Sözer Esin B, Wu Yu-Hsuan, Romeo Stefania, Vernier P Thomas
Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way. STE 300, Norfolk, VA, USA.
Mork Family Department of Chemical Engineering and Materials Science, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA.
J Membr Biol. 2017 Feb;250(1):21-30. doi: 10.1007/s00232-016-9918-x. Epub 2016 Jul 19.
High-intensity nanosecond pulsed electric fields (nsPEFs) permeabilize cell membranes. Although progress has been made toward an understanding of the mechanism of nsPEF-induced membrane poration, the dependence of pore size and distribution on pulse duration, strength, number, and repetition rate remains poorly defined experimentally. In this paper, we characterize the size of nsPEF-induced pores in living cell membranes by isosmotically replacing the solutes in pulsing media with polyethylene glycols and sugars before exposing Jurkat T lymphoblasts to 5 ns, 10 MV/m electric pulses. Pore size was evaluated by analyzing cell volume changes resulting from the permeation of osmolytes through the plasma membrane. We find that pores created by 5 ns pulses have a diameter between 0.7 and 0.9 nm at pulse counts up to 100 with a repetition rate of 1 kHz. For larger number of pulses, either the pore diameter or the number of pores created, or both, increase with increasing pulse counts. But the prevention of cell swelling by PEG 1000 even after 2000 pulses suggests that 5 ns, 10 MV/m pulses cannot produce pores with a diameter larger than 1.9 nm.
高强度纳秒脉冲电场（nsPEF）可使细胞膜通透性增加。尽管在理解nsPEF诱导膜形成孔道的机制方面已取得进展，但孔径和分布对脉冲持续时间、强度、数量及重复频率的依赖性在实验上仍未明确界定。在本文中，我们通过在将Jurkat T淋巴母细胞暴露于5纳秒、10兆伏/米的电脉冲之前，用聚乙二醇和糖类等渗替代脉冲介质中的溶质，来表征活细胞膜中nsPEF诱导形成的孔道大小。通过分析渗透溶质透过质膜导致的细胞体积变化来评估孔径。我们发现，在脉冲次数高达100次、重复频率为1千赫时，5纳秒脉冲形成的孔道直径在0.7至0.9纳米之间。对于更多的脉冲次数，形成的孔径或孔道数量，或两者都会随着脉冲次数的增加而增加。但即使在2000次脉冲后，聚乙二醇1000能防止细胞肿胀，这表明5纳秒、10兆伏/米的脉冲无法产生直径大于1.9纳米的孔道。
