Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford OX3 7DQ, U.K.
State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, Guangdong University of Technology, Guangzhou 510006, China.
Langmuir. 2020 Jun 16;36(23):6388-6398. doi: 10.1021/acs.langmuir.0c00536. Epub 2020 Jun 2.
Studies on the bioeffects produced by ultrasound and microbubbles have focused primarily on transport in bulk tissue, drug uptake by individual cells, and disruption of biological membranes. Relatively little is known about the physical perturbations and fluid dynamics of the intracellular environment during ultrasound exposure. To investigate this, a custom acoustofluidic chamber was designed to expose model cells, in the form of giant unilamellar vesicles, to ultrasound and microbubbles. The motion of fluorescent tracer beads within the lumen of the vesicles was tracked during exposure to laminar flow (∼1 mm s), ultrasound (1 MHz, ∼150 kPa, 60 s), and phospholipid-coated microbubbles, alone and in combination. To decouple the effects of fluid flow and ultrasound exposure, the system was also modeled numerically by using boundary-driven streaming field equations. Both the experimental and numerical results indicate that all conditions produced internal streaming within the vesicles. Ultrasound alone produced an average bead velocity of 6.5 ± 1.3 μm/s, which increased to 8.5 ± 3.8 μm/s in the presence of microbubbles compared to 12 ± 0.12 μm/s under laminar flow. Further research on intracellular forces in mammalian cells and the associated biological effects and are required to fully determine the implications for safety and/or therapy.
超声和微泡产生的生物效应研究主要集中在大块组织的传输、单个细胞的药物摄取和生物膜的破坏上。在超声照射期间，细胞内环境的物理干扰和流体动力学相对知之甚少。为了研究这一点，设计了一个定制的声流控室，将模型细胞（以巨大的单层囊泡的形式）暴露于超声和微泡中。在层流（约 1 毫米/秒）、超声（1 兆赫，约 150 千帕，60 秒）和单独以及组合使用磷脂涂层微泡暴露期间，跟踪荧光示踪剂珠在囊泡管腔中的运动。为了分离流体流动和超声照射的影响，还通过使用边界驱动的流场方程对系统进行了数值建模。实验和数值结果都表明，所有条件都在囊泡内产生了内部流动。单独的超声产生的平均珠速度为 6.5 ± 1.3 μm/s，而在存在微泡的情况下增加到 8.5 ± 3.8 μm/s，而在层流下为 12 ± 0.12 μm/s。需要进一步研究哺乳动物细胞内的力和相关的生物学效应，以充分确定其对安全性和/或治疗的影响。
