Development and Characterisation of Human Skin Equivalents and Their Potential Application as a Burn Wound Model

Wound healing is a complex physiological process; hence a reproducible in vitro model of skin provides a valuable tool to further understand the biology of dermal wound repair and to investigate techniques to improve wound healing. Human skin equivalent models (HSEs) have been proposed to serve as an in vitro model for these purposes; however, there is currently no readily available HSE model in Australia. In this study, we describe the production of a HSE obtained by seeding human keratinocytes onto a de-epidermised dermis, (DED) which was then submerged in medium for 3 days and subsequently cultured at the air-liquid interface for up to 20 days. The model was characterised morphologically and biochemically over the 20 days of culture at the air-liquid interface and showed histological features similar to those observed in an in vivo epidermis. Immunohistochemistry of the epidermal markers keratin 6, keratin 14, keratins 1/10/11 and the basement membrane marker collagen type IV, revealed typical differentiation. The HSE was then examined for its potential as a burn wound healing model. Burn wounds were created in the model and the re-epithelialisation of the wounds was followed for 6 days by keratinocyte morphology; metabolic activity was analysed every 2 days. Keratinocytes began to migrate into the wound bed after 2 days and continued to migrate for the next 4 days, suggesting that the HSEs generated may be of great value for studies of the wound healing process and for the evaluation of new therapies.