Figure 1

Application of a 300 °C hot soldering iron for 15 s induces deep second-degree burn wounds to human skin explants. Macroscopic (top) and microscopic PAS appearance (bottom) of skin after burn injury shows mild to profound tissue damage (burned, non-debrided, non-infected, no neutrophil supplementation). Cold burn induced by pressing liquid nitrogen-cooled brass nail for 1 min to the skin surface resulted in darkening of the skin surface and a separation of the epidermis from the dermis, inducing only a first-degree burn (day 6; N = n = 2). Hot burn was induced by using a preheated soldering iron. Only the condition of 300 °C and 15 s induced a deep second-degree burn as indicated by the disrupted collagen structure (day 1; 200 °C 15 s N = n = 1, 300 °C 5 s N = n = 1, 300 °C 15 s N = 3, n = 6). N = number of donors, n = number of technical replicates. Lines and arrows indicate the border from the intact to the disrupted collagen tissue.