Stacey M, Stickley J, Fox P, Statler V, Schoenbach K, Beebe S J, Buescher S
Center for Pediatric Research, Eastern Virginia Medical School, 855, W Brambleton Ave, Norfolk, VA 23510, USA.
Mutat Res. 2003 Dec 9;542(1-2):65-75. doi: 10.1016/j.mrgentox.2003.08.006.
High power, nanosecond pulsed electric field (nsPEF) effects have been focused on bacterial decontamination, but the impact on mammalian cells is now being revealed. During nsPEF applications, electrical pulses of 10, 60 or 300 ns durations were applied to cells using electric field amplitudes as high as 300 kV/cm. Because of the ultra-short pulse durations, the energy transferred to cells is negligible, and only non-thermal effects are observed. We investigated the genotoxicity of nsPEF on adherent and non-adherent cell lines including 10 human lines and one mouse cell line with different origin and growth characteristics. We present data examining the effects of nsPEF exposure on cell survival assessed by clonogenic formation or live cell count; DNA damage determined by the comet assay and chromosome aberrations; and cell cycle parameters by measuring the mitotic indices of exposed cells. Using each of these indicators, we observed differential effects among cell types with non-adherent cells being more sensitive to the genotoxic effects of nsPEF exposures than adherent cells. Non-adherent cultures showed a rapid decrease in cell viability (90%), induction of DNA damage, and a decrease in the number of cells reaching mitosis after one 60 ns pulse with an electric field intensity of 60 kV/cm. These effects were not observed in cells grown as adherent cultures, with the exception of the mouse 3T3 cell line, which showed survival characteristics similar to non-adherent cultures. These data suggest that nsPEF genotoxicity may be cell type specific, and therefore have potential applications in the selective removal of one cell type from another, for example, in diseased states.
高功率纳秒脉冲电场（nsPEF）效应一直聚焦于细菌去污，但现在其对哺乳动物细胞的影响正逐渐显现。在nsPEF应用过程中，使用高达300 kV/cm的电场幅度，将持续时间为10、60或300 ns的电脉冲施加于细胞。由于脉冲持续时间极短，传递到细胞的能量可忽略不计，仅观察到非热效应。我们研究了nsPEF对贴壁和非贴壁细胞系的遗传毒性，包括10种人类细胞系和1种具有不同来源和生长特性的小鼠细胞系。我们展示了通过克隆形成或活细胞计数评估nsPEF暴露对细胞存活的影响的数据；通过彗星试验和染色体畸变确定DNA损伤；以及通过测量暴露细胞的有丝分裂指数确定细胞周期参数。使用这些指标中的每一个，我们观察到不同细胞类型之间存在差异效应，非贴壁细胞比贴壁细胞对nsPEF暴露的遗传毒性更敏感。非贴壁培养物在施加一个电场强度为60 kV/cm、持续时间为60 ns的脉冲后，细胞活力迅速下降（90%），诱导DNA损伤，且进入有丝分裂的细胞数量减少。除小鼠3T3细胞系外，贴壁培养的细胞未观察到这些效应，该细胞系表现出与非贴壁培养物相似的存活特征。这些数据表明，nsPEF遗传毒性可能具有细胞类型特异性，因此在例如疾病状态下从另一种细胞类型中选择性去除一种细胞类型方面具有潜在应用。
