conducting polymer microparticles, which were loaded into the hydrogel network during the physical cross-linking step, were appropriately connected through the in situ anodic polymerization of a similar conducting polymer in aqueous medium, thus creating conduction paths. The performance of the assembled supercapacitors has been proved by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. This design opens a new window for the green and mass production of flexible cellulose-based supercapacitors.
JTD Keywords: Conducting polymer, Energy storage, Flexible electrodes, In situ polymerization, Wearable electronics
Vidal, E., Buxadera-Palomero, J., Pierre, C., Manero, J. M., Ginebra, M. P., Cazalbou, S., Combes, C., Rupérez, E., Rodríguez, D., (2019). Single-step pulsed electrodeposition of calcium phosphate coatings on titanium for drug delivery Surface and Coatings Technology 358, 266-275
Metallic implants have some limitations related to bioactivity and bacteria colonization leading to infections. In this regard, calcium phosphate coatings can be used as carrier for drug delivery in order to improve the mentioned drawbacks. The present work proposes the introduction of an antibacterial agent in the course of a pulsed and reverse pulsed electrodeposition. Calcium phosphate coatings were prepared in 30 min using different pulse waveforms (unipolar-bipolar), current densities (2–5 mA/cm2) and temperatures (40–60 °C). Mechanical stability of the as-coated surfaces was studied in order to select the optimal electrodeposition conditions. Subsequently, selected coatings were loaded with an antiseptic agent, chlorhexidine digluconate (CHX), via a single-step co-deposition procedure. CHX concentration added to the electrolyte was adjusted to 3 mM based on the antibacterial efficacy of the loaded coatings evaluated in vitro with Staphylococcus aureus and Escherichia coli bacteria strains. Whereas the same chlorhexidine concentration was added to the electrolyte, results showed that the amount of CHX loaded was different for each condition while release kinetics was maintained. The results of this work demonstrate that a pulsed co-deposition strategy has great potential to modulate local delivery of antibacterial agents such as chlorhexidine digluconate, which may prevent early phase infections of metallic implants after insertion.
JTD Keywords: Antibacterial agent, Calcium phosphate, Characterization, Coating, Pulse electrodeposition, Titanium
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
Enshaei, H., Molina, B. G., del Valle, L. J., Estrany, F., Arnan, C., Puiggalí, J., Saperas, N., Alemán, C., (2019). Scaffolds for sustained release of ambroxol hydrochloride, a pharmacological chaperone that increases the activity of misfolded β-glucocerebrosidase. Macromolecular Bioscience 19, (8), 1900130
Ambroxol is a pharmacological chaperone (PC) for Gaucher disease that increases lysosomal activity of misfolded β-glucocerebrosidase (GCase) while displaying a safe toxicological profile. In this work, different poly(ε-caprolactone) (PCL)-based systems are developed to regulate the sustained release of small polar drugs in physiological environments. For this purpose, ambroxol is selected as test case since the encapsulation and release of PCs using polymeric scaffolds have not been explored yet. More specifically, ambroxol is successfully loaded in electrospun PCL microfibers, which are subsequently coated with additional PCL layers using dip-coating or spin-coating. The time needed to achieve 80% release of loaded ambroxol increases from ≈15 min for uncoated fibrous scaffolds to 3 days and 1 week for dip-coated and spin-coated systems, respectively. Furthermore, it is proven that the released drug maintains its bioactivity, protecting GCase against induced thermal denaturation.
JTD Keywords: Electrospinning, Gaucher's disease, Lysosomal storage disorders, Misfolding diseases, Poly(ε-caprolactone), Polyester, Release regulation
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
Campillo, N., Falcones, B., Otero, J., Colina, R., Gozal, D., Navajas, D., Farré, R., Almendros, I., (2019). Differential oxygenation in tumor microenvironment modulates macrophage and cancer cell crosstalk: Novel experimental settingand proof of concept Frontiers in Oncology 9, 43
Hypoxia is a common characteristic of many solid tumors that has been associated with tumor aggressiveness. Limited diffusion of oxygen generates a gradient of oxygen availability from the blood vessel to the interstitial space and may underlie the recruitment of macrophages fostering cancer progression. However, the available data based on the recruitment of circulating cells to the tumor microenvironment has been so far carried out by conventional co-culture systems which ignore the hypoxic gradient between the vessel to the tumor interstitium. Here, we have designed a novel easy-to-build cell culture device that enables evaluation of cellular cross-talk and cell migration while they are being simultaneously exposed to different oxygenation environments. As a proof-of-concept of the potential role of differential oxygenation among interacting cells we have evaluated the activation and recruitment of macrophages in response to hypoxic melanoma, breast, and kidney cancer cells. We found that hypoxic melanoma and breast cancer cells co-cultured with normoxic macrophages enhanced their directional migration. By contrast, hypoxic kidney cells were not able to increase their recruitment. We also identified well-described hypoxia-induced pathways which could contribute in the immune cell recruitment (VEGFA and PTGS2 genes). Moreover, melanoma and breast cancer increased their proliferation. However, oxygenation levels affected neither kidney cancer cell proliferation nor gene expression, which in turn resulted in no significant changes in macrophage migration and polarization. Therefore, the cell culture device presented here provides an excellent opportunity for researchers to reproduce the in vivo hypoxic gradients in solid tumors and to study their role in recruiting circulating cells to the tumor in specific types of cancer.
JTD Keywords: Hypoxia gradient, Macrophage motility, Models of host-tumor interactions, Novel assay technology, Tumor progression
Ferrer, I., Zelaya, M. V., Aguiló García, M., Carmona, M., López-González, I., Andrés-Benito, P., Lidón, L., Gavín, R., Garcia-Esparcia, P., del Rio, J. A., (2019). Relevance of host tau in tau seeding and spreading in tauopathies Brain Pathology Early View
Human tau seeding and spreading occur following intracerebral inoculation of brain homogenates obtained from tauopathies in transgenic mice expressing natural or mutant tau, and in wild-type (WT) mice. The present study was geared to learning about the patterns of tau seeding, the cells involved and the characteristics of tau following intracerebral inoculation of homogenates from primary age-related tauopathy (PART: neuronal 4Rtau and 3Rtau), aging-related tau astrogliopathy (ARTAG: astrocytic 4Rtau) and globular glial tauopathy (GGT: 4Rtau with neuronal deposits and specific tau inclusions in astrocytes and oligodendrocytes). For this purpose, young and adult WT mice were inoculated unilaterally in the hippocampus or in the lateral corpus callosum with sarkosyl-insoluble fractions from PART, ARTAG and GGT cases, and were killed at variable periods of three to seven months. Brains were processed for immunohistochemistry in paraffin sections. Tau seeding occurred in the ipsilateral hippocampus and corpus callosum and spread to the septal nuclei, periventricular hypothalamus and contralateral corpus callosum, respectively. Tau deposits were mainly found in neurons, oligodendrocytes and threads; the deposits were diffuse or granular, composed of phosphorylated tau, tau with abnormal conformation and 3Rtau and 4Rtau independently of the type of tauopathy. Truncated tau at the aspartic acid 421 and ubiquitination were absent. Tau deposits had the characteristics of pre-tangles. A percentage of intracellular tau deposits co-localized with active (phosphorylated) tau kinases p38 and ERK 1/2. Present study shows that seeding and spreading of human tau into the brain of WT mice involves neurons and glial cells, mainly oligodendrocytes, thereby supporting the idea of a primary role of oligodendrogliopathy, together with neuronopathy, in the progression of tauopathies. In addition, it suggests that human tau inoculation modifies murine tau metabolism with the production and deposition of 3Rtau and 4Rtau, and by activation of specific tau kinases in affected cells.
JTD Keywords: Aging-related tau astrogliopathy, Globular glial tauopathy, Primary age-related tauopathy, Seeding, Spreading, Tau, Tauopathies
Calvo, M., Cano, I., Hernández, C., Ribas, V., Miralles, F., Roca, J., Jané, R., (2019). Class imbalance impact on the prediction of complications during home hospitalization: A comparative study Engineering in Medicine and Biology Society (EMBC)
41st Annual International Conference of the IEEE , IEEE (Berlín, Germany) , 3446-3449
Home hospitalization (HH) is presented as a healthcare alternative capable of providing high standards of care when patients no longer need hospital facilities. Although HH seems to lower healthcare costs by shortening hospital stays and improving patient's quality of life, the lack of continuous observation at home may lead to complications in some patients. Since blood tests have been proven to provide relevant prognosis information in many diseases, this paper analyzes the impact of different sampling methods on the prediction of HH outcomes. After a first exploratory analysis, some variables extracted from routine blood tests performed at the moment of HH admission, such as hemoglobin, lymphocytes or creatinine, were found to unmask statistically significant differences between patients undergoing successful and unsucessful HH stays. Then, predictive models were built with these data, in order to identify unsuccessful cases eventually needing hospital facilities. However, since these hospital admissions during HH programs are rare, their identification through conventional machine-learning approaches is challenging. Thus, several sampling strategies designed to face class imbalance were herein overviewed and compared. Among the analyzed approaches, over-sampling strategies, such as ROSE (Random Over-Sampling Examples) and conventional random over-sampling, showed the best performances. Nevertheless, further improvements should be proposed in the future so as to better identify those patients not benefiting from HH.
