A novel chemical modification of bioprosthetic tissues using L-arginine.

A novel chemical modification of biological tissues was developed by the direct coupling of bioactive molecule, L-arginine to bovine pericardium (BP). The modification involves pretreatment of BP using GA and followed by grafting arginine to BP by the reaction of residual aldehyde and amine group of L-arginine. BP was modified by direct coupling of bioactive molecules and the effect of L-arginine coupling on calcification and biocompatibility was evaluated in vitro and in vivo. Modified BPs were characterized by measuring shrinkage temperature, mechanical properties, digestion resistance to collagenase enzyme, in vitro plasma protein adsorption and platelet adhesion, and in vivo calcification. Thermal and mechanical properties showed that the durability of arginine treated tissue increased as compared with fresh tissue and GA treated tissue. Resistance to collagenase digestion revealed that modified tissues have greater resistance to enzyme digestion than did fresh tissue and GA treated tissue. Lower protein adsorption and platelet adhesion were observed on modified tissue than non-modified tissue. In vivo calcification study demonstrated much less calcium deposition on arginine treated BP than GA treated one. Obtained results attest to the usefulness of L-arginine treated BP for cardiovascular bioprostheses.