by Keyword: Gel
Barbosa F, Garrudo FFF, Alberte PS, Resina L, Carvalho MS, Jain A, Marques AC, Estrany F, Rawson FJ, Aléman C, Ferreira FC, Silva JC, (2023). Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering Science And Technology Of Advanced Materials 24, 2242242
Osteoporotic-related fractures are among the leading causes of chronic disease morbidity in Europe and in the US. While a significant percentage of fractures can be repaired naturally, in delayed-union and non-union fractures surgical intervention is necessary for proper bone regeneration. Given the current lack of optimized clinical techniques to adequately address this issue, bone tissue engineering (BTE) strategies focusing on the development of scaffolds for temporarily replacing damaged bone and supporting its regeneration process have been gaining interest. The piezoelectric properties of bone, which have an important role in tissue homeostasis and regeneration, have been frequently neglected in the design of BTE scaffolds. Therefore, in this study, we developed novel hydroxyapatite (HAp)-filled osteoinductive and piezoelectric poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-TrFE) nanofibers via electrospinning capable of replicating the tissue's fibrous extracellular matrix (ECM) composition and native piezoelectric properties. The developed PVDF-TrFE/HAp nanofibers had biomimetic collagen fibril-like diameters, as well as enhanced piezoelectric and surface properties, which translated into a better capacity to assist the mineralization process and cell proliferation. The biological cues provided by the HAp nanoparticles enhanced the osteogenic differentiation of seeded human mesenchymal stem/stromal cells (MSCs) as observed by the increased ALP activity, cell-secreted calcium deposition and osteogenic gene expression levels observed for the HAp-containing fibers. Overall, our findings describe the potential of combining PVDF-TrFE and HAp for developing electroactive and osteoinductive nanofibers capable of supporting bone tissue regeneration.© 2023 The Author(s). Published by National Institute for Materials Science in partnership with Taylor & Francis Group.
JTD Keywords: composites, electrospinning, hydroxyapatite, piezoelectricity, promote, pvdf, pvdf-trfe, removal, scaffolds, temperature, Bone tissue engineering, Electrospinning, Electrospun polycaprolactone, Hydroxyapatite, Piezoelectricity, Pvdf-trfe
Martínez-Blanco Á, Noé S, Carreras-Vidal L, Otero J, Gavara N, (2023). Cryosectioning of Hydrogels as a Reliable Approach to Increase Yield and Further Tune Mechanical Properties Gels 9, 834
Decellularized extracellular matrix (dECM) hydrogels have emerged as promising materials in tissue engineering. The steps to produce dECM hydrogels containing the bioactive epitopes found in the native matrix are often laborious, including the initial harvesting and decellularization of the animal organ. Furthermore, resulting hydrogels often exhibit weak mechanical properties that require the use of additional crosslinkers such as genipin to truly simulate the mechanical properties of the desired study tissue. In this work, we have developed a protocol to readily obtain tens of thin dECM hydrogel cryosections attached to a glass slide as support, to serve as scaffolds for two-dimensional (2D) or three-dimensional (3D) cell culture. Following extensive atomic force microscopy (AFM)-based mechanical characterization of dECM hydrogels crosslinked with increasing genipin concentrations (5 mM, 10 mM, and 20 mM), we provide detailed protocol recommendations for achieving dECM hydrogels of any biologically relevant stiffness. Given that our protocol requires hydrogel freezing, we also confirm that the approach taken can be further used to increase the mechanical properties of the scaffold in a controlled manner exhibiting twice the stiffness in highly crosslinked arrays. Finally, we explored the effect of ethanol-based short- and long-term sterilization on dECM hydrogels, showing that in some situations it may give rise to significant changes in hydrogel mechanical properties that need to be taken into account in experimental design. The hydrogel cryosections produced were shown to be biocompatible and support cell attachment and spreading for at least 72 h in culture. In brief, our proposed method may provide several advantages for tissue engineering: (1) easy availability and reduction in preparation time, (2) increase in the total hydrogel volume eventually used for experiments being able to obtain 15-22 slides from a 250 µL hydrogel) with a (3) reduction in scaffold variability (only a 17.5 ± 9.5% intraslide variability provided by the method), and (4) compatibility with live-cell imaging techniques or further cell characterization of cells.
JTD Keywords: Atomic force microscopy, Cryogel, Cryosectioning, Decellularization, Extracellular matrix, Genipin, Hydrogel, Sterilization, Stiffness, Young’s modulus
Torras N, Zabalo J, Abril E, Carré A, García-Díaz M, Martínez E, (2023). A bioprinted 3D gut model with crypt-villus structures to mimic the intestinal epithelial-stromal microenvironment Biomaterials Advances 153, 213534
The intestine is a complex tissue with a characteristic three-dimensional (3D) crypt-villus architecture, which plays a key role in the intestinal function. This function is also regulated by the intestinal stroma that actively supports the intestinal epithelium, maintaining the homeostasis of the tissue. Efforts to account for the 3D complex structure of the intestinal tissue have been focused mainly in mimicking the epithelial barrier, while solutions to include the stromal compartment are scarce and unpractical to be used in routine experiments. Here we demonstrate that by employing an optimized bioink formulation and the suitable printing parameters it is possible to produce fibroblast-laden crypt-villus structures by means of digital light projection stereolithography (DLP-SLA). This process provides excellent cell viability, accurate spatial resolution, and high printing throughput, resulting in a robust biofabrication approach that yields functional gut mucosa tissues compatible with conventional testing techniques.Copyright © 2023 Elsevier B.V. All rights reserved.
JTD Keywords: 3d microstructure, barrier, cells, epithelial-stromal interactions, gelma-pegda soft hydrogels, growth, hydrogel, intestinal mucosa model, methacrylamide, microfabrication, proliferation, scaffold, stereolithography, 3d bioprinting, 3d microstructure, Epithelial-stromal interactions, Fibroblasts, Gelma-pegda soft hydrogels, Intestinal mucosa model
Sanz-Fraile H, Herranz-Diez C, Ulldemolins A, Falcones B, Almendros I, Gavara N, Sunyer R, Farré R, Otero J, (2023). Characterization of Bioinks Prepared via Gelifying Extracellular Matrix from Decellularized Porcine Myocardia Gels 9, 745
Since the emergence of 3D bioprinting technology, both synthetic and natural materials have been used to develop bioinks for producing cell-laden cardiac grafts. To this end, extracellular-matrix (ECM)-derived hydrogels can be used to develop scaffolds that closely mimic the complex 3D environments for cell culture. This study presents a novel cardiac bioink based on hydrogels exclusively derived from decellularized porcine myocardium loaded with human-bone-marrow-derived mesenchymal stromal cells. Hence, the hydrogel can be used to develop cell-laden cardiac patches without the need to add other biomaterials or use additional crosslinkers. The scaffold ultrastructure and mechanical properties of the bioink were characterized to optimize its production, specifically focusing on the matrix enzymatic digestion time. The cells were cultured in 3D within the developed hydrogels to assess their response. The results indicate that the hydrogels fostered inter-cell and cell-matrix crosstalk after 1 week of culture. In conclusion, the bioink developed and presented in this study holds great potential for developing cell-laden customized patches for cardiac repair.
JTD Keywords: 3d bioprinting, Biomaterials, Decellularized cardiac tissue, Extracellular matrix, Hydrogels, Mesenchymal stromal cells
Malandain, N, Sanz-Fraile, H, Farre, R, Otero, J, Roig, A, Laromaine, A, (2023). Cell-Laden 3D Hydrogels of Type I Collagen Incorporating Bacterial Nanocellulose Fibers Acs Applied Bio Materials 6, 3638-3647
There is a growing interest in developing natural hydrogel-based scaffolds to culture cells in a three-dimensional (3D) millieu that better mimics the in vivo cells' microenvironment. A promising approach is to use hydrogels from animal tissues, such as decellularized extracellular matrices; however, they usually exhibit suboptimal mechanical properties compared to native tissue and their composition with hundreds of different protein complicates to elucidate which stimulus triggers cell's responses. As simpler scaffolds, type I collagen hydrogels are used to study cell behavior in mechanobiology even though they are also softer than native tissues. In this work, type I collagen is mixed with bacterial nanocellulose fibers (BCf) to develop reinforced scaffolds with mechanical properties suitable for 3D cell culture. BCf were produced from blended pellicles biosynthesized from Komagataeibacter xylinus. Then, BCf were mixed with concentrated collagen from rat-tail tendons to form composite hydrogels. Confocal laser scanning microscopy and scanning electron microscopy images confirmed the homogeneous macro- and microdistribution of both natural polymers. Porosity analysis confirmed that BCf do not disrupt the scaffold structure. Tensile strength and rheology measurements demonstrated the reinforcement action of BCf (43% increased stiffness) compared to the collagen hydrogel while maintaining the same viscoelastic response. Additionally, this reinforcement of collagen hydrogels with BCf offers the possibility to mix cells before gelation and then proceed to the culture of the 3D cell scaffolds. We obtained scaffolds with human bone marrow-derived mesenchymal stromal cells or human fibroblasts within the composite hydrogels, allowing a homogeneous 3D viable culture for at least 7 days. A smaller surface shrinkage in the reinforced hydrogels compared to type I collagen hydrogels confirmed the strengthening of the composite hydrogels. These collagen hydrogels reinforced with BCf might emerge as a promising platform for 3D in vitro organ modeling, tissue-engineering applications, and suitable to conduct fundamental mechanobiology studies.
JTD Keywords: 3d cell culture, bacterial cellulose, collagen, composite hydrogels, 3d cell culture, Bacterial cellulose, Cellulose/collagen composite, Collagen, Composite hydrogels, Contraction, Cross-linking, Cytocompatibility, Fibroblasts, Matrix, Mechanical-properties, Reinforcement, Stiffness, Tissue engineering
Fontana-Escartín, A, Lanzalaco, S, Bertran, O, Aradilla, D, Alemán, C, (2023). Aqueous alginate/MXene inks for 3D printable biomedical devices Colloids And Surfaces A-Physicochemical And Engineering Aspects 671, 131632
Electrochemically responsive hydrogel networks have been obtained usin g printable inks made of a biopolymer, alginate (Alg), and an inorganic 2D material , MXene (titaniu m carbide, Ti3C2Tx) nanosheets. While MXene offers an electrically conductive pathway for electron transfer and Alg provides an interconnected framework for ion diffusion, the printed nanocomposite results, after gelation, in an extended active interface for redox reactions, being an ideal framework to design and construct flexible devices for biomedical applications. In this work, after characterization, we demonstrate that hydrogels obtained by cross-linking printed Alg /MXene inks exhibit great potential for bioelectronics. More specifically, we prove that flexible Alg/MXene hydrogels act as self-supported electroactive electrodes for the electrochemical detection of bioanalytes, such as dopamine, with a performance similar to that achieved using more sophisticated electrodes, as for example those containing conducting poly-mers and electrocatalytic gold nanoparticles. In addition, Alg/MXene hydrogels have been successfully used to regulate the release of a previously loaded broad spectrum antibiotic (chloramphenicol) by electrical stimulation.
JTD Keywords: 3d-printing, Biomedical application s, Composites, Conducting polymers, Drug release, Electroresponsive hydrogels, Fabrication, Hydrogels, Platform, Sensors, Strategy, Surface, Thin-film, Titanium carbide
García-Lizarribar A, Villasante A, Lopez-Martin JA, Flandez M, Soler-Vázquez MC, Serra D, Herrero L, Sagrera A, Efeyan A, Samitier J, (2023). 3D bioprinted functional skeletal muscle models have potential applications for studies of muscle wasting in cancer cachexia Biomaterials Advances 150, 213426
Acquired muscle diseases such as cancer cachexia are responsible for the poor prognosis of many patients suffering from cancer. In vitro models are needed to study the underlying mechanisms of those pathologies. Extrusion bioprinting is an emerging tool to emulate the aligned architecture of fibers while implementing additive manufacturing techniques in tissue engineering. However, designing bioinks that reconcile the rheological needs of bioprinting and the biological requirements of muscle tissue is a challenging matter. Here we formulate a biomaterial with dual crosslinking to modulate the physical properties of bioprinted models. We design 3D bioprinted muscle models that resemble the mechanical properties of native tissue and show improved proliferation and high maturation of differentiated myotubes suggesting that the GelMA-AlgMA-Fibrin biomaterial possesses myogenic properties. The electrical stimulation of the 3D model confirmed the contractile capability of the tissue and enhanced the formation of sarcomeres. Regarding the functionality of the models, they served as platforms to recapitulate skeletal muscle diseases such as muscle wasting produced by cancer cachexia. The genetic expression of 3D models demonstrated a better resemblance to the muscular biopsies of cachectic mouse models. Altogether, this biomaterial is aimed to fabricate manipulable skeletal muscle in vitro models in a non-costly, fast and feasible manner.Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.
JTD Keywords: cachexia, constructs, skeletal muscle, tissue-engineering, Bioprinting, Cachexia, Hydrogels, Skeletal muscle, Tissue-engineering
Lanzalaco S, Weis C, Traeger KA, Turon P, Alemán C, Armelin E, (2023). Mechanical Properties of Smart Polypropylene Meshes: Effects of Mesh Architecture, Plasma Treatment, Thermosensitive Coating, and Sterilization Process Acs Biomaterials Science & Engineering 9, 3699-3711
Smart polypropylene (PP) hernia meshes were proposed to detect surgical infections and to regulate cell attachment-modulated properties. For this purpose, lightweight and midweight meshes were modified by applying a plasma treatment for subsequent grafting of a thermosensitive hydrogel, poly(N-isopropylacrylamide) (PNIPAAm). However, both the physical treatment with plasma and the chemical processes required for the covalent incorporation of PNIPAAm can modify the mechanical properties of the mesh and thus have an influence in hernia repair procedures. In this work, the mechanical performance of plasma-treated and hydrogel-grafted meshes preheated at 37 °C has been compared with standard meshes using bursting and the suture pull out tests. Furthermore, the influence of the mesh architecture, the amount of grafted hydrogel, and the sterilization process on such properties have been examined. Results reveal that although the plasma treatment reduces the bursting and suture pull out forces, the thermosensitive hydrogel improves the mechanical resistance of the meshes. Moreover, the mechanical performance of the meshes coated with the PNIPAAm hydrogel is not influenced by ethylene oxide gas sterilization. Micrographs of the broken meshes evidence the role of the hydrogel as reinforcing coating for the PP filaments. Overall, results confirm that the modification of PP medical textiles with a biocompatible thermosensitive hydrogel do not affect, and even improve, the mechanical requirements necessary for the implantation of these prostheses in vivo.
JTD Keywords: biomaterials, bursting test, etox sterilization, hernia repair, hydrogels, infection, poly(n-isopropylacrylamide), pull outtest, surgical mesh, Abdominal-wall, Biomedical implant, Bursting test, Etox sterilization, Poly(n-isopropylacrylamide), Pull out test, Surgical mesh
Oliver-Cervelló L, Martin-Gómez H, Gonzalez-Garcia C, Salmeron-Sanchez M, Ginebra MP, Mas-Moruno C, (2023). Protease-degradable hydrogels with multifunctional biomimetic peptides for bone tissue engineering Frontiers In Bioengineering And Biotechnology 11, 1192436
Mimicking bone extracellular matrix (ECM) is paramount to develop novel biomaterials for bone tissue engineering. In this regard, the combination of integrin-binding ligands together with osteogenic peptides represents a powerful approach to recapitulate the healing microenvironment of bone. In the present work, we designed polyethylene glycol (PEG)-based hydrogels functionalized with cell instructive multifunctional biomimetic peptides (either with cyclic RGD-DWIVA or cyclic RGD-cyclic DWIVA) and cross-linked with matrix metalloproteinases (MMPs)-degradable sequences to enable dynamic enzymatic biodegradation and cell spreading and differentiation. The analysis of the intrinsic properties of the hydrogel revealed relevant mechanical properties, porosity, swelling and degradability to engineer hydrogels for bone tissue engineering. Moreover, the engineered hydrogels were able to promote human mesenchymal stem cells (MSCs) spreading and significantly improve their osteogenic differentiation. Thus, these novel hydrogels could be a promising candidate for applications in bone tissue engineering, such as acellular systems to be implanted and regenerate bone or in stem cells therapy.Copyright © 2023 Oliver-Cervelló, Martin-Gómez, Gonzalez-Garcia, Salmeron-Sanchez, Ginebra and Mas-Moruno.
JTD Keywords: biomaterials, cross-linking, dwiva, functionalization, hydrogel, integrin, kinetics, marrow stromal cells, matrices, multifunctionality, myogenic differentiation, osteogenic differentiation, regeneration, stem-cells, Biomimetic peptides, Dwiva, Functionalization, Hydrogel, Multifunctionality, Osteogenic differentiation, Poly(ethylene glycol) hydrogels
Mingot J, Benejam N, Víllora G, Alemán C, Armelin E, Lanzalaco S, (2023). Multimodal Biomedical Implant with Plasmonic and Simulated Body Temperature Responses Macromolecular Bioscience 23, e2300118
This work presents a novel nanoparticle-based thermosensor implant able to reveal the precise temperature variations along the polymer filaments, as it contracts and expands due to changes in the macroscale local temperature. The multimodal device is able to trace the position and the temperature of a polypropylene mesh, employed in abdominal hernia repair, by combining plasmon resonance and Raman spectroscopy with hydrogel responsive system. The novelty relies on the attachment of the biocompatible nanoparticles, based on gold stabilized by a chitosan-shell, already charged with the Raman reporter (RaR) molecules, to the robust prosthesis, without the need of chemical linkers. The SERS enhanced effect observed is potentiated by the presence of a quite thick layer of the copolymer (poly(N-isopropylacrylamide)-co-poly(acrylamide)) hydrogel. At temperatures above the LCST of PNIPAAm-co-PAAm, the water molecules are expulsed and the hydrogel layer contracts, leaving the RaR molecules more accessible to the Raman source. In vitro studies with fibroblast cells reveal that the functionalized surgical mesh is biocompatible and no toxic substances are leached in the medium. The mesh sensor opens new frontiers to semi-invasive diagnosis and infection prevention in hernia repair by using SERS spectroscopy. It also offers new possibilities to the functionalization of other healthcare products.© 2023 Wiley-VCH GmbH.
JTD Keywords: adhesion, blends, chitosan, gold nanoparticles, poly(n-isopropylacrylamide), polypropylene mesh, polypropylene meshes, repair, scattering, silver, surgical implants, thermosensitive hydrogels, toxicity, Chitosan, Gold nanoparticles, Polypropylene meshes, Surgical implants, Thermosensitive hydrogels
Garcia-Torres, J, Colombi, S, Mahamed, I, Sylla, D, Arnau, M, Sans, J, Ginebra, MP, Aleman, C, (2023). Nanocomposite Hydrogels with Temperature Response for Capacitive Energy Storage Acs Applied Energy Materials 6, 4487-4495
Castrejón-Comas, Víctor, Alemán, Carlos, Pérez-Madrigal, Maria M., (2023). Multifunctional conductive hyaluronic acid hydrogels for wound care and skin regeneration Biomaterials Science 11, 2266-2276
Conductive and interactive hydrogels based on hyaluronic acid are engineered as wound dressings that enhance skin tissue regeneration either through electrical stimulation or by displaying multifunctional performance and, ultimately, interactivity.
JTD Keywords: antibacterial, fields, Injectable hydrogels
Pereira, I, Lopez-Martinez, MJ, Villasante, A, Introna, C, Tornero, D, Canals, JM, Samitier, J, (2023). Hyaluronic acid-based bioink improves the differentiation and network formation of neural progenitor cells Frontiers In Bioengineering And Biotechnology 11, 1110547
Introduction: Three-dimensional (3D) bioprinting is a promising technique for the development of neuronal in vitro models because it controls the deposition of materials and cells. Finding a biomaterial that supports neural differentiation in vitro while ensuring compatibility with the technique of 3D bioprinting of a self-standing construct is a challenge.Methods: In this study, gelatin methacryloyl (GelMA), methacrylated alginate (AlgMA), and hyaluronic acid (HA) were examined by exploiting their biocompatibility and tunable mechanical properties to resemble the extracellular matrix (ECM) and to create a suitable material for printing neural progenitor cells (NPCs), supporting their long-term differentiation. NPCs were printed and differentiated for up to 15 days, and cell viability and neuronal differentiation markers were assessed throughout the culture.Results and Discussion: This composite biomaterial presented the desired physical properties to mimic the ECM of the brain with high water intake, low stiffness, and slow degradation while allowing the printing of defined structures. The viability rates were maintained at approximately 80% at all time points. However, the levels of beta-III tubulin marker increased over time, demonstrating the compatibility of this biomaterial with neuronal cell culture and differentiation. Furthermore, these cells showed increased maturation with corresponding functional properties, which was also demonstrated by the formation of a neuronal network that was observed by recording spontaneous activity via Ca2+ imaging.
