Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
Anal Chem. 2011 Jun 1;83(11):3998-4003. doi: 10.1021/ac1019649. Epub 2011 May 6.
Electropermeabilization or electroporation is the electrical disruption of a cell's membrane to introduce drugs, DNA/RNA, proteins, or other therapies into the cell. Despite four decades of study, the fundamental science of the process remains poorly understood and controversial. We measured the minimum applied electric field required for permeabilization of suspended spherical cells as a function of the cell radius for three cell lines. Key to this work is our use of optical tweezers to precisely position individual cells and enable well-defined, repeatable measurements on cells in suspension. Our findings call into question fundamental assumptions common to all theoretical treatments that we know of. It is generally expected that, for individual cells from a particular cell line, large cells should be easier to electroporate than small ones: the minimum electric field to cause electropermeabilization should scale inversely with the cell diameter. We found instead that each cell line has its own characteristic field that will, on average, cause permeabilization in cells of that line. Electropermeabilization is a stochastic process: two cells which appear identical may have different permeabilization thresholds. However, for all three cell lines, we found that the minimum permeabilization field for any given cell does not depend on its size.
电穿孔或电穿孔是细胞膜的电破坏，将药物、DNA/RNA、蛋白质或其他疗法引入细胞。尽管已经进行了四十年的研究，但该过程的基础科学仍未得到很好的理解和存在争议。我们测量了悬浮球形细胞电穿孔所需的最小应用电场作为三个细胞系的细胞半径的函数。这项工作的关键是我们使用光学镊子精确地定位单个细胞，并能够对悬浮细胞进行明确定义且可重复的测量。我们的发现质疑了我们所知道的所有理论处理中常见的基本假设。一般来说，对于来自特定细胞系的单个细胞，大细胞应该比小细胞更容易电穿孔：引起电穿孔的最小电场应与细胞直径成反比。相反，我们发现每个细胞系都有其自身的特征场，该特征场将平均导致该系的细胞发生渗透性。电穿孔是一个随机过程：两个看起来相同的细胞可能具有不同的通透性阈值。然而，对于所有三种细胞系，我们发现任何给定细胞的最小通透性场都不取决于其大小。
