Effect of mixed transplantation of autologous and allogeneic microskin grafts on wound healing in a rat model of acute skin defect.

The treatment of extensive thermal injuries with insufficient autologous skin remains a great challenge to burn surgeons. In this study, we investigated the influence of the ratio of autologous and allogeneic tissue in mixed microskin grafts on wound healing in order to develop an effective method for using limited donor skin to cover a large open wound. Four different mixtures were tested: autologous microskin at an area expansion ratio of 10∶1 with allogeneic microskin at an area expansion ratio of 10∶1 or 10∶3 and autologous microskin at an expansion ratio of 20∶1 with allogeneic microskin at an expansion ratio of 20∶3 or 20∶6. Wound healing, wound contraction, and integrin β1 expression were measured. Mixed microskin grafting facilitated wound healing substantially. The mixture of autologous microskin at an expansion ratio of 10∶1 with the same amount of allogeneic microskin achieved the most satisfactory wound healing among the 4 tested mixtures. Histological examination revealed the presence of obviously thickened epidermis and ectopic integrin β1 expression. Keratinocytes expressing integrin β1 were scattered in the suprabasal layer. Higher levels of integrin β1 expression were associated with faster wound healing, implying that ectopic expression of integrin β1 in keratinocytes may play a pivotal role in wound healing. In conclusion, this study proves that this new skin grafting technique may improve wound healing.