Preclinical evaluation of melanocyte transplantation by chitosan-based melanocyte spheroid patch to skin prepared by controlled sunburn blistering.

Transplantation of autologous cultured melanocytes as cell suspension has been used for the treatment of vitiligo. The recipient site is often prepared by laser-mediated dermabrasion. Such procedures encounter disadvantages including prolonged transplantation duration, unsecured cell adherence to lesional skin and potential scarring. To improve this, here we propose a method by preparing recipient sites before transplantation by psoralen and ultraviolet A (PUVA)-induced sunburn followed by transplanting cells with a chitosan-based melanocyte spheroid patch. We evaluated the method in nude mice. Application of methoxsalen-soaked filter paper on skin for 30 min followed by ultraviolet A exposure induced controlled sunburn blisters in 2 days. Upon transplantation, the blister roof could be quickly peeled off by a waxing patch. The chitosan membrane on which melanocytes were precultured into multicellular spheroids was transplanted with cells facing the skin. The chitosan patch adhered well to skin and secured the contact of melanocytes with the recipient site. One day later, melanocyte spheroids already detached from the chitosan membrane and adhered to the recipient skin. Our results suggest that the combination of chitosan-based melanocyte spheroid patch with epidermal ablation by PUVA-induced sunburn reaction can be a feasible method to facilitate melanocyte transplantation.