Physical contact between dendritic melanocytes and squamous keratinocytes is a prerequisite for melanosome transfer to occur, so that co-culture system using collagen type-I would be essential. Co-culture of melanocytes and keratinocytes suggests that melanin exocytosis is specifically induced by keratinocytes activated by UV and secretion of alpha-MSH. This hormone is derived from POMC, which is secreted mainly from pituitary gland, but the local skin area on the exposure to UV light also produce POMC and alpha-MSH, one of the cleavage hormones.  

However, the establishment of cell-to-cell contact communication will be challenging. Rab11b is involved in the predominant mechanism of melanin transfer is keratinocyte-induced exocytosis. That is why transfection to overexpress Rab11b might be helpful.