JTD Keywords: Hospitals, Blood, Training, Standards, Diseases, Prognostics and health management
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
Martinez-Hernandez, Uriel, Vouloutsi, Vasiliki, Mura, Anna, Mangan, Michael, Asada, Minoru, Prescott, T. J., Verschure, P., (2019). Biomimetic and Biohybrid Systems
8th International Conference, Living Machines 2019, Nara, Japan, July 9–12, 2019, Proceedings , Springer, Cham (Lausanne, Switzerland) 11556, 1-384
This book constitutes the proceedings of the 8th International Conference on Biomimetic and Biohybrid Systems, Living Machines 2019, held in Nara, Japan, in July 2019. The 26 full and 16 short papers presented in this volume were carefully reviewed and selected from 45 submissions. They deal with research on novel life-like technologies inspired by the scientific investigation of biological systems, biomimetics, and research that seeks to interface biological and artificial systems to create biohybrid systems.
JTD Keywords: Artificial intelligence, Biomimetics, Computer architecture, Human robot interaction, Human-Computer Interaction (HCI), Humanoid robot, Image processing, Learning algorithms, Mobile robots, Multipurpose robots, Neural networks, Quadruped robots, Reinforcement learning, Robot learning, Robotics, Robots, Sensor, Sensors, Swarm robotics, User interfaces
Hervera, A., De Virgiliis, F., Palmisano, I., Zhou, L., Tantardini, E., Kong, G., Hutson, T., Danzi, M. C., Perry, R. B. T., Santos, C. X. C., Kapustin, A. N., Fleck, R. A., Del Río, J. A., Carroll, T., Lemmon, V., Bixby, J. L., Shah, A. M., Fainzilber, M., Di Giovanni, S., (2018). Reactive oxygen species regulate axonal regeneration through the release of exosomal NADPH oxidase 2 complexes into injured axons Nature Cell Biology 20, (3), 307-319
Reactive oxygen species (ROS) contribute to tissue damage and remodelling mediated by the inflammatory response after injury. Here we show that ROS, which promote axonal dieback and degeneration after injury, are also required for axonal regeneration and functional recovery after spinal injury. We find that ROS production in the injured sciatic nerve and dorsal root ganglia requires CX3CR1-dependent recruitment of inflammatory cells. Next, exosomes containing functional NADPH oxidase 2 complexes are released from macrophages and incorporated into injured axons via endocytosis. Once in axonal endosomes, active NOX2 is retrogradely transported to the cell body through an importin-β1–dynein-dependent mechanism. Endosomal NOX2 oxidizes PTEN, which leads to its inactivation, thus stimulating PI3K–phosporylated (p-)Akt signalling and regenerative outgrowth. Challenging the view that ROS are exclusively involved in nerve degeneration, we propose a previously unrecognized role of ROS in mammalian axonal regeneration through a NOX2–PI3K–p-Akt signalling pathway.
JTD Keywords: Adult neurogenesis, Endocytosis, Exocytosis, Monocytes and macrophages, Stress signalling
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
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
Freire, I. T., Arsiwalla, X. D., Puigbò, J. Y., Verschure, P., (2018). Limits of multi-agent predictive models in the formation of social conventions
Frontiers in Artificial Intelligence and Applications (ed. Falomir, Z., Gibert, K., Plaza, E.), IOS Press (Amsterdam, The Netherlands) Volume 308: Artificial Intelligence Research and Development, 297-301
A major challenge in cognitive science and AI is to understand how intelligent agents might be able to predict mental states of other agents during complex social interactions. What are the computational principles of such a Theory of Mind (ToM)? In previous work, we have investigated hypotheses of how the human brain might realize a ToM of other agents in a multi-agent social scenario. In particular, we have proposed control-based cognitive architectures to predict the model of other agents in a game-theoretic task (Battle of the Exes). Our multi-layer architecture implements top-down predictions from adaptive to reactive layers of control and bottom-up error feedback from reactive to adaptive layers. We tested cooperative and competitive strategies among different multi-agent models, demonstrating that while pure RL leads to reasonable efficiency and fairness in social interactions, there are other architectures that can perform better in specific circumstances. However, we found that even the best predictive models fall short of human data in terms of stability of social convention formation. In order to explain this gap between humans and predictive AI agents, in this work we propose introducing the notion of trust in the form of mutual agreements between agents that might enhance stability in the formation of conventions such as turn-taking.
JTD Keywords: Cognitive Architectures, Game Theory, Multi-Agent Models, Reinforcement Learning, Theory of Mind
Hristova-Panusheva, K., Keremidarska-Markova, M., Altankov, G., Krasteva, N., (2017). Age-related changes in adhesive phenotype of bone marrow-derived mesenchymal stem cells on extracellular matrix proteins
Journal of New Results in Science , 6, (1), 11-19
Mesenchymal stem cells (MSCs) are a promising cell source for cell-based therapies because of their self-renewal and multi-lineage differentiation potential. Unlike embryonic stem cells adult stem cells are subject of aging processes and the concomitant decline in their function. Age-related changes in MSCs have to be well understood in order to develop clinical techniques and therapeutics based on these cells. In this work we have studied the effect of aging on adhesive behaviour of bone marrow-derived MSC and MG- 63 osteoblastic cells onto three extracellular matrix proteins: fibronectin (FN), vitronectin (VN) and collagen I (Coll I). The results revealed substantial differences in adhesive behaviour of both cell types during 21 days in culture. Bone-marrow derived MSCs decreased significantly their adhesive affinity to all studied proteins after 7th day in culture with further incubation. In contrast, MG-63 cells, demonstrated a stable cell adhesive phenotype with high affinity to FN and Coll I and low affinity to vitronectin over the whole culture period. These data suggest that adhesive behaviour of MSCs to matrix proteins is affected by aging processes unlike MG-63 cells and the age-related changes have to be considered when expanding adult stem cells for clinical applications.
JTD Keywords: Cell morphology, Cell attachment and spreading, Fibronectin, Vitronectin, Collagen I
Matalonga, J., Glaria, E., Bresque, M., Escande, C., Carbó, J. M., Kiefer, K., Vicente, R., León, T. E., Beceiro, S., Pascual-García, M., Serret, J., Sanjurjo, L., Morón-Ros, S., Riera, A., Paytubi, S., Juarez, A., Sotillo, F., Lindbom, L., Caelles, C., Sarrias, M. R., Sancho, J., Castrillo, A., Chini, E. N., Valledor, A. F., (2017). The nuclear receptor LXR limits bacterial infection of host macrophages through a mechanism that impacts cellular NAD metabolism Cell Reports 18, (5), 1241-1255
Macrophages exert potent effector functions against invading microorganisms but constitute, paradoxically, a preferential niche for many bacterial strains to replicate. Using a model of infection by Salmonella Typhimurium, we have identified a molecular mechanism regulated by the nuclear receptor LXR that limits infection of host macrophages through transcriptional activation of the multifunctional enzyme CD38. LXR agonists reduced the intracellular levels of NAD+ in a CD38-dependent manner, counteracting pathogen-induced changes in macrophage morphology and the distribution of the F-actin cytoskeleton and reducing the capability of non-opsonized Salmonella to infect macrophages. Remarkably, pharmacological treatment with an LXR agonist ameliorated clinical signs associated with Salmonella infection in vivo, and these effects were dependent on CD38 expression in bone-marrow-derived cells. Altogether, this work reveals an unappreciated role for CD38 in bacterial-host cell interaction that can be pharmacologically exploited by activation of the LXR pathway.
JTD Keywords: Bacterial infection, CD38, Cytoskeleton, LXR, Macrophage, NAD, Nuclear receptor
Bianchi, M. V., Awaja, F., Altankov, G., (2017). Dynamic adhesive environment alters the differentiation potential of young and ageing mesenchymal stem cells Materials Science and Engineering: C 78, 467-474
Engineering dynamic stem cell niche-like environment offers opportunity to obtain better control of the fate of stem cells. We identified, for the first time, that periodic changes in the adhesive environment of human adipose derived mesenchymal stem cells (ADSCs) alters dramatically their asymmetric division but not their ability for symmetric renewal. Hereby, we used smart thermo-responsive polymer (PNIPAM) to create a dynamic adhesive environment for ADSCs by applying periodic temperature cycles to perturb adsorbed adhesive proteins to substratum interaction. Cumulative population doubling time (CPDT) curves showed insignificant decline in the symmetric cell growth studied for up to 13th passages accompanied with small changes in the overall cell morphology and moderately declined fibronectin (FN) matrix deposition probably as a functional consequence of ADSCs ageing. However, a substantial alteration in the differentiation potential of ADSCs from both early and late passages (3rd and 14th, respectively) was found when the cells were switched to osteogenic differentiation conditions. This behavior was evidenced by the significantly altered alkaline phosphatase activity and Ca deposition (Alizarin red) assayed at 3, 14 and 21 day in comparison to the control samples of regular TC polystyrene processed under same temperature settings.
