Encontrados 25 documentos, a visualizar página 1 de 3
Effect of neutralization and cross-linking on the thermal degradation of chitos...
Correia, D. M.; Gámiz- González, M. A.; Botelho, G.; Vidaurre, A.; Gomez Ribelles, J. L.; Lanceros-Mendez, S.; Sencadas, V.Thermal degradation of as electrospun chitosan membranes and samples subsequently treated with ethanol and cross-linked with glutaraldehyde (GA) have been studied by thermogravimetry (TG) coupled with an infrared spectrometer (FTIR). The influence of the electrospinning process and cross-linking in the electrospun chitosan thermal stability was evaluated. Up to three degradation steps were observed in the TG da...
Different hyaluronic acid morphology modulates primary articular chondrocyte be...
Lebourg, Myriam; Rodenas Rochina, Joaquín; Sousa, Tiago; Mano, J. F.; Gómez Ribelles, J. L.Scaffolds for cartilage tissue engineering should promote both adequate biomechanical environment and chondrogenic stimulation. Hyaluronic acid (HA) has been used in cartilage engineering for its chondrogenic and chondroprotective properties, nevertheless its mechanical properties are limited. Influence of HA microstructure in chondrocyte response has not been addressed yet. In this work, polycaprolactone (PCL)...
Gelatin microparticles aggregates as three-dimensional scaffolding system in ca...
García Cruz, D. M.; Sardinha, Vanessa Morais; Escobar Ivirico, J. L.; Mano, J. F.; Gómez Ribelles, J. L.A three-dimensional (3D) scaffolding system for chondrocytes culture has been produced by agglomeration of cells and gelatin microparticles with a mild centrifuging process. The diameter of the microparticles, around 10 μ, was selected to be in the order of magnitude of the chondrocytes. No gel was used to stabilize the construct that maintained consistency just because of cell and extracellular matrix (ECM) ad...
Physical-chemical properties of cross-linked chitosan electrospun fiber mats
Sencadas, V.; Correia, D. M.; Ribeiro, C.; Moreira, Susana; Botelho, Gabriela; Gómez Ribelles, J. L.; Lanceros-Méndez, S.Chitosan fiber mats were successfully processed by electrospinning. The as-spun fiber mats were neutralized with ethanol and cross-linked with glutaraldehyde. A decrease of the fiber average diameter from 243 ± 43 nm down to 215.53 nm was observed for the neutralized and cross-linking chitosan membrane. It was found that the processing conditions do not alter the initial deacetylation degree of the polymer. Pol...
Determination of the parameters affecting electrospun chitosan fiber size distr...
Lanceros-Méndez, S.; Sencadas, V.; Correia, D. M.; Gómez Ribelles, J. L.; Botelho, Gabriela; Areias, A. C.; Fonseca, A. Maurício C.; Neves, I. C.The production of chitosan nanofiber mats by electrospinning presents serious difficulties due to the lack of suitable solvents and the strong influence of processing parameters on the fiber properties. Two are the main problems to be solved: to control the properties of the solution in order to obtain large area uniform fiber mats by having a stable flow rate and to avoid sparks during the process, dam...
Fabrication of poly(lactic acid) – poly(ethylene oxide) electrospun membranes w...
Ribeiro, C.; Sencadas, V.; Caparrós Vásquez, Cristina Maria; Gómez Ribelles, J. L.; Lanceros-Méndez, S.Biodegradable poly(L-lactide acid) (PLLA) nanofiber membranes were prepared by electrospinning of PLLA and poly(ethylene oxide) (PEO). The selective removal of PEO by water allows to obtain smaller fiber diameters and to increase the porosity of the membranes in comparison to PLLA membranes obtained under the same electrospinning conditions. After removal of PEO membranes with fiber sizes of 260 nm and average ...
Poly(vinylidene fluoride-trifluoroethylene) (72/28) interconnected porous membr...
Ferreira, Armando José Barros; Silva, Jaime; Sencadas, V.; Gómez Ribelles, J. L.; Lanceros-Méndez, S.Electroactive macroporous poly[(vinylidene fluoride)-co-trifluoroethylene] mambranes membranes have been processed by solvent evaporation at room temperature with different polymer/solvent concentrations. The pore architecture consists of on an interconnected spherical pores and this morphology is independent of the membrane thickness. The porosity of the produced membranes increases from 57% for the higher pol...
Tailoring porous structure of ferroelectric poly(vinylidene fluoride-trifluoroe...
California, A.; Cardoso, V. F.; Costa, Carlos M.; Sencadas, V.; Botelho, Gabriela; Gómez Ribelles, J. L.; Lanceros-Méndez, S.Ferroelectric macroporous poly(vinylidene fluoride-trifuoroethylene) membranes have been produced by isothermal crystallization from the solution at different temperatures starting from different diluted solutions of the co-polymer in dimethylformamide. In this way pore architecture, consisting in interconnected spherical pores can be obtained. The mechanism and kinetics of solvent evaporation was investigated ...
Influence of ferrite nanoparticle type and content on the crystallization kinet...
Sencadas, V.; Martins, P.; Pitães, A.; Benelmekki, M.; Gómez Ribelles, J. L.; Lanceros-Méndez, S.This work reports on the nucleation of the β-phase of poly(vinylidene fluoride), PVDF, by incorporating CoFe2O4 and NiFe2O4 nanoparticles, leading in this way, to the preparation of magnetoelectric composites. The fraction of filler nanoparticles needed to produce the same β- to α-phase ratio in crystallized PVDF is one order of magnitude lower in the Cobalt nanoparticles. The interaction between nanoparticles ...
Novel poly(L-lactic acid)/hyaluronic acid macroporous hybrid scaffolds : charac...
Antunes, Joana Costa; Oliveira, Joaquim M.; Reis, R. L.; Soria, Jose Miguel; Gómez Ribelles, J. L.; Mano, J. F.Poly(L-lactic acid), PLLA, a synthetic biodegradable polyester, is widely accepted in tissue engineering. Hyaluronic acid (HA), a natural polymer, exhibits an excellent biocompatibility, influences cell signaling, proliferation, and differentiation. In this study, HA crosslinking was performed by immersion of the polysaccharide in water-acetone mixtures containing glutaraldehyde (GA). The objective of this work...
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