JTD Keywords: biomaterials, bioprinting, differentiation, in vitro models, neural progenitor cells, 2d, Biomaterials, Bioprinting, C17.2, Differentiation, Extracellular-matrix, Hydrogels, In vitro models, In-vitro, Neural progenitor cells, Neuronal models, Proliferation, Scaffolds, Stem-cells, Substrate stiffness
Borras, N, Sanchez-Sanz, A, Sans, J, Estrany, F, Perez-Madrigal, MM, Aleman, C, (2023). Flexible electroactive membranes for the electrochemical detection of dopamine European Polymer Journal 187, 111915
In addition of a key catecholamine neurotransmitter, dopamine is is the metabolite predominantly produced by specific types of tumors (e.g. paragangliomas and neuroblastomas), which cannot be diagnosed using conven-tional sensitive tests. Within this context, development of flexible electrochemical sensors to monitor dopamine levels in physiological fluids for the early diagnosis and control of diseases related to abnormal levels of such compound, is necessary. In this work, a flexible self-supported membrane, which acts directly as electrode, has been developed to detect dopamine. The membrane consists of three nanoperforated polylactic acid (PLA) layers, which provide flexibility and mechanical integrity, separated by two layers of an electroactive copolymer, which are obtained by electrochemical copolymerization of 3,4-ethylenedioxythiophene and aniline. The sensitivity and detection limit provided by the electroactive copolymer, which is accessible to dopamine molecules through the nanoperforations of the PLA outer layers, is 1.846 mu A/(cm2.mu M) and 1.7 mu M, respectively, in a urea-rich environments that mimics urine. These values allow us to propose the self-standing flexible electrodes devel-oped in this study for the detection of dopamine in patients affected by paragangliomas and neuroblastomas tumors, which typically present dopamine concentrations between 2 and 7 mu M.
JTD Keywords: 4-ethylenedioxythiophene), Conducting polymer, Electrochemical sensor, Electrodes, Hydrogels, Poly(3, Polyaniline, Polylactic acid, Selective detection, Sensors, Supercapacitors
Lanzalaco, Sonia, Mingot, Júlia, Torras, Juan, Alemán, Carlos, Armelin, Elaine, (2023). Recent Advances in Poly(N-isopropylacrylamide) Hydrogels and Derivatives as Promising Materials for Biomedical and Engineering Emerging Applications Advanced Engineering Materials 25, 2201303
JTD Keywords: capacitive deionization, chitosan-based hydrogels, composite, desalination, n-isopropylacrylamide, poly(n-isopropylacrylamide), polymers, swelling behavior, thermosensitive hydrogels, walled carbon nanotubes, water cleaning, water evaporation, Biomedical sensors, Critical solution temperature
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
Jurado A, Ulldemolins A, Lluís H, Gasull X, Gavara N, Sunyer R, Otero J, Gozal D, Almendros I, Farré R, (2023). Fast cycling of intermittent hypoxia in a physiomimetic 3D environment: A novel tool for the study of the parenchymal effects of sleep apnea Frontiers In Pharmacology 13, 1081345
Background: Patients with obstructive sleep apnea (OSA) experience recurrent hypoxemic events with a frequency sometimes exceeding 60 events/h. These episodic events induce downstream transient hypoxia in the parenchymal tissue of all organs, thereby eliciting the pathological consequences of OSA. Whereas experimental models currently apply intermittent hypoxia to cells conventionally cultured in 2D plates, there is no well-characterized setting that will subject cells to well-controlled intermittent hypoxia in a 3D environment and enable the study of the effects of OSA on the cells of interest while preserving the underlying tissue environment.Aim: To design and characterize an experimental approach that exposes cells to high-frequency intermittent hypoxia mimicking OSA in 3D (hydrogels or tissue slices).Methods: Hydrogels made from lung extracellular matrix (L-ECM) or brain tissue slices (300-800-mu m thickness) were placed on a well whose bottom consisted of a permeable silicone membrane. The chamber beneath the membrane was subjected to a square wave of hypoxic/normoxic air. The oxygen concentration at different depths within the hydrogel/tissue slice was measured with an oxygen microsensor.Results: 3D-seeded cells could be subjected to well-controlled and realistic intermittent hypoxia patterns mimicking 60 apneas/h when cultured in L-ECM hydrogels & AP;500 mu m-thick or ex-vivo in brain slices 300-500 mu m-thick.Conclusion: This novel approach will facilitate the investigation of the effects of intermittent hypoxia simulating OSA in 3D-residing cells within the parenchyma of different tissues/organs.
JTD Keywords: 3d culture, cell culture, diffusion, disease model, hydrogels, hypoxia, model, oxygen diffusion, tissue slice, transport, 3d culture, Cell culture, Disease model, Hydrogels, Hypoxia, Obstructive sleep apnea, Oxygen, Oxygen diffusion, Tissue slice
Sole-Marti, X, Labay, C, Raymond, Y, Franch, J, Benitez, R, Ginebra, MP, Canal, C, (2023). Ceramic-hydrogel composite as carrier for cold-plasma reactive-species: Safety and osteogenic capacity in vivo Plasma Processes And Polymers 20, 2200155
Plasma-treated hydrogels have been put forward as a potential selective osteosarcoma therapy through the release of reactive species to the diseased site. To allow their translation to the clinics, it is crucial to show that the oxidative stress delivered by such hydrogels does not adversely affect healthy tissues. This is evaluated here by investigating the in vivo performance of a robocasted calcium phosphate cement infiltrated by a plasma-treated hydrogel. The plasma-treated composite implanted in a critical size bone defect of healthy rabbits revealed its safety, allowing equivalent bone ingrowth compared to the control scaffolds and to that of direct plasma treatment of the bone defect. This opens the door for using composite biomaterials containing plasma-generated reactive species in bone therapies.
JTD Keywords: Atmospheric plasma, Bone, Bone graft, Ceramic-hydrogel composite, Cold atmospheric plasma, Local therapy, Osteosarcoma, Plasma-treated polymer solutions, Substitutes, Survival
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
Munoz-Galan, H, Molina, BG, Bertran, O, Perez-Madrigal, MM, Aleman, C, (2022). Combining rapid and sustained insulin release from conducting hydrogels for glycemic control br European Polymer Journal 181, 111670
Innovative insulin delivery systems contemplate combining multi-pharmacokinetic profiles for glycemic control. Two device configurations have been designed for the controlled release of insulin using the same chemical compounds. The first insulin delivery system, which displays a rapid release response that, in addition, is enhanced on a short time scale by electrical stimulation, consists on an insulin layer sandwiched between a conducting poly(3,4-ethylenedioxythiophene) (PEDOT) film and a poly-gamma-glutamic acid (gamma-PGA) hydrogel. The second system is constituted by gamma-PGA hydrogel loaded with insulin and PEDOT nanoparticles by in situ gelation. In this case, the insulin release, which only starts after the degradation of the hydrogel over time (i.e. on a long time scale), is slow and sustained. The combination of an on-demand and fast release profile with a sustained and slow profile, which act on different time scales, would result in a very efficient regulation of diabetes therapy in comparison to current systems, allowing to control both fast and sustained glycemic events. Considering that the two systems developed in this work are based on the same chemical components, future work will be focused on the combination of the two kinetic profiles by re-engineering a unique insulin release device using gamma-PGA, PEDOT and insulin.
JTD Keywords: Conducting polymer, Constant, Diabetes, Diabetes-mellitus, Drug-delivery, Electrodes, Electrostimulation, Glucose-responsive hydrogels, Hydrogel, Molecular dynamics, Molecular-dynamics, Nanogels, Nanoparticles, Poly(3,4-ethylenedioxythiophene), Risk
Ulldemolins A, Jurado A, Herranz-Diez C, Gavara N, Otero J, Farré R, Almendros I, (2022). Lung Extracellular Matrix Hydrogels-Derived Vesicles Contribute to Epithelial Lung Repair Polymers 14, 4907
The use of physiomimetic decellularized extracellular matrix-derived hydrogels is attracting interest since they can modulate the therapeutic capacity of numerous cell types, including mesenchymal stromal cells (MSCs). Remarkably, extracellular vesicles (EVs) derived from MSCs display similar functions as their parental cells, mitigating tissue damage in lung diseases. However, recent data have shown that ECM-derived hydrogels could release other resident vesicles similar to EVs. Here, we aim to better understand the contribution of EVs and ECM-vesicles released from MSCs and/or lung-derived hydrogel (L-HG) in lung repair by using an in vitro lung injury model. L-HG derived-vesicles and MSCs EVs cultured either in L-HG or conventional plates were isolated and characterized. The therapeutic capacity of vesicles obtained from each experimental condition was tested by using an alveolar epithelial wound-healing assay. The number of ECM-vesicles released from acellular L-HG was 10-fold greater than EVs from conventional MSCs cell culture revealing that L-HG is an important source of bioactive vesicles. MSCs-derived EVs and L-HG vesicles have similar therapeutic capacity in lung repair. However, when wound closure rate was normalized by total proteins, the MSCs-derived EVs shows higher therapeutic potential to those released by L-HG. The EVs released from L-HG must be considered when HG is used as substrate for cell culture and EVs isolation.
JTD Keywords: cell, extracellular vesicles, hydrogel, lung epithelial cells, lung repair, mesenchymal stem cells, Extracellular matrix, Extracellular vesicles, Hydrogel, Lung epithelial cells, Lung repair, Mesenchymal stem cells, Respiratory-distress-syndrome
Andrade, F, Roca-Melendres, MM, Llaguno, M, Hide, D, Raurell, I, Martell, M, Vijayakumar, S, Oliva, M, Jr, SS, Duran-Lara, EF, Rafael, D, Abasolo, I, (2022). Smart and eco-friendly N-isopropylacrylamide and cellulose hydrogels as a safe dual-drug local cancer therapy approach Carbohydrate Polymers 295, 119859
Local cancer treatment by in situ injections of thermo-responsive hydrogels (HG) offers several advantages over conventional systemic anti-cancer treatments. In this work, a biodegradable and multicompartmental HG composed of N-isopropylacrylamide, cellulose, citric acid, and ceric ammonium nitrate was developed for the controlled release of hydrophilic (doxorubicin) and hydrophobic (niclosamide) drugs. The formulation presented ideal properties regarding thermo-responsiveness, rheological behavior, drug release profile, biocompatibility, and biological activity in colon and ovarian cancer cells. Cellulose was found to retard drugs release rate, being only 4 % of doxorubicin and 30 % of niclosamide released after 1 week. This low release was sufficient to cause cell death in both cell lines. Moreover, HG demonstrated a proper injectability, in situ prevalence, and safety profile in vivo. Overall, the HG properties, together with its natural and eco-friendly composition, create a safe and efficient platform for the local treatment of non-resectable tumors or tumors requiring pre-surgical adjuvant therapy.
JTD Keywords: biodegradable, cellulose, controlled-release formulation, drug delivery systems, hydrogel, thermo-responsiveness, Ammonium-nitrate, Biodegradable, Cancer treatment, Cellulose, Controlled-release formulation, Delivery, Drug delivery systems, Hydrogel, Reduce, Thermo-responsiveness
Altay G, Abad-Lázaro A, Gualda EJ, Folch J, Insa C, Tosi S, Hernando-Momblona X, Batlle E, Loza-Álvarez P, Fernández-Majada V, Martinez E, (2022). Modeling Biochemical Gradients In Vitro to Control Cell Compartmentalization in a Microengineered 3D Model of the Intestinal Epithelium Advanced Healthcare Materials 11, 2201172
Gradients of signaling pathways within the intestinal stem cell (ISC) niche are instrumental for cellular compartmentalization and tissue function, yet how are they sensed by the epithelium is still not fully understood. Here a new in vitro model of the small intestine based on primary epithelial cells (i), apically accessible (ii), with native tissue mechanical properties and controlled mesh size (iii), 3D villus-like architecture (iv), and precisely controlled biomolecular gradients of the ISC niche (v) is presented. Biochemical gradients are formed through hydrogel-based scaffolds by free diffusion from a source to a sink chamber. To confirm the establishment of spatiotemporally controlled gradients, light-sheet fluorescence microscopy and in-silico modeling are employed. The ISC niche biochemical gradients coming from the stroma and applied along the villus axis lead to the in vivo-like compartmentalization of the proliferative and differentiated cells, while changing the composition and concentration of the biochemical factors affects the cellular organization along the villus axis. This novel 3D in vitro intestinal model derived from organoids recapitulates both the villus-like architecture and the gradients of ISC biochemical factors, thus opening the possibility to study in vitro the nature of such gradients and the resulting cellular response.© 2022 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.
JTD Keywords: 3d architectures, biomolecular gradients, colon, crypt, engineering organoids, hydrogels, identification, in silico modeling, intestinal stem cell niches, light sheet fluorescence microscopy, niche, permeability, photolithography, regeneration, villus, wnt, 3d architectures, Biomolecular gradients, Engineering organoids, In silico modeling, Intestinal stem cell niches, Light sheet fluorescence microscopy, Photolithography, Stem-cell
García-Torres J, Colombi S, Macor LP, Alemán C, (2022). Multitasking smart hydrogels based on the combination of alginate and poly(3,4-ethylenedioxythiophene) properties: A review International Journal Of Biological Macromolecules 219, 312-332
Poly(3,4-ethylenedioxythiophene) (PEDOT), a very stable and biocompatible conducting polymer, and alginate (Alg), a natural water-soluble polysaccharide mainly found in the cell wall of various species of brown algae, exhibit very different but at the same complementary properties. In the last few years, the remarkable capacity of Alg to form hydrogels and the electro-responsive properties of PEDOT have been combined to form not only layered composites (PEDOT-Alg) but also interpenetrated multi-responsive PEDOT/Alg hydrogels. These materials have been found to display outstanding properties, such as electrical conductivity, piezoelectricity, biocompatibility, self-healing and re-usability properties, pH and thermoelectric responsiveness, among others. Consequently, a wide number of applications are being proposed for PEDOT-Alg composites and, especially, PEDOT/Alg hydrogels, which should be considered as a new kind of hybrid material because of the very different chemical nature of the two polymeric components. This review summarizes the applications of PEDOT-Alg and PEDOT/Alg in tissue interfaces and regeneration, drug delivery, sensors, microfluidics, energy storage and evaporators for desalination. Special attention has been given to the discussion of multi-tasking applications, while the new challenges to be tackled based on aspects not yet considered in either of the two polymers have also been highlighted.Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.
JTD Keywords: aerogels, composite, conducting polymer, conducting polymers, electrodes, pedotpss, ph, platform, release, scaffold, semi-interpenetrated hydrogels, Alginic acid, Conducting polymer, Drug-delivery, Semi-interpenetrated hydrogels
Romero, D, Calvo, M, Le Rolle, V, Behar, N, Mabo, P, Hernandez, A, (2022). Multivariate ensemble classification for the prediction of symptoms in patients with Brugada syndrome Medical & Biological Engineering & Computing 60, 81-94
Identification of asymptomatic patients at higher risk for suffering cardiac events remains controversial and challenging in Brugada syndrome (BS). In this work, we proposed an ECG-based classifier to predict BS-related symptoms, by merging the most predictive electrophysiological features derived from the ventricular depolarization and repolarization periods, along with autonomic-related markers. The initial feature space included local and dynamic ECG markers, assessed during a physical exercise test performed in 110 BS patients (25 symptomatic). Morphological, temporal and spatial properties quantifying the ECG dynamic response to exercise and recovery were considered. Our model was obtained by proposing a two-stage feature selection process that combined a resampled-based regularization approach with a wrapper model assessment for balancing, simplicity and performance. For the classification step, an ensemble was constructed by several logistic regression base classifiers, whose outputs were fused using a performance-based weighted average. The most relevant predictors corresponded to the repolarization interval, followed by two autonomic markers and two other makers of depolarization dynamics. Our classifier allowed for the identification of novel symptom-related markers from autonomic and dynamic ECG responses during exercise testing, suggesting the need for multifactorial risk stratification approaches in order to predict future cardiac events in asymptomatic BS patients.
JTD Keywords: brugada syndrome, depolarization disorders, ensemble classifier, heart-rate recovery, Acute myocardial-ischemia, Autonomics, Brugada syndrome, Brugadum syndrome, Cardiac death, Depolarization, Depolarization disorder, Depolarization disorders, Dynamic ecg, Electrocardiography, Electrophysiology, Ensemble classifier, Ensemble-classifier, Events, Exercise, Forecasting, Heart, Heart-rate, Heart-rate recovery, Prognosis, Qrs, Quantification, Recovery, Repolarization, Sudden cardiac death
Mughal, S, Lopez-Munoz, GA, Fernandez-Costa, JM, Cortes-Resendiz, A, De Chiara, F, Ramon-Azcon, J, (2022). Organs-on-Chips: Trends and Challenges in Advanced Systems Integration Advanced Materials Interfaces 9, 2201618
Organ-on-chip platforms combined with high-throughput sensing technology allow bridging gaps in information presented by 2D cultures modeled on static microphysiological systems. While these platforms do not aim to replicate whole organ systems with all physiological nuances, they try to mimic relevant structural, physiological, and functional features of organoids and tissues to best model disease and/or healthy states. The advent of this platform has not only challenged animal testing but has also presented the opportunity to acquire real-time, high-throughput data about the pathophysiology of disease progression by employing biosensors. Biosensors allow monitoring of the release of relevant biomarkers and metabolites as a result of physicochemical stress. It, therefore, helps conduct quick lead validation to achieve personalized medicine objectives. The organ-on-chip industry is currently embarking on an exponential growth trajectory. Multiple pharmaceutical and biotechnology companies are adopting this technology to enable quick patient-specific data acquisition at substantially low costs.
JTD Keywords: A-chip, Biosensor, Biosensors, Cancer, Cells, Culture, Disease models, Epithelial electrical-resistance, Hydrogel, Microfabrication, Microphysiological systems, Models, Niches, Organ-on-a-chips, Platform
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
García-Díaz, María, Cendra, Maria del Mar, Alonso-Roman, Raquel, Urdániz, María, Torrents, Eduard, Martínez, Elena, (2022). Mimicking the Intestinal Host–Pathogen Interactions in a 3D In Vitro Model: The Role of the Mucus Layer Pharmaceutics 14, 1552
The intestinal mucus lines the luminal surface of the intestinal epithelium. This mucus is a dynamic semipermeable barrier and one of the first-line defense mechanisms against the outside environment, protecting the body against chemical, mechanical, or biological external insults. At the same time, the intestinal mucus accommodates the resident microbiota, providing nutrients and attachment sites, and therefore playing an essential role in the host–pathogen interactions and gut homeostasis. Underneath this mucus layer, the intestinal epithelium is organized into finger-like protrusions called villi and invaginations called crypts. This characteristic 3D architecture is known to influence the epithelial cell differentiation and function. However, when modelling in vitro the intestinal host–pathogen interactions, these two essential features, the intestinal mucus and the 3D topography are often not represented, thus limiting the relevance of the models. Here we present an in vitro model that mimics the small intestinal mucosa and its interactions with intestinal pathogens in a relevant manner, containing the secreted mucus layer and the epithelial barrier in a 3D villus-like hydrogel scaffold. This 3D architecture significantly enhanced the secretion of mucus. In infection with the pathogenic adherent invasive E. coli strain LF82, characteristic of Crohn’s disease, we observed that this secreted mucus promoted the adhesion of the pathogen and at the same time had a protective effect upon its invasion. This pathogenic strain was able to survive inside the epithelial cells and trigger an inflammatory response that was milder when a thick mucus layer was present. Thus, we demonstrated that our model faithfully mimics the key features of the intestinal mucosa necessary to study the interactions with intestinal pathogens.
JTD Keywords: 3d in vitro models, barrier function, bile-salts, cells, drug-delivery, host-pathogen interaction, host–pathogen interaction, hydrogels, ileal mucosa, infection, intestinal models, intestinal mucus, microbiome, patient, responses, 3d in vitro models, Intestinal mucus, Invasive escherichia-coli
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
Chulia-Peris, L, Carreres-Rey, C, Gabasa, M, Alcaraz, J, Carretero, J, Pereda, J, (2022). Matrix Metalloproteinases and Their Inhibitors in Pulmonary Fibrosis: EMMPRIN/CD147 Comes into Play International Journal Of Molecular Sciences 23, 6894
Pulmonary fibrosis (PF) is characterized by aberrant extracellular matrix (ECM) deposition, activation of fibroblasts to myofibroblasts and parenchymal disorganization, which have an impact on the biomechanical traits of the lung. In this context, the balance between matrix metalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs) is lost. Interestingly, several MMPs are overexpressed during PF and exhibit a clear profibrotic role (MMP-2, -3, -8, -11, -12 and -28), but a few are antifibrotic (MMP-19), have both profibrotic and antifibrotic capacity (MMP7), or execute an unclear (MMP-1, -9, -10, -13, -14) or unknown function. TIMPs are also overexpressed in PF; hence, the modulation and function of MMPs and TIMP are more complex than expected. EMMPRIN/CD147 (also known as basigin) is a transmembrane glycoprotein from the immunoglobulin superfamily (IgSF) that was first described to induce MMP activity in fibroblasts. It also interacts with other molecules to execute non-related MMP aactions well-described in cancer progression, migration, and invasion. Emerging evidence strongly suggests that CD147 plays a key role in PF not only by MMP induction but also by stimulating fibroblast myofibroblast transition. In this review, we study the structure and function of MMPs, TIMPs and CD147 in PF and their complex crosstalk between them.