JTD Keywords: Cell ageing, Dynamic adhesive environment, Extracellular matrix, Mesenchymal stem cells, PNIPAM, Stem cell niche, Symmetric and asymmetric cell growth, Thermo-cycling, Thermo-responsive polymer
Li, Haiyue, Xu, Bin, Zhou, Enhua H., Sunyer, Raimon, Zhang, Yanhang, (2017). Multiscale measurements of the mechanical properties of collagen matrix ACS Biomaterials Science & Engineering 3, (11), 2815-2824
The underlying mechanisms by which extracellular matrix (ECM) mechanics influences cell and tissue function remain to be elucidated because the events associated with this process span size scales from tissue to molecular level. Furthermore, ECM has an extremely complex hierarchical 3D structure and the load distribution is highly dependent on the architecture and mechanical properties of ECM. In the present study, the macro- and microscale mechanical properties of collagen gel were studied. Dynamic rheological testing was performed to study the macroscale mechanical properties of collagen gel. The microscale mechanical properties of collagen gel were measured using optical magnetic twisting cytometry (OMTC). Ferromagnetic beads embedded in the matrix were used as mechanical probes. Our study on the multiscale mechanical properties of collage matrix suggests several interesting differences between macro and microscale mechanical properties originated from the scales of measurements. At the macroscopic scale, storage and loss modulus increase with collagen concentrations. Nonaffine collagen fibril structural network deformation plays an important role in determining the macroscopic mechanical properties of the collagen matrix. At the microscopic scale, however, the local mechanical properties are less sensitive to changes in collagen concentration because of the more immediate/direct deformation of collagen fibrils in the OMTC measurements through forces exerted by locally attached ferromagnetic beads. The loss modulus is more affected by the local interstitial fluid environment, leading to a rather dramatic increase in viscosity with frequency, especially at higher frequencies (>10 Hz). A finite element model was developed to study the geometric factors in the OMTC measurements when the collagen matrix was considered to be hyperelastic. Our results show that the geometric factors are dependent on collagen concentration, or the stiffness of matrix, when nonlinear material properties of the matrix are considered, and thus interpretation of the apparent modulus from OMTC measurements should be conducted carefully.
JTD Keywords: Keywords: collagen, Extracellular matrix, Geometric factor, Nonaffine deformation, Optical magnetic twisting cytometry
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
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
Zhao, M., Altankov, G., Grabiec, U., Bennett, M., Salmeron-Sanchez, M., Dehghani, F., Groth, T., (2016). Molecular composition of GAG-collagen I multilayers affects remodeling of terminal layers and osteogenic differentiation of adipose-derived stem cells Acta Biomaterialia 41, 86-99
The effect of molecular composition of multilayers, by pairing type I collagen (Col I) with either hyaluronic acid (HA) or chondroitin sulfate (CS) was studied regarding the osteogenic differentiation of adhering human adipose-derived stem cells (hADSCs). Polyelectrolyte multilayer (PEM) formation was based primarily on ion pairing and on additional intrinsic cross-linking through imine bond formation with Col I replacing native by oxidized HA (oHA) or CS (oCS). Significant amounts of Col I fibrils were found on both native and oxidized CS-based PEMs, resulting in higher water contact angles and surface potential under physiological condition, while much less organized Col I was detected in either HA-based multilayers, which were more hydrophilic and negatively charged. An important finding was that hADSCs remodeled Col I at the terminal layers of PEMs by mechanical reorganization and pericellular proteolytic degradation, being more pronounced on CS-based PEMs. This was in accordance with the higher quantity of Col I deposition in this system, accompanied by more cell spreading, focal adhesions (FA) formation and significant α2β1 integrin recruitment compared to HA-based PEMs. Both CS-based PEMs caused also an increased fibronectin (FN) secretion and cell growth. Furthermore, significant calcium phosphate deposition, enhanced ALP, Col I and Runx2 expression were observed in hADSCs on CS-based PEMs, particularly on oCS-containing one. Overall, multilayer composition can be used to direct cell-matrix interactions, and hence stem cell fates showing for the first time that PEMs made of biogenic polyelectrolytes undergo significant remodeling of terminal protein layers, which seems to enable cells to form a more adequate extracellular matrix-like environment. Statement of Significance: Natural polymer derived polyelectrolyte multilayers (PEMs) have been recently applied to adjust biomaterials to meet specific tissue demands. However, the effect of molecular composition of multilayers on both surface properties and cellular response, especially the fate of human adipose derived stem cells (hADSCs) upon osteogenic differentiation has not been studied extensively, yet. In addition, no studies exist that investigate a potential cell-dependent remodeling of PEMs made of extracellular matrix (ECM) components like collagens and glycosaminoglycans (GAGs). Furthermore, there is no knowledge whether the ability of cells to remodel PEM components may provide an added value regarding cell growth and differentiation. Finally, it has not been explored yet, how intrinsic cross-linking of ECM derived polyelectrolytes that improve the stability of PEMs will affect the differentiation potential of hADSCs. The current work aims to address these questions and found that the type of GAG has a strong effect on properties of multilayers and osteogenic differentiation of hADSCs. Additionally, we also show for the first time that PEMs made of biogenic polyelectrolytes undergo significant remodeling of terminal layers as completely new finding, which allows cells to form an ECM-like environment supporting differentiation upon osteogenic lineage. The finding of this work may open new avenues of application of PEM systems made by layer by layer (LbL) technique in tissue engineering and regenerative medicine.
JTD Keywords: Collagen reorganization, Glycosaminoglycans, Layer-by-layer technique, Mesenchymal stem cells, Osteogenic differentiation
Forget, J., Awaja, F., Gugutkov, D., Gustavsson, J., Gallego Ferrer, G., Coelho-Sampaio, T., Hochman-Mendez, C., Salmeron-Sánchez, M., Altankov, G., (2016). Differentiation of human mesenchymal stem cells toward quality cartilage using fibrinogen-based nanofibers Macromolecular Bioscience 16, (9), 1348-1359
Mimicking the complex intricacies of the extra cellular matrix including 3D configurations and aligned fibrous structures were traditionally perused for producing cartilage tissue from stem cells. This study shows that human adipose derived mesenchymal stem cells (hADMSCs) establishes significant chondrogenic differentiation and may generate quality cartilage when cultured on 2D and randomly oriented fibrinogen/poly-lactic acid nanofibers compared to 3D sandwich-like environments. The adhering cells show well-developed focal adhesion complexes and actin cytoskeleton arrangements confirming the proper cellular interaction with either random or aligned nanofibers. However, quantitative reverse transcription-polymerase chain reaction analysis for Collagen 2 and Collagen 10 genes expression confirms favorable chondrogenic response of hADMSCs on random nanofibers and shows substantially higher efficacy of their differentiation in 2D configuration versus 3D constructs. These findings introduce a new direction for cartilage tissue engineering through providing a simple platform for the routine generation of transplantable stem cells derived articular cartilage replacement that might improve joint function.
JTD Keywords: Cartilage, Chondrogenic response, Collagen, FBG/PLA nanofibers, Mesenchymal stem cells
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
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
Fernandez, L., Marco, S., Gutierrez-Galvez, A., (2015). Robustness to sensor damage of a highly redundant gas sensor array Sensors and Actuators B: Chemical 218, 296-302
Abstract In this paper we study the role of redundant sensory information to prevent the performance degradation of a chemical sensor array for different distributions of sensor failures across sensor types. The large amount of sensing conditions with two different types of redundancy provided by our sensor array makes possible a comprehensive experimental study. Particularly, our sensor array is composed of 8 different types of commercial MOX sensors modulated in temperature with two redundancy levels: (1) 12 replicates of each sensor type for a total of 96 sensors and (2) measurements using 16 load resistors per sensors for a total of 1536 redundant measures per second. We perform two experiments to determine the performance degradation of the array with increasing number of damaged sensors in two different scenarios of sensor faults distributions across sensor types. In the first experiment, we characterize the diversity and redundancy of the array for increasing number of damaged sensors. To measure diversity and redundancy, we proposed a functional definition based on clustering of sensor features. The second experiment is devoted to determine the performance degradation of the array for the effect of faulty sensors. To this end, the system is trained to separate ethanol, acetone and butanone at different concentrations using a PCA–LDA model. Test set samples are corrupted by means of three different simulated types of faults. To evaluate the performance of the array we used the Fisher score as a measure of odour separability. Our results show that to exploit to the utmost the redundancy of the sensor array faulty sensory units have to be distributed uniformly across the different sensor types.
JTD Keywords: Gas sensor arrays, Sensor redundancy, Sensor diversity, Sensor faults aging, Sensor damage, MOX sensors, Large sensor arrays
Solórzano, Carla, Srikumar, Shabarinath, Canals, Rocío, Juárez, Antonio, Paytubi, Sonia, Madrid, Cristina, (2015). Hha has a defined regulatory role that is not dependent upon H-NS or StpA Frontiers in Microbiology 6, Article 773
The Hha family of proteins is involved in the regulation of gene expression in enterobacteria by forming complexes with H-NS-like proteins. Whereas several amino acid residues of both proteins participate in the interaction, some of them play a key role. Residue D48 of Hha protein is essential for the interaction with H-NS, thus the D48N substitution in Hha protein abrogates H-NS/Hha interaction. Despite being a paralog of H-NS protein, StpA interacts with HhaD48N with higher affinity than with the wild type Hha protein. To analyze whether Hha is capable of acting independently of H-NS and StpA, we conducted transcriptomic analysis on the hha and stpA deletion strains and the hhaD48N substitution strain of Salmonella Typhimurium using a custom microarray. The results obtained allowed the identification of 120 genes regulated by Hha in an H-NS/StpA-independent manner, 38% of which are horizontally acquired genes. A significant number of the identified genes are involved in functions related to cell motility, iron uptake, and pathogenicity. Thus, motility assays, siderophore detection and intra-macrophage replication assays were performed to confirm the transcriptomic data. Our findings point out the importance of Hha protein as an independent regulator in S. Typhimurium, highlighting a regulatory role on virulence.
