BIOCOMPATIBILITY AND TISSUE REGENERATING CAPACITY OF CROSS-LINKED DERMAL SHEEP COLLAGEN

The biocompatibility and tissue regenerating capacity of four crosslin ked dermal sheep collagens (DSC) was studied. In vitro, the four DSC v ersions were found to be noncytotoxic or very low in cytoxicity. After subcutaneous implantation in rats, hexamethylenediisocyanate-crosslin ked DSC (HDSC) seldom induced an increased infiltration of neutrophils or macrophages, as compared with normal wound healing; whereas new fo rmation of collagen was observed. DSC crosslinked with glutaraldehyde (GDSC) followed by reaction with NaBH4 shortly after implantation show ed an increased infiltration of neutrophils with a deviant morphology. Furthermore, a high incidence of calcification was observed, which ma y explain the minor ingrowth of giant cells and fibroblasts, and the p oor formation of new rat collagen. Acyl azide-crosslinked DSC (AaDSC) first induced an increased infiltration of macrophages, and then of gi ant cells, both with high lipid formation. AaDSC degraded at least twi ce as slowly as HDSC and GDSC, finally leaving a matrix of newly forme d rat collagen. Samples crosslinked with 1-ethyl-3-(3-dimethylaminopro pyl)carbodiimide hydrochloride and N-hydroxysuccinimide (ENDSC) induce d the same mild cellular reaction as HDSC; whereas, similar to AaDSC, the degradation rate was slow and an-optimal rat collagen matrix was f ormed. Of the crosslinked DSC samples, ENDSC seems most promising for tissue regeneration. (C) 1994 John Wiley and Sons, Inc.