JTD Keywords: basigin, cd147, emmprin, mmps, timps, Basigin, Cd147, Cell-surface, Emmprin, Extracellular-matrix, Gelatinase-b, Gene-expression profiles, Growth-factor-beta, Immunoglobulin superfamily, Induced lung injury, Inducer emmprin, Mmps, Pulmonary fibrosis, Timps, Tissue inhibitor, Transforming growth-factor-beta-1
Kim, YH, Dawson, JI, Oreffo, ROC, Tabata, Y, Kumar, D, Aparicio, C, Mutreja, I, (2022). Gelatin Methacryloyl Hydrogels for Musculoskeletal Tissue Regeneration Bioengineering (Basel) 9, 332
Musculoskeletal disorders are a significant burden on the global economy and public health. Hydrogels have significant potential for enhancing the repair of damaged and injured musculoskeletal tissues as cell or drug delivery systems. Hydrogels have unique physicochemical properties which make them promising platforms for controlling cell functions. Gelatin methacryloyl (GelMA) hydrogel in particular has been extensively investigated as a promising biomaterial due to its tuneable and beneficial properties and has been widely used in different biomedical applications. In this review, a detailed overview of GelMA synthesis, hydrogel design and applications in regenerative medicine is provided. After summarising recent progress in hydrogels more broadly, we highlight recent advances of GelMA hydrogels in the emerging fields of musculoskeletal drug delivery, involving therapeutic drugs (e.g., growth factors, antimicrobial molecules, immunomodulatory drugs and cells), delivery approaches (e.g., single-, dual-release system), and material design (e.g., addition of organic or inorganic materials, 3D printing). The review concludes with future perspectives and associated challenges for developing local drug delivery for musculoskeletal applications.
JTD Keywords: drug delivery, gelatin, gelma, hydrogel, Drug delivery, Gelatin, Gelma, Hydrogel, Musculoskeletal tissue
Marhuenda, Esther, Villarino, Alvaro, Narciso, Maria Leonor, Camprubí-Rimblas, Marta, Farré, Ramon, Gavara, Núria, Artigas, Antonio, Almendros, Isaac, Otero, Jorge, (2022). Lung Extracellular Matrix Hydrogels Enhance Preservation of Type II Phenotype in Primary Alveolar Epithelial Cells International Journal Of Molecular Sciences 23, 4888
One of the main limitations of in vitro studies on lung diseases is the difficulty of maintaining the type II phenotype of alveolar epithelial cells in culture. This fact has previously been related to the translocation of the mechanosensing Yes-associated protein (YAP) to the nuclei and Rho signaling pathway. In this work, we aimed to culture and subculture primary alveolar type II cells on extracellular matrix lung-derived hydrogels to assess their suitability for phenotype maintenance. Cells cultured on lung hydrogels formed monolayers and maintained type II phenotype for a longer time as compared with those conventionally cultured. Interestingly, cells successfully grew when they were subsequently cultured on a dish. Moreover, cells cultured on a plate showed the active form of the YAP protein and the formation of stress fibers and focal adhesions. The results of chemically inhibiting the Rho pathway strongly suggest that this is one of the mechanisms by which the hydrogel promotes type II phenotype maintenance. These results regarding protein expression strongly suggest that the chemical and biophysical properties of the hydrogel have a considerable impact on the transition from ATII to ATI phenotypes. In conclusion, culturing primary alveolar epithelial cells on lung ECM-derived hydrogels may facilitate the prolonged culturing of these cells, and thus help in the research on lung diseases.
JTD Keywords: adhesion, alveolar cells, expression, extracellular matrix, hydrogels, pathway, surfactant, type ii phenotype, yap, Extracellular matrix, Transplantation, Type ii phenotype
Otero, J, Falcones, B, Sanz, H, Marhuenda, E, Mendizabal, I, Cabrera, I, Almendros, I, Navajas, D, Farre, R, (2022). EXTRACELLULAR MATRIX HYDROGELS FOR 3D BIOPRINTING LUNG RESIDENT MESENCHYMAL STROMAL CELLS (Abstract 1412) Tissue Engineering Part a 28, S396
INTRODUCTION: One of the main hypotheses in mesenchymalstromal cells ( MSCs) research is that the microenvironment deter-mines the way that cells behave. Our aim is to investigate how bio-printing and 3D culturing lung resident MSCs in porcine lung-derived extracellular matrix (ECM) hydrogels produce changes incell behavior. METHODS: Rat primary lung resident MSCs werebioprinted and 3D cultured in porcine lung ECM hydrogels pre-senting a stiffness of 0.7kPa. After seven days of 3D culture, cellswere harvested from the scaffolds. Cell adhesion and actin/paxillinstaining tests were conducted with the harvested and control cells byseeding them onto specific well-plates for optical imaging and al-lowed to attach them to the plate for 2h. The expression of surfacechemokine receptor CXCR4 was quantified by qRT-PCR. RE-SULTS: Compared with cells cultured in standard tissue cultureplates, cells harvested from the lung ECM hydrogel scaffolds formedfocal adhesions 2-fold longer. Moreover, 10-fold more cells wereadhered to the substrate after 2h. Finally, the expression of CXCR4chemokine receptor showed a more than 20-fold increase in thepreconditioned cells. DISCUSSION: The data indicate that culturinglung MSCs in the ECM has major impact in their adhesion capacityand in the expression of one the main receptors involved in severalrelevant processes in vivo. Thus, lung ECM-derived hydrogels havethe potential to be used as a scaffold to develop novel in vitro modelsto better understand mechanisms in MSCs.
JTD Keywords: Bioprinting, Hydrogel, Mesenchymal stromal cells
Blanco-Fernandez, B, Ibanez-Fonseca, A, Orbanic, D, Perez-Amodio, S, Rodriguez-Cabello, JC, Engel, E, (2022). RECREATING THE BREAST CANCER MICROENVIROMENT USING ELASTIN-LIKE RECOMBINAMER HYDROGELS (Abstract 1118) Tissue Engineering Part a 28, S313-S314
Rodriguez-Comas, J, Velasco-Mallorqui, F, Ramon-Azcon, J, (2022). CELLULOSE-BASED SCAFFOLDS ENHANCE PSEUDOISLETS FORMATION AND FUNCTIONALITY (Abstract 2021) Tissue Engineering Part a 28, S573
The limitations of obtaining pancreatic islets from differentsources as animal models or human donors complicate the study oftype 2 diabetes (T2D) in vitro. Immortalized cell lines as the in-sulin-producing INS1Eb-cells appeared as a valid alternative tomodel insulin-related diseases. The formation of 3D structures topromote cell aggregations from single cells is a handy tool togenerate resemblance islet-like pseudoislets. Traditionally usedhydrogel encapsulation methods induce a lack of nutrient and ox-ygen diffusion for pancreatic tissue engineering. Here, we usecryogelation technology to develop a more resemblance scaffoldwith the mechanical and physical properties needed to engineerpancreatic tissue. This study shows that carboxymethyl cellulose(CMC) cryogels prompted cells to generateb-cell clusters. Thehigh porosity achieved with this approach allowed us to createspecific range pseudoislets. However, gelatin-based scaffolds didnot induce this cell organization. Pseudoislets formed within CMC-scaffolds showed cell viability for up to 7 days and responded betterto the glucose over conventional monolayer cultures. Overall, ourresults demonstrate that CMC-scaffolds can be used to control theorganization and function of insulin-producingb-cells, represent-ing a suitable technique to generateb-cell clusters to study pan-creatic islet function.
JTD Keywords: Cellulose, Cryogel, Diabetes
Bonilla-Pons SÀ, Nakagawa S, Bahima EG, Fernández-Blanco Á, Pesaresi M, D'Antin JC, Sebastian-Perez R, Greco D, Domínguez-Sala E, Gómez-Riera R, Compte RIB, Dierssen M, Pulido NM, Cosma MP, (2022). Müller glia fused with adult stem cells undergo neural differentiation in human retinal models Ebiomedicine 77, 103914
Visual impairments are a critical medical hurdle to be addressed in modern society. Müller glia (MG) have regenerative potential in the retina in lower vertebrates, but not in mammals. However, in mice, in vivo cell fusion between MG and adult stem cells forms hybrids that can partially regenerate ablated neurons.We used organotypic cultures of human retina and preparations of dissociated cells to test the hypothesis that cell fusion between human MG and adult stem cells can induce neuronal regeneration in human systems. Moreover, we established a microinjection system for transplanting human retinal organoids to demonstrate hybrid differentiation.We first found that cell fusion occurs between MG and adult stem cells, in organotypic cultures of human retina as well as in cell cultures. Next, we showed that the resulting hybrids can differentiate and acquire a proto-neural electrophysiology profile when the Wnt/beta-catenin pathway is activated in the adult stem cells prior fusion. Finally, we demonstrated the engraftment and differentiation of these hybrids into human retinal organoids.We show fusion between human MG and adult stem cells, and demonstrate that the resulting hybrid cells can differentiate towards neural fate in human model systems. Our results suggest that cell fusion-mediated therapy is a potential regenerative approach for treating human retinal dystrophies.This work was supported by La Caixa Health (HR17-00231), Velux Stiftung (976a) and the Ministerio de Ciencia e Innovación, (BFU2017-86760-P) (AEI/FEDER, UE), AGAUR (2017 SGR 689, 2017 SGR 926).Published by Elsevier B.V.
JTD Keywords: cell fusion, expression, fusion, ganglion-cells, in-vitro, mouse, müller glia, neural differentiation, organoids, regeneration, retina regeneration, stem cells, stromal cells, transplantation, 4',6 diamidino 2 phenylindole, 5' nucleotidase, Agarose, Alcohol, Arpe-19 cell line, Article, Beta catenin, Beta tubulin, Bone-marrow-cells, Bromophenol blue, Buffer, Calcium cell level, Calcium phosphate, Calretinin, Canonical wnt signaling, Cd34 antigen, Cell culture, Cell fusion, Cell viability, Coculture, Complementary dna, Confocal microscopy, Cornea transplantation, Cryopreservation, Cryoprotection, Crystal structure, Current clamp technique, Dimethyl sulfoxide, Dodecyl sulfate sodium, Edetic acid, Electrophysiology, Endoglin, Fetal bovine serum, Fibroblast growth factor 2, Flow cytometry, Fluorescence activated cell sorting, Fluorescence intensity, Glyceraldehyde 3 phosphate dehydrogenase, Glycerol, Glycine, Hoe 33342, Immunofluorescence, Immunohistochemistry, Incubation time, Interleukin 1beta, Lentivirus vector, Matrigel, Mercaptoethanol, Microinjection, Mueller cell, Müller glia, N methyl dextro aspartic acid, Nerve cell differentiation, Neural differentiation, Nitrogen, Nonhuman, Organoids, Paraffin, Paraffin embedding, Paraformaldehyde, Patch clamp technique, Penicillin derivative, Phenolsulfonphthalein, Phenotype, Phosphate buffered saline, Phosphoprotein phosphatase inhibitor, Polyacrylamide gel electrophoresis, Potassium chloride, Povidone iodine, Promoter region, Proteinase inhibitor, Real time polymerase chain reaction, Receptor type tyrosine protein phosphatase c, Restriction endonuclease, Retina, Retina dystrophy, Retina regeneration, Retinol, Rhodopsin, Rna extraction, Stem cell, Stem cells, Subcutaneous fat, Tunel assay, Visual impairment, Western blotting
Dias JMS, Estima D, Punte H, Klingner A, Marques L, Magdanz V, Khalil ISM, (2022). Modeling and Characterization of the Passive Bending Stiffness of Nanoparticle-Coated Sperm Cells using Magnetic Excitation Advanced Theory And Simulations 5,
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
Georgiev VN, Avalos-Padilla Y, Fernàndez-Busquets X, Dimova R, (2022). Femtoliter Injection of ESCRT-III Proteins into Adhered Giant Unilamellar Vesicles Bio Protoc 12, e4328
The endosomal sorting complex required for transport (ESCRT) machinery mediates membrane fission reactions that exhibit a different topology from that observed in clathrin-coated vesicles. In all of the ESCRT-mediated events, the nascent vesicle buds away from the cytosol. However, ESCRT proteins are able to act upon membranes with different geometries. For instance, the formation of multivesicular bodies (MVBs) and the biogenesis of extracellular vesicles both require the participation of the ESCRT-III sub-complex, and they differ in their initial membrane geometry before budding starts: the protein complex acts either from outside the membrane organelle (causing inward budding) or from within (causing outward budding). Several studies have reconstituted the action of the ESCRT-III subunits in supported bilayers and cell-sized vesicles mimicking the geometry occurring during MVBs formation (in-bud), but extracellular vesicle budding (out-bud) mechanisms remain less explored, because of the outstanding difficulties encountered in encapsulation of functional ESCRT-III in vesicles. Here, we provide a different approach that allows the recreation of the out-bud formation, by combining giant unilamellar vesicles as a membrane model and a microinjection system. The vesicles are immobilized prior to injection via weak adhesion to the chamber coverslip, which also ensures preserving the membrane excess area required for budding. After protein injection, vesicles exhibit outward budding. The approach presented in this work can be used in the future to disentangle the mechanisms underlying ESCRT-III-mediated fission, recreating the geometry of extracellular bud production, which remains a challenge. Moreover, the microinjection methodology can be also adapted to interrogate the action of other cytosolic components on the encapsulating membranous organelle. Copyright: © 2022 The Authors.
JTD Keywords: adhesion, budding, electroformation, escrt-iii, exosomes, extracellular vesicles, giant unilamellar vesicle (guv), light, microinjection, microparticles, plasma, Adhesion, Budding, Escrt-iii, Extracellular vesicles, Giant unilamellar vesicle (guv), Membrane, Microinjection
Jain, A, Calo, A, Barcelo, D, Kumar, M, (2022). Supramolecular systems chemistry through advanced analytical techniques Analytical And Bioanalytical Chemistry 414, 5105-5119
Supramolecular chemistry is the quintessential backbone of all biological processes. It encompasses a wide range from the metabolic network to the self-assembled cytoskeletal network. Combining the chemical diversity with the plethora of functional depth that biological systems possess is a daunting task for synthetic chemists to emulate. The only route for approaching such a challenge lies in understanding the complex and dynamic systems through advanced analytical techniques. The supramolecular complexity that can be successfully generated and analyzed is directly dependent on the analytical treatment of the system parameters. In this review, we illustrate advanced analytical techniques that have been used to investigate various supramolecular systems including complex mixtures, dynamic self-assembly, and functional nanomaterials. The underlying theme of such an overview is not only the exceeding detail with which traditional experiments can be probed but also the fact that complex experiments can now be attempted owing to the analytical techniques that can resolve an ensemble in astounding detail. Furthermore, the review critically analyzes the current state of the art analytical techniques and suggests the direction of future development. Finally, we envision that integrating multiple analytical methods into a common platform will open completely new possibilities for developing functional chemical systems.
JTD Keywords: analytical techniques, dynamic self-assembly, high-speed afm, liquid cell tem, Analytical technique, Analytical techniques, Biological process, Chemical analysis, Chemical diversity, Complex networks, Cytoskeletal network, Dynamic self-assembly, High-speed afm, Hydrogels, In-situ, Liquid cell tem, Metabolic network, Microscopy, Nanoscale, Proteins, Self assembly, Supramolecular chemistry, Supramolecular systems, System chemistry, Systems chemistry
Tejo-Otero A, Fenollosa-Artés F, Achaerandio I, Rey-Vinolas S, Buj-Corral I, Mateos-Timoneda MÁ, Engel E, (2022). Soft-Tissue-Mimicking Using Hydrogels for the Development of Phantoms Gels 8,
With the currently available materials and technologies it is difficult to mimic the mechanical properties of soft living tissues. Additionally, another significant problem is the lack of information about the mechanical properties of these tissues. Alternatively, the use of phantoms offers a promising solution to simulate biological bodies. For this reason, to advance in the state-of-the-art a wide range of organs (e.g., liver, heart, kidney as well as brain) and hydrogels (e.g., agarose, polyvinyl alcohol –PVA–, Phytagel –PHY– and methacrylate gelatine –GelMA–) were tested regarding their mechanical properties. For that, viscoelastic behavior, hardness, as well as a non-linear elastic mechanical response were measured. It was seen that there was a significant difference among the results for the different mentioned soft tissues. Some of them appear to be more elastic than viscous as well as being softer or harder. With all this information in mind, a correlation between the mechanical properties of the organs and the different materials was performed. The next conclusions were drawn: (1) to mimic the liver, the best material is 1% wt agarose; (2) to mimic the heart, the best material is 2% wt agarose; (3) to mimic the kidney, the best material is 4% wt GelMA; and (4) to mimic the brain, the best materials are 4% wt GelMA and 1% wt agarose. Neither PVA nor PHY was selected to mimic any of the studied tissues. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
JTD Keywords: brain, composite hydrogel, dynamic mechanical analysis, elastography, hardness, hydrogels, in-vitro, liver, materials, mechanical-properties, mimicking, soft tissues, tissue scaffolding, viscoelasticity, warner-braztler shear test, warner–braztler shear test, Dynamic mechanical analysis, Hardness, Hydrogels, Materials, Mimicking, Soft tissues, Tissue scaffolding, Viscoelastic characterization, Viscoelasticity, Warner–braztler shear test
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
Perez-Madrigal, MM, Gilb, AM, Casanovas, J, Jimenez, AI, Macor, LP, Aleman, C, (2022). Self-assembly pathways in a triphenylalanine peptide capped with aromatic groups Colloids And Surfaces B-Biointerfaces 216, 112522
Peptide derivatives and, most specifically, their self-assembled supramolecular structures are being considered in the design of novel biofunctional materials. Although the self-assembly of triphenylalanine homopeptides has been found to be more versatile than that of homopeptides containing an even number of residues (i.e. diphe-nylalanine and tetraphenylalanine), only uncapped triphenylalanine (FFF) and a highly aromatic analog blocked at both the N-and C-termini with fluorenyl-containing groups (Fmoc-FFF-OFm), have been deeply studied before. In this work, we have examined the self-assembly of a triphenylalanine derivative bearing 9-fluorenylme-thyloxycarbonyl and benzyl ester end-capping groups at the N-and C-termini, respectively (Fmoc-FFF-OBzl). The antiparallel arrangement clearly dominates in beta-sheets formed by Fmoc-FFF-OBzl, whereas the parallel and antiparallel dispositions are almost isoenergetic in Fmoc-FFF-OFm beta-sheets and the parallel one is slightly favored for FFF. The effects of both the peptide concentration and the mediu m on the self-assembly process have been examined considering Fmoc-FFF-OBzl solutions in a wide variety of solvent:co-solvent mixtures. In addi-tion, Fmoc-FFF-OBzl supramolecular structures have been compared to those obtained for FFF and Fmoc-FFF-OFm under identical experimental conditions. The strength of pi-pi stacking interactions involving the end-capping groups plays a crucial role in the nucleation and growth of supramolecular structures, which de-termines the resulting morphology. Finally, the influence of a non-invasive external stimulus, ultrasounds, on the nucleation and growth of supramolecular structures has been examined. Overall, FFF-based peptides provide a wide range of supramolecular structures that can be of interest in the biotechnological field.
JTD Keywords: aromatic interactions, beta-sheet, hierarchical structures, phenylalanine homopeptides, supramolecular structures, Amino-acids, Aromatic interactions, Beta-sheet, Fmoc, Hierarchical struc tures, Hydrogels, Phenylalanine homopeptides, Solvent, Spectroscopy, Supramolecular structures, Triphenylalanine
Sole-Marti, X, Vilella, T, Labay, C, Tampieri, F, Ginebra, MP, Canal, C, (2022). Thermosensitive hydrogels to deliver reactive species generated by cold atmospheric plasma: a case study with methylcellulose Biomaterials Science 10, 3845-3855
Hydrogels have been recently proposed as suitable materials to generate reactive oxygen and nitrogen species (RONS) upon gas-plasma treatment, and postulated as promising alternatives to conventional cancer therapies. Acting as delivery vehicles that allow a controlled release of RONS to the diseased site, plasma-treated hydrogels can overcome some of the limitations presented by plasma-treated liquids in in vivo therapies. In this work, we optimized the composition of a methylcellulose (MC) hydrogel to confer it with the ability to form a gel at physiological temperatures while remaining in the liquid phase at room temperature to allow gas-plasma treatment with suitable formation of plasma-generated RONS. MC hydrogels demonstrated the capacity for generation, prolonged storage and release of RONS. This release induced cytotoxic effects on the osteosarcoma cancer cell line MG-63, reducing its cell viability in a dose-response manner. These promising results postulate plasma-treated thermosensitive hydrogels as good candidates to provide local anticancer therapies.
JTD Keywords: Cellulose, Phase-separation, Stability, Substituent, Thermoreversible gelation
Sans, J, Arnau, M, Roa, JJ, Turon, P, Alernan, C, (2022). Tailorable Nanoporous Hydroxyapatite Scaffolds for Electrothermal Catalysis Acs Applied Nano Materials 5, 8526-8536
Polarized hydroxyapatite (HAp) scaffolds with customized architecture at the nanoscale have been presented as a green alternative to conventional catalysts used for carbon and dinitrogen fixation. HAp printable inks with controlled nanoporosity and rheological properties have been successfully achieved by incorporating Pluronic hydrogel. Nanoporous scaffolds with good mechanical properties, as demonstrated by means of the nanoindentation technique, have been obtained by a sintering treatment and the posterior thermally induced polarization process. Their catalytic activity has been evaluated by considering three different key reactions (all in the presence of liquid water): (1) the synthesis of amino acids from gas mixtures of N-2, CO2, and CH4; (2) the production of ethanol from gas mixtures of CO2 and CH4; and (3) the synthesis of ammonia from N-2 gas. Comparison of the yields obtained by using nanoporous and nonporous (conventional) polarized HAp catalysts shows that both the nanoporosity and water absorption capacity of the former represent a drawback when the catalytic reaction requires auxiliary coating layers, as for example for the production of amino acids. This is because the surface nanopores achieved by incorporating Pluronic hydrogel are completely hindered by such auxiliary coating layers. On the contrary, the catalytic activity improves drastically for reactions in which the HAp-based scaffolds with enhanced nanoporosity are used as catalysts. More specifically, the carbon fixation from CO2 and CH4 to yield ethanol improves by more than 3000% when compared with nonporous HAp catalyst. Similarly, the synthesis of ammonia by dinitrogen fixation increases by more than 2000%. Therefore, HAp catalysts based on nanoporous scaffolds exhibit an extraordinary potential for scalability and industrial utilization for many chemical reactions, enabling a feasible green chemistry alternative to catalysts based on heavy metals.
