A stable protocol for the fabrication of transplantable human oral mucosal epithelial cell sheets for clinical application.

Introduction: Cultured stratified epithelial cell sheets have been clinically utilized as transplantable grafts for the regeneration of epithelial tissues, such as the esophagus, cornea, skin, and intraoral cavity. These cell sheets are expected to gain widespread use as regenerative medicine products and save many patients. For this purpose, establishing and disseminating the stale protocol of fabricating the cell sheet is crucial. The fabrication of cultured stratified epithelial cell sheets consists of many important steps, and since the patients' epithelial cell conditions vary widely and are sometimes unstable, the qualities of the epithelial cell grafts are likewise potentially unstable. Therefore, in this paper, we report the stable protocol for fabrication of the transplantable cell sheet particularly from patient-derived oral mucosal tissues.

Methods: Serum extracted from blood and buccal mucosal tissue were collected in Nagasaki University and transported to Tokyo Women's Medical University. Oral mucosal epithelial cells were collected by minimum trypsin method, and this treatment was studied whether to be a critical procedure. After 14 days cultivation, cultured cells were examined whether to be transplantable as cell sheets.

Results: We successfully transported buccal mucosal tissue and serum without damage and contamination. Oral mucosal epithelial cells were collected with high viability by minimum trypsin method. Finally, we succeeded to stably fabricate oral mucosal epithelial cell sheets in all 10 patients.

Conclusions: We established a stable protocol for the fabrication of human oral mucosal epithelial cell sheets and their transportation in clinical settings in this study. These methodologies could also be basis for transplantation therapy using cultured cell sheets of various types other than oral mucosal epithelial cell and will contribute largely to the future development of regenerative medicine.