Abstract:

BACKGROUND: Extracorporeal shock wave therapy is indicated as an effective method for treatment of delayed fracture healing or nonunion. Osteoblasts plays an important role in this process.
OBJECTIVE: To investigate the function of osteoblasts in the process of extracorporeal shock wave promoting fractures healing, and to provide theoretical support for improving shock wave therapy on fracture healing.
METHODS: Primary cultured ostsoblasts were isolated from newborn SD rat calvaria and randomly divided into two groups, shock wave and control. Treated by different energies of extracorporeal shock wave, cells were incubated onto 96-well culture plate. An optimal dose of extracorporeal shock wave was selected according to survival and proliferation of osteoblasts. The osteoblasts treated by optimal energy of extracorporeal shock wave were cultured and harvested for the analysis of alkaline phosphatase by calcium cobolt stain, cell survival by CCK-8 Kit, alkaline phosphatase expression by AKP kit, mineralized nodules by Alizarin red staining, integrin β1 and β1 mRNA expressions by flow cytometry and RT-PCR, cell migration by wound healing assay.
RESULTS AND CONCLUSION: The optimal energy of extracorporeal shock wave treating primary cultured osteoblasts was   10 kV (500 impulses). Following extracorporeal shock wave therapy, the cell proliferation, alkaline phosphatase activity, cell mineralization, rates of cell adhesion, as well as β1 integrin and its mRNA expressions were increased as compared with those in control group (P < 0.01). Further distance of cell migration was found in extracorporeal shock wave group (P < 0.05). The results showed that the optimal energy of extracorporeal shock wave could promote the proliferation, differentiation, adhesion and migration of osteoblasts in vitro, and β1 integrin may play an important role in the process of cell adhesion and migration.