In vitro blood compatibility of glycosaminoglycan-precipitated collagens

Precipitation of bovine hide collagen by chondroitin 6-sulfate at low pH and subsequent crosslinking enhances the blood compatibility of native collagen. Both dehydrothermal crosslinking and complexation with chrondroitin 6-sulfate separately decrease the platelet-aggregating activity of collagen. Crosslinking also decreases the number of free acidic and free basic residues on collagen, which suggests that crosslinking involves these residues in condensation reactions with formation of intrachain and interchain synthetic peptide bonds. Clotting times for collagen precipitated with chondroitin 6-sulfate indicate that this surface does not activate or interfere with coagulation via either the intrinsic or extrinsic pathway. These findings support further consideration of collagen modified by chondroitin 6-sulfate as a blood compatible material.