UMR Structure et Réactivité des Systèmes Moléculaires Complexes, CNRS-Université de Lorraine, Vandoeuvre-lès-Nancy, Cedex, France.
J Membr Biol. 2012 Sep;245(9):531-43. doi: 10.1007/s00232-012-9434-6. Epub 2012 May 30.
The permeability of cell membranes can be transiently increased following the application of external electric fields. Theoretical approaches such as molecular modeling provide a significant insight into the processes affecting, at the molecular level, the integrity of lipid cell membranes when these are subject to voltage gradients under similar conditions as those used in experiments. This article reports on the progress made so far using such simulations to model membrane-lipid bilayer-electroporation. We first describe the methods devised to perform in silico experiments of membranes subject to nanosecond, megavolt-per-meter pulsed electric fields and of membranes subject to charge imbalance, mimicking therefore the application of low-voltage, long-duration pulses. We show then that, at the molecular level, the two types of pulses produce similar effects: provided the TM voltage these pulses create are higher than a certain threshold, hydrophilic pores stabilized by the membrane lipid headgroups form within the nanosecond time scale across the lipid core. Similarly, when the pulses are switched off, the pores collapse (close) within similar time scales. It is shown that for similar TM voltages applied, both methods induce similar electric field distributions within the membrane core. The cascade of events following the application of the pulses, and taking place at the membrane, is a direct consequence of such an electric field distribution.
细胞膜的通透性可以在施加外部电场后短暂增加。理论方法，如分子建模，为理解在实验中类似条件下，电压梯度对脂质细胞膜完整性的影响提供了重要的见解。本文报告了迄今为止使用这些模拟来模拟膜-脂质双层电穿孔的进展。我们首先描述了为在纳秒、兆伏特/米的脉冲电场和模拟电荷失衡的膜中进行计算机实验而设计的方法，因此模拟了低电压、长持续时间脉冲的应用。然后我们表明，在分子水平上，这两种类型的脉冲产生相似的效果：只要这些脉冲在 TM 电压上产生的电压高于某个阈值，由膜脂质头部稳定的亲水头孔就在纳秒时间尺度内在脂质核心内形成。同样，当脉冲关闭时，孔在相似的时间尺度内坍塌（关闭）。结果表明，对于施加的类似 TM 电压，这两种方法在膜内引起相似的电场分布。脉冲施加后发生在膜上的一系列事件是这种电场分布的直接结果。