JTD Keywords: Amino acids, Amino-acids, Ammonium production, Bone, Carbon fixation, Composites, Constitutive phases, Decarbonization, Dinitrogen, Ditrogen fixation, Elastic-modulus, Electrophotosynthesis, Ethanol production, Hardness, Indentation, Nanoindentation, Pluronic hydrogel, Polarized hydroxyapatite
Blanco-Fernandez, B, Rey-Vinolas, S, Bagci, G, Rubi-Sans, G, Otero, J, Navajas, D, Perez-Amodio, S, Engel, E, (2022). Bioprinting Decellularized Breast Tissue for the Development of Three-Dimensional Breast Cancer Models Acs Applied Materials & Interfaces 14, 29467-29482
The tumor extracellular matrix (ECM) plays a vital role in tumor progression and drug resistance. Previous studies have shown that breast tissue-derived matrices could be an important biomaterial to recreate the complexity of the tumor ECM. We have developed a method for decellularizing and delipidating a porcine breast tissue (TDM) compatible with hydrogel formation. The addition of gelatin methacrylamide and alginate allows this TDM to be bioprinted by itself with good printability, shape fidelity, and cytocompatibility. Furthermore, this bioink has been tuned to more closely recreate the breast tumor by incorporating collagen type I (Col1). Breast cancer cells (BCCs) proliferate in both TDM bioinks forming cell clusters and spheroids. The addition of Col1 improves the printability of the bioink as well as increases BCC proliferation and reduces doxorubicin sensitivity due to a downregulation of HSP90. TDM bioinks also allow a precise three-dimensional printing of scaffolds containing BCCs and stromal cells and could be used to fabricate artificial tumors. Taken together, we have proven that these novel bioinks are good candidates for biofabricating breast cancer models.
JTD Keywords: 3d in vitro cancer model, bioprinting, breast tissue, 3d in vitro cancer model, Bioink, Bioprinting, Breast tissue, Crosstalk, Decellularization, Extracellular-matrix, Growth, Hydrogels, In-vitro, Inhibition, Mechanical-properties, Metastasis, Proliferation
Marhuenda, E, Villarino, A, Narciso, M, Elowsson, L, Almendros, I, Westergren-Thorsson, G, Farre, R, Gavara, N, Otero, J, (2022). Development of a physiomimetic model of acute respiratory distress syndrome by using ECM hydrogels and organ-on-a-chip devices Frontiers In Pharmacology 13, 945134
Acute Respiratory Distress Syndrome is one of the more common fatal complications in COVID-19, characterized by a highly aberrant inflammatory response. Pre-clinical models to study the effect of cell therapy and anti-inflammatory treatments have not comprehensively reproduced the disease due to its high complexity. This work presents a novel physiomimetic in vitro model for Acute Respiratory Distress Syndrome using lung extracellular matrix-derived hydrogels and organ-on-a-chip devices. Monolayres of primary alveolar epithelial cells were cultured on top of decellullarized lung hydrogels containing primary lung mesenchymal stromal cells. Then, cyclic stretch was applied to mimic breathing, and an inflammatory response was induced by using a bacteriotoxin hit. Having simulated the inflamed breathing lung environment, we assessed the effect of an anti-inflammatory drug (i.e., dexamethasone) by studying the secretion of the most relevant inflammatory cytokines. To better identify key players in our model, the impact of the individual factors (cyclic stretch, decellularized lung hydrogel scaffold, and the presence of mesenchymal stromal cells) was studied separately. Results showed that developed model presented a more reduced inflammatory response than traditional models, which is in line with what is expected from the response commonly observed in patients. Further, from the individual analysis of the different stimuli, it was observed that the use of extracellular matrix hydrogels obtained from decellularized lungs had the most significant impact on the change of the inflammatory response. The developed model then opens the door for further in vitro studies with a better-adjusted response to the inflammatory hit and more robust results in the test of different drugs or cell therapy.
JTD Keywords: alveolar epithelial cells, ards, extracellular matrix, hydrogels, inflammation, lung-on-a-chip, Acute lung injury, Alveolar epithelial cells, Ards, Dexamethasone, Epithelial-mesenchymal transition, Extracellular matrix, Extracellular-matrix, Hydrogels, Inflammation, Lung-on-a-chip, Mesenchymal stromal cells, Oxygen, Stem-cells
Bonany, M, del-Mazo-Barbara, L, Espanol, M, Ginebra, MP, (2022). Microsphere incorporation as a strategy to tune the biological performance of bioinks Journal Of Tissue Engineering 13, 20417314221119895
Although alginate is widely used as a matrix in the formulation of cell-laden inks, this polymer often requires laborious processing strategies due to its lack of cell adhesion moieties. The main objective of the present work was to explore the incorporation of microspheres into alginate-based bioinks as a simple and tuneable way to solve the cell adhesion problems, while adding extra biological functionality and improving their mechanical properties. To this end, three types of microspheres with different mineral contents (i.e. gelatine with 0% of hydroxyapatite, gelatine with 25 wt% of hydroxyapatite nanoparticles and 100 wt% of calcium -deficient hydroxyapatite) were synthesised and incorporated into the formulation of cell-laden inks. The results showed that the addition of microspheres generally improved the rheological properties of the ink, favoured cell proliferation and positively affected osteogenic cell differentiation. Furthermore, this differentiation was found to be influenced by the type of microsphere and the ability of the cells to migrate towards them, which was highly dependent on the stiffness of the bioink. In this regard, Ca2+ supplementation in the cell culture medium had a pronounced effect on the relaxation of the stiffness of these cell-loaded inks, influencing the overall cell performance. In conclusion, we have developed a powerful and tuneable strategy for the fabrication of alginate-based bioinks with enhanced biological characteristics by incorporating microspheres into the initial ink formulation.; [GRAPHICS]; .
JTD Keywords: 3d bioprinting, alginate, bioink, gelatine, hydroxyapatite, 3d bioprinting, Alginate, Behavior, Bioink, Cell-culture, Gelatin, Gelatine, Hydrogels, Hydroxyapatite, Laden, Microspheres, Mineralization, Scaffolds
Duro-Castano, Aroa, Rodríguez-Arco, Laura, Ruiz-Pérez, Lorena, De Pace, Cesare, Marchello, Gabriele, Noble-Jesus, Carlos, Battaglia, Giuseppe, (2021). One-Pot Synthesis of Oxidation-Sensitive Supramolecular Gels and Vesicles Biomacromolecules 22, 5052-5064
Polypeptide-based nanoparticles offer unique advantages from a nanomedicine perspective such as biocompatibility, biodegradability, and stimuli-responsive properties to (patho)physiological conditions. Conventionally, self-assembled polypeptide nanostructures are prepared by first synthesizing their constituent amphiphilic polypeptides followed by postpolymerization self-assembly. Herein, we describe the one-pot synthesis of oxidation-sensitive supramolecular micelles and vesicles. This was achieved by polymerization-induced self-assembly (PISA) of the N-carboxyanhydride (NCA) precursor of methionine using poly(ethylene oxide) as a stabilizing and hydrophilic block in dimethyl sulfoxide (DMSO). By adjusting the hydrophobic block length and concentration, we obtained a range of morphologies from spherical to wormlike micelles, to vesicles. Remarkably, the secondary structure of polypeptides greatly influenced the final morphology of the assemblies. Surprisingly, wormlike micellar morphologies were obtained for a wide range of methionine block lengths and solid contents, with spherical micelles restricted to very short hydrophobic lengths. Wormlike micelles further assembled into oxidation-sensitive, self-standing gels in the reaction pot. Both vesicles and wormlike micelles obtained using this method demonstrated to degrade under controlled oxidant conditions, which would expand their biomedical applications such as in sustained drug release or as cellular scaffolds in tissue engineering.
JTD Keywords: alpha-amino-acid, hydrogels, leuchs anhydrides, platform, polypeptides, transformation, triggered cargo release, Amino acids, Amphiphilics, Biocompatibility, Biodegradability, Block lengths, Controlled drug delivery, Dimethyl sulfoxide, Ethylene, Gels, Hydrophobicity, Medical nanotechnology, Methionine, Micelles, Morphology, One-pot synthesis, Organic solvents, Oxidation, Physiological condition, Polyethylene oxides, Post-polymerization, Ring-opening polymerization, Scaffolds (biology), Self assembly, Stimuli-responsive properties, Supramolecular chemistry, Supramolecular gels, Supramolecular micelles, Wormlike micelle
del-Mazo-Barbara L, Ginebra MP, (2021). Rheological characterisation of ceramic inks for 3D direct ink writing: A review Journal Of The European Ceramic Society 41, 18-33
3D printing is a competitive manufacturing technology, which has opened up new possibilities for the fabrication of complex ceramic structures and customised parts. Extrusion-based technologies, also known as direct ink writing (DIW) or robocasting, are amongst the most used for ceramic materials. In them, the rheological properties of the ink play a crucial role, determining both the extrudability of the paste and the shape fidelity of the printed parts. However, comprehensive rheological studies of printable ceramic inks are scarce and may be difficult to understand for non-specialists. The aim of this review is to provide an overview of the main types of ceramic ink formulations developed for DIW and a detailed description of the more relevant rheological tests for assessing the printability of ceramic pastes. Moreover, the key rheological parameters are identified and linked to printability aspects, including the values reported in the literature for different ink compositions.
JTD Keywords: 3-dimensional structures, behavior, deposition, direct ink writing, freeform fabrication, gelation, glass scaffolds, mechanical-properties, printability, rheology, robocasting, suspensions, 3d printing, Direct ink writing, Phosphate scaffolds, Printability, Rheology, Robocasting
Chausse, Victor, Schieber, Romain, Raymond, Yago, Ségry, Brian, Sabaté, Ramon, Kolandaivelu, Kumaran, Ginebra, Maria-Pau, Pegueroles, Marta, (2021). Solvent-cast direct-writing as a fabrication strategy for radiopaque stents Additive Manufacturing 48,
JTD Keywords: biocompatibility, bioresorbable stents, degradation, mechanical-properties, poly(epsilon-caprolactone), poly-l-lactic acid, polylactide, radiopacity, thermogel, x-ray imaging, Barium sulfate, Biocompatibility, Bioresorbable, Bioresorbable scaffolds, Bioresorbable stent, Bioresorbable stents, Blood vessels, Computerized tomography, Controlled drug delivery, Coronary heart disease, Direct-writing, Endothelial cells, Fabrication strategies, Injection molding, Lactic acid, Poly-l-lactic acid, Poly-l-lactic acids, Radiopacity, Scaffolds (biology), Solvent cast, Solvent-cast direct-writing, Solvents, Stents, Struts, Sulfur compounds, Targeted drug delivery, X-ray imaging
Konka J, Buxadera-Palomero J, Espanol M, Ginebra M-P, (2021). 3D printing of hierarchical porous biomimetic hydroxyapatite scaffolds: Adding concavities to the convex filaments Acta Biomaterialia 134, 744-759
Porosity plays a key role on the osteogenic performance of bone scaffolds. Direct Ink Writing (DIW) allows the design of customized synthetic bone grafts with patient-specific architecture and controlled macroporosity. Being an extrusion-based technique, the scaffolds obtained are formed by arrays of cylindrical filaments, and therefore have convex surfaces. This may represent a serious limitation, as the role of surface curvature and more specifically the stimulating role of concave surfaces in osteoinduction and bone growth has been recently highlighted. Hence the need to design strategies that allow the introduction of concave pores in DIW scaffolds. In the current study, we propose to add gelatin microspheres as a sacrificial material in a self-setting calcium phosphate ink. Neither the phase transformation responsible for the hardening of the scaffold nor the formation of characteristic network of needle-like hydroxyapatite crystals was affected by the addition of gelatin microspheres. The partial dissolution of the gelatin resulted in the creation of spherical pores throughout the filaments and exposed on the surface, increasing filament porosity from 0.2 % to 67.9 %. Moreover, the presence of retained gelatin proved to have a significant effect on the mechanical properties, reducing the strength but simultaneously giving the scaffolds an elastic behavior, despite the high content of ceramic as a continuous phase. Notwithstanding the inherent difficulty of in vitro cultures with this highly reactive material an enhancement of MG-63 cell proliferation, as well as better spreading of hMSCs was recorded on the developed scaffolds. Statement of significance: Recent studies have stressed the role that concave surfaces play in tissue regeneration and, more specifically, in osteoinduction and osteogenesis. Direct ink writing enables the production of patient-specific bone grafts with controlled architecture. However, besides many advantages, it has the serious limitation that the surfaces obtained are convex. In this article, for the first time we develop a strategy to introduce concave pores in the printed filaments of biomimetic hydroxyapatite by incorporation and partial dissolution of gelatin microspheres. The retention of part of the gelatin results in a more elastic behavior compared to the brittleness of hydroxyapatite scaffolds, while the needle-shaped nanostructure of biomimetic hydroxyapatite is maintained and gelatin-coated concave pores on the surface of the filaments enhance cell spreading. © 2021 The Authors
JTD Keywords: 3d printing, bioceramics, biomimetic, bone, bone regeneration, concavity, concavity, bone regeneration, gelatin, hydrogel, hydroxyapatite, microspheres, osteoinduction, porosity, porous filament, substitutes, tissue-growth, 3d printing, Biomimetic, Calcium-phosphate scaffolds, Concavity, bone regeneration, Gelatin, Hydroxyapatite, Porous filament
Pérez-Rafael S, Ivanova K, Stefanov I, Puiggalí J, del Valle LJ, Todorova K, Dimitrov P, Hinojosa-Caballero D, Tzanov T, (2021). Nanoparticle-driven self-assembling injectable hydrogels provide a multi-factorial approach for chronic wound treatment Acta Biomaterialia 134, 131-143
Chronic wounds represent a major health burden and drain on medical system. Efficient wound repair is only possible if the dressing materials target simultaneously multiple factors involved in wound chronicity, such as deleterious proteolytic and oxidative enzymes and high bacterial load. Here we develop multifunctional hydrogels for chronic wound management through self-assembling of thiolated hyaluronic acid (HA-SH) and bioactive silver-lignin nanoparticles (Ag@Lig NPs). Dynamic and reversible interactions between the polymer and Ag@Lig NPs yield hybrid nanocomposite hydrogels with shear-thinning and self-healing properties, coupled to zero-order kinetics release of antimicrobial silver in response to infection-related hyalurodinase. The hydrogels inhibit the major enzymes myeloperoxidase and matrix metalloproteinases responsible for wound chronicity in a patient's wound exudate. Furthermore, the lignin-capped AgNPs provide the hydrogel with antioxidant properties and strong antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa. The nanocomposite hydrogels are not toxic to human keratinocytes after 7 days of direct contact. Complete tissue remodeling and restoration of skin integrity is demonstrated in vivo in a diabetic mouse model. Hematological analysis reveals lack of wound inflammation due to bacterial infection or toxicity, confirming the potential of HA-SH/Ag@Lig NPs hydrogels for chronic wound management. Statement of significance: Multifunctional hydrogels are promising materials to promote healing of complex wounds. Herein, we report simple and versatile route to prepare biocompatible and multifunctional self-assembled hydrogels for efficient chronic wound treatment utilizing polymer-nanoparticle interactions. Hybrid silver-lignin nanoparticles (Ag@Lig NPs) played both: i) structural role, acting as crosslinking nodes in the hydrogel and endowing it with shear-thinning (ability to flow under applied shear stress) and self-healing properties, and ii) functional role, imparting strong antibacterial and antioxidant activity. Remarkably, the in situ self-assembling of thiolated hyaluronic acid and Ag@Lig NPs yields nanocomposite hydrogels able to simultaneously inhibits the major factors involved in wound chronicity, namely the overexpressed deleterious proteolytic and oxidative enzymes, and high bacterial load.
JTD Keywords: catechol, chronic wounds, dressing materials, inhibition, mechanism, nano-enabled hydrogels, polyphenols, promogran, self-assembling, silver-lignin nanoparticles, systems, tannins, Chronic wounds, Degradation, Dressing materials, Nano-enabled hydrogels, Self-assembling, Silver-lignin nanoparticles, Thiolated hyaluronic acid
Veronika Magdanz, Arnau Llobera, Judith Fuentes, Dalia Mahdy, Islam S. M. Khalil, Maria Guix, Samuel Sanchez, (2021). 3D printed magnet robots for cell delivery with tuned flexibility 25th International Conference On Miniaturized Systems For Chemistry And Life Sciences, µTas 2021 ,
Magnetically actuated microrobots have the potential to make medical operations less invasive, more precise and remotely controlled. Therefore, they are promising for many applications such as targeted therapy or minimally invasive surgeries. Current challenges in the field of magnetic microrobotics include efficient propulsion and biocompatibility. This article addresses both of these aspects and aims to optimize the flexibility of a soft magnetic swimmer by tuning its material properties, define different magnetic segments and investigate its biocompatibility and potential as cell delivery machine.
JTD Keywords: 3d printing, Elastómeros, Sensores remotos
Puiggalí-Jou A, Babeli I, Roa JJ, Zoppe JO, Garcia-Amorós J, Ginebra MP, Alemán C, Garciá-Torres J, (2021). Remote Spatiotemporal Control of a Magnetic and Electroconductive Hydrogel Network via Magnetic Fields for Soft Electronic Applications Acs Applied Materials & Interfaces 13, 42486-42501
Multifunctional hydrogels are a class of materials offering new opportunities for interfacing living organisms with machines due to their mechanical compliance, biocompatibility, and capacity to be triggered by external stimuli. Here, we report a dual magnetic- and electric-stimuli-responsive hydrogel with the capacity to be disassembled and reassembled up to three times through reversible cross-links. This allows its use as an electronic device (e.g., temperature sensor) in the cross-linked state and spatiotemporal control through narrow channels in the disassembled state via the application of magnetic fields, followed by reassembly. The hydrogel consists of an interpenetrated polymer network of alginate (Alg) and poly(3,4-ethylenedioxythiophene) (PEDOT), which imparts mechanical and electrical properties, respectively. In addition, the incorporation of magnetite nanoparticles (Fe3O4 NPs) endows the hydrogel with magnetic properties. After structural, (electro)chemical, and physical characterization, we successfully performed dynamic and continuous transport of the hydrogel through disassembly, transporting the polymer-Fe3O4 NP aggregates toward a target using magnetic fields and its final reassembly to recover the multifunctional hydrogel in the cross-linked state. We also successfully tested the PEDOT/Alg/Fe3O4 NP hydrogel for temperature sensing and magnetic hyperthermia after various disassembly/re-cross-linking cycles. The present methodology can pave the way to a new generation of soft electronic devices with the capacity to be remotely transported.
JTD Keywords: conductive hydrogel, constructs, magnetic field, magnetite nanoparticle, nanoindentation, soft electronics, spatiotemporal control, Conductive hydrogel, Conductive hydrogels, Magnetic field, Magnetite nanoparticle, Soft electronics, Spatiotemporal control
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
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
Fernández-Garibay X, Ortega MA, Cerro-Herreros E, Comelles J, Martínez E, Artero R, Fernández-Costa JM, Ramón-Azcón J, (2021). Bioengineered in vitro 3D model of myotonic dystrophy type 1 human skeletal muscle Biofabrication 13, 035035
Myotonic dystrophy type 1 (DM1) is the most common hereditary myopathy in the adult population. The disease is characterized by progressive skeletal muscle degeneration that produces severe disability. At present, there is still no effective treatment for DM1 patients, but the breakthroughs in understanding the molecular pathogenic mechanisms in DM1 have allowed the testing of new therapeutic strategies. Animal models and in vitro two-dimensional cell cultures have been essential for these advances. However, serious concerns exist regarding how faithfully these models reproduce the biological complexity of the disease. Biofabrication tools can be applied to engineer human three-dimensional (3D) culture systems that complement current preclinical research models. Here, we describe the development of the first in vitro 3D model of DM1 human skeletal muscle. Transdifferentiated myoblasts from patient-derived fibroblasts were encapsulated in micromolded gelatin methacryloyl-carboxymethyl cellulose methacrylate hydrogels through photomold patterning on functionalized glass coverslips. These hydrogels present a microstructured topography that promotes myoblasts alignment and differentiation resulting in highly aligned myotubes from both healthy and DM1 cells in a long-lasting cell culture. The DM1 3D microtissues recapitulate the molecular alterations detected in patient biopsies. Importantly, fusion index analyses demonstrate that 3D micropatterning significantly improved DM1 cell differentiation into multinucleated myotubes compared to standard cell cultures. Moreover, the characterization of the 3D cultures of DM1 myotubes detects phenotypes as the reduced thickness of myotubes that can be used for drug testing. Finally, we evaluated the therapeutic effect of antagomiR-23b administration on bioengineered DM1 skeletal muscle microtissues. AntagomiR-23b treatment rescues both molecular DM1 hallmarks and structural phenotype, restoring myotube diameter to healthy control sizes. Overall, these new microtissues represent an improvement over conventional cell culture models and can be used as biomimetic platforms to establish preclinical studies for myotonic dystrophy.
