Abstract: A biomaterial excellent in biocompatibility comprising a composite material of an N-acylchitosan and collagen is described. This biomaterial is suitable for used as a wound dressing material, vascular prosthesis, artificial skin or hemostatic agent.

Abstract: In a method of preparing an antithrombogenic medical material having a heparinized collagen as an antithrombogenic component, there is provided a method comprising the steps of fixing a protamine to a collagen through a polyepoxy compound, and heparinizing the collagen by fixing heparin to the protamine.

Abstract: This invention relates to a hemostatic agent used in surgical operations, which can be produced in two ways: one blending collagen/gelatin with protamine, the other blending collagen/gelatin with protamine and a bi-functional cross-linking agent so as to make said collagen/gelatin have a covalent bond with said protamine. The produced hemostatic agent can stop bleeding within far less time than a conventional hemostatic agent made out of pure collagen.

Abstract: This invention concerns a production process of an antithrombogenic and antiadhesive material which can favorably be used as artificial blood vessels, artificial valves, grafting patches for cardiovascular organs, artificial heart catheters and so on. The gist of this invention is constructed substantially of subjecting glycidyltrialkylammonium halide such as glycidyltrimethylammonium chloride to the reaction with a material comprising pure collagen or collagen and other components like mucopolysaccharide in order to introduce a cationic quaternary functional group in collagen molecules of the material and then subjecting heparin to the ionic combination with the cationic functional group introduced.