Thermal and Acoustical Insult to Cells as Studied by In-Vivo Acoustic Microscopy

A plurality of articles discussing combined effects of acoustic high-pressure and heat caused by acoustic vibration on biological tissues and cells has been published. Herein, we contribute the article describing the behavior of living human skin cells when separately applying the pressure and the heat to them. First, for finding the heat effect, we located a container including living human skin cells and a culturing medium on the X-Y stage equipped with the heating plate with temperature controller of the Scanning Acoustic Microscope (SAM). Then, we gradually increased temperature of the culturing medium, and carried out in-situ observation. Second, for finding the acoustic high-power effect, we provided the pressure using high power ultrasonic pulses generated by a laser induced ultrasonic shock wave system to the cells, wherein the pressures caused by the pulses were measured by a hydrophone, and wherein temperature was monitored by thermocouples. The cells were observed with the SAM just after giving the impact. The difference between phenomena indicating cellular insult and injury (e.g., shrinkage or lift-off) were clearly visualized by the SAM with frequency at 1.0 GHz.