Papers by RAQUEL PATRICIA SILVA
Journal of Materials Chemistry B, 2014
Microencapsulation of cells by using biodegradable hydrogels offers numerous attractive features ... more Microencapsulation of cells by using biodegradable hydrogels offers numerous attractive features for a variety of biomedical applications including tissue engineering. This study highlights the fabrication of microcapsules from an alginate-gelatin crosslinked hydrogel (ADA-GEL) and presents the evaluation of the physico-chemical properties of the new microcapsules which are relevant for designing suitable microcapsules for tissue engineering. Alginate di-aldehyde (ADA) was synthesized by periodate oxidation of alginate which facilitates crosslinking with gelatin through Schiff's base formation between the free amino groups of gelatin and the available aldehyde groups of ADA. Formation of Schiff's base in ADA-GEL and aldehyde groups in ADA was confirmed by FTIR and NMR spectroscopy, respectively. Thermal degradation behavior of films and microcapsules fabricated from alginate, ADA and ADA-GEL was dependent on the hydrogel composition. The gelation time of ADA-GEL was found to decrease with increasing gelatin content. The swelling ratio of ADA-GEL microcapsules of all compositions was significantly decreased, whereas the degradability was found to increase with the increase of gelatin ratio. The surface morphology of the ADA-GEL microcapsules was totally different from that of alginate and ADA microcapsules, observed by SEM. Two different buffer solutions (with and without calcium salt) have an influence on the stability of microcapsules which had a significant effect on the gelatin release profile of ADA-GEL microcapsules in these two buffer solutions.
Applied biochemistry and biotechnology, Jan 27, 2017
In this work, chitosan-based films containing gelatin and chondroitin-4-sulfate (C4S) with and wi... more In this work, chitosan-based films containing gelatin and chondroitin-4-sulfate (C4S) with and without ZnO particles were produced and tested in vitro to investigate their potential wound healing properties. Chitosans were produced from shrimp-head processing waste by alkaline deacetylation of chitin to obtain chitosans differing in molecular weight and degree of deacetylation (80 ± 0.5%). The film-forming solutions (chitosan, C4S and gelatin) and ZnO suspension showed no toxicity towards fibroblasts or keratinocytes. Chitosan was able to agglutinate red blood cells, and film-forming solutions induced no hemolysis. Film components were released into solution when incubated in PBS as demonstrated by protein and sugar determination. These data suggest that a stable, chitosan-based film with low toxicity and an ability to release components would be able to establish a biocompatible microenvironment for cell growth. Chitosan-based films significantly increased the percentage of wound h...
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Papers by RAQUEL PATRICIA SILVA