Magalhaes J.,CIBER ISCIII |
Magalhaes J.,University of La Coruna |
Crawford A.,Center for Biomaterials and Tissue Engineering |
Hatton P.V.,Center for Biomaterials and Tissue Engineering |
And 3 more authors.
Journal of Bioactive and Compatible Polymers | Year: 2014
Poly(2-ethyl-(2-pyrrolidone)methacrylate)-hyaluronic acid hydrogels based on the free radical polymerization of 2-ethyl-(2-pyrrolidone)methacrylate combined with hyaluronic acid, using N,N′-methylenebisacrylamide or triethylene glycol dimethacrylate, as cross-linking agents, were considered for tissue engineering applications. Bovine articular chondrocytes were seeded onto the poly(2-ethyl-(2-pyrrolidone)methacrylate)-hyaluronic acid hydrogels, under orbital agitation, for a total of 40 days. The engineered cell-constructs were characterized according to cell proliferation, morphology and distribution as well as the biochemical composition of the tissue formed. The chondrocytes were found to be attached and presented a typical spherical morphology. Cells were able to proliferate and synthesize a hyaline-like matrix rich in glycosaminoglycans and collagen type II which were mainly located on the superficial area. Increased content of individual components poly(2-ethyl-(2-pyrrolidone)methacrylate) and hyaluronic acid, in triethylene glycol dimethacrylate-cross-linked networks led to enhanced cell distribution and total glycosaminoglycans content, supporting their potential application for the repair of cartilaginous tissues. © The Author(s) 2014.
Rodenas-Rochina J.,Center for Biomaterials and Tissue Engineering |
Vidaurre A.,CIBER ISCIII |
Vidaurre A.,Center for Biomaterials and Tissue Engineering |
Castilla Cortazar I.,Center for Biomaterials and Tissue Engineering |
And 2 more authors.
Polymer Degradation and Stability | Year: 2015
Poly(L-lactic acid)(PLLA)/poly(ε-caprolactone)(PCL)/hydroxyapatite(HAp) composites appear as promising materials for healing large bone defects. Highly porous PLLA/PCL scaffolds, 80/20, 20/80 weight ratios, porosity >85%, were prepared by a dual technique of freeze extraction and porogen leaching, with and without HAp. A double pore structure was obtained, with interconnected macroporosity together with interconnected microporosity. Subsequent long-term (78 weeks = 1.5 years) hydrolytic degradation behavior was investigated in terms of the samples' mechanical properties, molecular weight (Mw), mass changes, thermal characteristics, X-ray Diffraction and Thermogravimetric Analysis. Elastic modulus and yield strength of as-synthesized scaffolds were higher for PLLA rich blends and including the inorganic phase does not lead to a mechanical strengthening in these materials. Nevertheless, after 30 weeks of degradation, PLLA rich scaffolds lost more than half of their strength and rigidity. On the contrary, the densification modulus of the PLLA based blends increased with degradation time, whereas PCL-based blends had a relatively constant densification modulus. PCL-based samples showed lower hydrolysis coefficients k than PLLA-based samples, as expected from the higher density of ester bonds in the latter. Interestingly, although including HAp leads to a lower hydrolysis coefficient k in PCL rich samples, it increases k in the PLLA-based sample, which is consistent with the other results obtained. © 2015 Elsevier Ltd. All rights reserved.