JTD Keywords: 3d cell culture, hydrogel micropatterning, myotonic dystrophy, skeletal muscle, tissue engineering, 3d cell culture, Hydrogel micropatterning, Myotonic dystrophy, Skeletal muscle, Tissue engineering
López-Canosa A, Perez-Amodio S, Yanac-Huertas E, Ordoño J, Rodriguez-Trujillo R, Samitier J, Castaño O, Engel E, (2021). A microphysiological system combining electrospun fibers and electrical stimulation for the maturation of highly anisotropic cardiac tissue Biofabrication 13, 035047
The creation of cardiac tissue models for preclinical testing is still a non-solved problem in drug discovery, due to the limitations related to thein vitroreplication of cardiac tissue complexity. Among these limitations, the difficulty of mimicking the functional properties of the myocardium due to the immaturity of the used cells hampers the obtention of reliable results that could be translated into human patients.In vivomodels are the current gold standard to test new treatments, although it is widely acknowledged that the used animals are unable to fully recapitulate human physiology, which often leads to failures during clinical trials. In the present work, we present a microfluidic platform that aims to provide a range of signaling cues to immature cardiac cells to drive them towards an adult phenotype. The device combines topographical electrospun nanofibers with electrical stimulation in a microfabricated system. We validated our platform using a co-culture of neonatal mouse cardiomyocytes and cardiac fibroblasts, showing that it allows us to control the degree of anisotropy of the cardiac tissue inside the microdevice in a cost-effective way. Moreover, a 3D computational model of the electrical field was created and validated to demonstrate that our platform is able to closely match the distribution obtained with the gold standard (planar electrode technology) using inexpensive rod-shaped biocompatible stainless-steel electrodes. The functionality of the electrical stimulation was shown to induce a higher expression of the tight junction protein Cx-43, as well as the upregulation of several key genes involved in conductive and structural cardiac properties. These results validate our platform as a powerful tool for the tissue engineering community due to its low cost, high imaging compatibility, versatility, and high-throughput configuration capabilities.
JTD Keywords: bioreactor, cardiac tissue engineering, cardiomyocytes, electrospinning, fabrication, fibroblasts, heart-on-a-chip, heart-tissue, in vitro models, myocardium, orientation, platform, scaffolds, Cardiac tissue engineering, Electrospinning, Field stimulation, Heart-on-a-chip, In vitro models, Microphysiological system
Velasco-Mallorqui, F, Rodriguez-Comas, J, Ramon-Azcon, J, (2021). Cellulose-based scaffolds enhance pseudoislets formation and functionality Biofabrication 13, 035044
In vitro research for the study of type 2 diabetes (T2D) is frequently limited by the availability of a functional model for islets of Langerhans. To overcome the limitations of obtaining pancreatic islets from different sources, such as animal models or human donors, immortalized cell lines as the insulin-producing INS1E beta-cells have appeared as a valid alternative to model insulin-related diseases. However, immortalized cell lines are mainly used in flat surfaces or monolayer distributions, not resembling the spheroid-like architecture of the pancreatic islets. To generate islet-like structures, the use of scaffolds appeared as a valid tool to promote cell aggregations. Traditionally-used hydrogel encapsulation methods do not accomplish all the requisites for pancreatic tissue engineering, as its poor nutrient and oxygen diffusion induces cell death. Here, we use cryogelation technology to develop a more resemblance scaffold with the mechanical and physical properties needed to engineer pancreatic tissue. This study shows that carboxymethyl cellulose (CMC) cryogels prompted cells to generate beta-cell clusters in comparison to gelatin-based scaffolds, that did not induce this cell organization. Moreover, the high porosity achieved with CMC cryogels allowed us to create specific range pseudoislets. Pseudoislets formed within CMC-scaffolds showed cell viability for up to 7 d and a better response to glucose over conventional monolayer cultures. Overall, our results demonstrate that CMC-scaffolds can be used to control the organization and function of insulin-producing beta-cells, representing a suitable technique to generate beta-cell clusters to study pancreatic islet function.
JTD Keywords: biomaterial, cryogel, pancreatic islets, scaffold, tissue engineering, ?-cell, Architecture, Beta-cell, Beta-cell heterogeneity, Biomaterial, Carboxymethyl cellulose, Cell culture, Cell death, Cell engineering, Cell organization, Cells, Cellulose, Cryogel, Cryogels, Cytoarchitecture, Delivery, Encapsulation methods, Gelation, Gene-expression, Immortalized cells, Insulin, Insulin secretory responses, Islets of langerhans, Mechanical and physical properties, Monolayer culture, Monolayers, Pancreatic islets, Pancreatic tissue, Pancreatic-islets, Proliferation, Scaffold, Scaffolds, Scaffolds (biology), Size, Tissue, Tissue engineering, Β-cell
Wang Y, Friedrich H, Voets IK, Zijlstra P, Albertazzi L, (2021). Correlative imaging for polymer science Journal Of Polymer Science 59, 1232-1240
The characterization of polymeric materials is key towards the understanding of structure–activity relations and therefore for the rational design of novel and improved materials for a myriad of applications. Many microscopy techniques are currently used, with electron microscopy, fluorescence microscopy, and atomic force microscopy being the most relevant. In this perspective paper, we discuss the use of correlative imaging, that is, the combination of multiple imaging methodologies on the same sample, in the field of polymeric materials. This innovative approach is emerging as a powerful tool to unveil the structure and functional properties of biological and synthetic structures. Here we discuss the possibilities of correlative imaging and highlight their potential to answer open questions in polymer science.
JTD Keywords: correlative imaging, electron microscopy, material characterization, resolution microscopy, super‐, Atomic force microscopy, Correlative imaging, Electron microscopy, Material characterization, Super-resolution microscopy
Elosegui-Artola A, (2021). The extracellular matrix viscoelasticity as a regulator of cell and tissue dynamics Current Opinion In Cell Biology 72, 10-18
The extracellular matrix mechanical properties regulate processes in development, cancer, and fibrosis. Among the distinct mechanical properties, the vast majority of research has focused on the extracellular matrix's elasticity as the primary determinant of cell and tissue behavior. However, both cells and the extracellular matrix are not only elastic but also viscous. Despite viscoelasticity being a universal feature of living tissues, our knowledge of the influence of the extracellular matrix's viscoelasticity in cell behavior is limited. This mini-review describes some of the recent findings that have highlighted the role of the extracellular matrix's viscoelasticity in cell and tissue dynamics.
JTD Keywords: behavior, cell adhesion, cell mechanics, cell migration, deformability, extracellular matrix, extracellular matrix mechanics, fluidity, forces, hydrogels, mechanobiology, mechanotransduction, tissue mechanics, viscoelasticity, viscosity, Cell adhesion, Cell mechanics, Cell migration, Extracellular matrix, Extracellular matrix mechanics, Fluidity, Mechanobiology, Mechanotransduction, Migration, Tissue mechanics, Viscoelasticity, Viscosity
Dulay S, Rivas L, Miserere S, Pla L, Berdún S, Parra J, Eixarch E, Gratacós E, Illa M, Mir M, Samitier J, (2021). in vivo Monitoring with micro-implantable hypoxia sensor based on tissue acidosis Talanta 226, 122045
© 2020 Elsevier B.V. Hypoxia is a common medical problem, sometimes difficult to detect and caused by different situations. Control of hypoxia is of great medical importance and early detection is essential to prevent life threatening complications. However, the few current methods are invasive, expensive, and risky. Thus, the development of reliable and accurate sensors for the continuous monitoring of hypoxia is of vital importance for clinical monitoring. Herein, we report an implantable sensor to address these needs. The developed device is a low-cost, miniaturised implantable electrochemical sensor for monitoring hypoxia in tissue by means of pH detection. This technology is based on protonation/deprotonation of polypyrrole conductive polymer. The sensor was optimized in vitro and tested in vivo intramuscularly and ex vivo in blood in adult rabbits with respiration-induced hypoxia and correlated with the standard device ePOCTM. The sensor demonstrated excellent sensitivity and reproducibility; 46.4 ± 0.4 mV/pH in the pH range of 4–9 and the selectivity coefficient exhibited low interference activity in vitro. The device was linear (R2 = 0.925) with a low dispersion of the values (n = 11) with a cut-off of 7.1 for hypoxia in vivo and ex vivo. Statistics with one-way ANOVA (α = 0.05), shows statistical differences between hypoxia and normoxia states and the good performance of the pH sensor, which demonstrated good agreement with the standard device. The sensor was stable and functional after 18 months. The excellent results demonstrated the feasibility of the sensors in real-time monitoring of intramuscular tissue and blood for medical applications.
JTD Keywords: biocompatibility, blood-flow, clinical monitoring, electrochemical biosensor, electrodes, hypoxia, implantable sensor, in vivo tissue monitoring, ischemia, lactate, ph, ph sensor, rabbits, responses, vitro, Clinical monitoring, Dual signal outputs, Hypoxia, Implantable sensor, In vivo tissue monitoring, Ischemia, Ph sensor
Badiola-Mateos M, Di Giuseppe D, Paoli R, Lopez-Martinez MJ, Mencattini A, Samitier J, Martinelli E, (2021). A novel multi-frequency trans-endothelial electrical resistance (MTEER) sensor array to monitor blood-brain barrier integrity Sensors And Actuators B-Chemical 334, 129599
© 2021 Elsevier B.V. The blood-brain barrier (BBB) is a dynamic cellular barrier that regulates brain nutrient supply, waste efflux, and paracellular diffusion through specialized junctional complexes. Finding a system to mimic and monitor BBB integrity (i.e., to be able to assess the effect of certain compounds on opening or closing the barrier) is of vital importance in several pathologies. This work aims to overcome some limitations of current barrier integrity measuring techniques thanks to a multi-layer microfluidic platform with integrated electrodes and Multi-frequency Trans-Endothelial Electrical Resistance (MTEER) in synergy with machine learning algorithms. MTEER measurements are performed across the barrier in a range of frequencies up to 10 MHz highlighting the presence of information on different frequency ranges. Results show that the proposed platform can detect barrier formation, opening, and regeneration afterwards, correlating with the results obtained from immunostaining of junctional complexes. This model presents novel techniques for a future biological barrier in-vitro studies that could potentially help on elucidating barrier opening or sealing on treatments with different drugs.
JTD Keywords: blood-brain barrier, cellular barrier integrity monitoring, impedance sensors, machine learning, microelectrodes, mteer, rapid prototyping, Blood-brain barrier, Cellular barrier integrity monitoring, Electrical impedance spectroscopy, Impedance sensors, Machine learning, Microelectrodes, Mteer, Rapid prototyping
Babeli I, Ruano G, Puiggalí-Jou A, Ginebra MP, Alemán C, Garcia-Torres J, (2021). Self-Healable and Eco-Friendly Hydrogels for Flexible Supercapacitors Advanced Sustainable Systems 5,
© 2021 Wiley-VCH GmbH One limitation of wearable electronics, and at the same time a challenge, is the lack of energy storage devices with multiple functionalities produced using clean and environmental-friendly strategies. Here, a multifunctional conductive hydrogel containing poly(3,4-ethylenedioxythiophene) (PEDOT) and alginate is fabricated, to be used as electrodes in supercapacitors, by applying water-mediated self-assembly and polymerization processes at room temperature. The interpenetration of both polymers allows the combination of flexibility and self-healing properties within the same hydrogel together with the intrinsic biocompatibility and sustainability of such materials. Initially, PEDOT:polystyrene sulfonate and alginate aqueous solutions are mixed in two different proportions (1:1 and 1:3) and ionically crosslinked with CaCl2. Subsequently, re-interpenetration of poly(hydroxymethyl-3,4-ethylenedioxythiophene) by anodic polymerization in CaCl2 aqueous solution is achieved. Re-interpenetrated 1:3 PEDOT/alginate hydrogels show excellent capacitance values (35 mF cm−2) and good capacitance retention. In addition, the electrochemical properties are not significantly changed after many cutting/self-healing cycles as observed by cyclic voltammetry. Therefore, this sustainably produced hydrogel shows promising properties for use in wearable energy storage devices.
JTD Keywords: flexibility, pedot:pss-alginate hydrogels, self-healing, sustainability, Electrochemical supercapacitors, Flexibility, Pedot:pss-alginate hydrogels, Self-healing, Sustainability
Ortega MA, Rodríguez-Comas J, Yavas O, Velasco-Mallorquí F, Balaguer-Trias J, Parra V, Novials A, Servitja JM, Quidant R, Ramón-Azcón J, (2021). In Situ LSPR Sensing of Secreted Insulin in Organ-on-Chip Biosensors 11,
Organ-on-a-chip (OOC) devices offer new approaches for metabolic disease modeling and drug discovery by providing biologically relevant models of tissues and organs in vitro with a high degree of control over experimental variables for high-content screening applications. Yet, to fully exploit the potential of these platforms, there is a need to interface them with integrated non-labeled sensing modules, capable of monitoring, in situ, their biochemical response to external stimuli, such as stress or drugs. In order to meet this need, we aim here to develop an integrated technology based on coupling a localized surface plasmon resonance (LSPR) sensing module to an OOC device to monitor the insulin in situ secretion in pancreatic islets, a key physiological event that is usually perturbed in metabolic diseases such as type 2 diabetes (T2D). As a proof of concept, we developed a biomimetic islet-on-a-chip (IOC) device composed of mouse pancreatic islets hosted in a cellulose-based scaffold as a novel approach. The IOC was interfaced with a state-of-the-art on-chip LSPR sensing platform to monitor the in situ insulin secretion. The developed platform offers a powerful tool to enable the in situ response study of microtissues to external stimuli for applications such as a drug-screening platform for human models, bypassing animal testing.
JTD Keywords: biosensor, cytoarchitecture, dna hybridization, gelatin, in situ insulin monitoring, langerhans, lspr sensors, microfluidic device, organ-on-a-chip, parallel, platform, scaffold, Human pancreatic-islets, In situ insulin monitoring, Lspr sensors, Organ-on-a-chip
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
Ruano G, Iribarren JI, Pérez-Madrigal MM, Torras J, Alemán C, (2021). Electrical and capacitive response of hydrogel solid-like electrolytes for supercapacitors Polymers 13,
Flexible hydrogels are attracting significant interest as solid-like electrolytes for energy storage devices, especially for supercapacitors, because of their lightweight and anti-deformation features. Here, we present a comparative study of four ionic conductive hydrogels derived from biopolymers and doped with 0.1 M NaCl. More specifically, such hydrogels are constituted by κcarrageenan (κC), carboxymethyl cellulose (CMC), poly-γ-glutamic acid (PGGA) or a phenylalaninecontaining polyesteramide (PEA). After examining the morphology and the swelling ratio of the four hydrogels, which varies between 483% and 2356%, their electrical and capacitive behaviors were examined using electrochemical impedance spectroscopy. Measurements were conducted on devices where a hydrogel film was sandwiched between two identical poly(3,4-ethylenedioxythiophene) electrodes. The bulk conductivity of the prepared doped hydrogels is 76, 48, 36 and 34 mS/cm for PEA, PGGA, κC and CMC, respectively. Overall, the polyesteramide hydrogel exhibits the most adequate properties (i.e., low electrical resistance and high capacitance) to be used as semi-solid electrolyte for supercapacitors, which has been attributed to its distinctive structure based on the homogeneous and abundant distribution of both micro-and nanopores. Indeed, the morphology of the polyestermide hydrogel reduces the hydrogel resistance, enhances the transport of ions, and results in a better interfacial contact between the electrodes and solid electrolyte. The correlation between the supercapacitor performance and the hydrogel porous morphology is presented as an important design feature for the next generation of light and flexible energy storage devices for wearable electronics.
JTD Keywords: biopolymers, electrochemical impedance spectroscopy, flexible hydrogels, supercapacitor, Biopolymers, Electrochemical impedance spectroscopy, Flexible hydrogels, Supercapacitor
Vera D, García-Díaz M, Torras N, Álvarez M, Villa R, Martinez E, (2021). Engineering Tissue Barrier Models on Hydrogel Microfluidic Platforms Acs Applied Materials & Interfaces 13, 13920-13933
Tissue barriers play a crucial role in human physiology by establishing tissue compartmentalization and regulating organ homeostasis. At the interface between the extracellular matrix (ECM) and flowing fluids, epithelial and endothelial barriers are responsible for solute and gas exchange. In the past decade, microfluidic technologies and organ-on-chip devices became popular as in vitro models able to recapitulate these biological barriers. However, in conventional microfluidic devices, cell barriers are primarily grown on hard polymeric membranes within polydimethylsiloxane (PDMS) channels that do not mimic the cell-ECM interactions nor allow the incorporation of other cellular compartments such as stromal tissue or vascular structures. To develop models that accurately account for the different cellular and acellular compartments of tissue barriers, researchers have integrated hydrogels into microfluidic setups for tissue barrier-on-chips, either as cell substrates inside the chip, or as self-contained devices. These biomaterials provide the soft mechanical properties of tissue barriers and allow the embedding of stromal cells. Combining hydrogels with microfluidics technology provides unique opportunities to better recreate in vitro the tissue barrier models including the cellular components and the functionality of the in vivo tissues. Such platforms have the potential of greatly improving the predictive capacities of the in vitro systems in applications such as drug development, or disease modeling. Nevertheless, their development is not without challenges in their microfabrication. In this review, we will discuss the recent advances driving the fabrication of hydrogel microfluidic platforms and their applications in multiple tissue barrier models.
JTD Keywords: hydrogel, microfabrication, microfluidics, organ-on-chip, tissue barrier, Hydrogel, Microfabrication, Microfluidics, Organ-on-chip, Tissue barrier
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
Blanco-Fernandez B, Gaspar VM, Engel E, Mano JF, (2021). Proteinaceous Hydrogels for Bioengineering Advanced 3D Tumor Models Advanced Science 8, 2003129
© 2020 The Authors. Advanced Science published by Wiley-VCH GmbH The establishment of tumor microenvironment using biomimetic in vitro models that recapitulate key tumor hallmarks including the tumor supporting extracellular matrix (ECM) is in high demand for accelerating the discovery and preclinical validation of more effective anticancer therapeutics. To date, ECM-mimetic hydrogels have been widely explored for 3D in vitro disease modeling owing to their bioactive properties that can be further adapted to the biochemical and biophysical properties of native tumors. Gathering on this momentum, herein the current landscape of intrinsically bioactive protein and peptide hydrogels that have been employed for 3D tumor modeling are discussed. Initially, the importance of recreating such microenvironment and the main considerations for generating ECM-mimetic 3D hydrogel in vitro tumor models are showcased. A comprehensive discussion focusing protein, peptide, or hybrid ECM-mimetic platforms employed for modeling cancer cells/stroma cross-talk and for the preclinical evaluation of candidate anticancer therapies is also provided. Further development of tumor-tunable, proteinaceous or peptide 3D microtesting platforms with microenvironment-specific biophysical and biomolecular cues will contribute to better mimic the in vivo scenario, and improve the predictability of preclinical screening of generalized or personalized therapeutics.
JTD Keywords: 3d in vitro models, cancers, hydrogels, peptides, 3d in vitro models, Cancers, Hydrogels, Peptides, Proteins
Puiggalí-Jou A, Wedepohl S, Theune LE, Alemán C, Calderón M, (2021). Effect of conducting/thermoresponsive polymer ratio on multitasking nanogels Materials Science & Engineering C-Materials For Biological Applications 119, 111598
© 2020 Elsevier B.V. Semi-interpenetrated nanogels (NGs) able to release and sense diclofenac (DIC) have been designed to act as photothermal agents with the possibility to ablate cancer cells using mild-temperatures (<45 °C). Combining mild heat treatments with simultaneous chemotherapy appears as a very promising therapeutic strategy to avoid heat resistance or damaging the surrounding tissues. Particularly, NGs consisted on a poly(N-isopropylacrylamide) (PNIPAM) and dendritic polyglycerol (dPG) mesh containing a semi-interpenetrating network (SIPN) of poly(hydroxymethyl 3,4-ethylenedioxythiophene) (PHMeEDOT). The PHMeEDOT acted as photothermal and conducting agent, while PNIPAM-dPG NG provided thermoresponsivity and acted as stabilizer. We studied how semi-interpenetration modified the physicochemical characteristics of the thermoresponsive SIPN NGs and selected the best condition to generate a multifunctional photothermal agent. The thermoswitchable conductiveness of the multifunctional NGs and the redox activity of DIC could be utilized for its electrochemical detection. Besides, as proof of the therapeutic concept, we investigated the combinatorial effect of photothermal therapy (PTT) and DIC treatment using the HeLa cancer cell line in vitro. Within 15 min NIR irradiation without surpassing 45 °C we were able to kill 95% of the cells, demonstrating the potential of SIPN NGs as drug carriers, sensors and agents for mild PTT.
