Chitosan-graft-poly(N-hydroxy ethyl acrylamide) copolymers: Synthesis, characterization and preliminary blood compatibility in vitro.

Poly(N-hydroxy ethyl acrylamide) was grafted onto chitosan in aqueous acidic medium using potassium per sulphate initiator to obtain polymer surfaces with blood compatibility for potential biomedical applications. Thermally cross-linked products were obtained upon drying at 60 °C overnight. Chemically cross-linked films were prepared using methylene bis acrylamide (MBA) cross-linker. The products were characterized by FTIR, XRD and SEM analyses. Protein adsorption onto the film surfaces gave, on the average, 30% bovine serum albumin (BSA) and 10% human serum albumin (HSA) removal from aqueous solution, in vitro. Blood compatibility was evaluated with respect to activated prothrombin time (PT), activated partial thromboplastin time (APTT), and platelet adhesion. PT and APTT values remained within normal ranges after blood-polymer contact, with chitosan-graft-polyHEAA films, in vitro. Chitosan-graft-MBA or chitosan-graft-(polyHEAA;MBA), and blank chitosan films produced higher PT and APTT values under similar experimental conditions with chitosan-graft-polyHEAA films, exhibiting blood anticoagulant activity. SEM pictures taken before and after contact with blood sample did not reveal any significant blood component adhesion on the chitosan-graft-(polyHEAA;MBA) film surface contrary to the observation made on the blank chitosan film.