Glutaraldehyde crosslinking of collagen substrates inhibits degradation in skin substitutes grafted to athymic mice.

Collagen-based implants have been described as vehicles for transplantation of cultured skin cells for treatment of burn wounds. To optimize vascularization and repair of connective tissue, collagen solubility and glutaraldehyde crosslinking were evaluated. Cultured skin substitutes consisted of human keratinocytes and fibroblasts attached to collagen-glycosaminoglycan substrates that were prepared from acid-insoluble, or partially soluble collagen. Substrates were crosslinked with 0% or 0.25% glutaraldehyde, populated with cells, and grafted to full-thickness wounds on athymic mice (n = 6/condition). After 6 weeks, the wound area was measured by planimetry, and healed wounds were scored by histochemistry for immunoreactivity to HLA-ABC and bovine collagen. Data analysis shows that crosslinking of collagen implants with glutaraldehyde is associated (p < 0.001) with detection of the implant. No association was found between solubility of bovine collagen and immunodetection. Epidermis of all wounds was positive for HLA-ABC, and no differences in wound areas were found. These results suggest that glutaraldehyde crosslinking of collagen implants decreases the rate of biodegradation. Delayed degradation of crosslinked collagen may result clinically in reduced engraftment of skin substitutes.