Properties of polyvinyl pyrrolidone/beta-chitosan hydrogel membranes and their biocompatibility evaluation by haemorheological method

The semi-IPN hydrogel membranes of polyvinyl pyrrolidone (PVP) and beta -ch itosan were synthesized by crosslinking beta -chitosan with glutaraldehyde. Hydrogel membranes were characterized by spectroscopic, swelling, thermal and mechanical properties. The in vitro biocompatibility of hydrogel membra nes was studied by haemorheological method. These hydrogels have water cont ents in the range of 60-70% with a high fraction contributed by free water (> 45%). The gel composition, amount of cross-linking agent and swelling te mperature plays an important role in swelling kinetics of these semi-IPN me mbranes. Melting temperature (T-m) of membranes increased with a decrease i n endothermic peak with increasing beta -chitosan content. The tensile stre ngth of membranes in the dry state was found to be high (29-43 MPa) and it increased with increasing beta -chitosan content. The in vitro haemorheolog ical studies indicated the biocompatible nature of membranes with no signif icant changes in whole blood and plasma viscosity and red blood cell rigidi ty. (C) 2001 Kluwer Academic Publishers.