Shock wave therapy applied to rat bone marrow-derived mononuclear cells enhances formation of cells stained positive for CD31 and vascular endothelial growth factor

Background: This study tested the hypothesis that shock wave (SW) therapy applied to bone marrow-derived mononuclear cells (BMDMNCs) enhances the formation of vascular endothelial growth factor (VEGF) and positively stained CD31 (CD31+) cells, an endothelial phenotype. Methods and Results: The BMDMNCs (∼1.2×10⁶ cells/2 femoral bones) were obtained from adult male Sprague-Dawley rats and SW therapy was applied once to BMDMNCs in group I (140 SW: defined as 140 shots in total, given at 0.09 mJ/mm²), group II (280 SW), and group III (560 SW). Group IV was not treated by SW and served as the control group. Six experiments were done in each group. The BMDMNCs were cultured following SW therapy and the supernatants were collected on days 1, 3, 7 and 14 for assessment of VEGF levels. Immunocytochemical staining and flow cytometric measurement were performed on days 0 and 14. Experimental results demonstrated that VEGF levels were significantly higher in groups I-III than in group IV, and in group II than in group I at all intervals, and in group II than in group III on day 14 (all p values <0.005). Additionally, the number of positively stained VEGF cells on days 1, 3 and 14 and the number of newly formed CD31+ cells on day 14 were significantly higher in group IV than in group IV (all p values <0.001). Conclusions: These data suggest that application of SW to BMDMNCs significantly enhanced VEGF production and promoted differentiation of BMDMNCs into endothelial phenotype cells.