Figure 6

Transplantation of cultured epidermal grafts onto nude mice. Human ABCG2-positive and ABCG2-negative keratinocytes were sorted out and used to prepare cultured epidermal grafts; unsorted keratinocytes and α6-integrin-positive keratinocytes were also used for comparison. All grafts survived for the duration of transplantation, and no signs of necrosis were observed. All grafts from four groups of animals showed no blistering, and the take rate was excellent. However, the whitish-covered grafts in ABCG2-negative groups were observed to be much thinner than in the other three groups. Four weeks after grafting, persistent human epidermis was observed in all groups except in the ABCG2-negative group in which the mouse epidermis was observed to have populated the skin wound. Eighteen weeks after grafting, well organized human epidermis, with all histological cell layers represented, was observed in ABCG2-positive, a6-integrin-positive and control groups, which indicated the complete maturation and differentiation of epidermal cells. Melanocytes were also observed within the basal layer, and distinct rete ridge structures could also be seen. Scale bars: 50 μm.