LAUSR

OBJECTIVES Severe oral mucosal and tissue defects can lead to pain, infection, and later undesirable healing of scarring and adhesion, resulting in a poor quality of life. In vitro-engineered oral mucosal equivalents for covering such defects are an alternative to avoiding the donor site morbidity of conventional skin or tissue grafts. We examined the efficacy of our newly developed three-dimensional mucosal cell sheets in an in vivo tongue wound model mimicking the surgical extirpation of tongue cancer. MATERIALS AND METHODS Small oral mucosal and autologous fibrin samples were obtained from surgical patients and Sprague-Dawley rats. The fibrin was mixed with fibroblasts and seeded with keratinocytes that had been primarily cultured for in vitro cell expansion. The three-dimensional autologous cell sheets, cultured in air-lift interface inserts, were transplanted into deep wounds of the rat ventral tongue. Gross and microscopic findings of the postsurgical wounds were compared between wound control and cell sheet groups. RESULTS The cell sheets were flexible, expandable, and easy to transfer, and had histological characteristics similar to that of the normal oral mucosa, with high p63 positivity. They promoted oral wound healing with earlier re-epithelialization and less fibrosis than that in the wound control. The cell sheet-healed tongue had similar histology to that of a normal tongue. CONCLUSIONS Our engineered cell sheets have potential applicability for the rapid healing of oral mucosal and soft tissue defects, without scarring, adhesion, and functional deficits. CONDENSED ABSTRACT The efficacy of in vitro-engineered mucosal equivalents, using completely autologous mucosa and plasma, was examined. Transplantation of the autologous cell sheets into deep wounds of the rat ventral tongue promoted oral wound healing with earlier re-epithelialization and less fibrosis than that in controls. Healed and normal tongues showed similar histology.