Modeling of wound healing processes in human skin using tissue culture

To facilitate the investigation of the complex process that leads to healing of a human skin wound we developed standardized and repeatable in vitro models for both incisional and burn wounds. Wounds with a standardized area and depth were created in normal human skin biopsies which were then incubated in vitro. It was shown, by cultivation, that both dermal and epidermal cells maintained their viability during a 14-day in vitro incubation if exposed to at least 2% fetal calf serum. By incubating in 10% serum, the skin samples were stimulated to completely re-epithelialize the wounded area. Because a large number of standardized wounds can be obtained from each donor, the re-epithelialization process can be studied histologically and immunohistochemically at several adjacent time points. The ability to keep the cells in the wound area viable without stimulating healing by incubating the wounds in suboptimal serum concentrations implies a way of studying the stimulatory effects of different agents, such as growth factors, on the wound healing process. There were some marked discrepancies in the healing process between the incisional and burn wounds which resemble the in vivo situation, indicating that the in vitro models could be used to more closely study differences between healing in different types of wounds. Our findings suggest that in vitro tissue culture can be of great value in attempting to better understand the complex process of wound healing in human skin.