Nanosecond, high‐intensity pulsed electric fields induce apoptosis in human cells

TLDR

Nanosecond pulsed electric fields are high‑intensity but brief, so they do not reach the plasma membrane charging time yet affect intracellular membranes, whereas longer pulses can fuse cells or introduce molecules. The study aimed to determine how high‑intensity nsPEF affect human cell structure and function. Human cells were exposed to nsPEF up to 300 kV/cm (10–300 ns) and analyzed at cellular and molecular levels. NsPEF induced rapid, caspase‑ and mitochondria‑dependent apoptosis within minutes, with shorter pulses reducing membrane electroporation yet still activating intracellular signaling that leads to cell death independent of thermal effects, highlighting nsPEF as a high‑power, energy‑independent tool to eliminate aberrant cells.

Abstract

Electroporation by using pulsed electric fields with long durations compared with the charging time of the plasma membrane can induce cell fusion or introduce xenomolecules into cells. Nanosecond pulse power technology generates pulses with high-intensity electric fields, but with such short durations that the charging time of the plasma membrane is not reached, but intracellular membranes are affected. To determine more specifically their effects on cell structure and function, human cells were exposed to high intensity (up to 300 kV/cm) nanosecond (10-300 ns) pulsed electric fields (nsPEF) and were analyzed at the cellular and molecular levels. As the pulse duration decreased, plasma membrane electroporation decreased and appearances of apoptosis markers were delayed. NsPEF induced apoptosis within tens of minutes, depending on the pulse duration. Annexin-V binding, caspase activation, decreased forward light scatter, and cytochrome c release into the cytoplasm were coincident. Apoptosis was caspase- and mitochondria-dependent but independent of plasma membrane electroporation and thermal changes. The results suggest that with decreasing pulse durations, nsPEF modulate cell signaling from the plasma membrane to intracellular structures and functions. NsPEF technology provides a unique, high-power, energy-independent tool to recruit plasma membrane and/or intracellular signaling mechanisms that can delete aberrant cells by apoptosis.