Faculty of Electronics, Vilnius Gediminas Technical University, 10223 Vilnius, Lithuania.
Department of Immunology and Bioelectrochemistry, State Research Institute Centre of Innovative Medicine, 08406 Vilnius, Lithuania.
Int J Mol Sci. 2024 Aug 12;25(16):8774. doi: 10.3390/ijms25168774.
Electroporation-based procedures employing nanosecond bipolar pulses are commonly linked to an undesirable phenomenon known as the cancelation effect. The cancellation effect arises when the second pulse partially or completely neutralizes the effects of the first pulse, simultaneously diminishing cells' plasma membrane permeabilization and the overall efficiency of the procedure. Introducing a temporal gap between the positive and negative phases of the bipolar pulses during electroporation procedures may help to overcome the cancellation phenomenon; however, the exact thresholds are not yet known. Therefore, in this work, we have tested the influence of different interphase delay values (from 0 ms to 95 ms) using symmetric bipolar nanoseconds (300 and 500 ns) on cell permeabilization using 10 Hz, 100 Hz, and 1 kHz protocols. As a model mouse hepatoma, the MH-22a cell line was employed. Additionally, we conducted in vitro electrochemotherapy with cisplatin, employing reduced interphase delay values (0 ms and 0.1 ms) at 10 Hz. Cell plasma membrane permeabilization and viability dependence on a variety of bipolar pulsed electric field protocols were characterized. It was shown that it is possible to minimize bipolar cancellation, enabling treatment efficiency comparable to monophasic pulses with identical parameters. At the same time, it was highlighted that bipolar cancellation has a significant influence on permeabilization, while the effects on the outcome of electrochemotherapy are minimal.
基于电穿孔的纳秒双相脉冲程序通常与一种称为“抵消效应”的不良现象有关。当第二个脉冲部分或完全中和第一个脉冲的效应时，就会出现抵消效应，同时降低细胞的质膜通透性和程序的整体效率。在电穿孔程序中，在双相脉冲的正相和负相之间引入时间间隔可能有助于克服抵消现象；然而，确切的阈值尚不清楚。因此，在这项工作中，我们使用 10 Hz、100 Hz 和 1 kHz 方案测试了不同相间延迟值（0 ms 至 95 ms）对使用对称双相纳秒（300 和 500 ns）的细胞通透性的影响。作为模型小鼠肝癌，MH-22a 细胞系被用于实验。此外，我们还进行了使用顺铂的体外电化学疗法，在 10 Hz 时采用缩短的相间延迟值（0 ms 和 0.1 ms）。研究了细胞质膜通透性和对各种双相脉冲电场方案的依赖性。结果表明，有可能最小化双相抵消，从而实现与具有相同参数的单相脉冲相当的治疗效率。同时，强调了双相抵消对通透性有显著影响，而对电化学治疗结果的影响则很小。