JTD Keywords: cells, cellulose, conducting polymers, controlled delivery, diclofenac, efficiency, electrochemical oxidation, electrochemical sensors, nanogels, nanoparticles, photothermal therapy, pnipam, poly(3,4-ethylenedioxythiophene), Conducting polymers, Electrochemical sensors, Nanogels, Photothermal therapy
Moreira VB, Puiggalí-Jou A, Jiménez-Piqué E, Alemán C, Meneguzzi A, Armelin E, (2021). Green nanocoatings based on the deposition of zirconium oxide: The role of the substrate Materials (Basel) 14,
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. Herein, the influence of the substrate in the formation of zirconium oxide monolayer, from an aqueous hexafluorozirconic acid solution, by chemical conversion and by electro-assisted deposi-tion, has been approached. The nanoscale dimensions of the ZrO2 film is affected by the substrate nature and roughness. This study evidenced that the mechanism of Zr-EAD is dependent on the potential applied and on the substrate composition, whereas conversion coating is uniquely dependent on the adsorption reaction time. The zirconium oxide based nanofilms were more homogenous in AA2024 substrates if compared to pure Al grade (AA1100). It was justified by the high content of Cu alloying element present in the grain boundaries of the latter. Such intermetallic active sites favor the obtaining of ZrO2 films, as demonstrated by XPS and AFM results. From a mechanistic point of view, the electrochemical reactions take place simultaneously with the conventional chemical conversion process driven by ions diffusion. Such findings will bring new perspectives for the generation of controlled oxide coatings in modified electrodes used, as for example, in the construction of battery cells; in automotive and in aerospace industries, to replace micrometric layers of zinc phosphate by light-weight zirconium oxide nanometric ones. This study is particularly addressed for the reduction of industrial waste by applying green bath solutions without the need of auxiliary compounds and using lightweight ceramic materials.
JTD Keywords: aluminum alloys, conversion coating, electro-assisted deposition, metal-oxide interface, nanocoating, zirconium oxide, Aluminum alloys, Conversion coating, Electro-assisted deposition, Metal-oxide interface, Nanocoating, Zirconium oxide
Perez-Amodio, Soledad, Rubio, Nuria, Vila, Olaia F, Navarro-Requena, Claudia, Castano, Oscar, Sanchez-Ferrero, Aitor, Marti-Munoz, Joan, Alsina-Giber, Merce, Blanco, Jeronimo, Engel, Elisabeth, (2021). Polymeric Composite Dressings Containing Calcium-Releasing Nanoparticles Accelerate Wound Healing in Diabetic Mice Advances In Wound Care 10, 301-316
Objective: Wound healing is a complex process that involves the interaction between different cell types and bioactive factors. Impaired wound healing is characterized by a loss in synchronization of these interactions, resulting in nonhealing chronic wounds. Chronic wounds are a socioeconomic burden, one of the most prominent clinical manifestations of diabetes, however, they lack satisfactory treatment options. The objective of this study was to develop polymeric composites that deliver ions having wound healing properties and evaluate its performance using a pressure ulcer model in diabetic mice. Approach: To develop a polymeric composite wound dressing containing ion-releasing nanoparticles for chronic wound healing. This composite was chemically and physically characterized and evaluated using a pressure ulcer wound model in diabetic (db/db) mice to explore their potential as novel wound dressing. Results: This dressing exhibits a controlled ion release and a goodin vitrobioactivity. The polymeric composite dressing treatment stimulates angiogenesis, collagen synthesis, granulation tissue formation, and accelerates wound closure of ischemic wounds created in diabetic mice. In addition, the performance of the newly designed composite is remarkably better than a commercially available dressing frequently used for the treatment of low-exuding chronic wounds. Innovation: The developed nanoplatforms are cell- and growth factor free and control the host microenvironment resulting in enhanced wound healing. These nanoplatforms are available by cost-effective synthesis with a defined composition, offering an additional advantage in potential clinical application. Conclusion: Based on the obtained results, these polymeric composites offer an optimum approach for chronic wound healing without adding cells or external biological factors.
JTD Keywords: angiogenesis, bioactive dressings, chronic wounds, Angiogenesis, Bioactive dressings, Bioactive glass, Bioglass, Cells, Chronic wounds, Diabetes, Endothelial growth-factor, Expression, Hydrogel, Induction
Romero D, Jane R, (2021). Global and Transient Effects of Intermittent Hypoxia on Heart Rate Variability Markers: Evaluation using an Obstructive Sleep Apnea Model Ieee Access 9, 19043-19052
CCBY Intermittent hypoxia (IH) produces autonomic dysfunction that promotes the development of arrhythmia and hypertension in patients with obstructive sleep apnea (OSA). This paper investigated different heart rate variability (HRV) indices in the context of IH using a rat model for OSA. Linear and non-linear HRV parameters were assessed from ultra-short (15-s segments) and short-term (5 min) analyses of heartbeat time-series. Transient changes observed from pre-apnea segments to hypoxia episodes were evaluated, besides the relative and global impact of IH, as a function of its severity. Results showed an overall increase in ultra-short HRV markers as immediate response to hypoxia: standard deviation of normal RR intervals, SDNN=1.2 ms (IQR: 1.1-2.1) vs 1.4 ms (IQR: 1.2-2.2), p=0.015; root mean square of the successive differences, RMSSD=1.7 ms (IQR: 1.5-2.2) vs 1.9 ms (IQR: 1.6-2.4), p=0.031. The power in the very low frequency (VLF) band also showed a significant increase: 0.09 ms2 (IQR: 0.05-0.20) vs 0.16 ms2 (IQR: 0.12-0.23), p=0.016, probably associated with the potentiation of the carotid body chemo-sensory response to hypoxia. Moreover, a clear link between severity of IH and short-term HRV measures was found in VLF and LF power, besides their progressive increase seen throughout the experiment after each apnea sequence. However, only those markers quantifying fragmentation levels in RR series were significantly affected when the experiment ended, as compared to baseline measures: percentage of inflection points, PIP=49% (IQR: 45-51) vs 53% (IQR: 47-53), p=0.031; percentage of short (≥3 RR intervals) accelerated/decelerated segments, PSS=75% (IQR: 51-81) vs 87% (IQR: 51-90), p=0.046. These findings suggest a significant deterioration of cardiac rhythm with a more erratic behavior beyond the normal sinus arrhythmia, that may lead to a future cardiac condition.
JTD Keywords: artificial intelligence, atmospheric modeling, electrocardiography, heart rate variability, hypoxia rat model, intermittent hypoxia, obstructive apneas, protocols, radio access technologies, Artificial intelligence, Atmospheric modeling, Electrocardiography, Heart rate variability, Hypoxia rat model, Intermittent hypoxia, Obstructive apneas, Protocols, Radio access technologies, Rats
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
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
Olate-Moya, F., Arens, L., Wilhelm, M., Mateos-Timoneda, M. A., Engel, E., Palza, H., (2020). Chondroinductive alginate-based hydrogels having graphene oxide for 3D printed scaffold fabrication ACS Applied Materials and Interfaces 12, (4), 4343-4357
Scaffolds based on bioconjugated hydrogels are attractive for tissue engineering because they can partly mimic human tissue characteristics. For example, they can further increase their bioactivity with cells. However, most of the hydrogels present problems related to their processability, consequently limiting their use in 3D printing to produce tailor-made scaffolds. The goal of this work is to develop bioconjugated hydrogel nanocomposite inks for 3D printed scaffold fabrication through a micro-extrusion process having improved both biocompatibility and processability. The hydrogel is based on a photocrosslinkable alginate bioconjugated with both gelatin and chondroitin sulfate in order to mimic the cartilage extracellular matrix, while the nanofiller is based on graphene oxide to enhance the printability and cell proliferation. Our results show that the incorporation of graphene oxide into the hydrogel inks considerably improved the shape fidelity and resolution of 3D printed scaffolds because of a faster viscosity recovery post extrusion of the ink. Moreover, the nanocomposite inks produce anisotropic threads after the 3D printing process because of the templating of the graphene oxide liquid crystal. The in vitro proliferation assay of human adipose tissue-derived mesenchymal stem cells (hADMSCs) shows that bioconjugated scaffolds present higher cell proliferation than pure alginate, with the nanocomposites presenting the highest values at long times. Live/Dead assay otherwise displays full viability of hADMSCs adhered on the different scaffolds at day 7. Notably, the scaffolds produced with nanocomposite hydrogel inks were able to guide the cell proliferation following the direction of the 3D printed threads. In addition, the bioconjugated alginate hydrogel matrix induced chondrogenic differentiation without exogenous pro-chondrogenesis factors as concluded from immunostaining after 28 days of culture. This high cytocompatibility and chondroinductive effect toward hADMSCs, together with the improved printability and anisotropic structures, makes these nanocomposite hydrogel inks a promising candidate for cartilage tissue engineering based on 3D printing.
JTD Keywords: 3D printing, Chondrogenesis, Graphene oxide, Hydrogels, Liquid crystals
Labay, C., Roldán, M., Tampieri, F., Stancampiano, A., Bocanegra, P. E., Ginebra, M. P., Canal, C., (2020). Enhanced generation of reactive species by cold plasma in gelatin solutions for selective cancer cell death ACS Applied Materials and Interfaces 12, (42), 47256-47269
Atmospheric pressure plasma jets generate reactive oxygen and nitrogen species (RONS) in liquids and biological media, which find application in the new area of plasma medicine. These plasma-treated liquids were demonstrated recently to possess selective properties on killing cancer cells and attracted attention toward new plasma-based cancer therapies. These allow for local delivery by injection in the tumor but can be quickly washed away by body fluids. By confining these RONS in a suitable biocompatible delivery system, great perspectives can be opened in the design of novel biomaterials aimed for cancer therapies. Gelatin solutions are evaluated here to store RONS generated by atmospheric pressure plasma jets, and their release properties are evaluated. The concentration of RONS was studied in 2% gelatin as a function of different plasma parameters (treatment time, nozzle distance, and gas flow) with two different plasma jets. Much higher production of reactive species (H2O2 and NO2-) was revealed in the polymer solution than in water after plasma treatment. The amount of RONS generated in gelatin is greatly improved with respect to water, with concentrations of H2O2 and NO2- between 2 and 12 times higher for the longest plasma treatments. Plasma-treated gelatin exhibited the release of these RONS to a liquid media, which induced an effective killing of bone cancer cells. Indeed, in vitro studies on the sarcoma osteogenic (SaOS-2) cell line exposed to plasma-treated gelatin led to time-dependent increasing cytotoxicity with the longer plasma treatment time of gelatin. While the SaOS-2 cell viability decreased to 12%-23% after 72 h for cells exposed to 3 min of treated gelatin, the viability of healthy cells (hMSC) was preserved (?90%), establishing the selectivity of the plasma-treated gelatin on cancer cells. This sets the basis for designing improved hydrogels with high capacity to deliver RONS locally to tumors.
JTD Keywords: Cold atmospheric plasma, Hydrogel, Osteosarcoma, Reactive oxygen and nitrogen species
Altay, Gizem, Tosi, Sébastien, García-Díaz, María, Martínez, Elena, (2020). Imaging the cell morphological response to 3D topography and curvature in engineered intestinal tissues Frontiers in Bioengineering and Biotechnology 8, 294
While conventional cell culture methodologies have relied on flat, two-dimensional cell monolayers, three-dimensional engineered tissues are becoming increasingly popular. Often, engineered tissues can mimic the complex architecture of native tissues, leading to advancements in reproducing physiological functional properties. In particular, engineered intestinal tissues often use hydrogels to mimic villi structures. These finger-like protrusions of a few hundred microns in height have a well-defined topography and curvature. Here, we examined the cell morphological response to these villus-like microstructures at single-cell resolution using a novel embedding method that allows for the histological processing of these delicate hydrogel structures. We demonstrated that by using photopolymerisable poly(ethylene) glycol as an embedding medium, the villus-like microstructures were successfully preserved after sectioning with vibratome or cryotome. Moreover, high-resolution imaging of these sections revealed that cell morphology, nuclei orientation, and the expression of epithelial polarization markers were spatially encoded along the vertical axis of the villus-like microstructures and that this cell morphological response was dramatically affected by the substrate curvature. These findings, which are in good agreement with the data reported for in vivo experiments on the native tissue, are likely to be the origin of more physiologically relevant barrier properties of engineered intestinal tissues when compared with standard monolayer cultures. By showcasing this example, we anticipate that the novel histological embedding procedure will have a positive impact on the study of epithelial cell behavior on three-dimensional substrates in both physiological and pathological situations.
JTD Keywords: Hydrogel scaffold, Confocal microscopy, Substrate curvature, Cell morphology, Cell orientation, Histological section, Small intestine, Villus
Altay, Gizem, Batlle, Eduard, Fernández-Majada, Vanesa, Martínez, Elena, (2020). In vitro self-organized mouse small intestinal epithelial monolayer protocol Bio-protocol 10, (3), e3514
Developing protocols to obtain intestinal epithelial monolayers that recapitulate in vivo physiology to overcome the limitations of the organoidsâ€™ closed geometry has become of great interest during the last few years. Most of the developed culture models showed physiological-relevant cell composition but did not prove self-renewing capacities. Here, we show a simple method to obtain mouse small intestine-derived epithelial monolayers organized into proliferative crypt-like domains, containing stem cells, and differentiated villus-like regions, closely resembling the in vivo cell composition and distribution. In addition, we adapted our model to a tissue culture format compatible with functional studies and prove close to physiological barrier properties of our in vitro epithelial monolayers. Thus, we have set-up a protocol to generate physiologically relevant intestinal epithelial monolayers to be employed in assays where independent access to both luminal and basolateral compartments is needed, such as drug absorption, intracellular trafficking and microbiome-epithelium interaction assays.
JTD Keywords: Mouse intestinal organoids, Adult intestinal stem cells, Matrigel, Intestinal epithelial monolayer, In vitro intestinal epithelial model, Tissue-like functionality, TEER
Hamouda, I., Labay, C., Ginebra, M. P., Nicol, E., Canal, C., (2020). Investigating the atmospheric pressure plasma jet modification of a photo-crosslinkable hydrogel Polymer 192, 122308
Atmospheric pressure plasma jets (APPJ) have great potential in wound healing, bacterial disinfection and in cancer therapy. Recent studies pointed out that hydrogels can be used as screens during APPJ treatment, or even be used as reservoirs for reactive oxygen and nitrogen species generated by APPJ in liquids. Thus, novel applications are emerging for hydrogels which deserve fundamental exploration of the possible modifications undergone by the polymers in solution due to the reactivity with plasmas. Here we investigate the possible modifications occurred by APPJ treatment of an amphiphilic poly(ethylene oxide)-based triblock copolymer (tPEO) photo-crosslinkable hydrogel. While APPJ treatments lead to a certain degradation of the self-assembly of the polymeric chains at low concentrations (<2 g/L), at the higher concentrations required to form a hydrogel (>2 g/L), the polymeric chains are unaffected by APPJ and the hydrogel forming ability is kept. APPJ treatments induced a pre-crosslinking of the network with an increase of the mechanical properties of the hydrogel. Overall, the small modifications induced allow thinking of polymer solutions with hydrogel forming ability a new platform for several applications related to plasma medicine, and thus, with potential in different therapies.
JTD Keywords: Atmospheric pressure plasma jet, Hydrogel, Photo-crosslinking, Polymer solution, Self-assembly
Bertran, O., Saldías, C., Díaz, D. D., Alemán, C., (2020). Molecular dynamics simulations on self-healing behavior of ionene polymer-based nanostructured hydrogels Polymer 211, 123072
The microscopic mechanism accounting for the self-healing attribute of aromatic ionene-forming hydrogels derived from 1,4-diazabicyclo [2.2.2]octane (DABCO) and N,N’-(x-phenylene)dibenzamide (x = ortho-/meta-/para-) is unknown. Interestingly, the self-healing property of such DABCO-containing hydrogels is largely dependent on the polymer topology, the ortho ionene being the only self-healable without adding oppositely charged species. In this work, Molecular Dynamics (MD) simulations have been conducted to evaluate the influence of the topology on ionene···ionene and ionene··water interactions, as well as their effect on the self-healing behavior. For this purpose, destabilized and structurally damaged models were produced for ionene hydrogels with ortho, meta and para topologies and used as starting geometries for simulations. These models were allowed to evolve without any restriction during MD production runs and, subsequently, the temporal evolution of ionene···ionene and water···ionene interactions was examined. Analysis of the results indicated that the ortho-isomer rapidly forms unique interactions that are not detected for other two isomers. Thus, in addition to the interactions also identified for the meta-and para-ionenes, the ortho-isomer exhibits the formation of strong intermolecular three-centered (N–)H⋯O (=C)⋯H (–N) hydrogen bonds, intramolecular planar sandwich π-π stacking interactions and Cl−···N+ electrostatic interactions. Furthermore, the amount of intermolecular π-π stacking interactions and the strength of water···polymer interaction are also influenced by the topology, favoring the stabilization of the ortho-ionene reconstituted hydrogels. Overall, the arrangement of the functional groups in the ortho topology favors the formation of more types of ionene···ionene interactions, as well as stronger interactions, than in the meta and para topologies.
JTD Keywords: DABCO, Econstituted hydrogels, Molecular dynamics, Polyelectrolyte hydrogels, Self-healing mechanism
Fuentes, E., Bohá, Fuentes-Caparrós, A. M., Schweins, R., Draper, E. R., Adams, D. J., Pujals, S., Albertazzi, L., (2020). PAINT-ing fluorenylmethoxycarbonyl (Fmoc)-diphenylalanine hydrogels Chemistry - A European Journal 26, (44), 9869-9873
Self-assembly of fluorenylmethoxycarbonyl-protected diphenylalanine (FmocFF) in water is widely known to produce hydrogels. Typically, confocal microscopy is used to visualize such hydrogels under wet conditions, that is, without freezing or drying. However, key aspects of hydrogels like fiber diameter, network morphology and mesh size are sub-diffraction limited features and cannot be visualized effectively using this approach. In this work, we show that it is possible to image FmocFF hydrogels by Points Accumulation for Imaging in Nanoscale Topography (PAINT) in native conditions and without direct gel labelling. We demonstrate that the fiber network can be visualized with improved resolution (â‰ˆ50 nm) both in 2D and 3D. Quantitative information is extracted such as mesh size and fiber diameter. This method can complement the existing characterization tools for hydrogels and provide useful information supporting the design of new materials.
JTD Keywords: FmocFF, Hydrogels, Mesh size, PAINT, Super-resolution
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
Maiti, B., Abramov, A., Franco, L., Puiggalí, J., Enshaei, H., Alemán, C., Díaz, D. D., (2020). Thermoresponsive shape-memory hydrogel actuators made by phototriggered click chemistry Advanced Functional Materials 30, (24), 2001683
This article describes the design and synthesis of a new series of hydrogel membranes composed of trialkyne derivatives of glycerol ethoxylate and bisphenol A diazide (BA-diazide) or diazide-terminated PEG600 monomer via a Cu(I)-catalyzed photoclick reaction. The water-swollen hydrogel membranes display thermoresponsive actuation and their lower critical solution temperature (LCST) values are determined by differential scanning calorimetry. Glycerol ethoxylate moiety serves as the thermoresponsive component and hydrophilic part, while the azide-based component acts as the hydrophobic comonomer and most likely provides a critical hydrophobic/hydrophilic balance contributing also to the significant mechanical strength of the membranes. These hydrogels exhibit a reversible shape-memory effect in response to temperature through a defined phase transition. The swelling and deswelling behavior of the membranes are systematically examined. Due to the click nature of the reaction, easy availability of azide and alkyne functional-monomers, and the polymer architecture, the glass transition temperature (Tg) is easily controlled through monomer design and crosslink density by varying the feed ratio of different monomers. The mechanical properties of the membranes are studied by universal tensile testing measurements. Moreover, the hydrogels show the ability to absorb a dye and release it in a controlled manner by applying heat below and above the LCST.
JTD Keywords: Hydrogels, Membranes, Photoclick, Polymers, Shape-memory, Thermoresponsive
Lanzalaco, S., Turon, P., Weis, C., Mata, C., Planas, E., Alemán, C., Armelin, E., (2020). Toward the new generation of surgical meshes with 4D response: Soft, dynamic, and adaptable Advanced Functional Materials 30, (36), 2004145
Herein, a facile approach toward transforming a 2D polypropylene flexible mesh material into a 4D dynamic system is presented. The versatile platform, composed by a substrate of knitted fibers of isotactic polypropylene (iPP) mesh and a coating of thermosensitive poly(N‐isopropylacrylamide‐co‐N,N’‐methylene bis(acrylamide) (PNIPAAm‐co‐MBA) hydrogel, covalently bonded to the mesh surface, after cold‐plasma surface treatment and radical polymerization, is intended to undergo variations in its geometry via its reversible folding/unfolding behavior. The study is the first to trace the 3D movement of a flat surgical mesh, intended to repair hernia defects, under temperature and humidity control. An infrared thermographic camera and an optical microscope are used to evaluate the macroscopic and microscopic structure stimulus response. The presence of the PP substrate and the distribution of the gel surrounding the PP threads, affect both the PNIPAAM gel expansion/contraction as well as the time of folding/unfolding response. Furthermore, PP‐g‐PNIPAAm meshes show an increase in the bursting strength of ≈16% with respect to the uncoated mesh, offering a strongest and adaptable system for its future implantation in human body. The findings reported offer unprecedented application possibilities in the biomedical field.
JTD Keywords: Dynamic devices, Polypropylene meshes, Surgical implants, Thermosensitive hydrogels
Otero, J., Navajas, D., Alcaraz, J., (2020). Characterization of the elastic properties of extracellular matrix models by atomic force microscopy Methods in Cell Biology (ed. Caballero, David, Kundu, Subhas C., Reis, Rui L.), Academic Press (Cambridge, USA) 156, 59-83
Tissue elasticity is a critical regulator of cell behavior in normal and diseased conditions like fibrosis and cancer. Since the extracellular matrix (ECM) is a major regulator of tissue elasticity and function, several ECM-based models have emerged in the last decades, including in vitro endogenous ECM, decellularized tissue ECM and ECM hydrogels. The development of such models has urged the need to quantify their elastic properties particularly at the nanometer scale, which is the relevant length scale for cell-ECM interactions. For this purpose, the versatility of atomic force microscopy (AFM) to quantify the nanomechanical properties of soft biomaterials like ECM models has emerged as a very suitable technique. In this chapter we provide a detailed protocol on how to assess the Young's elastic modulus of ECM models by AFM, discuss some of the critical issues, and provide troubleshooting guidelines as well as illustrative examples of AFM measurements, particularly in the context of cancer.
