Enzyme-Pretreatment Removes In Vitro Cytoxic Effects of Dermal Sheep Collagen

We investigated the in vitro cytotoxicity of commercially available hexamethylenediisocyanate-crosslinked dermal sheep collagen (HDSC). HDSC was found to induce medium cytotoxic effects, as measured with methylcellulose cell culture. Apart from primary cytotoxicity, due to direct release of (extractable) cytotoxic products, HDSC was found to contain secondary cytotoxicity, possibly released by enzymatic interactions. In this study we found proof for this hypothesis, by exposing extracted HDSC to enzyme-containing medium. Furthermore we observed, that enzymatic pre-treatment can remove all secondary cytotoxic products, possibly due to detachment of pendants, which are still coupled to fragments of collagen molecules. The possibility of enzymatic pretreatment of HDSC, to obtain a non-cytotoxic/biocompatible material, may be important for in vivo applications.