Hot Topic: A Human In Vitro Model for Epidermal Burn Wounds

Background: Two‐dimensional (2D) cell culture and animal ‐models show only limited comparability to the in vivo situation of burn wounds. Therefore, a human burn wound model, which is based on a reconstructed human epidermis (RHE), was developed. Methods: Burn injuries were introduced to RHE (based on an open source protocol developed by Pumay et al.; and refined by Groeber et al.). via contact with an 83°C heated metal rod and examined for up to 14 days subsequently. The properties of models were characterized by viability testing, electrical impedance measurement, measurement of secreted factors in the supernatant, glucose consumption and histological examination. Results: Burnt areas in wound models showed significantly lower viability in MTT tests, compared to surrounding tissue at the wound edges. Furthermore, burning led to significant differences concerning secretion of LDH, glucose consumption and barrier integrity over the course of 14 days in three different donors. Histological examination showed excessive damage of basal and suprabasal cells in the burn area, and ingrowing cells from the wound edges. Treatment of injuries with commercially available products showed promising results regarding wound healing, which were comparable to the in vivo situation. Moreover, in comparison to a non‐thermal wound model significant differences between the different wound models were found, comparable to those of the in vivo situation. Conclusions: Burned RHE models represent a reproducible in vitro test model for burn wounds and their treatment. The models showed symptoms of injury and healing comparable to clinical observation in histological examination, as well as in molecular and physical measurements. They therefore hold the potential to replace, or at least reduce, animal based test procedures.