^{Genomics and Molecular Biology}

Soft tissues such as skin and oral mucosa defi cits are usually corrected with autologous tissue collected from diff erent donor sites. Considered as the gold standard in damaged tissue reconstruction, this procedure is hampered by signifi cant limitations that include the limited amount of tissue to be collected, the creation of new fragile sites and the possible inappropriate healing of those donor sites. To overcome these limitations, some clinical initiatives have shown the possible use of engineered soft tissues such as oral mucosa for tissue reconstruction. Th us, our primary goal was to optimize the needed conditions for engineering clinically useful gingival human tissue. To reach our goal, we used primary human epithelial cells and fi broblasts that have been isolated from small gingival biopsies. Cells were propagated and then used to engineer human oral mucosa using a collagen scaff old. Before graft ing, tissue structure and protein production were investigated using histological and immunohistochemical techniques. Th e in vivo studies were performed by graft ing the engineered tissue onto the dorsa of immunodefi cient mice. Aft er 15 and 60 days post graft ing, biopsies were collected and used to evaluate the structure of the newly generated mucosa. Interestingly, our data demonstrated that isolated gingival cells were able to adhere and proliferate when seeded into collagen scaff old. Epithelial cells gave a well-structured and stratifi ed epithelium, basically being cultured into a connective tissue (collagen matrix populated with gingival fi broblasts). Following graft ing, the engineered human oral mucosa was able to generate mucosa that covers all available graft ing surfaces. Th e tissue contained a well-vascularised lamina propria and well-structured epithelium. Both structures communicate through a basement membrane containing lamini-5 and type IV collagen. All together, the results demonstrate the usefulness of engineered oral mucosa tissue as an alternative to replace damaged gingiva.