Brayman A A, Church C C, Miller M W
Department of Biophysics, School of Medicine and Dentistry, University of Rochester, NY 14642, USA.
Ultrasound Med Biol. 1996;22(4):497-514. doi: 10.1016/0301-5629(95)02078-0.
Diminution of apparent ultrasonic cell lysis in vitro with increasing cell concentration/volume fraction has often been observed. A substantial fraction of the cells may be lysed by ultrasound at low cell concentrations, but only a few percent are lysed when the concentration is a fraction of that of whole blood. This suggests that sonolysis of cells in vitro is suppressed by high cell concentrations, and, therefore, that sonolysis of cells in vivo is unlikely. We present the results of a retrospective analysis of experimental data and a theoretical analysis; these indicate that while relative sonolytic yield declines with increasing cell concentration, the "absolute" extent of ultrasound-induced lysis remains large. We find evidence that in vitro sonolysis of cells is limited at high cell densities by the number of available microbubbles and/or the number of cells each bubble may encounter and lyse prior to bubble "inactivation." Theory indicates the latter arises in consequence to the cell concentration-dependent formation of cell aggregates around pulsating bubbles.
体外实验中，随着细胞浓度/体积分数增加，表观超声细胞裂解减少的现象屡见不鲜。在低细胞浓度下，相当一部分细胞可能会被超声裂解，但当浓度为全血浓度的一小部分时，只有百分之几的细胞会被裂解。这表明高细胞浓度会抑制体外细胞的声裂解，因此，体内细胞的声裂解不太可能发生。我们展示了对实验数据的回顾性分析和理论分析结果；这些结果表明，虽然相对声裂解产率随着细胞浓度的增加而下降，但超声诱导裂解的“绝对”程度仍然很大。我们发现有证据表明，在高细胞密度下，体外细胞的声裂解受到可用微泡数量和/或每个微泡在“失活”前可能遇到并裂解的细胞数量的限制。理论表明，后者是由于脉动气泡周围细胞聚集体的形成与细胞浓度有关。
