Alternative model to human skin organ culture: a preliminary study with Leibovitz L15 medium

Organ culture has been used to maintain the three-dimensional structure of the skin and the interaction between melanocytes and keratinocytes, which is essential for melanin production. In the current study we aimed to evaluate the general morphology, viability, and distribution of human melanocytes in a system that uses Leibovitz L15 medium at room temperature. By comparison with human skin explants maintained in Dulbecco's minimum Eagle's medium at 37 degrees C, we found that the skin was better preserved with Leibovitz L15 after 7 days in culture. The addition of 10% fetal bovine serum to this medium did not promote any change. Dividing cells labeled with Ki-67 were visualized at the basal and suprabasal epidermal layers. Retinoic acid was tested at 1 microg/mL and we recorded a reduction of the corneal layer after 48 hours and a complete detachment of the epidermis after 7 days, probably due to a toxic effect in the medium. Melanin and melanocytes were detected by ammoniacal silver and Dopa stainings under light microscopy. We observed that cells were viable throughout the culture period and melanin was distributed in melanocytes and keratinocytes. In conclusion, we suggest that the use of Leibovitz L15 medium at room temperature can be a viable alternative to the normal organ culture of human skin, which is an important system to study the activity and reaction of melanocytes to dermatological products and cosmetics.