Intracellular effect of ultrashort electrical pulses

A simple electrical model for biological cells predicts an increasing proba bility for electric field interactions with cell substructures of prokaryot ic and eukaryotic cells when the electric pulse duration is reduced into th e sub-microsecond range. The validity of this hypothesis was verified exper imentally by applying electrical pulses with electric field intensities of up to 5.3 MV/m to human eosinophils in vitro. When 3-5 pulses of 60 ns dura tion were applied to human eosinophils, intracellular granules were modifie d without permanent disruption of the plasma membrane. In spite of the extr eme electrical power levels applied to the cells thermal effects could be n eglected because of the ultrashort pulse duration. The intracellular effect extends conventional electroporation to cellular substructures and opens t he potential for new applications in apoptosis induction, gene delivery to the nucleus, or altered cell functions, depending on the electrical pulse c onditions. Bioelectromagnetics 22:440-448, 2001. (C) 2001 Wiley-Liss. Inc.