Effects of UV irradiation on a living skin equivalent

The Living Skin Equivalent (LSE) is an organotypic coculture composed of human dermal fibroblasts interspersed in a collagen-containing matrix and overlaid with human keratinocytes forming a stratified epidermis. The LSE has a dry, air-exposed epidermal surface suitable for the application of oils, creams and emulsions. These features suggested its feasibility as an in vitro skin model for studying the protective effects of sunscreens. Using the thiazolyl blue (MTT) conversion assay as a measure of mitochondrial function, the extent of cytotoxicity induced by various doses of UV-R (280-400 nm) or UV-A (320-400 nm) was evaluated in the LSE