Mechanical and Aerospace Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
Bioelectrochemistry. 2011 Aug;82(1):10-21. doi: 10.1016/j.bioelechem.2011.04.006. Epub 2011 Apr 28.
A numerical study of electroporation-mediated molecular delivery is presented. The model consists of the Nernst-Planck equations for species transport, coupled with an asymptotic Smoluchowski equation for membrane permeabilization. The transfer of calcium ions into a Chinese Hamster Ovary cell is simulated. The results reveal important physical insights. First, for this particular case, ion electrophoresis plays an important role, and is an order of magnitude faster than free diffusion on a comparable time scale. Second, the maximum achievable concentration within the cell is reciprocally correlated with the extracellular electrical conductivity. This behavior is mediated by an electrokinetic mechanism known as field-amplified sample stacking. Through this mechanism, the intracellular ion concentration can reach a level higher than the extracellular one provided that the intra-to-extracellular conductivity ratio is greater than unity. The results corroborate well with data in the literature, and offer a mechanistic interpretation to previous experimental observations. This work is a step toward the quantification of molecular delivery via electroporation.
本文对电穿孔介导的分子传递进行了数值研究。该模型由物种传输的 Nernst-Planck 方程组成，与膜通透性的渐近 Smoluchowski 方程耦合。模拟了钙离子向中国仓鼠卵巢细胞的传递。结果揭示了重要的物理见解。首先，对于这种特殊情况，离子电泳起着重要作用，并且在可比的时间尺度上比自由扩散快一个数量级。其次，细胞内可达到的最大浓度与细胞外电导率成反比。这种行为是由一种称为场增强样品堆积的电动机制介导的。通过这种机制，只要细胞内到细胞外的电导率比大于 1，细胞内的离子浓度就可以达到高于细胞外的水平。结果与文献中的数据非常吻合，并对以前的实验观察结果提供了一种机制解释。这项工作是通过电穿孔定量分子传递的一步。
