IMPROVEMENTS TO MELANODERM™, AN EPIDERMAL MODEL CONTAINING FUNCTIONAL MELANOCYTES FOR SKIN LIGHTENING STUDIES.

Clinical skin lightening studies often run in excess of 3 months duration and are very costly. Therefore, there is considerable interest in developing methodology using cultured skin tissues to perform such studies in vitro. Towards this end, we have produced MelanoDerm, a highly differentiated, three-dimensional tissue culture model of human epidermis that contains normal human melanocytes (NHM) and keratinocytes (NHK). Cultures have been produced containing NHM of varying skin phototypes and pigmentation levels of the tissues follow the expected order, i.e. Black>Asian>Caucasian. One previous limitation in utilizing such tissues has been the gradual decline in the tissue morphology. Over a 3-week period, tissues maintained in medium containing β-FGF and α-MSH (LLMM) gradually decrease in the number of viable cell layers (basal to granular layer, inclusive). Also, melanocytes with tissue maintained in LLMM have a tendency to clump and lose dendricity over this time period. To address these drawbacks, a new maintenance medium (NMM) has been developed which omits stimulators of melanogenesis yet maintains epidermal structure (almost without any decline) over periods of at least 4 weeks. In addition, melanocytes within the tissue remain distinct and highly dendritic. Quantitative melanin assay results show that melanin levels in tissues grown in LLMM and NMM are equivalent. These results demonstrate that MelanoDerm cultured in NMM will be useful for extended studies of melanogenesis and skin lightening.

Alpha-MSH (Alpha-melanocyte stimulating hormone), Beta-FGF (b-FGF), Clinical studies, LLMM, MSH, MelanoDerm, Melanocyte stimulating hormone, Melanogenesis, NHEK, NHM, NMM, Normal human melanocytes, Pre-validation, Prevalidation, Skin lightening, Validation