基于网格传输网络模型的高频纳秒脉冲串作用下单细胞穿孔特性仿真

Simulation on Perforation Features in a Single-Cell System Exposed to High-Frequency Nanosecond Pulse Bursts Based on Mesh Transport Network Model

为研究高频纳秒脉冲串作用下细胞的穿孔特性,采用Matlab仿真软件对含核膜的典型二维单细胞空间区域进行离散,建立其网格传输网络模型,并对模型中的单元节点赋予电传输与孔传输双向耦合特性,以空间每个节点的电位及内外膜上每对节点不同孔半径下的孔密度为未知量,建立常微分方程组并进行求解。仿真模拟单细胞在电场强度为5k V/cm、脉宽250ns、上升沿30ns、仿真总时长为10s的10串高频纳秒脉冲作用下的电穿孔动态变化过程,并研究了串内脉冲个数及频率对内外膜穿孔规律的影响。结果表明:多脉冲作用时,穿孔数量基本不变,穿孔半径有一定的累积效应;重复脉冲串可以在一定程度上延缓孔数量衰减的幅度;增加串内脉冲个数可少量增加外膜孔数量,不会影响核膜孔数量;增加串内脉冲频率基本不会影响外膜孔数量,但可大幅度增加核膜孔数量。本文的仿真结果进一步丰富了脉冲电场作用于生物细胞的穿孔机制。

To study the perforation characteristics of cells under the action of high frequency nanosecond pulse bursts,a typical two-dimensional single cell system including nuclear membrane was discretized into nodes with the help of Matlab.The mesh transport network model(MTNM)was established,and the bidirectional coupling properties of electrical transport and pore transport were given to the nodes.The voltage of each node and the pore density at different discretization pore radii of each pair of membrane nodes were set to be unknown variables.Hence,the ordinary differential equations were formulated and solved.The dynamic process in single-cell electroporation was simulated when applying 10 high-frequency nanosecond pulse(electric field:5kV/cm,pulse width:250ns,rising edge time:30ns,total simulation time:10s)to the targeted system.Additionally,the influence of the intra-burst number and the intra-burst frequency of pulses on the perforation features of the inner and outer membranes was also examined.The results show that when multiple pulses are applied,the pore number is basically unchanged,but the pore radius has a cumulative effect.Repeating the pulse train can delay the magnitude of the pore number attenuation to some extent.Increasing the number of pulses in the train can increase the number of outer membrane pores,and does not affect the number of nuclear membrane pores.Increasing the intra-burst frequencies does not affect the number of outer membrane pores,and can greatly increase the number of nuclear membrane pores.The simulation results further enrich the perforation mechanism of pulsed electric field acting on biological cells.