A SUITABLE ADULT HUMAN PIGMENTED EPIDERMAL CONSTRUCT - A MORPHOLOGICAL AND PHYSIOLOGICAL APPROACH

Human adult keratinocytes and melanocytes obtained From skin biopsies can be serially cultured in vitro. When cells are co-seeded on human d e-epidermized dermis with no cytotoxin or tumor promoting agents in me dium [1]: firstly, a multi-layered epidermis is obtained with an overa ll structure resembling that of native human epidermis which expresses numerous morphological and differentiation biochemical markers, offer ing then, one of the best cultured skin substitutes with a well-struct ured basal lamina [2], secondly, combined with keratinocytes at two di fferent ratios (1 adult melanocyte for 10 adult keratinocytes or 1 for 5 melanocytes), they are located at the basal layer of the rebuilt ep idermis, maintaining the ratio plating and differentiated functions su ch as dentritic arborisation, dopa oxidase activity and melanin synthe sis. This reconstructed human adult epidermis populated by functionall y active adult human melanocytes, suggests the maintenance of a physio logical melanocyte/keratinocyte relationship and opens opportunities f or studying the biology and photobiology of adult human skin pigmentat ion.