JTD Keywords: Salmonella, Gene regulation, Motility, Pathogenicity island, H-NS, HHA, STPA
Gumí-Audenis, B., Carlà, F., Vitorino, M. V., Panzarella, A., Porcar, L., Boilot, M., Guerber, S., Bernard, P., Rodrigues, M. S., Sanz, F., Giannotti, M. I., Costa, L., (2015). Custom AFM for X-ray beamlines: in situ biological investigations under physiological conditions
Journal of Synchrotron Radiation , 22, 1364-1371
A fast atomic force microscope (AFM) has been developed that can be installed as a sample holder for grazing-incidence X-ray experiments at solid/gas or solid/liquid interfaces. It allows a wide range of possible investigations, including soft and biological samples under physiological conditions (hydrated specimens). The structural information obtained using the X-rays is combined with the data gathered with the AFM (morphology and mechanical properties), providing a unique characterization of the specimen and its dynamics in situ during an experiment. In this work, lipid monolayers and bilayers in air or liquid environment have been investigated by means of AFM, both with imaging and force spectroscopy, and X-ray reflectivity. In addition, this combination allows the radiation damage induced by the beam on the sample to be studied, as has been observed on DOPC and DPPC supported lipid bilayers under physiological conditions.
JTD Keywords: In situ atomic force microscopy, Grazing-incidence scattering and reflectivity, Radiation damage, Model lipid membranes
Alsaleh, S. M., Aviles, A. I., Sobrevilla, P., Casals, A., Hahn, J. K., (2015). Automatic and robust single-camera specular highlight removal in cardiac images Engineering in Medicine and Biology Society (EMBC)
37th Annual International Conference of the IEEE , IEEE (Milan, Italy) , 675-678
In computer-assisted beating heart surgeries, accurate tracking of the heart's motion is of huge importance and there is a continuous need to eliminate any source of error that might disturb the tracking process. One source of error is the specular reflection that appears on the glossy surface of the heart. In this paper, we propose a robust solution for the detection and removal of specular highlights. A hybrid color attributes and wavelet based edge projection approach is applied to accurately identify the affected regions. These regions are then recovered using a dynamic search-based inpainting with adaptive windowing. Experimental results demonstrate the precision and efficiency of the proposed method. Moreover, it has a real-time performance and can be generalized to various other applications.
JTD Keywords: Heart, Image color analysis, Image edge detection, Surgery, Tracking, Wavelet transforms
Aviles, A. I., Sobrevilla, P., Casals, A., (2014). An approach for physiological motion compensation in robotic-assisted cardiac surgery
Experimental & Clinical Cardiology , 20, (11), 6713-6724
The lack of physiological motion compensation is a major problem in robotic-assisted cardiac surgery. Since the heart is beating while the surgeon carried out the procedure, dexterity of the surgeon’s and precision are compromised. Due to the operative space and the visibility of the surgical field are reduced, the most practical solution is the use of computer vision techniques. The lack of efficiency and robustness of the existing proposals make physiological motion compensation to be considered an open problem. In this work a novel solution to solve this problem based on the minimization of an energy functional is presented. It is described in the three-dimensional space using the l1−regularized optimization class in which cubic b-splines are used to represent the changes produced on the heart surface. Moreover, the logarithmic barrier function is applied to create an approximation of the total energy in order to avoid its non-differentiability. According to the results, this proposal is able to deal with complex deformations, requires a short computational time and gives a small error.
JTD Keywords: Beating heart surgery, Image analysis, Motion compensation
Cuervo, A., Dans, P. D., Carrascosa, J. L., Orozco, M., Gomila, G., Fumagalli, L., (2014). Direct measurement of the dielectric polarization properties of DNA Proceedings of the National Academy of Sciences of the United States of America 111, (35), E3624-E3630
The electric polarizability of DNA, represented by the dielectric constant, is a key intrinsic property that modulates DNA interaction with effector proteins. Surprisingly, it has so far remained unknown owing to the lack of experimental tools able to access it. Here, we experimentally resolved it by detecting the ultraweak polarization forces of DNA inside single T7 bacteriophages particles using electrostatic force microscopy. In contrast to the common assumption of low-polarizable behavior like proteins (εr ~ 2–4), we found that the DNA dielectric constant is ~ 8, considerably higher than the value of ~ 3 found for capsid proteins. State-of-the-art molecular dynamic simulations confirm the experimental findings, which result in sensibly decreased DNA interaction free energy than normally predicted by Poisson–Boltzmann methods. Our findings reveal a property at the basis of DNA structure and functions that is needed for realistic theoretical descriptions, and illustrate the synergetic power of scanning probe microscopy and theoretical computation techniques.
JTD Keywords: Atomic force microscopy, Atomistic simulations, DNA packaging, DNA-ligand binding, Poisson-Boltzmann equation, capsid protein, DNA, double stranded DNA, amino acid composition, article, atomic force microscopy, bacteriophage, bacteriophage T7, dielectric constant, dipole, DNA binding, DNA packaging, DNA structure, electron microscopy, ligand binding, nonhuman, polarization, priority journal, protein analysis, protein DNA interaction, scanning probe microscopy, static electricity, virion, virus capsid, virus particle, atomic force microscopy, atomistic simulations, DNA packaging, DNA-ligand binding, Poisson-Boltzmann equation, Bacteriophage T7, Capsid, Cations, Dielectric Spectroscopy, DNA, DNA, Viral, DNA-Binding Proteins, Electrochemical Techniques, Ligands, Microscopy, Atomic Force, Models, Chemical, Nuclear Proteins
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
Navarro, S., Moleiro, V., Molina-Estevez, F. J., Lozano, M. L., Chinchon, R., Almarza, E., Quintana-Bustamante, O., Mostoslavsky, G., Maetzig, T., Galla, M., Heinz, N., Schiedlmeier, B., Torres, Y., Modlich, U., Samper, E., Río, P., Segovia, J. C., Raya, A., Güenechea, G., Izpisua-Belmonte, J. C., Bueren, J. A., (2014). Generation of iPSCs from genetically corrected Brca2 hypomorphic cells: Implications in cell reprogramming and stem cell therapy
Stem Cells , 32, (2), 436-446
Fanconi anemia (FA) is a complex genetic disease associated with a defective DNA repair pathway known as the FA pathway. In contrast to many other FA proteins, BRCA2 participates downstream in this pathway and has a critical role in homology-directed recombination (HDR). In our current studies, we have observed an extremely low reprogramming efficiency in cells with a hypomorphic mutation in Brca2 (Brca2Δ27/Δ27), that was associated with increased apoptosis and defective generation of nuclear RAD51 foci during the reprogramming process. Gene complementation facilitated the generation of Brca2Δ27/Δ27 induced pluripotent stem cells (iPSCs) with a disease-free FA phenotype. Karyotype analyses and comparative genome hybridization arrays of complemented Brca2Δ27/Δ27 iPSCs showed, however, the presence of different genetic alterations in these cells, most of which were not evident in their parental Brca2 Δ27/Δ27 mouse embryonic fibroblasts. Gene-corrected Brca2Δ27/Δ27 iPSCs could be differentiated in vitro toward the hematopoietic lineage, although with a more limited efficacy than WT iPSCs or mouse embryonic stem cells, and did not engraft in irradiated Brca2Δ27/Δ27 recipients. Our results are consistent with previous studies proposing that HDR is critical for cell reprogramming and demonstrate that reprogramming defects characteristic of Brca2 mutant cells can be efficiently overcome by gene complementation. Finally, based on analysis of the phenotype, genetic stability, and hematopoietic differentiation potential of gene-corrected Brca2Δ27/Δ27 iPSCs, achievements and limitations in the application of current reprogramming approaches in hematopoietic stem cell therapy are also discussed.
JTD Keywords: Bone marrow aplasia, Cellular therapy, Fanconi anemia, Gene therapy, Hematopoietic stem cells, Induced pluripotent stem cells
Arcos, D., Boccaccini, A. R., Bohner, M., Díez-Pérez, A., Epple, M., Gómez-Barrena, E., Herrera, A., Planell, J. A., Rodríguez-Mañas, L., Vallet-Regí, M., (2014). The relevance of biomaterials to the prevention and treatment of osteoporosis Acta Biomaterialia 10, (5), 1793-1805
Osteoporosis is a worldwide disease with a very high prevalence in humans older than 50. The main clinical consequences are bone fractures, which often lead to patient disability or even death. A number of commercial biomaterials are currently used to treat osteoporotic bone fractures, but most of these have not been specifically designed for that purpose. Many drug- or cell-loaded biomaterials have been proposed in research laboratories, but very few have received approval for commercial use. In order to analyze this scenario and propose alternatives to overcome it, the Spanish and European Network of Excellence for the Prevention and Treatment of Osteoporotic Fractures, "Ageing", was created. This network integrates three communities, e.g. clinicians, materials scientists and industrial advisors, tackling the same problem from three different points of view. Keeping in mind the premise "living longer, living better", this commentary is the result of the thoughts, proposals and conclusions obtained after one year working in the framework of this network.
