Crosslinked fibrous collagen for use as a dermal implant: control of the cytotoxic effects of glutaraldehyde and dimethylsuberimidate

Collagen intended for use as a dermal implant may be crosslinked to increase its strength and persistence in vivo. Sheets of rat fibrous dermal collagen were crosslinked with either glutaraldehyde or dimethylsuberimidate and the cytotoxicity to human dermal fibroblasts resulting from these treatments was measured by following the inhibition of 3H]leucine incorporation into protein. Both agents were cytotoxic at the concentrations required to effect adequate crosslinking (0.005% and 25 mM, respectively). This cytotoxicity could be limited by extensive washing and by incubation with 5 mM L-lysine, with 66 mM (0.25% w/v) sodium borohydride, or with 71.3 mM (1% w/v) dimedone. However, cytotoxicity was most efficiently controlled by treatment with a combination of 66 mM sodium borohydride and 5 mM L-lysine or 66 mM sodium borohydride and 71.3 mM dimedone. 3H]Leucine incorporation by cells exposed to crosslinked collagen treated with these combinations approached 100% of the values recorded with cells exposed to uncrosslinked collagen.