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-chitosan 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 membranes was studied by haemorheological method. These hydrogels have water contents 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 temperature plays an important role in swelling kinetics of these semi-IPN membranes. Melting temperature (Tm) of membranes increased with a decrease in endothermic peak with increasing beta-chitosan content. The tensile strength 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 haemorheological studies indicated the biocompatible nature of membranes with no significant changes in whole blood and plasma viscosity and red blood cell rigidity.