JTD Keywords: Ageing, Biomaterials, Bone, Osteoporosis
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
Melo, E., Cárdenes, N., Garreta, E., Luque, T., Rojas, M., Navajas, D., Farré, R., (2014). Inhomogeneity of local stiffness in the extracellular matrix scaffold of fibrotic mouse lungs
Journal of the Mechanical Behavior of Biomedical Materials , 37, 186-195
Lung disease models are useful to study how cell engraftment, proliferation and differentiation are modulated in lung bioengineering. The aim of this work was to characterize the local stiffness of decellularized lungs in aged and fibrotic mice. Mice (2- and 24-month old; 14 of each) with lung fibrosis (N=20) and healthy controls (N=8) were euthanized after 11 days of intratracheal bleomycin (fibrosis) or saline (controls) infusion. The lungs were excised, decellularized by a conventional detergent-based (sodium-dodecyl sulfate) procedure and slices of the acellular lungs were prepared to measure the local stiffness by means of atomic force microscopy. The local stiffness of the different sites in acellular fibrotic lungs was very inhomogeneous within the lung and increased according to the degree of the structural fibrotic lesion. Local stiffness of the acellular lungs did not show statistically significant differences caused by age. The group of mice most affected by fibrosis exhibited local stiffness that were ~2-fold higher than in the control mice: from 27.2±1.64 to 64.8±7.1. kPa in the alveolar septa, from 56.6±4.6 to 99.9±11.7. kPa in the visceral pleura, from 41.1±8.0 to 105.2±13.6. kPa in the tunica adventitia, and from 79.3±7.2 to 146.6±28.8. kPa in the tunica intima. Since acellular lungs from mice with bleomycin-induced fibrosis present considerable micromechanical inhomogeneity, this model can be a useful tool to better investigate how different degrees of extracellular matrix lesion modulate cell fate in the process of organ bioengineering from decellularized lungs.
JTD Keywords: Ageing, Atomic force microscopy, Decellularization, Lung fibrosis, Tissue engineering, Atomic force microscopy, Biological organs, Peptides, Sodium dodecyl sulfate, Sodium sulfate, Tissue engineering, Ageing, Decellularization, Extracellular matrices, Healthy controls, Inhomogeneities, Lung fibrosis, Micro-mechanical, Statistically significant difference, Mammals, bleomycin, adventitia, animal experiment, animal model, article, atomic force microscopy, bleomycin-induced pulmonary fibrosis, cell fate, controlled study, extracellular matrix, female, intima, lung alveolus, lung fibrosis, lung mechanics, mechanical probe, microenvironment, mouse, nonhuman, pleura, priority journal, rigidity, tissue engineering
Sánchez Egea, Antonio J., Valera, Marius, Parraga Quiroga, Juan Manuel, Proubasta, Ignasi, Noailly, J., Lacroix, Damien, (2014). Impact of hip anatomical variations on the cartilage stress: A finite element analysis towards the biomechanical exploration of the factors that may explain primary hip arthritis in morphologically normal subjects
Clinical Biomechanics , 29, (4), 444-450
AbstractBackground Hip arthritis is a pathology linked to hip-cartilage degeneration. Although the aetiology of this disease is not well defined, it is known that age is a determinant risk factor. However, hip arthritis in young patients could be largely promoted by biomechanical factors. The objective of this paper is to analyze the impact of some normal anatomical variations on the cartilage stress distributions numerically predicted at the hip joint during walking. Methods A three-dimensional finite element model of the femur and the pelvis with the most relevant axial components of muscle forces was used to simulate normal walking activity. The hip anatomical condition was defined by: neck shaft angle, femoral anteversion angle, and acetabular anteversion angle with a range of 110-130º, 0-20º, and 0-20º, respectively. The direct boundary method was used to simulate the hip contact. Findings The hydrostatic stress found at the cartilage and labrum showed that a ± 10º variation with respect to the reference brings significant differences between the anatomic models. Acetabular anteversion angle of 0º and femoral anteversion angle of 0º were the most affected anatomical conditions with values of hydrostatic stress in the cartilage near 5 MPa under compression. Interpretation Cartilage stresses and contact areas were equivalent to the results found in literature and the most critical anatomical regions in terms of tissue loads were in a good accordance with clinical evidence. Altogether, results showed that decreasing femoral or acetabular anteversion angles isolately causes a dramatic increase in cartilage loads.
JTD Keywords: Hip arthritis, Neck shaft angle, Femoral and acetabular anteversions, Cartilage load, Hip joint contact, Finite element analysis
Vaca, R., Aranda, J., (2014). Approximating coupler curves using strip trees Advanced Numerical Methods II
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
For the mechanisms considered under the title linkages, coupler curve is the path traced by one of the point on the coupler link considered as an output of the mechanism which is joined to a fixed link. The equation of the coupler curve generated can be obtained solving a set of equations which describes distance constancy between all points of a mechanism and this coupler curve is the eliminant of these equations. The proposal to this work is to approximate coupler curves using strip trees.
JTD Keywords: Coupler curves, Strip tress, Distance geometry, Affine arithmetics, Planar linkages
Martínez, Dani, Pallejà, T., Moreno, Javier, Tresanchez, Marcel, Teixidó, M., Font, Davinia, Pardo, Antonio, Marco, Santiago, Palacín, Jordi, (2014). A mobile robot agent for gas leak source detection Advances in Intelligent Systems and Computing
Trends in Practical Applications of Heterogeneous Multi-Agent Systems. The PAAMS Collection (ed. Bajo Perez, Javier, Corchado Rodríguez, Juan M., Mathieu, Philippe, Campbell, Andrew, Ortega, Alfonso, Adam, Emmanuel, Navarro, Elena M., Ahrndt, Sebastian, Moreno, Maríaa N., Julián, Vicente), Springer International Publishing 293, 19-25
This paper presents an autonomous agent for gas leak source detection. The main objective of the robot is to estimate the localization of the gas leak source in an indoor environment without any human intervention. The agent implements an SLAM procedure to scan and map the indoor area. The mobile robot samples gas concentrations with a gas and a wind sensor in order to estimate the source of the gas leak. The mobile robot agent will use the information obtained from the onboard sensors in order to define an efficient scanning path. This paper describes the measurement results obtained in a long corridor with a gas leak source placed close to a wall.
JTD Keywords: Gas detection, Mobile robot agent, Laser sensor, Self-localization
Juanola-Feliu, Esteve, Colomer-Farrarons, Jordi, Miribel-Català, Pere, González-Piñero, Manel, Samitier, Josep, (2014). Nano-enabled implantable device for glucose monitoring
Implantable Bioelectronics (ed. Katz, Evgeny), Wiley-VCH Verlag GmbH & Co. KGaA (Weinheim, Germany) , 247-263
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
Morgenstern, C., Randerath, W. J., Schwaibold, M., Bolz, A., Jané, R., (2013). Feasibility of noninvasive single-channel automated differentiation of obstructive and central hypopneas with nasal airflow
Respiration , 85, (4), 312-318
Background: The identification of obstructive and central hypopneas is considered challenging in clinical practice. Presently, obstructive and central hypopneas are usually not differentiated or scores lack reliability due to the technical limitations of standard polysomnography. Esophageal pressure measurement is the gold-standard for identifying these events but its invasiveness deters its usage in daily practice. Objectives: To determine the feasibility and efficacy of an automatic noninvasive analysis method for the differentiation of obstructive and central hypopneas based solely on a single-channel nasal airflow signal. The obtained results are compared with gold-standard esophageal pressure scores. Methods: A total of 41 patients underwent full night polysomnography with systematic esophageal pressure recording. Two experts in sleep medicine independently differentiated hypopneas with the gold-standard esophageal pressure signal. Features were automatically extracted from the nasal airflow signal of each annotated hypopnea to train and test the automatic analysis method. Interscorer agreement between automatic and visual scorers was measured with Cohen's kappa statistic (κ). Results: A total of 1,237 hypopneas were visually differentiated. The automatic analysis achieved an interscorer agreement of κ = 0.37 and an accuracy of 69% for scorer A, κ = 0.40 and 70% for scorer B and κ = 0.41 and 71% for the agreed scores of scorers A and B. Conclusions: The promising results obtained in this pilot study demonstrate the feasibility of noninvasive single-channel hypopnea differentiation. Further development of this method may help improving initial diagnosis with home screening devices and offering a means of therapy selection and/or control.
JTD Keywords: Central sleep hypopnea, Esophageal pressure, Home monitoring, Obstructive sleep hypopnea, Sleep disordered breathing
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
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
Esteban, O., Christ, D., Stock, D., (2013). Purification of molecular machines and nanomotors using phage-derived monoclonal antibody fragments
Protein Nanotechnology - Methods in Molecular Biology (ed. Gerrard, J. A.), Humana Press (New York, USA) 996, 203-217
Molecular machines and nanomotors are sophisticated biological assemblies that convert potential energy stored either in transmembrane ion gradients or in ATP into kinetic energy. Studying these highly dynamic biological devices by X-ray crystallography is challenging, as they are difficult to produce, purify, and crystallize. Phage display technology allows us to put a handle on these molecules in the form of highly specific antibody fragments that can also stabilize conformations and allow versatile labelling for electron microscopy, immunohistochemistry, and biophysics experiments. Here, we describe a widely applicable protocol for selecting high-affinity monoclonal antibody fragments against a complex molecular machine, the A-type ATPase from T. thermophilus that allows fast and simple purification of this transmembrane rotary motor from its wild-type source. The approach can be readily extended to other integral membrane proteins and protein complexes as well as to soluble molecular machines and nanomotors.
