Therapeutic ultrasound (US) is a biophysical stimulation resource widely used in order to promote better, faster muscle repair, but the effectiveness of continuous US in treating injuries is not fully established. The aim of the present in vitro study was to assess the effects of continuous ultrasound on viability and proliferation of skeletal muscle precursor cells (C2C12 myoblasts). C2C12 myoblasts were cultured in a medium containing 10% foetal bovine serum and irradiated with continuous ultrasound at 1 and 3 MHz frequencies, at intensities of 0.2 and 0.5 W/cm² for 2 and 5 minutes. Cell viability and proliferation were assessed after different incubation periods (24, 48 and 72 h). Non-irradiated groups served as control and data were statistically analysed. Results showed that no significant differences in cell viability or proliferation could be found between ultrasound-treated myoblasts and control cultures under all test parameters and durations. Hence continuous ultrasound, at the used parameters, was unable to alter myoblast proliferation and viability.
Cell proliferation; Muscle cells/ultrasonography; Myoblasts; Ultrasonic therapy