JTD Keywords: 3D ECM hydrogels, Atomic force microscopy, Decellularized tissue, Elastic modulus, Endogenous ECM, Extracellular matrix
Hernández-Albors, Alejandro, Castaño, Albert G., Fernández-Garibay, Xiomara, Ortega, María Alejandra, Balaguer, Jordina, Ramón-Azcón, Javier, (2019). Microphysiological sensing platform for an in-situ detection of tissue-secreted cytokines Biosensors and Bioelectronics: X 2, 100025
Understanding the protein-secretion dynamics from single, specific tissues is critical toward the advancement of disease detection and treatments. However, such secretion dynamics remain difficult to measure in vivo due to the uncontrolled contributions from other tissue populations. Here, we describe an integrated platform designed for the reliable, near real-time measurements of cytokines secreted from an in vitro single-tissue model. In our setup, we grow 3D biomimetic tissues to discretize cytokine source, and we separate them from a magnetic microbead-based biosensing system using a Transwell insert. This design integrates physiochemically controlled biological activity, high-sensitivity protein detection (LOD < 20 pg mL−1), and rapid protein diffusion to enable non-invasive, near real-time measurements. To showcase the specificity and sensitivity of the system, we use our setup to probe the inflammatory process related to the protein Interleukine 6 (IL-6) and to the Tumor Necrosis Factor (TNF-α). We show that our setup can monitor the time-dependence profile of IL-6 and TNF-α secretion that results from the electrical and chemical stimulation of 3D skeletal muscle tissues. We demonstrate a novel and affordable methodology for discretizing the secretion kinetics of specific tissues for advancing metabolic-disorder studies and drug-screening applications.
JTD Keywords: Microphysiological tissues, Tissue engineering, Electrochemical, biosensors, Magnetic particles, Skeletal muscle, Electric stimulation
Marti-Muñoz, Joan, Xuriguera, Elena, Layton, John W., Planell, Josep A., Rankin, Stephen E., Engel, Elisabeth, Castaño, Oscar, (2019). Feasible and pure P2O5-CaO nanoglasses: An in-depth NMR study of synthesis for the modulation of the bioactive ion release Acta Biomaterialia 94, 574-584
The use of bioactive glasses (e.g. silicates, phosphates, borates) has demonstrated to be an effective therapy for the restoration of bone fractures, wound healing and vascularization. Their partial dissolution towards the surrounding tissue has shown to trigger positive bioactive responses, without the necessity of using growth factors or cell therapy, which reduces money-costs, side effects and increases their translation to the clinics. However, bioactive glasses often need from stabilizers (e.g. SiO44−, Ti4+, Co2+, etc.) that are not highly abundant in the body and which metabolization is not fully understood. In this study, we were focused on synthesizing pure calcium phosphate glasses without the presence of such stabilizers. We combined a mixture of ethylphosphate and calcium 2-methoxyethoxide to synthesize nanoparticles with different compositions and degradability. Synthesis was followed by an in-depth nuclear magnetic resonance characterization, complemented with other techniques that helped us to correlate the chemical structure of the glasses with their physiochemical properties and reaction mechanism. After synthesis, the organically modified xerogel (i.e. calcium monoethylphosphate) was treated at 200 or 350 °C and its solubility was maintained and controlled due to the elimination of organics, increase of phosphate-calcium interactions and phosphate polycondensation. To the best of our knowledge, we are reporting the first sol-gel synthesis of binary (P2O5-CaO) calcium phosphate glass nanoparticles in terms of continuous polycondensated phosphate chains structure without the addition of extra ions. The main goal is to straightforward the synthesis, to get a safer metabolization and to modulate the bioactive ion release. Additionally, we shed light on the chemical structure, reaction mechanism and properties of calcium phosphate glasses with high calcium contents, which nowadays are poorly understood.
Statement of Significance
The use of bioactive inorganic materials (i.e. bioactive ceramics, glass-ceramics and glasses) for biomedical applications is attractive due to their good integration with the host tissue without the necessity of adding exogenous cells or growth factors. In particular, degradable calcium phosphate glasses are completely resorbable, avoiding the retention in the body of the highly stable silica network of silicate glasses, and inducing a more controllable degradability than bioactive ceramics. However, most calcium phosphate glasses include the presence of stabilizers (e.g. Ti4+, Na+, Co2+), which metabolization is not fully understood and complicates their synthesis. The development of binary calcium phosphate glasses with controlled degradability reduces these limitations, offering a simple and completely metabolizable material with higher transfer to the clinics.
JTD Keywords: Calcium phosphate glasses, Sol-gel process, NMR spectroscopy, Ion release, Biomaterials
Burgués, Javier, Hernández, Victor, Lilienthal, Achim J., Marco, Santiago, (2019). Smelling nano aerial vehicle for gas source localization and mapping Sensors 19, (3), 478
This paper describes the development and validation of the currently smallest aerial platform with olfaction capabilities. The developed Smelling Nano Aerial Vehicle (SNAV) is based on a lightweight commercial nano-quadcopter (27 g) equipped with a custom gas sensing board that can host up to two in situ metal oxide semiconductor (MOX) gas sensors. Due to its small form-factor, the SNAV is not a hazard for humans, enabling its use in public areas or inside buildings. It can autonomously carry out gas sensing missions of hazardous environments inaccessible to terrestrial robots and bigger drones, for example searching for victims and hazardous gas leaks inside pockets that form within the wreckage of collapsed buildings in the aftermath of an earthquake or explosion. The first contribution of this work is assessing the impact of the nano-propellers on the MOX sensor signals at different distances to a gas source. A second contribution is adapting the ‘bout’ detection algorithm, proposed by Schmuker et al. (2016) to extract specific features from the derivative of the MOX sensor response, for real-time operation. The third and main contribution is the experimental validation of the SNAV for gas source localization (GSL) and mapping in a large indoor environment (160 m2) with a gas source placed in challenging positions for the drone, for example hidden in the ceiling of the room or inside a power outlet box. Two GSL strategies are compared, one based on the instantaneous gas sensor response and the other one based on the bout frequency. From the measurements collected (in motion) along a predefined sweeping path we built (in less than 3 min) a 3D map of the gas distribution and identified the most likely source location. Using the bout frequency yielded on average a higher localization accuracy than using the instantaneous gas sensor response (1.38 m versus 2.05 m error), however accurate tuning of an additional parameter (the noise threshold) is required in the former case. The main conclusion of this paper is that a nano-drone has the potential to perform gas sensing tasks in complex environments.
JTD Keywords: Robotics, Signal processing, Electronics, Gas source localization, Gas distribution mapping, Gas sensors, Drone, UAV, MOX sensor, Quadcopter
Gil, V., Del Río, J. A., (2019). Generation of 3-d collagen-based hydrogels to analyze axonal growth and behavior during nervous system development Journal of Visualized Experiments , (148), e59481
This protocol uses natural type I collagen to generate three-dimensional (3-D) hydrogel for monitoring and analyzing the axonal growth. The protocol is centered on culturing small pieces of embryonic or early postnatal rodent brains inside a 3-D hydrogel formed by the rat tail tendon-derived type I collagen with specific porosity. Tissue pieces are cultured inside the hydrogel and confronted to specific brain fragments or genetically-modified cell aggregates to produce and secrete molecules suitable for creating a gradient inside the porous matrix. The steps of this protocol are simple and reproducible but include critical steps to be considered carefully during its development. Moreover, the behavior of growing axons can be monitored and analyzed directly using a phase-contrast microscope or mono/multiphoton fluorescence microscope after fixation by immunocytochemical methods.
JTD Keywords: 3-D hydrogel cultures, Axonal growth, Cell transfection, Chemoattraction, Chemorepulsion, Embryonic nervous system, Issue 148, Neuroscience, Tissue explants
Blanco-Almazán, D., Groenendaal, W., Catthoor, F., Jané, R., (2019). Analysis of time delay between bioimpedance and respiratory volume signals under inspiratory loaded breathing Engineering in Medicine and Biology Society (EMBC) 41st Annual International Conference of the IEEE , IEEE (Berlín, Germany) , 2365-2368
Bioimpedance is known for its linear relation with volume during normal breathing. For that reason, bioimpedance can be used as a noninvasive and comfortable technique for measuring respiration. The goal of this study is to analyze the temporal behavior of bioimpedance measured in four different electrode configurations during inspiratory loaded breathing. We measured four bioimpedance channels and airflow simultaneously in 10 healthy subjects while incremental inspiratory loads were imposed. Inspiratory loading threshold protocols are associated with breathing pattern changes and were used in respiratory mechanics studies. Consequently, this respiratory protocol allowed us to induce breathing pattern changes and evaluate the temporal relationship of bioimpedance with volume. We estimated the temporal delay between bioimpedance and volume respiratory cycles to evaluate the differences in their temporal behavior. The delays were computed as the lag which maximize the cross-correlation of the signals cycle by cycle. Six of the ten subjects showed delays in at least two different inspiratory loads. The delays were dependent on electrode configuration, hence the appearance of the delays between bioimpedance and volume were conditioned to the location and geometry of the electrode configuration. In conclusion, the delays between these signals could provide information about breathing pattern when breathing conditions change.
JTD Keywords: Bioimpedance, Delays, Electrodes, Protocols, Loading, Electrocardiography, Atmospheric measurements
Navarro-Requena, Claudia, Weaver, Jessica D., Clark, Amy Y., Clift, Douglas A., Pérez-Amodio, Soledad, Castaño, Óscar, Zhou, Dennis W., García, Andrés J., Engel, Elisabeth, (2018). PEG hydrogel containing calcium-releasing particles and mesenchymal stromal cells promote vessel maturation Acta Biomaterialia 67, 53-65
The use of human mesenchymal stromal cells (hMSC) for treating diseased tissues with poor vascularization has received significant attention, but low cell survival has hampered its translation to the clinic. Bioglasses and glass-ceramics have also been suggested as therapeutic agents for stimulating angiogenesis in soft tissues, but these effects need further evaluation in vivo. In this study, calcium-releasing particles and hMSC were combined within a hydrogel to examine their vasculogenic potential in vitro and in vivo. The particles provided sustained calcium release and showed proangiogenic stimulation in a chorioallantoic membrane (CAM) assay. The number of hMSC encapsulated in a degradable RGD-functionalized PEG hydrogel containing particles remained constant over time and IGF-1 release was increased. When implanted in the epidydimal fat pad of immunocompromised mice, this composite material improved cell survival and stimulated vessel formation and maturation. Thus, the combination of hMSC and calcium-releasing glass-ceramics represents a new strategy to achieve vessel stabilization, a key factor in the revascularization of ischemic tissues. Statement of Significance: Increasing blood vessel formation in diseased tissues with poor vascularization is a current clinical challenge. Cell therapy using human mesenchymal stem cells has received considerable interest, but low cell survival has hampered its translation to the clinic. Bioglasses and glass-ceramics have been explored as therapeutic agents for stimulating angiogenesis in soft tissues, but these effects need further evaluation in vivo. By incorporating both human mesenchymal stem cells and glass-ceramic particles in an implantable hydrogel, this study provides insights into the vasculogenic potential in soft tissues of the combined strategies. Enhancement of vessel formation and maturation supports further investigation of this strategy.
JTD Keywords: Calcium, Glass-ceramic particles, Vascularization, hMSC, Hydrogel
Punet, X., Levato, R., Bataille, I., Letourneur, D., Engel, E., Mateos-Timoneda, M. A., (2017). Polylactic acid organogel as versatile scaffolding technique Polymer 113, 81-91
Tissue engineering requires scaffolding techniques based on non-toxic processes that permits the fabrication of constructs with tailored properties. Here, a two-step methodology based on the gelation and precipitation of the poly(lactic) acid/ethyl lactate organogel system is presented. With this technique nanofibrous matrices that resemble natural extracellular matrix can be easily obtained, while allowing control over the mechanical properties of the device. Gelation temperature and the dynamics of the gelation of the organogel system are characterized, and the final mechanical and viscoelastic properties, as well as porosity, as function of the initial polymer concentration are described. We show that gelation temperature of the system is concentration independent and below 44.5 °C, which permits gelation at room temperature. Furthermore, mechanical properties are found in the range of the soft organic tissues, and the obtained micro-network architecture gives place to a flexible structure. Such structure presents tuneable elastic modulus and viscoelastic properties as function of nanofibers density. Moreover, centimetre-long tubular scaffolds with the diameter of medium-caliber blood vessels were produced. The fibrous nano-architecture mimics the native extracellular matrix fibres diameter and morphology was proven to be suitable to support endothelialization of the lumen of the tube. Thus, this strategy, based on biocompatible green compound might be promising for the fabrication of large 3D scaffolds for tissue engineering applications.
JTD Keywords: Gel, Gelation, Nanofibrous, Organogel, PLA, Poly(lactic) acid, Scaffold
De Koker, Stefaan, Cui, Jiwei, Vanparijs, Nane, Albertazzi, Lorenzo, Grooten, Johan, Caruso, Frank, De Geest, Bruno G., (2016). Engineering polymer hydrogel nanoparticles for lymph node-targeted delivery Angewandte Chemie - International Edition 55, (4), 1334-1339
The induction of antigen-specific adaptive immunity exclusively occurs in lymphoid organs. As a consequence, the efficacy by which vaccines reach these tissues strongly affects the efficacy of the vaccine. Here, we report the design of polymer hydrogel nanoparticles that efficiently target multiple immune cell subsets in the draining lymph nodes. Nanoparticles are fabricated by infiltrating mesoporous silica particles (ca. 200 nm) with poly(methacrylic acid) followed by disulfide-based crosslinking and template removal. PEGylation of these nanoparticles does not affect their cellular association in vitro, but dramatically improves their lymphatic drainage in vivo. The functional relevance of these observations is further illustrated by the increased priming of antigen-specific T cells. Our findings highlight the potential of engineered hydrogel nanoparticles for the lymphatic delivery of antigens and immune-modulating compounds.
JTD Keywords: Dendritic cells, Disulfides, Hydrogels, Nanoparticles, Vaccines
Estrada, L., Torres, A., Sarlabous, L., Jané, R., (2016). Evaluating respiratory muscle activity using a wireless sensor platform Engineering in Medicine and Biology Society (EMBC) 38th Annual International Conference of the IEEE , IEEE (Orlando, USA) , 5769-5772
Wireless sensors are an emerging technology that allows to assist physicians in the monitoring of patients health status. This approach can be used for the non-invasive recording of the electrical respiratory muscle activity of the diaphragm (EMGdi). In this work, we acquired the EMGdi signal of a healthy subject performing an inspiratory load test. To this end, the EMGdi activity was captured from a single channel of electromyography using a wireless platform which was compared with the EMGdi and the inspiratory mouth pressure (Pmouth) recorded with a conventional lab equipment. From the EMGdi signal we were able to evaluate the neural respiratory drive, a biomarker used for assessing the respiratory muscle function. In addition, we evaluated the breathing movement and the cardiac activity, estimating two cardio-respiratory parameters: the respiratory rate and the heart rate. The correlation between the two EMGdi signals and the Pmouth improved with increasing the respiratory load (Pearson's correlation coefficient ranges from 0.33 to 0.85). The neural respiratory drive estimated from both EMGdi signals showed a positive trend with an increase of the inspiratory load and being higher in the conventional EMGdi recording. The respiratory rate comparison between measurements revealed similar values of around 16 breaths per minute. The heart rate comparison showed a root mean error of less than 0.2 beats per minute which increased when incrementing the inspiratory load. In summary, this preliminary work explores the use of wireless devices to record the muscle respiratory activity to derive several physiological parameters. Its use can be an alternative to conventional measuring systems with the advantage of being portable, lightweight, flexible and operating at low energy. This technology can be attractive for medical staff and may have a positive impact in the way healthcare is being delivered.
JTD Keywords: Biomedical monitoring, Electrodes, Medical services, Monitoring, Muscles, Wireless communication, Wireless sensor networks
Sánchez-Ferrero, Aitor, Mata, Álvaro, Mateos-Timoneda, Miguel A., Rodríguez-Cabello, José C., Alonso, Matilde, Planell, Josep, Engel, Elisabeth, (2015). Development of tailored and self-mineralizing citric acid-crosslinked hydrogels for in situ bone regeneration Biomaterials 68, 42-53
Bone tissue engineering demands alternatives overcoming the limitations of traditional approaches in the context of a constantly aging global population. In the present study, elastin-like recombinamers hydrogels were produced by means of carbodiimide-catalyzed crosslinking with citric acid, a molecule suggested to be essential for bone nanostructure. By systematically studying the effect of the relative abundance of reactive species on gelation and hydrogel properties such as functional groups content, degradation and structure, we were able to understand and to control the crosslinking reaction to achieve hydrogels mimicking the fibrillary nature of the extracellular matrix. By studying the effect of polymer concentration on scaffold mechanical properties, we were able to produce hydrogels with a stiffness value of 36.13 ± 10.72 kPa, previously suggested to be osteoinductive. Microstructured and mechanically-tailored hydrogels supported the growth of human mesenchymal stem cells and led to higher osteopontin expression in comparison to their non-tailored counterparts. Additionally, tailored hydrogels were able to rapidly self-mineralize in biomimetic conditions, evidencing that citric acid was successfully used both as a crosslinker and a bioactive molecule providing polymers with calcium phosphate nucleation capacity.
JTD Keywords: Biomimetic material, Biomineralisation, Bone tissue engineering, Cross-linking, Hydrogel, Mesenchymal stem cell
Kovtun, A., Goeckelmann, M. J., Niclas, A. A., Montufar, E. B., Ginebra, M. P., Planell, J. A., Santin, M., Ignatius, A., (2015). In vivo performance of novel soybean/gelatin-based bioactive and injectable hydroxyapatite foams Acta Biomaterialia Elsevier Ltd 12, (1), 242-249
Major limitations of calcium phosphate cements (CPCs) are their relatively slow degradation rate and the lack of macropores allowing the ingrowth of bone tissue. The development of self-setting cement foams has been proposed as a suitable strategy to overcome these limitations. In previous work we developed a gelatine-based hydroxyapatite foam (G-foam), which exhibited good injectability and cohesion, interconnected porosity and good biocompatibility in vitro. In the present study we evaluated the in vivo performance of the G-foam. Furthermore, we investigated whether enrichment of the foam with soybean extract (SG-foam) increased its bioactivity. G-foam, SG-foam and non-foamed CPC were implanted in a critical-size bone defect in the distal femoral condyle of New Zealand white rabbits. Bone formation and degradation of the materials were investigated after 4, 12 and 20 weeks using histological and biomechanical methods. The foams maintained their macroporosity after injection and setting in vivo. Compared to non-foamed CPC, cellular degradation of the foams was considerably increased and accompanied by new bone formation. The additional functionalization with soybean extract in the SG-foam slightly reduced the degradation rate and positively influenced bone formation in the defect. Furthermore, both foams exhibited excellent biocompatibility, implying that these novel materials may be promising for clinical application in non-loaded bone defects.
JTD Keywords: Bone regeneration, Calcium phosphate cement, Gelatine, Rabbit model, Soybean
Abadías, Clara, Serés, Carme, Torrent-Burgués, J., (2015). AFM in peak force mode applied to worn siloxane-hydrogel contact lenses Colloids and Surfaces B: Biointerfaces 128, 61-66
The objective of this work is to apply Atomic Force Microscopy in Peak Force mode to obtain topographic characteristics (mean roughness, root-mean-square roughness, skewness and kurtosis) and mechanical characteristics (adhesion, elastic modulus) of Siloxane-Hydrogel Soft Contact Lenses (CLs) of two different materials, Lotrafilcon B of Air Optix (AO) and Asmofilcon A of PremiO (P), after use (worn CLs). Thus, the results obtained with both materials will be compared, as well as the changes produced by the wear at a nanoscopic level. The results show significant changes in the topographic and mechanical characteristics of the CLs, at a nanoscopic level, due to wear. The AO CL show values of the topographic parameters lower than those of the P CL after wear, which correlates with a better comfort qualification given to the former by the wearers. A significant correlation has also been obtained between the adhesion values found after the use of the CLs with tear quality tests, both break-up-time and Schirmer.
JTD Keywords: Adhesion, Atomic force microscopy-peak force mode, Surface topography, Worn siloxane-hydrogel contact lenses, Young modulus
Van Der Hofstadt, M., Hüttener, M., Juárez, A., Gomila, G., (2015). Nanoscale imaging of the growth and division of bacterial cells on planar substrates with the atomic force microscope Ultramicroscopy , 154, 29-36
Abstract With the use of the atomic force microscope (AFM), the Nanomicrobiology field has advanced drastically. Due to the complexity of imaging living bacterial processes in their natural growing environments, improvements have come to a standstill. Here we show the in situ nanoscale imaging of the growth and division of single bacterial cells on planar substrates with the atomic force microscope. To achieve this, we minimized the lateral shear forces responsible for the detachment of weakly adsorbed bacteria on planar substrates with the use of the so called dynamic jumping mode with very soft cantilever probes. With this approach, gentle imaging conditions can be maintained for long periods of time, enabling the continuous imaging of the bacterial cell growth and division, even on planar substrates. Present results offer the possibility to observe living processes of untrapped bacteria weakly attached to planar substrates.
