Osteogenic potential of cultured human periosteum-derived cells - A pilot study of human cell transplantation into a rat calvarial defect model

Background: Periosteum shows osteogenic potential and has received considerable attention as a grafting material for the repair of bone and joint defects. The osteogenic potential of cultured periosteal cells has also been reported. The findings of bone formation induced by cultured human periosteum-derived cells using a rat model are presented. Material and methods: Human mandibular periosteum was placed into a culture medium with 10% foetal bovine serum for 14 days. After reaching confluence, periosteal cells were re-suspended with 0.25% trypsin/EDTA and then re-cultured three dimensionally on a collagen sponge. The periosteal cell/collagen complex was grafted into rat calvarial defects and an immunosuppressant (FK506, 1.0 mg/kg/day) was administered intramuscularly. At 2, 3, and 5 weeks postoperatively, grafted tissue was extirpated and compared histologically and radiographically with tissue from a collagen-only grafted group. Results: In the experimental group, periosteal cells had proliferated and differentiated into osteogenic cells by 2 weeks post grafting. At 3 weeks, new bone formation was evident. By 5 weeks, bone growth was observed and new calcification was detected in the defect. Conclusion: Cultured human periosteum-derived cells showed osteogenic potential in a xenogeneic graft model using rat calvarial defects.