Ex vivo study of skin phototypes.

We studied skin phototypes ex vivo to validate a model of epidermal reconstruction with melanocytes. We made autologous epidermal reconstructs with keratinocytes and melanocytes of healthy donors of skin phototypes I to VI. Keratinocytes and melanocytes were seeded on a dead de-epidermized dermis (Prunieras type) at a 1:20 melanocyte/keratinocyte ratio. Reconstructed epidermis was grown for 15 d at the air-liquid interface with or without ultraviolet B irradiation. A macroscopic, chromometric, histologic, and ultrastructural evaluation was performed. Reconstructs reproduced the initial phototype with few modifications. The intensity of melanin transfer correlated with the in vivo situation and was stimulated after ultraviolet B irradiation in reconstructs of all categories of skin phototypes.