Application of Induced Pluripotent Stem Cells Derived from Human Periodontal Ligament Cells in Bone Regeneration

The purpose of this study was to primarily culture human periodontal ligament cells(hPDLCs) and to reprogram hPDLCs with exogenous genes via a lentivirus-mediated transfection system. Then induced pluripotent stem cells derived from h PDLCs(hPDLC-iPSCs) were identified. Alizarin red staining was used to observe the formation of mineralized nodules and real-time Polymerase Chain Reaction(PCR) was used to detect the expression of osteogenic genes. For the in vivo experiment, nude mouse skull defect models were established and cell sheets were made to repair the bone defect. The reprogrammed cells were positive for alkaline phosphatase(ALP) staining and embryonic stem cells(ESCs)-specific proteins, and could form teratomas. After osteogenic induction, alizarin red staining showed that the number of mineralized nodules in the h PDLC-i PSCs group was more and the osteogenic related factors ALP, osteocalcin(OCN), Col-I and Runx2 were also expressed higher in hPDLC-iPSCs. The hPDLC-iPSC cell sheets were all successfully made. Histological analysis showed that the h PDLC-i PSC cell sheet got new bone formation. These results demonstrated that hPDLC-iPSCs were successfully generated from human periodontal ligament fibroblasts and hPDLC-iPSC cell sheets provided new options for bone tissue engineering.