Effect of alternative crosslinking techniques on the enzymatic degradation of bovine pericardia and their calcification.

The in vitro calcification and enzymatic degradation of bovine pericardia (BP) after a series of surface treatments were studied as a function of exposure time. The degradation of these treated surfaces was monitored by scanning electron micrography and tensile strength measurements. Polyethylene glycol-(PEG) grafted BP and glutaraldehyde-(GA) treated BPs retained maximum stability in collagenase digestion compared with SDS-treated BP. The ability of alpha chymotrypsin, bromelain, esterase, trypsin, and collagenase to modulate the degradation of SDS-, GA-, PEG-, Carbodiimide-, and glycidylether-treated BPs also was investigated. Incubation of various enzymes to these crosslinked pericardia variably reduced the tensile strength of these tissues. It is conceivable that chemical treatments of pericardial tissues might have altered their physical and chemical configuration and the subsequent degradation properties. In vitro calcification studies showed a substantial reduction in the calcification profile of PEG-grafted bovine pericardia compared to other treated tissues. Furthermore, the biocompatibility aspects of pericardial tissues were established by platelet adhesion and octane contact angle. In conclusion, it seems that the surface modification of bovine pericardia via GA-PEG grafting may provide new ways of controlling biodegradation and calcification.