Ultrasound generated mechanical induction of mesenchymal stem cells

The hypothesis of this research is that ultrasound (US) can induce stem cell activity. Specifically, the aim for this study is to optimize the mechanical effect generated by US for the stimulation of mesenchymal stem cells (MSCs). MSCs were cultured on flexible membrane culture plates and stimulated by US for 10 min daily with acoustic intensity of 0, 6, 13.5, and 22.5 W/cm2 (control, P1, P2, and P3 respectively). Cell proliferation and viability were evaluated by direct cell count and Alamar Blue assay. Morphological evaluation was also performed. Cell-matrix interaction was analyzed by immunochemical staining of focal adhesion proteins. Our preliminary results showed that P2 and P3 groups had a better performance in cell proliferation compared to the results of P1 and control, and there was also an increase in cell viability from the Alamar Blue test after 4 consecutive days of US treatment (P2 vs. control). Although no morphological change was observed, expression of focal adhesion protein, vinculin, was enhanced after three consecutive days of US treatment (P3 vs. control). The conclusion is application of higher acoustic pressure on cell growth environment can stimulate MSC proliferation and focal adhesion. However, further studies are required to optimize the acoustic parameters.