JTD Keywords: ATP synthase, Crystallization, Domain antibodies, Electron microscopy, Labelling, Membrane proteins, Monoclonal antibody fragments, Phage display, Protein purification, X-ray crystallography
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
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
Fazel Zarandi, M. H., Avazbeigi, M., (2012). A multi-agent solution for reduction of bullwhip effect in fuzzy supply chains
Journal of Intelligent and Fuzzy Systems , 23, (5), 259-268
In this paper, we present a new Multi-Agent System for reduction of the bullwhip effect in fuzzy supply chains. First, we show that a supply chain that uses an optimal ordering policy without data sharing among echelons still suffers from the bullwhip effect. Then, we propose the multi-agent solution to manage and reduce the bullwhip effect. The proposed multi-agent system includes four different types of agents in which each agent has its own list of actions. The proposed Multi-agent System applies a new Tabu Search algorithm for fuzzy rule generation, and a new data filtering algorithm for extraction of the bullwhip-free data from supply chain data warehouse. We validate the multi-agent system under different conditions and discuss how the system responds to different factors. The results show that the proposed multi-agent system reduces the bullwhip effect significantly in a rational time.
JTD Keywords: Bullwhip effect, Bullwhip-free data, Decentralized decision making, Fuzzy rule base, Fuzzy supply chain, Fuzzy time series, Multi-agent system, Supply chain management
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
Antelis, J.M., Montesano, L., Giralt, X., Casals, A., Minguez, J., (2012). Detection of movements with attention or distraction to the motor task during robot-assisted passive movements of the upper limb Engineering in Medicine and Biology Society (EMBC)
34th Annual International Conference of the IEEE , IEEE (San Diego, USA) , 6410-6413
Robot-assisted rehabilitation therapies usually focus on physical aspects rather than on cognitive factors. However, cognitive aspects such as attention, motivation, and engagement play a critical role in motor learning and thus influence the long-term success of rehabilitation programs. This paper studies motor-related EEG activity during the execution of robot-assisted passive movements of the upper limb, while participants either: i) focused attention exclusively on the task; or ii) simultaneously performed another task. Six healthy subjects participated in the study and results showed lower desynchronization during passive movements with another task simultaneously being carried out (compared to passive movements with exclusive attention on the task). In addition, it was proved the feasibility to distinguish between the two conditions.
JTD Keywords: Electrodes, Electroencephalography, Induction motors, Medical treatment, Robot sensing systems, Time frequency analysis, Biomechanics, Cognition, Electroencephalography, Medical robotics, Medical signal detection, Medical signal processing, Patient rehabilitation, Attention, Cognitive aspects, Desynchronization, Engagement, Motivation, Motor learning, Motor task, Motor-related EEG activity, Physical aspects, Robot-assisted passive movement detection, Robot-assisted rehabilitation therapies, Upper limb
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
Melchels, Ferry P. W., Tonnarelli, Beatrice, Olivares, Andy L., Martin, Ivan, Lacroix, Damien, Feijen, Jan, Wendt, David J., Grijpma, Dirk W., (2011). The influence of the scaffold design on the distribution of adhering cells after perfusion cell seeding Biomaterials 32, (11), 2878-2884
In natural tissues, the extracellular matrix composition, cell density and physiological properties are often non-homogeneous. Here we describe a model system, in which the distribution of cells throughout tissue engineering scaffolds after perfusion seeding can be influenced by the pore architecture of the scaffold. Two scaffold types, both with gyroid pore architectures, were designed and built by stereolithography: one with isotropic pore size (412 ± 13 [mu]m) and porosity (62 ± 1%), and another with a gradient in pore size (250-500 [mu]m) and porosity (35%-85%). Computational fluid flow modelling showed a uniform distribution of flow velocities and wall shear rates (15-24 s-1) for the isotropic architecture, and a gradient in the distribution of flow velocities and wall shear rates (12-38 s-1) for the other architecture. The distribution of cells throughout perfusion-seeded scaffolds was visualised by confocal microscopy. The highest densities of cells correlated with regions of the scaffolds where the pores were larger, and the fluid velocities and wall shear rates were the highest. Under the applied perfusion conditions, cell deposition is mainly determined by local wall shear stress, which, in turn, is strongly influenced by the architecture of the pore network of the scaffold.
JTD Keywords: Scaffolds, Microstructure, Cell adhesion, Confocal microscopy, Image analysis, Computational fluid dynamics
Crona, Mikael, Torrents, Eduard, Rohr, Asmund K., Hofer, Anders, Furrer, Ernst, Tomter, Ane B., Andersson, K. Kristoffer, Sahlin, Margareta, Sjoberg, Britt-Marie, (2011). NrdH-redoxin protein mediates high enzyme activity in manganese-reconstituted ribonucleotide reductase from bacillus anthracis
Journal of Biological Chemistry , 286, (38), 33053-33060
Bacillus anthracis is a severe mammalian pathogen encoding a class Ib ribonucleotide reductase (RNR). RNR is a universal enzyme that provides the four essential deoxyribonucleotides needed for DNA replication and repair. Almost all Bacillus spp. encode both class Ib and class III RNR operons, but the B. anthracis class III operon was reported to encode a pseudogene, and conceivably class Ib RNR is necessary for spore germination and proliferation of B. anthracis upon infection. The class Ib RNR operon in B. anthracis encodes genes for the catalytic NrdE protein, the tyrosyl radical metalloprotein NrdF, and the flavodoxin protein NrdI. The tyrosyl radical in NrdF is stabilized by an adjacent Mn(2)(III) site (Mn-NrdF) formed by the action of the NrdI protein or by a Fe(2)(III) site (Fe-NrdF) formed spontaneously from Fe(2+) and O(2). In this study, we show that the properties of B. anthracis Mn-NrdF and Fe-NrdF are in general similar for interaction with NrdE and NrdI. Intriguingly, the enzyme activity of Mn-NrdF was approximately an order of magnitude higher than that of Fe-NrdF in the presence of the class Ib-specific physiological reductant NrdH, strongly suggesting that the Mn-NrdF form is important in the life cycle of B. anthracis. Whether the Fe-NrdF form only exists in vitro or whether the NrdF protein in B. anthracis is a true cambialistic enzyme that can work with either manganese or iron remains to be established.
JTD Keywords: Escherichia-coli, Corynebacterium-ammoniagenes, Crystal-structure, Cofactor, Cubunit, Growth, Genes
Miranda Coelho, Nuno, Gonzalez-Garcia, Cristina, Salmeron-Sanchez, Manuel, Altankov, George, (2011). Arrangement of type IV collagen on NH(2) and COOH functionalized surfaces
Biotechnology and Bioengineering , 108, (12), 3009-3018
Apart from the paradigm that cell-biomaterials interaction depends on the adsorption of soluble adhesive proteins we anticipate that upon distinct conditions also other, less soluble ECM proteins such as collagens, associate with the biomaterials interface with consequences for cellular response that might be of significant bioengineering interest. Using atomic force microscopy (AFM) we seek to follow the nanoscale behavior of adsorbed type IV collagen (Col IV)-a unique multifunctional matrix protein involved in the organization of basement membranes (BMs) including vascular ones. We have previously shown that substratum wettability significantly affects Col IV adsorption pattern, and in turn alters endothelial cells interaction. Here we introduce two new model surfaces based on self-assembled monolayers (SAMs), a positively charged - NH(2), and negatively charged -COOH surface, to learn more about their particular effect on Col IV behavior. AFM studies revealed distinct pattern of Col IV assembly onto the two SAMs resembling different aspects of network-like structure or aggregates (suggesting altered protein conformation). Moreover, the amount of adsorbed FITC-labeled Col IV was quantified and showed about twice more protein on NH(2) substrata. Human umbilical vein endothelial cells attached less efficiently to Col IV adsorbed on negatively charged COOH surface judged by altered cell spreading, focal adhesions formation, and actin cytoskeleton development. Immunofluorescence studies also revealed better Col IV recognition by both alpha(1) and alpha(2) integrins on positively charged NH(2) substrata resulting in higher phosphorylated focal adhesion kinase recruitment in the focal adhesion complexes. On COOH surface, no integrin clustering was observed. Taken altogether these results, point to the possibility that combined NH(2) and Col IV functionalization may support endothelization of cardiovascular implants.
JTD Keywords: Collagen type IV, SAMs, AFM, Surface-induced protein assembly, Endothelial cells, Vascular grafts
Coelho, N. M., Gonzalez-Garcia, C., Planell, J. A., Salmeron-Sanchez, M., Altankov, G., (2010). Different assembly of type iv collagen on hydrophilic and hydrophobic substrata alters endothelial cells interaction
European Cells & Materials , 19, 262-272
Considering the structural role of type IV collagen (Col IV) in the assembly of the basement membrane (BM) and the perspective of mimicking its organization for vascular tissue engineering purposes, we studied the adsorption pattern of this protein on model hydrophilic (clean glass) and hydrophobic trichloro(octadecyl) silane (ODS) surfaces known to strongly affect the behavior of other matrix proteins. The amount of fluorescently labeled Col IV was quantified showing saturation of the surface for concentration of the adsorbing solution of about 50 mu g/ml, but with approximately twice more adsorbed protein on ODS. AFM studies revealed a fine-nearly single molecular size-network arrangement of Col IV on hydrophilic glass, which turns into a prominent and growing polygonal network consisting of molecular aggregates on hydrophobic ODS. The protein layer forms within minutes in a concentration-dependent manner. We further found that human umbilical vein endothelial cells (HUVEC) attach less efficiently to the aggregated Col IV (on ODS), as judged by the significantly altered cell spreading, focal adhesions formation and the development of actin cytoskeleton. Conversely, the immunofluorescence studies for integrins revealed that the fine Col IV network formed on hydrophilic substrata is better recognized by the cells via both alpha 1 and alpha 2 heterodimers which support cellular interaction, apart from these on hydrophobic ODS where almost no clustering of integrins was observed.
