A biodegradable antiadhesion collagen membrane with slow release heparin

A biodegradable antiadhesion collagen membrane with slow heparin release was developed. It was totally antiadhesive on the large intestinal surface in an animal study. Four months after implantation, the membrane was absorbed and the wound surface was covered with mesothelial cells. In general, deposition of fibrin on a wound surface leads to the formation of fibrous adhesions. Therefore, heparin, which inhibits the precipitation of fibrin, is effective in preventing these adhesions. Human amnion was cross-linked with a polyepoxy compound after the impregnation of protamine sulfate into its collagen matrix and was heparinized. Nine adult mongrel dogs were used, five for the heparinized experiment and four as controls. In each animal, two 5 X 5 cm2 areas of the serosa were peeled from the large intestine. The exposed areas were covered with the membrane. The membrane showed an excellent antiadhesion effect in both areas in all five dogs (10 areas). In controls, no membrane was used. The greater omentum, uterus or urinary bladder adhered in five of eight areas. An antiadhesion membrane for soft tissue must not interfere with wound healing as well as prevent adhesions.