The effect of intense subnanosecond electrical pulses on biological cells
The effect of intense subnanosecond electrical pulses on biological cells
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DOI：
10.1109/tps.2008.918786
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发表时间：
2008-04-01
影响因子：
1.5
通讯作者：
Beebe, Stephen J.
中科院分区：
文献类型：
--
作者：
Schoenbach, Karl H.;Xiao, Shu;Beebe, Stephen J.
纳秒电脉冲已成功地用于治疗黑色素瘤肿瘤，通过使用针阵列作为脉冲输送系统。将强电场脉冲的脉冲持续时间从纳秒减少到亚纳秒范围将允许我们使用宽带天线以厘米范围内的空间分辨率将电磁场传递到组织中。为了探索强烈的亚纳秒脉冲的生物效应，我们已经开发出一种发生器，提供160 kV的幅度，200 ps的上升时间，和800 ps的脉冲宽度的电压脉冲。脉冲被传送到一个圆柱形的特氟隆腔室，腔室的两端都有抛光的平面电极。电极之间的距离是可变的，并允许我们在细胞悬浮液中产生高达1 MV/cm的电场。将脉冲施加于B16（小鼠黑色素瘤）细胞，并通过台盼蓝排除法研究了质膜完整性。对于550 kV/cm的脉冲幅度，大约50%的细胞在脉冲后立即摄取台盼蓝，而在1 h后仅20%的细胞摄取台盼蓝。这表明受脉冲影响的大多数细胞中的质膜以约1小时的时间常数恢复。在此时间之后显示台盼蓝摄取的细胞通过细胞凋亡遭受细胞死亡。实验结果和分子动力学建模结果的评价表明，在800 ps的脉冲持续时间下，膜充电和纳米孔形成是对B16细胞的主要生物电效应。该信息已被用于连续模型中，以估计膜渗透性的增加，并因此估计由重复脉冲引起的孔径的增加。
Nanosecond electrical pulses have been successfully used to treat melanoma tumors by using needle arrays as pulse delivery systems. Reducing the pulse duration of intense electric field pulses from nanoseconds into the sulnanosecond range will allow us to use wideband antennas to deliver the electromagnetic fields into tissue with a spatial resolution in the centimeter range. To explore the biological effect of intense sulnanosecond pulses, we have developed a generator that provides voltage pulses of 160 kV amplitude, 200 ps rise time, and 800 ps pulse width. The pulses are delivered to a cylindrical Teflon chamber with polished flat electrodes at either end. The distance between the electrodes is variable and allows us to generate electric fields of up to I MV/cm in cell suspensions. The pulses have been applied to B16 (murine melanoma) cells, and the plasma membrane integrity was studied by means of trypan blue exclusion. For pulse amplitudes of 550 kV/cm, approximately 50% of the cells took up trypan blue right after pulsing, whereas only 20% were taking it up after I h. This indicates that the plasma membrane in a majority of the cells affected by the pulses recovers with a time constant of about I h. The cells that show trypan blue uptake after this time suffer cell death through apoptosis. Evaluation of the experimental results and molecular dynamics modeling results indicate that with a pulse duration of 800 ps, membrane charging and nanopore formation are the dominant bioelectric effects on B16 cells. This information has been used in a continuum model to estimate the increase in membrane permeability and, consequently, the increase in pore size caused by repetitive pulsing.