JTD Keywords: Atomic Force Microscope (AFM), Living cell imaging, Bacteria division, Gelatine immobilization, Dynamic jumping mode
Seo, K. D., Kwak, B. K., Sánchez, S., Kim, D. S., (2015). Microfluidic-assisted fabrication of flexible and location traceable organo-motor IEEE Transactions on Nanobioscience , 14, (3), 298-304
In this paper, we fabricate a flexible and location traceable micromotor, called organo-motor, assisted by microfluidic devices and with high throughput. The organo-motors are composed of organic hydrogel material, poly (ethylene glycol) diacrylate (PEGDA), which can provide the flexibility of their structure. For spatial and temporal traceability of the organo-motors under magnetic resonance imaging (MRI), superparamagnetic iron oxide nanoparticles (SPION; Fe
JTD Keywords: Flexible, Hydrogel, Magnetic resonance imaging, Microfluidics, Micromotor, Microparticle, Organo-motor, Poly (ethylene glycol) diacrylate, Self-propulsion, Superparamagnetic iron oxide nanoparticles
Urra, O., Casals, A., Jané, R., (2015). The impact of visual feedback on the motor control of the upper-limb Engineering in Medicine and Biology Society (EMBC) 37th Annual International Conference of the IEEE , IEEE (Milan, Italy) , 3945-3948
Stroke is a leading cause of adult disability with upper-limb hemiparesis being one of the most frequent consequences. Given that stroke only affects the paretic arm's control structure (the set of synergies and activation vectors needed to perform a movement), we propose that the control structure of the non-affected arm can serve as a physiological reference to rehabilitate the paretic arm. However, it is unclear how rehabilitation can effectively tune the control structure of a patient. The use of Visual Feedback (VF) is recommended to boost stroke rehabilitation, as it is able to positively modify neural mechanisms and improve motor performance. Thus, in this study we investigate whether VF can effectively modify the control structure of the upper-limb. We asked six neurologically intact subjects to perform a complete upper-limb rehabilitation routine comprised of 12 movements in absence and presence of VF. Our results indicate that VF significantly increases interlimb similarity both in terms of synergies and activation coefficients. However, the magnitude of improvement depended upon each subject. In general, VF brings the control structure of the nondominant side closer to the control structure of dominant side, suggesting that VF modifies the control structure towards more optimized motor patterns. This is especially interesting because stroke mainly affects the activation coefficients of patients and because it has been shown that the control of the affected side resembles that of the nondominant side. In conclusion, VF may enhance motor performance by effectively tuning the control-structure. Notably, this finding offers new insights to design improved stroke rehabilitation.
JTD Keywords: Bars, Biomedical engineering, Electrodes, Electromyography, Mirrors, Muscles, Visualization
Castaño, O., Sachot, N., Xuriguera, E., Engel, E., Planell, J. A., Park, J. H., Jin, G. Z., Kim, T. H., Kim, J. H., Kim, H. W., (2014). Angiogenesis in bone regeneration: Tailored calcium release in hybrid fibrous scaffolds ACS Applied Materials & Interfaces 6, (10), 7512-7522
In bone regeneration, silicon-based calcium phosphate glasses (Bioglasses) have been widely used since the 1970s. However, they dissolve very slowly because of their high amount of Si (SiO2 > 45%). Recently, our group has found that calcium ions released by the degradation of glasses in which the job of silicon is done by just 5% of TiO2 are effective angiogenic promoters, because of their stimulation of a cell-membrane calcium sensing receptor (CaSR). Based on this, other focused tests on angiogenesis have found that Bioglasses also have the potential to be angiogenic promoters even with high contents of silicon (80%); however, their slow degradation is still a problem, as the levels of silicon cannot be decreased any lower than 45%. In this work, we propose a new generation of hybrid organically modified glasses, ormoglasses, that enable the levels of silicon to be reduced, therefore speeding up the degradation process. Using electrospinning as a faithful way to mimic the extracellular matrix (ECM), we successfully produced hybrid fibrous mats with three different contents of Si (40, 52, and 70%), and thus three different calcium ion release rates, using an ormoglass–polycaprolactone blend approach. These mats offered a good platform to evaluate different calcium release rates as osteogenic promoters in an in vivo subcutaneous environment. Complementary data were collected to complement Ca2+ release analysis, such as stiffness evaluation by AFM, ζ-potential, morphology evaluation by FESEM, proliferation and differentiation analysis, as well as in vivo subcutaneous implantations. Material and biological characterization suggested that compositions of organic/inorganic hybrid materials with a Si content equivalent to 40%, which were also those that released more calcium, were osteogenic. They also showed a greater ability to form blood vessels. These results suggest that Si-based ormoglasses can be considered an efficient tool for calcium release modulation, which could play a key role in the angiogenic promoting process.
JTD Keywords: Biological materials, Blood vessels, Calcium, Electrospinning, Glass, Hybrid materials, Silicon oxides, Sol-gel process, Sol-gels, Angiogenesis, Biological characterization, Calcium phosphate glass, Calcium-sensing receptors, Degradation process, Extracellular matrices, Organic/inorganic hybrid materials, ormoglasses, Silicon
Rajzer, I., Menaszek, E., Kwiatkowski, R., Planell, J. A., Castaño, O., (2014). Electrospun gelatin/poly(ε-caprolactone) fibrous scaffold modified with calcium phosphate for bone tissue engineering Materials Science and Engineering: C 44, 183-190
In this study gelatin (Gel) modified with calcium phosphate nanoparticles (SG5) and polycaprolactone (PCL) were used to prepare a 3D bi-layer scaffold by collecting electrospun PCL and gelatin/SG5 fibers separately in the same collector. The objective of this study was to combine the desired properties of PCL and Gel/SG5 in the same scaffold in order to enhance mineralization, thus improving the ability of the scaffold to bond to the bone tissue. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and the wide angle X-ray diffraction (WAXD) measurements confirmed that SG5 nanoparticles were successfully incorporated into the fibrous gelatin matrix. The composite Gel/SG5/PCL scaffold exhibited more enhanced mechanical properties than individual Gel and Gel/SG5 scaffolds. The presence of SG5 nanoparticles accelerated the nucleation and growth of apatite crystals on the surface of the composite Gel/SG5/PCL scaffold in simulated body fluid (SBF). The osteoblast response in vitro to developed electrospun scaffolds (PCL and Gel/SG5/PCL) was investigated by using normal human primary NHOst cell lines. NHOst cell culture studies showed that higher alkaline phosphatase (ALP) activity and better mineralization were obtained in the case of composite materials than in pure PCL scaffolds. The mechanically strong PCL scaffold served as a skeleton, while the Gel/SG5 fibers facilitated cell spreading and mineralization of the scaffold.
JTD Keywords: Bilayer fibrous scaffold, Ceramic nanoparticles, Electrospinning, Gelatin, Polycaprolactone, Biomechanics, Bone, Calcium phosphate, Cell culture, Electrospinning, Fourier transform infrared spectroscopy, Mechanical properties, Mineralogy, Nanoparticles, Phosphatases, Polycaprolactone, Scanning electron microscopy, X ray diffraction, Polycaprolactone, Alkaline phosphatase activity, Bone tissue engineering, Calcium phosphate nanoparticles, Ceramic nanoparticles, Fibrous scaffolds, Gelatin, Simulated body fluids, Wide-angle x-ray diffraction, Electrospuns, Scaffolds (biology), Electrospinning
Giraldo, B. F., Tellez, J. P., Herrera, S., Benito, S., (2013). Analysis of heart rate variability in elderly patients with chronic heart failure during periodic breathing CinC 2013 Computing in Cardiology Conference (CinC) , IEEE (Zaragoza, Spain) , 991-994
Assessment of the dynamic interactions between cardiovascular signals can provide valuable information that improves the understanding of cardiovascular control. Heart rate variability (HRV) analysis is known to provide information about the autonomic heart rate modulation mechanism. Using the HRV signal, we aimed to obtain parameters for classifying patients with and without chronic heart failure (CHF), and with periodic breathing (PB), non-periodic breathing (nPB), and Cheyne-Stokes respiration (CSR) patterns. An electrocardiogram (ECG) and a respiratory flow signal were recorded in 36 elderly patients: 18 patients with CHF and 18 patients without CHF. According to the clinical criteria, the patients were classified into the follow groups: 19 patients with nPB pattern, 7 with PB pattern, 4 with Cheyne-Stokes respiration (CSR), and 6 non-classified patients (problems with respiratory signal). From the HRV signal, parameters in the time and frequency domain were calculated. Frequency domain parameters were the most discriminant in comparisons of patients with and without CHF: PTot (p = 0.02), PLF (p = 0.022) and fpHF (p = 0.021). For the comparison of the nPB vs. CSR patients groups, the best parameters were RMSSD (p = 0.028) and SDSD (p = 0.028). Therefore, the parameters appear to be suitable for enhanced diagnosis of decompensated CHF patients and the possibility of developed periodic breathing and a CSR pattern.
JTD Keywords: cardiovascular system, diseases, electrocardiography, frequency-domain analysis, geriatrics, medical signal processing, patient diagnosis, pneumodynamics, signal classification, Cheyne-Stokes respiration patterns, ECG, autonomic heart rate modulation mechanism, cardiovascular control, cardiovascular signals, chronic heart failure, decompensated CHF patients, dynamic interaction assessment, elderly patients, electrocardiogram, enhanced diagnosis, frequency domain parameters, heart rate variability analysis, patient classification, periodic breathing, respiratory flow signal recording, Electrocardiography, Frequency modulation, Frequency-domain analysis, Heart rate variability, Senior citizens, Standards
Giraldo, B. F., Chaparro, J. A., Caminal, P., Benito, S., (2013). Characterization of the respiratory pattern variability of patients with different pressure support levels Engineering in Medicine and Biology Society (EMBC) 35th Annual International Conference of the IEEE , IEEE (Osaka, Japan) , 3849-3852
One of the most challenging problems in intensive care is still the process of discontinuing mechanical ventilation, called weaning process. Both an unnecessary delay in the discontinuation process and a weaning trial that is undertaken too early are undesirable. In this study, we analyzed respiratory pattern variability using the respiratory volume signal of patients submitted to two different levels of pressure support ventilation (PSV), prior to withdrawal of the mechanical ventilation. In order to characterize the respiratory pattern, we analyzed the following time series: inspiratory time, expiratory time, breath duration, tidal volume, fractional inspiratory time, mean inspiratory flow and rapid shallow breathing. Several autoregressive modeling techniques were considered: autoregressive models (AR), autoregressive moving average models (ARMA), and autoregressive models with exogenous input (ARX). The following classification methods were used: logistic regression (LR), linear discriminant analysis (LDA) and support vector machines (SVM). 20 patients on weaning trials from mechanical ventilation were analyzed. The patients, submitted to two different levels of PSV, were classified as low PSV and high PSV. The variability of the respiratory patterns of these patients were analyzed. The most relevant parameters were extracted using the classifiers methods. The best results were obtained with the interquartile range and the final prediction errors of AR, ARMA and ARX models. An accuracy of 95% (93% sensitivity and 90% specificity) was obtained when the interquartile range of the expiratory time and the breath duration time series were used a LDA model. All classifiers showed a good compromise between sensitivity and specificity.
JTD Keywords: autoregressive moving average processes, feature extraction, medical signal processing, patient care, pneumodynamics, signal classification, support vector machines, time series, ARX, autoregressive modeling techniques, autoregressive models with exogenous input, autoregressive moving average model, breath duration time series, classification method, classifier method, discontinuing mechanical ventilation, expiratory time, feature extraction, final prediction errors, fractional inspiratory time, intensive care, interquartile range, linear discriminant analysis, logistic regression analysis, mean inspiratory flow, patient respiratory volume signal, pressure support level, pressure support ventilation, rapid shallow breathing, respiratory pattern variability characterization, support vector machines, tidal volume, weaning trial, Analytical models, Autoregressive processes, Biological system modeling, Estimation, Support vector machines, Time series analysis, Ventilation
Jané, R., Lazaro, J., Ruiz, P., Gil, E., Navajas, D., Farre, R., Laguna, P., (2013). Obstructive Sleep Apnea in a rat model: Effects of anesthesia on autonomic evaluation from heart rate variability measures CinC 2013 Computing in Cardiology Conference (CinC) , IEEE (Zaragoza, Spain) , 1011-1014
Rat model of Obstructive Sleep Apnea (OSA) is a realistic approach for studying physiological mechanisms involved in sleep. Rats are usually anesthetized and autonomic nervous system (ANS) could be blocked. This study aimed to assess the effect of anesthesia on ANS activity during OSA episodes. Seven male Sprague-Dawley rats were anesthetized intraperitoneally with urethane (1g/kg). The experiments were conducted applying airway obstructions, simulating 15s-apnea episodes for 15 minutes. Five signals were acquired: respiratory pressure and flow, SaO2, ECG and photoplethysmography (PPG). In total, 210 apnea episodes were studied. Normalized power spectrum of Pulse Rate Variability (PRV) was analyzed in the Low Frequency (LF) and High Frequency (HF) bands, for each episode in consecutive 15s intervals (before, during and after the apnea). All episodes showed changes in respiratory flow and SaO2 signal. Conversely, decreases in the amplitude fluctuations of PPG (DAP) were not observed. Normalized LF presented extremely low values during breathing (median=7,67%), suggesting inhibition of sympathetic system due to anesthetic effect. Subtle increases of LF were observed during apnea. HRV and PPG analysis during apnea could be an indirect tool to assess the effect and deep of anesthesia.
JTD Keywords: electrocardiography, fluctuations, medical disorders, medical signal detection, medical signal processing, neurophysiology, photoplethysmography, pneumodynamics, sleep, ECG, SaO2 flow, SaO2 signal, airway obstructions, amplitude fluctuations, anesthesia effects, anesthetized nervous system, autonomic evaluation, autonomic nervous system, breathing, heart rate variability, high-frequency bands, low-frequency bands, male Sprague-Dawley rats, normalized power spectrum, obstructive sleep apnea, photoplethysmography, physiological mechanisms, pulse rate variability, rat model, respiratory flow, respiratory pressure, signal acquisition, sympathetic system inhibition, time 15 min, time 15 s, Abstracts, Atmospheric modeling, Computational modeling, Electrocardiography, Rats, Resonant frequency
Azevedo, S., Diéguez, L., Carvalho, P., Carneiro, J. O., Teixeira, V., Martínez, Elena, Samitier, J., (2012). Deposition of ITO thin films onto PMMA substrates for waveguide based biosensing devices Journal of Nano Research , 17, 75-83
Biosensors' research filed has clearly been changing towards the production of multifunctional and innovative design concepts to address the needs related with sensitivity and selectivity of the devices. More recently, waveguide biosensors, that do not require any label procedure to detect biomolecules adsorbed on its surface, have been pointed out as one of the most promising technologies for the production of biosensing devices with enhanced performance. Moreover the combination of optical and electrochemical measurements through the integration of transparent and conducting oxides in the multilayer structures can greatly enhance the biosensors' sensitivity. Furthermore, the integration of polymeric substrates may bring powerful advantages in comparison with silicon based ones. The biosensors will have a lower production costs being possible to disposable them after use ("one use sensor chip"). This research work represents a preliminary study about the influence of substrate temperature on the overall properties of ITO thin films deposited by DC magnetron sputtering onto 0,5 mm thick PMMA sheets.
JTD Keywords: ITO thin films, PMMA sheets, Waveguide biosensing devices, Biosensing devices, Conducting oxides, Dc magnetron sputtering, Electrochemical measurements, Enhanced performance, Innovative design, ITO thin films, Multilayer structures, Overall properties, PMMA sheets, Polymeric substrate, Production cost, Sensor chips, Silicon-based, Substrate temperature, Biosensors, Deposition, Design, Film preparation, Optical multilayers, Thin films, Vapor deposition, Waveguides, Substrates
Yue, J. J., Morgenstern, R., Morgenstern, C., Lauryssen, C., (2011). Shape memory hydrogels - A novel material for treating age-related degenerative conditions of the Spine European Musculoskeletal Review , 6, (3), 184-188
Hydrogels are water-insoluble hydrophilic polymers used in a wide range of medical products such as, drug delivery, tissue replacement, heart surgery, gynaecology, ophthalmology, plastic surgery and orthopaedic surgery. These polymers exhibit low toxicity, reduced tissue adherence, and are highly biocompatible. A class of hydrogels, hydrolysed polyacrylonitriles, possess unique shape memory properties, which, when combined with biodurability, mechanical strength and viscoelasticity make them ideal for treating certain degenerative conditions of the spine. Animal and other in vitro studies have shown that the hydrogel is biocompatible and well tolerated by host tissues. This article focuses on two specific indications in spine surgery that demonstrate the potential of hydrogel-based technology to provide significant treatment advantages.
JTD Keywords: Biocompatibility, Degenerative disc disease, Hydrolysed polyacrylonitrile, Minimally invasive surgery, Shape memory hydrogel, Spinal stenosis
Banos, R. C., Vivero, A., Aznar, S., Garcia, J., Pons, M., Madrid, C., Juarez, A., (2009). Differential regulation of horizontally acquired and core genome genes by the bacterial modulator H-NS PLoS Genetics 5, (6), 8
Horizontal acquisition of DNA by bacteria dramatically increases genetic diversity and hence successful bacterial colonization of several niches, including the human host. A relevant issue is how this newly acquired DNA interacts and integrates in the regulatory networks of the bacterial cell. The global modulator H-NS targets both core genome and HGT genes and silences gene expression in response to external stimuli such as osmolarity and temperature. Here we provide evidence that H-NS discriminates and differentially modulates core and HGT DNA. As an example of this, plasmid R27-encoded H-NS protein has evolved to selectively silence HGT genes and does not interfere with core genome regulation. In turn, differential regulation of both gene lineages by resident chromosomal H-NS requires a helper protein: the Hha protein. Tight silencing of HGT DNA is accomplished by H-NS-Hha complexes. In contrast, core genes are modulated by H-NS homoligomers. Remarkably, the presence of Hha-like proteins is restricted to the Enterobacteriaceae. In addition, conjugative plasmids encoding H-NS variants have hitherto been isolated only from members of the family. Thus, the H-NS system in enteric bacteria presents unique evolutionary features. The capacity to selectively discriminate between core and HGT DNA may help to maintain horizontally transmitted DNA in silent form and may give these bacteria a competitive advantage in adapting to new environments, including host colonization.
JTD Keywords: 2A strain 2457T, Escherichia-Coli, Salmonella-Enterica, Protein, DNA, Expression, Binding, HHA, Shigella, Plasmid
Montufar, E. B., Traykova, T., Schacht, E., Ambrosio, L., Santin, M., Planell, J. A., Ginebra, M. P., (2009). Self-hardening calcium deficient hydroxyapatite/gelatine foams for bone regeneration Journal of Materials Science-Materials in Medicine 22nd European Conference on Biomaterials , Springer Netherlands (Lausanne, Switzerland) 21, (3), 863-869
In this work gelatine was used as multifunctional additive to obtain injectable self-setting hydroxyapatite/gelatine composite foams for bone regeneration. The foaming and colloidal stabilization properties of gelatine are well known in food and pharmaceutical applications. Solid foams were obtained by foaming liquid gelatine solutions at 50A degrees C, followed by mixing them with a cement powder consisting of alpha tricalcium phosphate. Gelatine addition improved the cohesion and injectability of the cement paste. After setting the foamed paste transformed into a calcium deficient hydroxyapatite. The final porosity, pore interconnectivity and pore size were modulated by modifying the gelatine content in the liquid phase.
JTD Keywords: Phosphate cement, Gelatin, Behavior
Banos, R. C., Pons, J. I., Madrid, C., Juarez, A., (2008). A global modulatory role for the Yersinia enterocolitica H-NS protein Microbiology , 154, (5), 1281-1289
The H-NS protein plays a significant role in the modulation of gene expression in Gram-negative bacteria. Whereas isolation and characterization of hns mutants in Escherichia coli, Salmonella and Shigella represented critical steps to gain insight into the modulatory role of H-NS, it has hitherto not been possible to isolate hns mutants in Yersinia. The hns mutation is considered to be deleterious in this genus. To study the modulatory role of H-NS in Yersinia we circumvented hns lethality by expressing in Y. enterocolitica a truncated H-NS protein known to exhibit anti-H-NS activity in E. coli (H-NST(EPEC)). Y. enterocolitica cells expressing H-NST(EPEC) showed an altered growth rate and several differences in the protein expression pattern, including the ProV protein, which is modulated by H-NS in other enteric bacteria. To further confirm that H-NST(EPEC) expression in Yersinia can be used to demonstrate H-NS-dependent regulation in this genus, we used this approach to show that H-NS modulates expression of the YmoA protein.
JTD Keywords: Bacterial Proteins/biosynthesis/genetics/ physiology, DNA-Binding Proteins/biosynthesis/genetics/ physiology, Electrophoresis, Gel, Two-Dimensional, Gene Expression Profiling, Gene Expression Regulation, Bacterial, Genes, Essential, Proteome/analysis, RNA, Bacterial/biosynthesis, RNA, Messenger/biosynthesis, Reverse Transcriptase Polymerase Chain Reaction, Sequence Deletion, Yersinia enterocolitica/chemistry/genetics/growth & development/ physiology
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