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Arnal-Pastor M.,Polytechnic University of Valencia | Valles-Lluch A.,Polytechnic University of Valencia | Valles-Lluch A.,Regenerative Medicine Unit | Keicher M.,Polytechnic University of Valencia | And 3 more authors.
Journal of Colloid and Interface Science | Year: 2011

A set of elastomeric scaffolds with a well defined porous structure was prepared with a template leaching procedure and coated with hyaluronic acid solutions. Depending on the coating process parameters the hyaluronic acid deposited on the pores had configurations ranging from thin disconnected aggregates to a thick continuous layer on the pore surface. The development of the coating layer was studied by scanning electron microscopy and the materials were subjected to dynamical and equilibrium swelling experiments in a water vapor ambient of fixed activity. The porosity change due to coating and to swelling of the coating layer were determined. The hyaluronic acid coating the pores has a different swelling capacity depending on the type of layer formed, as a consequence of the scaffold constraint and of the layer typology. These factors were investigated analytically by modifying the standard theory of gel swelling. An experimental quantity is introduced which reflects the constrainment build-up on gel swelling. © 2011 Elsevier Inc. Source


Alvarez S.,Hospital General Universitario Gregorio Maranon | Alvarez S.,Institute Investigacion Sanitaria Gregorio Maranon | Munoz-Fernandez M.A.,Hospital General Universitario Gregorio Maranon | Munoz-Fernandez M.A.,Institute Investigacion Sanitaria Gregorio Maranon | Munoz-Fernandez M.A.,Networking Research Center on Bioengineering
PLoS ONE | Year: 2013

Members of the mammalian nucleotide binding domain, leucine-rich repeat (LRR)-containing receptor family of proteins are key modulators of innate immunity regulating inflammation. To date, microbial pathogen-associated molecules and toxins have been identified as key triggers of activation of inflammasomes. However, recently, environmental, and neurodegenerative stimuli have been identified that lead to IL-1β release by means of inflammasomes. IL-1β plays a crucial role during brain inflammation, and caspase-1 appears to be a key modulator of IL-1β bioactivity and the consequent transcriptional regulation of gene expression within the brain during inflammation. We show here that exposure of a human neuroblastoma cell line (SK-N-MC cells) to TNF-α promotes ROS-mediated caspase-1 activation and IL-1β secretion. The involvement of NF-κB in the regulation of IL-1β synthesis is investigated through specific inhibition of this transcription factor. The effect of TNF-α was abolished in the presence of ROS inhibitors as NAC, or DPI. Remarkably, SK-N-MC cells do not respond to ATP stimulation in spite of P2X7R expression. These results provide a mechanism by which danger signals and particulate matter mediate inflammation via the inflammasome in the absence of microbial infection. © 2013 Álvarez, Muñoz-Fernández. Source


Arnal-Pastor M.,Polytechnic University of Valencia | Martinez Ramos C.,Polytechnic University of Valencia | Perez Garnes M.,Polytechnic University of Valencia | Monleon Pradas M.,Polytechnic University of Valencia | And 2 more authors.
Materials Science and Engineering C | Year: 2013

A procedure to obtain electrospun mats of hyaluronic acid (HA) stable in aqueous media in one single step has been developed. It consists in combining an HA solution with a divinyl sulfone one as cross-linker in a three-way valve to immediately electroblow their mixture. Membranes obtained with this method, after sterilization and conditioning, are ready to use in cell culture without need of any additional post-treatment. HA nanofibers are deposited onto previously electrospun poly(l-lactic acid) (PLLA) mats in order to obtain stably joined bilayered membranes with an adherent face and the opposite face non-adherent, despite their different hydrophilicity and mechanical properties. These bilayered HA/PLLA membranes may be of use, for example, in applications seeking to transplant cells on a tissue surface and keep them protected from the environment: the PLLA nanofiber face is cell friendly and promotes cell attachment and spreading and can thus be used as a cell supply vehicle, while the HA face hinders cell adhesion and thus may prevent post-surgical adherences, a major issue in many surgeries. © 2013 Elsevier B.V. Source


Valles-Lluch A.,Polytechnic University of Valencia | Poveda-Reyes S.,Polytechnic University of Valencia | Amoros P.,University of Valencia | Beltran D.,University of Valencia | And 2 more authors.
Biomacromolecules | Year: 2013

Excessive water sorption and low mechanical properties are a severe drawback in some biomedical applications of hyaluronic acid (HA). A way to improve these properties is here explored through the novel concept of nanohybrid hydrogels consisting of a HA matrix including different amounts of silica-derived species. This inorganic filler phase controls the mechanical and swelling properties of HA cross-linked matrices. Below a 2 wt % of silica in the systems, nanoparticle aggregates of tens of nanometers and silica oligomers are distributed more or less homogeneously throughout the organic matrix, without percolating. This morphology of the silica phase is accompanied by an increased swelling degree of the composite when compared with pure HA. For higher silica mass ratios in the composites the inorganic counterpart coalesces, leading to a continuous inorganic silica network interpenetrated with the organic HA network, which coexists with a dispersed phase of silica-nanoparticle aggregates. Silica oligomers originating in the exposition of the nanoparticles to reactives during the composite preparation procedure contribute to the continuity of the silica network. For these compositions, swelling is reduced three times when compared with pure HA, and a significant improvement of the mechanical properties occurs. Water-containing samples of these materials exhibited a glass transition, which pure dry HA does not. None of the compositions studied showed any cytotoxicity. Thus, the materials could be of use in tissue engineering applications where these properties of HA need to be modulated. © 2013 American Chemical Society. Source


Arnal-Pastor M.,Polytechnic University of Valencia | Perez-Garnes M.,Polytechnic University of Valencia | Monleon Pradas M.,Polytechnic University of Valencia | Monleon Pradas M.,Networking Research Center on Bioengineering | Valles Lluch A.,Polytechnic University of Valencia
Colloids and Surfaces B: Biointerfaces | Year: 2016

Scaffolds based on poly(ethyl acrylate) having interwoven channels were coated with a hyaluronan (HA) hydrogel to be used in tissue engineering applications. Controlled typologies of coatings evolving from isolated aggregates to continuous layers, which eventually clog the channels, were obtained by using hyaluronan solutions of different concentrations. The efficiency of the HA loading was determined using gravimetric and thermogravimetric methods, and the hydrogel loss during the subsequent crosslinking process was quantified, seeming to depend on the mass fraction of hyaluronan initially incorporated to the pores. The effect of the topologically different coatings on the scaffolds, in terms of mechanical properties and swelling at equilibrium under different conditions was evaluated and correlated with the hyaluronan mass fraction. The potential of these hydrogel coatings as vehicle for controlled drug release from the scaffolds was validated using a protein model. © 2016 Elsevier B.V. Source

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