A Study of Reconstructed Human Epidermis Model in vitro

Objective To establish a reconstructed human epidermis model in vitro, and to study the process of re-epithelialization. Methods A dermal substrate devoid of epidermis was prepared; a 2 mm skin biopsy explant was transplanted onto the dermal substrates. Visualization of epidermal cell migration was carried out by fluorescence imaging. The proliferation and differentiation of the new epithelial cells were observed using histopathological and immunohistochemical staining (Ki67). EGF was added to the culture medium of the experimental samples but not to that of the controls. Results After 3 days of culture, re-epithelialization was observed on the surface of the dermal substrate. A complete structure resembling regular epidermis was noted in 10 days. As compared to control samples, EGF-treated samples had larger area of re-epithelialization (t= 3.02, P 0.01), greater thickness (t=2.87,P0.01), more layers of cells (t=2.43, P 0.05), higher keratinocyte proliferation indices (t=2.29,P0.01), and higher cell density (t=2.33, P0.05). Conclusion A reconstructed dermal substrate could induce epidermal regeneration, development and differentiation in vitro.