Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA.
J Control Release. 2012 Jun 28;160(3):570-6. doi: 10.1016/j.jconrel.2012.04.006. Epub 2012 Apr 10.
Conventional electroporation has been conducted by employing short direct current (dc) pulses for delivery of macromolecules such as DNA into cells. The use of alternating current (ac) field for electroporation has mostly been explored in the frequency range of 10kHz-1MHz. Based on Schwan equation, it was thought that with low ac frequencies (10Hz-10kHz), the transmembrane potential does not vary with the frequency. In this report, we utilized a flow-through electroporation technique that employed continuous 10Hz-10kHz ac field (based on either sine waves or square waves) for electroporation of cells with defined duration and intensity. Our results reveal that electropermeabilization becomes weaker with increased frequency in this range. In contrast, transfection efficiency with DNA reaches its maximum at medium frequencies (100-1000Hz) in the range. We postulate that the relationship between the transfection efficiency and the ac frequency is determined by combined effects from electrophoretic movement of DNA in the ac field, dependence of the DNA/membrane interaction on the ac frequency, and variation of transfection under different electropermeabilization intensities. The fact that ac electroporation in this frequency range yields high efficiency for transfection (up to ~71% for Chinese hamster ovary cells) and permeabilization suggests its potential for gene delivery.
传统的电穿孔技术通过施加短的直流电脉冲将大分子如 DNA 导入细胞。交流电（AC）场在电穿孔中的应用主要在 10kHz-1MHz 的频率范围内进行了探索。根据 Schwan 方程，人们认为在低频 AC（10Hz-10kHz）下，跨膜电位不随频率变化。在本报告中，我们利用了一种流动电穿孔技术，该技术采用连续的 10Hz-10kHz AC 场（基于正弦波或方波）对细胞进行电穿孔，持续时间和强度可定义。我们的结果表明，在此范围内，随着频率的增加，电穿孔的渗透率会减弱。相比之下，在该范围内的中频（100-1000Hz）时，DNA 的转染效率达到最大值。我们推测，转染效率与 AC 频率之间的关系是由 DNA 在 AC 场中的电泳运动、DNA/膜相互作用对 AC 频率的依赖性以及不同电穿孔强度下转染的变化等综合效应决定的。事实上，在此频率范围内的 AC 电穿孔在转染（对于中国仓鼠卵巢细胞高达约 71%）和通透性方面具有高效性，这表明其在基因传递方面具有潜力。
