Fig. 3

Preparing the gingival defect animal model and transplanting human fetal GMSCs. a Six days after gingival tissue was resected, human fetal GMSCs were transplanted to the labial gingiva defect of the anterior teeth in rats. In the control group, rats were not intervened with during the experimental period. In the transplanted GMSC group, after the gingival defect model was established, 2 × 10⁶ human fetal GMSCs were transplanted into the defect area of each rat; 3 weeks after stem cell transplantation, gingival tissues were almost the same as the control group. In the gingival defect model group, after resection of gingival tissue, no other procedures were performed; 3 weeks after resection of gingival tissue, the defect area was not healed completely. In the saline group, saline was used instead of stem cells in the defect area, and gingival healing was similar to that in the third group. b Four weeks after transplantation, gingival tissues where stem cells were transplanted and normal tissue was removed; histological sections stained with HE, mouse anti-human mitochondrial (Mito) antibody, rabbit anti-rat CD3 antibody, and goat anti-rat CD20 antibody. Mito section displays negative result, CD3 and CD20 sections display negative results; arrows denote transplanted stem cell masses. GMSC gingival mesenchymal stem cell