Heparinized bovine pericardium as a novel cardiovascular bioprosthesis

A novel chemical modification of biological tissues was developed by the di rect coupling heparin to bovine pericardium (BP). The heparinization involv es pretreatment of BP using GA and followed by grafting heparin to BP by th e reaction of residual aldehyde and amine group of heparin. BP was modified by direct coupling of heparin and the effect of heparin coupling on calcif ication was evaluated in vitro and in vivo. Heparinized BP was characterize d by measuring shrinkage temperature, mechanical properties, digestion resi stance to collagenase enzyme, in vitro cytotoxicity, and in vivo calcificat ion. Thermal and mechanical properties showed that the durability of hepari n-treated tissue increased as compared with fresh tissue and GA-treated tis sue. Resistance to collagenase digestion revealed thatheparin-treated tissu e has greater resistance to enzyme digestion than did fresh tissue and GA-t reated tissue. Heparinized tissue had shown to be non-cytotoxic, however, r elatively high cytotoxicity was observed in the GA-treated tissues due to t he release of GA. In vivo calcification study demonstrated much less calciu m deposition on heparin-treated BP than GA-treated one. Obtained results at test to the usefulness of heparinized BP for cardiovascular bioprostheses. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.