Effect of ultrasonic vibration on the orientation of C2C12 cells

Control of orientation direction of tissues is important for regenerative medicine techniques. This paper investigates effects of ultrasound vibration on a culture dish on the orientation of myoblast C2C12 cells. A piezoelectric ultrasonic transducer (PZT) was fixed to the bottom of a culture dish. A continuous sinusoidal signal with 10 to 30 Vpp at the resonant frequency of 86kHz was input to the transducer to generate a concentric flexural vibration mode on the bottom surface of the dish. C2C12 cells were cultured on the dish for 2 days under continuous ultrasonic vibration. The ultrasound excitation was then stopped, resulting in the differentiation of the cells into myotube cells through 7 days. The orientation distribution of the cells on the dish was evaluated by spatial Fourier transform in the microscopic images. Compared with the control, the orientation of C2C12 cells was changed significantly under ultrasonication; the concentric pattern of the cell orientation appeared, which corresponds to the concentric vibration mode generated on the bottom of the dish. Larger vibrational amplitude of the dish gave a larger effect on the cell orientation.