零质量射流作用下红细胞在微管道中变形的数值模拟  

Numerical simulation of red blood cells deformation in microchannel under zero-net-mass-flux jet

作　　者：艾晋芳 解军 胡国辉[1] Ai Jin-Fang;Xie Jun;Hu Guo-Hui(Shanghai Key Laboratory of Mechanics in Energy Engineering,Shanghai Institute of Applied Mathematics and Mechanics,School of Mechanics and Engineering Science,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学力学与工程科学学院,上海市应用数学和力学研究所,上海市力学在能源工程中的应用重点实验室,上海200072

出　　处：《物理学报》2020年第23期181-189,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11772183,11832017)资助的课题.

摘　　要：因为在生物安全性和导入效率等方面的优势,基于力学方法实现基因导入日益得到学术界的重视.本文提出了一种基于零质量射流,对微管道中运动的细胞施加流体作用力,引起其发生变形,进而促使细胞膜上力敏通道开启的方法,并通过数值模拟进行了理论验证.本文采用浸没有限元法,对红细胞在微管道内运动过程中受到零质量射流作用的变形情况进行数值模拟,探讨了如何高效地实现小分子物质导入细胞.数值模拟的重要参数有微管道内压力梯度Δp,零质量射流的振幅Am和频率f.经过对流场特征和红细胞受力情况的分析,发现当细胞某处表面张力T0大于临界表面张力τc时,细胞表面力敏通道打开,并得到每一时刻细胞力敏通道打开的百分比Popen.本文定义了通道开启积分I,以衡量在不同的流动参数情况下,细胞膜力敏通道的开启程度,进而探讨了压力梯度和射流振动频率、振幅对I值的影响,以寻找优化的工艺参数.该方法具有微制造工艺简单易行,在保证高通量导入的同时,便于对所施加的流体作用力进行精确控制的特点,这使得蛋白质、基因等物质实现跨膜输运,进入细胞并发生重编程成为可能.With advantages in biosafety and efficiency,gene delivery based on mechanical approaches has received more and more attention in academic research.In the present paper,a method based on zero-net-mass-flux jet is proposed to apply fluid shear to the moving cells in the microchannel,which causes cell to deform,and then open its mechano-sensitive channel on the cell membrane.This novel method is verified theoretically by numerical simulation in this study.In this paper,an immersed finite element method is utilized to numerically simulate the deformation of red blood cells subjected to zero-net-mass-flux jet during the movement of red blood cells in microchannel,aiming at investigating how to efficiently introduce small molecules into cells.The important parameters of numerical simulation are pressure gradient Δp along the microchannel,the amplitude Am and frequency f of the zero-net-mass-flux jet.Through the analysis of the characteristic of flow field and the stress on the red blood cells,we find that when cell surface tension T0 is greater than critical surface tension τc,the gating of cell surface mechano-sensitive channel will occur,and the percentage of gating Popen on the cell membrane can be obtained at each moment.Addtionally,the channel opening integral I is defined to measure the gating degree of the membrane mechano-sensitive channel under different flow parameters,and the influences of pressure gradient,jet vibration frequency and amplitude on the I are further discussed in order to find the optimized process parameters,The method we proposed is simpler and easier to implement,and the applied fluid shear stress can be controlled precisely,so that it is possible for proteins,genes and other substances to be transported into the cell across the membrane,and to implement reprogramming.

关 键 词：浸没有限元法 零质量射流 力敏通道 跨膜输运 

分 类 号：O242[理学—计算数学] Q27[理学—数学]