JTD Keywords: Collagen type IV, Adsorption, Assembly, Hydrophilic, Hydrophobic, Surfaces
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
Valente, T., Gella, A., Fernàndez-Busquets, X., Unzeta, M., Durany, N., (2010). Immunohistochemical analysis of human brain suggests pathological synergism of Alzheimer's disease and diabetes mellitus
Neurobiology of Disease , 37, (1), 67-76
It has been extensively reported that diabetes mellitus (DM) patients have a higher risk of developing Alzheimer's disease (AD). but a mechanistic connection between both pathologies has not been provided so far Carbohydrate-derived advanced glycation endproducts (AGEs) have been implicated in the chronic complications of DM and have been reported to play an important role in the pathogenesis of AD. The earliest histopathological manifestation of AD is the apparition of extracellular aggregates of the amyloid beta peptide (A beta). To investigate possible correlations between AGEs and A beta aggregates with both pathologies. we have performed an immuhistochemical study in human post-mortem samples of AD, AD with diabetes (ADD). diabetic and nondemented controls ADD brains showed increased number of A beta dense plaques and receptor for AGEs (RACE)-positive and Tau-positive cells, higher AGEs levels and major microglial activation, compared to AD brain. Our results indicate that ADD patients present a significant increase of cell damage through a RAGE-dependent mechanism, suggesting that AGEs may promote the generation of an oxidative stress vicious cycle, which can explain the severe progression of patients with both pathologies.
JTD Keywords: Abeta, Alzheimer's disease, Rage, Ages, Diabetes, Immunohistochemistry, Advanced glycation endproducts, Beta-amyloid peptide, End-products, Oxidative stress, Advanced glycosylation, Synaptic dysfunction, Cross-linking
Harder, A., Walhorn, V., Dierks, T., Fernàndez-Busquets, X., Anselmetti, D., (2010). Single-molecule force spectroscopy of cartilage aggrecan self-adhesion
Biophysical Journal , 99, (10), 3498-3504
We investigated self-adhesion between highly negatively charged aggrecan macromolecules extracted from bovine cartilage extracellular matrix by performing atomic force microscopy (AFM) imaging and single-molecule force spectroscopy (SMFS) in saline solutions. By controlling the density of aggrecan molecules on both the gold substrate and the gold-coated tip surface at submonolayer densities, we were able to detect and quantify the Ca2+-dependent homodimeric interaction between individual aggrecan molecules at the single-molecule level. We found a typical nonlinear sawtooth profile in the AFM force-versus-distance curves with a molecular persistence length of I-p = 0.31 +/- 0.04 nm. This is attributed to the stepwise dissociation of individual glycosaminoglycan (GAG) side chains in aggrecans, which is very similar to the known force fingerprints of other cell adhesion proteoglycan systems. After studying the GAG-GAG dissociation in a dynamic, loading-rate-dependent manner (dynamic SMFS) and analyzing the data according to the stochastic Bell-Evans model for a thermally activated decay of a metastable state under an external force, we estimated for the single glycan interaction a mean lifetime of tau = 7.9 +/- 4.9 s and a reaction bond length of x(beta) = 0.31 +/- 0.08 nm. Whereas the x(beta)-value compares well with values from other cell adhesion carbohydrate recognition motifs in evolutionary distant marine sponge proteoglycans, the rather short GAG interaction lifetime reflects high intermolecular dynamics within aggrecan complexes, which may be relevant for the viscoelastic properties of cartilage tissue.
JTD Keywords: Bovine nasal cartilage, Articular-cartilage, Sinorhizobium-meliloti, Proteoglycan, Microscopy, DNA, Macromolecules, Binding, Protein, Glycosaminoglycans
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
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
Correa, R., Laciar, E., Arini, P., Jané, R., (2010). Analysis of QRS loop in the Vectorcardiogram of patients with Chagas' disease Engineering in Medicine and Biology Society (EMBC)
32nd Annual International Conference of the IEEE , IEEE (Buenos Aires, Argentina) , 2561-2564
In the present work, we have studied the QRS loop in the Vectorcardiogram (VCG) of 95 chronic chagasic patients classified in different groups (I, II and III) according to their degree of myocardial damage. For comparison, the VCGs of 11 healthy subjects used as control group (Group O) were also examined. The QRS loop was obtained for each patient from the XYZ orthogonal leads of their High-Resolution Electrocardiogram (HRECG) records. In order to analyze the variations of QRS loop in each detected beat, it has been proposed in this study the following vectorcardiographic parameters a) Maximum magnitude of the cardiac depolarization vector, b) Volume, c) Area of QRS loop, d) Ratio between the Area and Perimeter, e) Ratio between the major and minor axes of the QRS loop and f) QRS loop Energy. It has been found that one or more indexes exhibited statistical differences (p<0.05) between groups 0-II, O-III, I-II, I-III and II-III. We concluded that the proposed method could be use as complementary diagnosis technique to evaluate the degree of myocardial damage in chronic chagasic patients.
JTD Keywords: Practical, Experimental/ bioelectric phenomena, Diseases, Electrocardiography, Medical signal, Processing/ QRS loop, Vectorcardiogram, Cardiac depolarization vector, Myocardial damage, Chagas disease, Complementary diagnosis technique, High-resolution electrocardiogram
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
Tarzan-Lorente, M., Gutierrez-Galvez, A., Martinez, D., Marco, S., (2010). A biologically inspired associative memory for artificial olfaction Practica
2010 International Joint Conference on Neural Networks (IJCNN 2010) , IEEE, Piscataway, NJ, USA (Barcelona, Spain) , 6 pp.
In this paper, we propose a biologically inspired architecture for a Hopfield-like associative memory applied to artificial olfaction. The proposed algorithm captures the projection between two neural layers of the insect olfactory system (Antennal Lobe and Mushroom Body) with a kernel based projection. We have tested its classification performance as a function of the size of the training set and the time elapsed since training and compared it with that obtained with a Support Vector Machine.
JTD Keywords: Biocomputing, Chemioception, Content-addressable storage, Hopfield neural nets, Support vector machines
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
Caballero-Briones, F., Artes, J. M., Diez-Perez, I., Gorostiza, P., Sanz, F., (2009). Direct observation of the valence band edge by in situ ECSTM-ECTS in p-type Cu2O layers prepared by copper anodization Journal of Physical Chemistry C 113, (3), 1028-1036
Polycrystalline Cu2O layers have been selectively grown by electrochemical anodization of polycrystalline Cu electrodes in an alkaline medium (pH 12.85). Uniform layers with thicknesses around 100 nm have been obtained. Using electrochemical impedance spectroscopy, it was concluded that the Cu2O films behave as a p-type semiconductor. The Mott-Schottky plot gives a value for the flat band potential of U-FB = -255 mV vs silver/silver chloride electrode (SSC), an estimated carrier density N-A = 6.1 x 10(17) cm(-3), and the space charge layer width was calculated to be W-SCL = 9 nm at a band bending of 120 mV. The electronic structure of the Cu vertical bar Cu2O vertical bar electrolyte interface was for the first time probed by in situ electrochemical tunneling spectroscopy. The use of in situ electrochemical scanning tunneling microscopy allows us to directly observed the valence band edge and determine its position against the absolute energy scale to be E-VB = -4.9 eV. Finally, we constructed a quantitative electronic diagram of the Cu vertical bar Cu2O vertical bar electrolyte interface, where the positions of the valence and conduction band edges are depicted, as well as the edge of the previously reported electronic subband.
JTD Keywords: 0.1 m NaOH, Electrochemical tunneling spectroscopy, Cuprous-oxide films, Anodic-oxidation, Electronic-structure, Alkaline-solution, Aqueous-solution, Initial-stages, Passive film, Thin-films
Fonollosa, J., Halford, B., Fonseca, L., Santander, J., Udina, S., Moreno, M., Hildenbrand, J., Wöllenstein, J., Marco, S., (2009). Ethylene optical spectrometer for apple ripening monitoring in controlled atmosphere store-houses Sensors and Actuators B: Chemical 136, (2), 546-554
In today's store-houses the ripening of fruit is controlled by managing the ethylene concentration in the ambient atmosphere. Precise and continuous ethylene monitoring is very advantageous since low ethylene concentrations are produced by the fruit itself and are indicative of its ripeness, and on other occasions, ethylene is externally added when ripeness or degreening of the product must be promoted. In this work, a multichannel mid-infrared spectrometer for ethylene measurement is built and characterized. The instrument contains additional channels to reject potential cross-interferences like ammonia and ethanol. Additionally, these channels are useful for monitoring a potential malfunction of the cooling system and possible fouling of the fruit, respectively. The complete spectrometer contains a silicon-based macroporous infrared (IR) emitter, a miniaturized long path cell (white cell), a four-channel detector module, low-noise analog amplification and filtering, and a microcontroller-based lock-in amplifier. The new inner architecture of the detector module features a fourfold thermopile array with narrow band optical filters attached by flip-chip technology, and a Fresnel lens array attached on the lid of the package. Laboratory tests show that the system is able to distinguish between ammonia and ethylene, featuring a detection limit of 30 ppm and 160 ppm (95% confidence) for ethylene and ammonia, respectively. Field tests show that the spectrometer is suitable as an ethylene alarm to detect fruit ripening and prevent fruit to decline into senescence. Simulation results show that system selectivity could be improved by setting ammonia channel to another absorption wavelength.
