IN-VITRO DEGRADATION OF DERMAL SHEEP COLLAGEN CROSS-LINKED USING A WATER-SOLUBLE CARBODIIMIDE

Bacterial collagenase was used to study the susceptibility of dermal s heep collagen (DSC) cross-inked with a mixture of the water-soluble ca rbodiimide 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide hydrochlorid e and N-hydroxysuccinimide (EIN-DSC) towards enzymatic degradation. Co ntrary to non-cross-linked DSC (N-DSC), which had a rate of weight-los s of 18.1% per hour upon degradation, no weight loss was observed for E/N-DSC during a 24 h degradation period. The tensile strength of the EIN-DSC samples decreased during this time period, resulting in partia lly degraded samples having 80% of the initial tensile strength remain ing. The susceptibility of EIN-DSC samples towards enzymatic degradati on could be controlled by varying the degree of cross-linking of the s amples. Ethylene oxide sterilization of EIN-DSC samples made the mater ial more resistant against degradation compared with non-sterilized E/ N-DSC samples. This may be explained by a decrease of the adsorption o f bacterial collagenase onto the collagen owing to reaction of ethylen e oxide with remaining free amine groups in the collagen matrix.