Modeling Intracellular Ca2+ Transient Induced by Low-Intensity Ultrasound

Intracellular Ca2+ transients have been shown to be induced by ultrasound in various types of cells and Ca2+ plays an important role in cell recovery after sonoporation. To achieve a complete understanding of Ca2+ dynamics during insonation and get clues for suitable parameters of ultrasound to accelerate its clinical application, a new model of ultrasound-induced Ca2+ dynamics has been developed. In the model, effects of ultrasound stimulation on calcium influx and mobilization have been numerically investigated with an assumed linear relation between the low-level ultrasound intensity and induced membrane strain density. The modeling results reproduced the characteristics of elevated intracellular Ca2+ transients induced by ultrasound, showing a biphasic response of intracellular [Ca2+] for about 3 minutes. Numerical results suggested that ultrasound intensity should be between 40 and 1200 mW/cm2 to induce recoverable Ca2+ transients. Stimulation above this intensity range may cause cell damage. This range of intensity changes with cell types.