Effect of Ultrasonic Vibration on Proliferation and Differentiation of Cells

摘要

The effect of mechanical stimulation of vibration on proliferation and differentiation of cells has been studied in vitro. To apply the vibration on the cells, a piezoelectric element was attached on the outside surface of the bottom of the culture plate of six wells. The piezoelectric element was vibrated by sinusoidal alternating voltage at 1.0 MHz generated by a function generator. Five kinds of cells were used in the experiment: C2C12 (mouse myoblast cell), L929 (fibroblast connective tissue of mouse), Hepal-6 (mouse hepatoma cell), HUVEC (human umbilical vein endothelial cells), and Neuro-2a (mouse neural crest-derived cell line). After the incubation for 24 hours, cells were exposed to the ultrasonic vibration intermittently for three days: for thirty minutes per day. At the end of the experiment, the number of cells was counted by colorimetric method with a microplate photometer. In the case of Neuro-2a, the total length of the neurite is calculated at the microscopic image. Cells were exfoliated by the strong vibration. The experimental results show that proliferation and differentiation of cells are accelerated with mild vibration, and that the optimum intensity of vibration depends on the kind of cells.