SHED Cells Labeled with MIRB can be Tracked in Repairing Periodontal Bone Defects in Rats

Abstract

Background: Chronic periodontitis could lead to alveolar bone resorption and even tooth loss. Stem cells from exfoliated deciduous teeth (SHED) are the proper seed cells for bone regeneration because of their potential in osteogenic differentiation. However tracking the survival, migration and differentiation of the transplanted stem cells is necessary to improve the transplantation success. Methods: Superparamagnetic iron oxide particles (SPIO) Molday ION Rhodamine-BTM (MIRB) were used for labeling and monitoring SHED cells in vivo by magnetic resonance imaging (MRI). Proper labeling concentration of MIRB was determined by cell viability, proliferation, osteogenic differentiation and MRI analysis in vitro after SHED cells were labeled with MIRB at different concentration of 12.5, 25, 50, 100μgFe/mL. MIRB labeled SHED were transplanted to the periodontal bone defect model in rats and tracked by MRI in vivo. The regeneration of periodontal bone were calculated with HE and immunohistochemical analysis. The survival of transplanted SHED cells in vivo was verified with Prussian blue staining.Results: After testing 25μg Fe/mL MIRB was used in vivo cells tracking. After transplanted to the periodontal bone defect model in rats, the MIRB labeled SHED could be tracked in vivo through the artifact of the low intensity signal caused by Fe3+ at 6 and 9 weeks post-surgery. HE and immunohistochemical analysis showed that both SHED labeled and unlabeled with MIRB could promote regeneration of periodontal bone defect. Prussian blue staining further verified the survival of transplanted SHED cells in vivo. Conclusions: Overall, SHED cells could promote the regeneration of periodontal bone in rats and the survival of SHED cells could be tracked by labeling with MIRB in vivo. However the distribution of the positive cells at the edge of the regenerated new bone remind us the SHED cell could promote the regeneration of new bone by factors section.