Abstract:

Objective · To observe the effects of different intensity of extracorporeal shock wave (ESW) combined with bone marrow mesenchymal stem cells (BMMSCs) transplantation on the repair of bone defect in rats and explore the optimal stimulation parameters of ESW in this therapy. Methods · A total of 150 SD rats were randomly divided into 5 groups. The bone defect model was built by drilling a round hole in the femur middle segment with a dental drill. BMMSCs of SD rats were isolated and cultivated in vitro. The third generation of BMMSCs was implanted into the bone defects where ESW with different stimulation parameters was applied. Ten rats in each group were sacrificed 2, 4, and 6 weeks after treatment. X-ray examination and HE staining were respectively used for radiological and histological observations. Radiological and histological scores were evaluated. Expressions of osteogenic related proteins were measured using Western blotting. Results · ESW significantly promoted the local osteogenic activity of the bone defect model. The rats receiving ESW of 8.5 kV and 2 Hz generated calluses earlier and more than other rats. Histological staining showed that their new bones were more mature and Western blotting indicated that the increase in expressions of osteogenic related proteins (RUNX2, ALP, and Col I) was more significant as well. Conclusion · ESW combined with BMMSCs transplantation can promote the expression of osteogenic related proteins and accelerate the healing of bone defect. 8.5 kV and 2 Hz are the optimal stimulation parameters of ESW for the repair of bone defect in this study.

Key words: extracorporeal shock wave, bone marrow mesenchymal stem cell, bone defect, osteogenic differentiation