Using human hair follicle‐derived keratinocytes and melanocytes for constructing pigmented tissue‐engineered skin

Background: Traditional tissue‐engineered skin does not produce a satisfactory long‐term result because it lacks natural skin pigmentation and leads to discolored cosmetically unpleasing skin that only functions to cover the body of patients. Additionally, the cell sources for tissue‐engineered skin are generally derived from normal skin, which is often limited in patients with skin defects. Methods: In this study, hair follicle melanocytes and keratinocytes were isolated from human scalp. The melanocytes were co‐cultured with keratinocytes until the second passage and then purified. Purified melanocytes and keratinocytes were seeded onto the chitosan–gelatin membrane for 1 week to construct pigmented tissue‐engineered skin. The pigmented skin equivalent was used to resurface the skin defect in nude mice. Four weeks after grafting, skin biopsies were harvested to take hematoxylin and eosin staining and immunohistochemistry staining of Melan‐A and HLA‐ABC. Results: Large quantities of purified melanocytes can be obtained with co‐culture method. The hematoxylin and eosin staining of repaired skin biopsy demonstrated that the tissue‐engineered skin can repair skin defects successfully. Engineered skin contained pigmentation and stained positive for Melan‐A and HLA‐ABC, which confirmed the presence of melanocytes and its sources were of human origin. Conclusion: This study demonstrated the possibility of constructing pigmented tissue‐engineered skin with human hair follicle‐derived keratinocytes and melanocytes, which brings a promising method to make up for the deficiency of traditional tissue‐engineered skin and provides an alternative treatment for depigmentation diseases.