Changes in the mechanical properties of dermal sheep collagen during in vitro degradation

The changes in tensile strength, elongation at break, and high strain modulus of dermal sheep collagen (DSC) during in vitro degradation using bacterial collagenase were studied. The changes in mechanical properties were compared with the change in weight of the samples as a function of degradation time. DSC was crosslinked with either glutaraldehyde (GA) or hexamethylene diisocyanate (HMDIC). During degradation, the changes in mechanical properties of the N-DSC, H-DSC or G-DSC samples were more pronounced than the changes in the weight of the samples. Of the mechanical properties studied, the tensile strength was most susceptible to degradation of the DSC samples. After 2.5 h, N-DSC samples had lost only 55% of their initial weight, but the samples had no tensile strength left. Similar results were obtained for H-DSC, which retained no tensile strength after 24 h degradation, whereas only 45% of the initial weight was lost. G-DSC lost 3.5% of its weight after 24 h degradation, but only 25% of the initial tensile strength remained.