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Preincubation Reduces Epithelialization Period after Grafting in Cell‐Precomfluent Cultured Skin

Purpose: We have developed a cultured skin with both epidermal and dermal components using two different types of collagen sponges as a scaffold. In addition, we succeeded in grafting cell‐preconfluent cultured skin immediately after seeding the cells. In this study, we examined whether the incubation before grafting can reduce the period of epithelization after grafting. Method: We produced cultured skin as follow. We seeded fibroblasts on the dermal collagen sponge with a seeding density of 100,000 cells per square centimeter. After incubation for 4 hours, an epidermal collagen sponge was put on the dermal collagen sponge, and keratinocytes were seeded on the epidermal collagen sponge with a seeding density again of 100,000 cells per square centimeter. The cultured skin was incubated for 1, 2, and 3 days (n = 3), and grafted them onto skin defects in SCID mice. Three, 5, 7, and 14 days after grafting, tissue specimens were harvested for histological and immunohistochemical examination. Result: Three days after grafting, in 3 days incubation group, the cultured skins formed epithelium with a few layers, while in other groups, they did not. Five days after grafting, in 3 days incubation group, the cultured skins formed 6–8 epithelium layers, while in other groups, they did fewer layers. Seven days after grafting, in 3 days incubation group, the cultured skin formed epithelial layers consisiting of cornified layers, and human type IV collagen was stained at the dermal‐epidermal junction. In other groups, it was not stained. Fourteen days after grafting, all samples formed epithelial layers, and human type IV collagen was stained. Conclusion: In 3 days incubation group, the epithelization was completed earlier than that in the other groups.