H-22细胞声孔效应的应力阈值

Threshold value of shear stress in H-22 cells generated sonoporation

理论和实验研究了超声空化场中的H-22型肝癌细胞产生可逆声孔效应的剪应力阈值.本文用1.37MHz的聚焦声场,当超顺磁性纳米氧化铁在细胞悬液中的终浓度为410μg/mL,换能器负载电功率为2W,超声辐照60s,细胞存活率90%以上时,有45.9±13.5%的细胞显示普鲁士蓝染阳性,暗示超声作用下,这些细胞表面曾出现可逆性微孔而使磁性微粒由此进入细胞内.利用无界自由空间微泡运动方程的球对称稳态解对实验条件下细胞膜表面的切变应力进行数值估算,结果表明,使H-22细胞产生可逆性声孔效应的微流剪应力阈值为697Pa.

Based on a spherically symmetric bubble model,the threshold shear stress for H-22 cells which are irradiated by continuous focused ultrasound is estimated.On the condition that the final concentration of the superparamagnetic iron oxide （SPIO） in the cell suspension is 410 μg/mL,the focused ultrasound sonication is at a frequency of 1.37 MHz,the power from amplifer is 2 W,and H-22 cells are exposed to the ultrasound for 60 s,the labeling efficiency is about 45.9%±13.5%.Prussian blue staining confirms iron uptake and shows numerous blue-stained iron particles in the cytoplasm,while more than 90% labeled cells remained viable.The results show that the reparable sonoporation arises in plasma membrane and SPIO nanoparticles enter into the H-22 cells.Numerical calculations show that the shear stress acting on the cell is 697 Pa,which is the threshold shear stress for H-22 cell sonoporation.