| The essential task of burn treatment remains cutaneous wound closure. This goal can be achieved through skin grafting from spared burned body sites. Extensive burn coverage is often limited by the scarce healthy skin surface remaining post-trauma. Within the last decade, the grafting of autologous cultured epidermal cell sheets (CECS) has contributed to save several lifes. However, the main drawback about CECS lies in their lack of important dermal properties. The aim of this project was to create dermo-epidermal skin equivalents (SE), to improve burn wound healing post-grafting.;The main obstacles raised by the first skin models were their structural weakness and limited size. We solved such problems by the peripheral anchorage of SE using a porous material ring. Histological analyses of our anchored SE dermal layer showed an orientation of collagen fibers and fibroblasts similar to normal skin. Planimetric measurement of SE diameter, following anchorage release, showed a 10% surface contraction. This may be explained by the presence of myofibroblasts detected by electron microscopy in SE dermal layer.;Our study implied the development of a surgical model to assess SE transplantation. Our nude mouse model allows early and long-term monitoring of SE evolution post-grafting. Bovine and human type I collagens were used to produce three types of anchored SE (bSE, hSE and hSE+: supplemented with glycosaminoglycans), to evaluate the effects of different dermal components on SE take and evolution in vivo. The take of all SE types was reproducibly superior to CECS and contracted less than CECS post-transplantation. Immunohistological studies of all SE groups showed a good organization of epidermal and dermal layers in culture and post-grafting. Keratin and lipid analyses of SE epidermal layers indicated a normal pattern or keratinocyte differentiation in vitro and in vivo. Moreover, comparative zymography analysis of secreted gelatinases showed lower enzymatic activity in culture supernatants of SE produced with human collagen.;We are the first at developing a completely autologous approach to produce SE in vitro. Our SE could lead to an improved burn wound treatment and be used as an experimental tool for toxicological, pharmacological and cosmetological studies. |
