Exploration of Optimum Conditions for Sonoporation Effect by Controlling Multi-Phase Flow Field with Microscopic Visualization

在附着的Sonazoid微泡的第二次塌陷中，在单个小气泡的塌陷期间产生精细的液体射流。凝胶表面有明显的凹坑。0.01 s &lt; T &lt; 1 s时，纳米级凹坑<ex>主要由Sonazoid微泡溃灭引起，而T&gt; 1 s时，微米级凹坑<ex>主要由空化作用引起。我们发现，当施加0.45 MPa的中等压力振幅，连同占空比为0.1和20个脉冲时，凹坑的最大数量，结果几乎等于在0.75 MPa的压力下通过连续超声获得的结果。这些结果表明，更合适的条件下，可以通过系统地探索超声的特性。

A fine liquid jet was produced during the collapse of individual small gas bubbles in the second collapse of an attached Sonazoid microbubble. Evidential pits are found on the gel surface. Nanoscale pits are dominant in 0.01 s < T_<ex> < 1 s, and caused by the collapse of Sonazoid microbubbles, whereas microscale pits in T_<ex> > 1 s mainly resulted from cavitation. We found the maximum number of pits when a moderate pressure amplitude of 0.45 MPa was applied, together with a duty ratio of 0.1 and 20 pulses, a result that nearly equals that obtained by continuous ultrasound at a pressure of 0.75 MPa. These results suggests that more suitable conditions for sonoporation can be determined by systematically exploring the characteristics of ultrasound.