Melanocyte repopulation in full-thickness wounds using a cell spray apparatus

Melanocyte restoration is critical in reconstituting skin color. We developed a spotted (pie-bald) pig wound model to study methods of restoring melanocytes to the epidermis. Paired, full-thickness, porcine wounds were covered with nonpigmented, fully expanded, 3:1 meshed, split-thickness skin grafts and were sprayed with an epidermal cell suspension. The suspensions were highly pigmented skin (HPS) cell isolates for half of the wounds (n = 16) and nonpigmented skin (NPS) cell isolates for the remaining wounds (n = 16). Histologic sections showed 6.0 ± 3.0 and 15 ± 4.0 pigmented melanocytes per high-power field on days 8 and 20 in HPS-treated wounds and no pigmented melanocytes in NPS-treated wounds. Melanin pigment was dispersed in all layers of the epithelium for the HPS group on day 20 compared with a lack of melanin pigment observed in the NPS group. Cell spraying may provide a clinical method to restore color to skin; further work is needed to control the expression of melanin.