Chang D C
Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030.
Biophys J. 1989 Oct;56(4):641-52. doi: 10.1016/S0006-3495(89)82711-0.
It has been shown in previous studies that cell poration (i.e., reversible permeabilization of cell membrane) and cell fusion can be induced by applying a pulse (or pulses) of high-intensity DC (direct current) electric field. Recently we suggested that such electro-poration or electro-fusion can also be accomplished by using an oscillating electric field. The DC field relies solely on the dielectric breakdown of the cell membrane to induce cell fusion. The oscillating field, on the other hand, can produce not only a dielectric breakdown, but also a sonicating motion in the membrane that could result in a structural fatigue. Thus, a combination of a DC field and an oscillating field is expected to enhance the efficiency of cell poration and cell fusion. This study is an experimental test of such an idea. Here, pulses of high-intensity, DC-shifted RF (radio frequency) electric field were used to induce cell poration and cell fusion. The fusion experiments were done on human red blood cells. The poration experiments were done on a fibroblast cell line using a molecular probe (which is a DNA plasmid containing the marker gene chloramphenicol acetyltransferase, CAT) and assayed by a gene transfection technique. It was found that the pulsed RF field is highly efficient in both cell fusion and cell poration. Also, in comparison with electro-poration using a DC field, the RF field results in a higher percentage of cells surviving the exposure to the electric field.
先前的研究表明，施加一个或多个高强度直流（DC）电场脉冲可诱导细胞穿孔（即细胞膜的可逆通透化）和细胞融合。最近我们提出，这种电穿孔或电融合也可以通过使用振荡电场来实现。直流电场仅依靠细胞膜的介电击穿来诱导细胞融合。另一方面，振荡电场不仅可以产生介电击穿，还可以在膜中产生超声运动，这可能导致结构疲劳。因此，直流电场和振荡电场的组合有望提高细胞穿孔和细胞融合的效率。本研究是对这一想法的实验验证。在这里，使用高强度、直流偏移的射频（RF）电场脉冲来诱导细胞穿孔和细胞融合。融合实验在人类红细胞上进行。穿孔实验在一种成纤维细胞系上进行，使用一种分子探针（这是一种含有标记基因氯霉素乙酰转移酶，即CAT的DNA质粒），并通过基因转染技术进行检测。结果发现，脉冲射频场在细胞融合和细胞穿孔方面都非常高效。此外，与使用直流电场的电穿孔相比，射频场使暴露于电场中的细胞存活率更高。
