Feasibility by transplantation of gingival mesenchymal cell sheets as a reconstructive material for palatal full thickness defects

Abstract

Purpose: Full thickness oral mucosal defects are common following resection of various oral mucosal lesions such as oral cancerous or precancerous lesions. Our laboratory investigated cell sheet technology to overcome the unmet medical needs. In this study, we evaluated the feasibility of tissue-engineered gingival mesenchymal cell sheets for treating palatal full thickness defects in rats. Materials and Methods: Gingival mesenchymal cells were obtained from mandibular attached gingival tissues of EGFP rats and cultured. Cells were cultured using thermo-responsive culture dishes to form cell sheets for transplantation onto palatal full thickness defects (3mm in diameter) of SD rats. Six rats were divided into two groups, a transplant group and a control group. Three animals were used in each group. After the cell sheet was transplanted, macroscopic images of palatal wound were taken until complete wound closure. Wound area was analyzed using Image J software. Results: The cells exhibited colony forming potential and formed calcified nodules when they were cultured in osteoinductive medium. Wound healing was accelerated when the cell sheet was transplanted at 3.3 ± 0.6 days (mean ± SD) postoperation in the test group. In the control group, healing was accelerated at 4.7 ± 0.6 days after the transplantation. The palatal full thickness defects were well-regenerated, and wound healing in the transplant group was completed at day 6.6 ± 0.6. In contrast, wound healing in the control group was completed at day 8.6 ± 1.2. It was statistically significant difference between two groups. Histological examination showed similar wound healing patterns in the two groups. After using H.E. staining, dense hyperplasy of the connective tissue is detected in the transplant group compared to the control group. Conclusion: Gingival mesenchymal cell sheet can be served as a new reconstruction material for palatal full thickness oral defects.