500-gray γ-irradiation may increase adhesion strength of lyophilized cadaveric split-thickness skin graft to wound bed

Background: Human cadaveric skin grafts are considered as the 'gold standard' for temporary wound coverage because they provide a more conductive environment for natural wound healing. Lyophilization, packing, and terminal sterilization with gamma-ray can facilitate the application of cadaveric split-thickness skin grafts, but may alter the adhesion properties of the grafts. In a pilot study, we found that 500 Gy γ-irradiation seemed not to reduce the adherence between the grafts and wound beds. Aim and Objectives: We conducted this experiment to compare the adherences of lyophilized, 500-Gy γ-irradiated skin grafts to that of lyophilized, nonirradiated grafts. Materials and Methods: Pairs of wounds were created over the backs of Sprague- Dawley rats. Pairs of 'lyophilized, 500-Gy γ-irradiated' and 'lyophilized, nonirradiated' cadaveric split-thickness skin grafts were fixed to the wound beds. Adhesion strength between the grafts and the wound beds was measured and compared. Results: On post-skin-graft day 7 and day 10, the adhesion strength of γ-irradiated grafts was greater than that of the nonirradiated grafts. Conclusions: Because lyophilized cadaveric skin grafts can be vascularized and the collagen of its dermal component can be remodeled after grafting, the superior adhesion strength of 500-Gy γ-irradiated grafts can be explained by the collagen changes from irradiation.