JTD Keywords: IR spectrometer, Ethylene, Fruit storage, Fresnel lens, White cell, Lock-in amplifier
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
Merolli, A., Rocchi, L., Catalano, F., Planell, J., Engel, E., Martinez, E., Sbernardori, M. C., Marceddu, S., Leali, P. T., (2009). In vivo regeneration of rat sciatic nerve in a double-halved stitch-less guide: a pilot-study
Microsurgery , 29, (4), 310-318
It is about 20 years that tubular nerve guides have been introduced into clinical practice as a reliable alternative to autograft, in gaps not-longer-than 20 mm, bringing the advantage of avoiding donor site sacrifice and morbidity. There are limitations in the application of tubular guides. First, tubular structure in itself makes surgical implantation difficult; second, stitch sutures required to secure the guide may represent a site of unfavorable fibroblastic reaction; third, maximum length and diameter of the guide correlate with the occurrence of a poorer central vascularization of regenerated nerve. We report on the in vivo testing of a new concept of nerve-guide (named NeuroBox) which is double-halved, not-degradable, rigid, and does not require any stitch to be held in place, employing acrylate glue instead. Five male Wistar rats had the new guide implanted in a 4-mm sciatic nerve defect; two guides incorporated a surface constituted of microtrenches aligned longitudinally. Further five rats had the 4-mm gap left without repair. Contralateral intact nerves were used as controls. After 2 months, nerve regeneration occurred in all animals treated by the NeuroBox; fine blood vessels were well represented. There was no regeneration in the un-treated animals. Even if the limited number of animals does not allow to draw definitive conclusions, some result can be highlighted: an easy surgical technique was associated with the box-shaped guide and acrylate glue was easily applied; an adequate intraneural vascularization was found concurrently with the regeneration of the nerve and no adverse fibroblastic proliferation was present.
JTD Keywords: Peripheral-nerve, Polyglycolic acid, Guidance cues, Collagen tube, Median nerve, Repair, Growth, Cyanoacrylate, Complications, Anastomosis
Lacroix, D., (2009). Biomechanical aspects of bone repair
Bone repair biomaterials (ed. Planell, J. A., Lacroix, D., Best, S., Merolli, A.), Woodhead (Cambridge, UK)
A fundamental aspect of the rapidly expanding medical care sector, bone repair continues to benefit from emerging technological developments. This text provides researchers and students with a comprehensive review of the materials science and engineering principles behind these developments. The first part reviews the fundamentals of bone repair and regeneration. Further chapters discuss the science and properties of biomaterials used in bone repair, including both metals and biocomposites. Final chapters analyze device considerations such as implant lifetime and failure, and discuss potential applications, as well as the ethical issues that continually confront researchers and clinicians.
JTD Keywords: Bone composition and structure, Biomechanical properties of bone, Bone damage and repair
Zazoua, A., Morakchi, K., Kherrat, R., Samar, M. H., Errachid, A., Jaffrezic-Renault, N., Boubellout, R., (2008). Electrochemical characterization of an EIS sensor functionalized with a TOPO doped polymeric layer for Cr(VI) detection
IRBM , 29, (2-3), 187-191
A hexavalent chromium-selective sensor, based on polymeric membranes containing trioctylphosphine oxide (TOPO) deposited on a Si/Sio(2)/Si3N4 structure, has been developed. The ion-sensitivity of TOPO was investigated by capacitance measurements (C-V) and electrochemical impedance spectroscopy. A quasi-nernstian response for Cr2O72- exchange is shown. Selectivity coefficients and detection limits of Cr(VI) in the presence of interfering anions were determined experimentally using the fixed interference method. A detection limit of 10(-5) M of Cr(VI) is obtained even in presence of sulphate and chloride ions.
JTD Keywords: Hexavalent chromium, Trioctylphosphine oxide, EIS, Siloprene membrane, Capacitance-voltage
Roca, Ignasi, Torrents, Eduard, Sahlin, Margareta, Gibert, Isidre, Sjoberg, Britt-Marie, (2008). NrdI essentiality for class Ib ribonucleotide reduction in streptococcus pyogenes
Journal of Bacteriology , 190, (14), 4849-4858
The Streptococcus pyogenes genome harbors two clusters of class Ib ribonucleotide reductase genes, nrdHEF and nrdF*I*E*, and a second stand-alone nrdI gene, designated nrdI2. We show that both clusters are expressed simultaneously as two independent operons. The NrdEF enzyme is functionally active in vitro, while the NrdE*F* enzyme is not. The NrdF* protein lacks three of the six highly conserved iron-liganding side chains and cannot form a dinuclear iron site or a tyrosyl radical. In vivo, on the other hand, both operons are functional in heterologous complementation in Escherichia coli. The nrdF*I*E* operon requires the presence of the nrdI* gene, and the nrdHEF operon gained activity upon cotranscription of the heterologous nrdI gene from Streptococcus pneumoniae, while neither nrdI* nor nrdI2 from S. pyogenes rendered it active. Our results highlight the essential role of the flavodoxin NrdI protein in vivo, and we suggest that it is needed to reduce met-NrdF, thereby enabling the spontaneous reformation of the tyrosyl radical. The NrdI* flavodoxin may play a more direct role in ribonucleotide reduction by the NrdF*I*E* system. We discuss the possibility that the nrdF*I*E* operon has been horizontally transferred to S. pyogenes from Mycoplasma spp.
JTD Keywords: Group-a streptococcus, Bacillus-subtilis genes, Escherichia-coli, Corynebacterium-ammoniagenes, Mycobacterium-tuberculosis, Expression analysis, Genome sequence, Small-subunit, Salmonella-typhimurium, Iron center
Maneva-Radicheva, L., Ebert, U., Dimoudis, N., Altankov, G., (2008). Fibroblast remodeling of adsorbed collagen type IV is altered in contact with cancer cells
Histology and Histopathology , 23, (7), 833-842
A series of co-culture experiments between fibroblasts and H-460 human lung carcinoma cells were performed to learn more about the fate of adsorbed type IV collagen (Coll IV). Fibroblasts were able to spatially rearrange Coll IV in a specific linear pattern, similar but not identical to the fibronectin (FN) fibrils. Coll IV partly co-aligns with fibroblast actin cytoskeleton and transiently co-localize with FN, as well as with beta 1 and a 2 integrin clusters, suggesting a cell-dependent process. We further found that this Coll IV reorganization is suppressed in contact with H460 cells. Zymography revealed strongly elevated MMP-2 activity in supernatants of co-cultures, but no activity when fibroblasts or cancer cells were cultured alone. Thus, we provide evidence that reorganization of substrate associated Coll IV is a useful morphological approach for in vitro studies on matrix remodeling activity during tumorigenesis.
JTD Keywords: Adsorbed collagen IV reorganization, Fibroblasts and cancer cells co-culture, MMP-2
Manara, S., Paolucci, F., Palazzo, B., Marcaccio, M., Foresti, E., Tosi, G., Sabbatini, S., Sabatino, P., Altankov, G., Roveri, N., (2008). Electrochemically-assisted deposition of biomimetic hydroxyapatite-collagen coatings on titanium plate Inorganica Chimica Acta 361, (6), 1634-1645
A biomimetic bone-like composite, made of self-assembled collagen fibrils and carbonate hydroxyapatite nanocrystals, has been performed by an electrochemically-assisted deposition on titanium plate. The electrolytic processes have been carried out using a single type I collagen molecules suspension in a diluted Ca(NO3)(2) and NH4H2PO4 solution at room temperature and applying a constant current for different periods of time. Using the same electrochemical conditions, carbonate hydroxyapatite nanocrystals or reconstituted collagen. brils coatings were obtained. The reconstituted collagen. brils, hydroxyapatite nanocrystals and collagen fibrils/apatite nanocrystals coatings have been characterized chemically, structurally and morphologically, as well as for their ability to bind fibronectin (FN). Fourier Transform Infrared microscopy has been used to map the topographic distribution of the coating components at different times of electrochemical deposition, allowing to single out the individual deposition steps. Moreover, roughness of Ti plate has been found to affect appreciably the nucleation region of the inorganic nanocrystals. Laser scanning confocal microscopy has been used to characterize the FN adsorption pattern on a synthetic biomimetic apatitic phase, which exhibits a higher affinity when it is inter-grown with the collagen fibrils. The results offer auspicious applications in the preparation of medical devices such as biomimetic bone-like composite-coated metallic implants.
JTD Keywords: Hydroxyapatite-collagen coating, Electrochemically-assisted deposition, Micro-imaging FTIR spectroscopy, Laser scanning confocal microscopy, Biomimetic crystal growth, Fibronectin binding
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