Shafiee Hadi, Garcia Paulo A, Davalos Rafael V
Bioelectromechanical Systems Laboratory, Department of Engineering Science and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
J Biomech Eng. 2009 Jul;131(7):074509. doi: 10.1115/1.3143027.
Intense but short electrical fields can increase the permeability of the cell membrane in a process referred to as electroporation. Reversible electroporation has become an important tool in biotechnology and medicine. The various applications of reversible electroporation require cells to survive the procedure, and therefore the occurrence of irreversible electroporation (IRE), following which cells die, is obviously undesirable. However, for the past few years, IRE has begun to emerge as an important minimally invasive nonthermal ablation technique in its own right as a method to treat tumors and arrhythmogenic regions in the heart. IRE had been studied primarily to define the upper limit of electrical parameters that induce reversible electroporation. Thus, the delineation of IRE from thermal damage due to Joule heating has not been thoroughly investigated. The goal of this study was to express the upper bound of IRE (onset of thermal damage) theoretically as a function of physical properties and electrical pulse parameters. Electrical pulses were applied to THP-1 human monocyte cells, and the percentage of irreversibly electroporated (dead) cells in the sample was quantified. We also determined the upper bound of IRE (onset of thermal damage) through a theoretical calculation that takes into account the physical properties of the sample and the electric pulse characteristics. Our experimental results were achieved below the theoretical curve for the onset of thermal damage. These results confirm that the region to induce IRE without thermal damage is substantial. We believe that our new theoretical analysis will allow researchers to optimize IRE parameters without inducing deleterious thermal effects.
强烈但短暂的电场可在一种称为电穿孔的过程中增加细胞膜的通透性。可逆电穿孔已成为生物技术和医学中的一项重要工具。可逆电穿孔的各种应用要求细胞在该过程后存活，因此，细胞死亡的不可逆电穿孔（IRE）的发生显然是不可取的。然而，在过去几年中，IRE本身已开始成为一种重要的微创非热消融技术，作为治疗肿瘤和心脏致心律失常区域的一种方法。IRE的研究主要是为了确定诱导可逆电穿孔的电参数上限。因此，IRE与焦耳热引起的热损伤的区分尚未得到充分研究。本研究的目的是从理论上表达IRE的上限（热损伤的起始点）作为物理性质和电脉冲参数的函数。将电脉冲施加于THP-1人单核细胞，并对样品中不可逆电穿孔（死亡）细胞的百分比进行定量。我们还通过考虑样品物理性质和电脉冲特性的理论计算确定了IRE的上限（热损伤的起始点）。我们的实验结果是在热损伤起始点的理论曲线以下获得的。这些结果证实，在不产生热损伤的情况下诱导IRE的区域是相当大的。我们相信，我们的新理论分析将使研究人员能够优化IRE参数而不产生有害的热效应。
