title: Nanometer-Scale Permeabilization and Osmotic Swelling Induced by 5-ns Pulsed Electric Fields.
abstract: High-intensity nanosecond pulsed electric fields (nsPEFs) permeabilize cell membranes. Although progress has been made toward an understanding of the mechanism of nsPEF-induced membrane poration, the dependence of pore size and distribution on pulse duration, strength, number, and repetition rate remains poorly defined experimentally. In this paper, we characterize the size of nsPEF-induced pores in living cell membranes by isosmotically replacing the solutes in pulsing media with polyethylene glycols and sugars before exposing Jurkat T lymphoblasts to 5 ns, 10 MV/m electric pulses. Pore size was evaluated by analyzing cell volume changes resulting from the permeation of osmolytes through the plasma membrane. We find that pores created by 5 ns pulses have a diameter between 0.7 and 0.9 nm at pulse counts up to 100 with a repetition rate of 1 kHz. For larger number of pulses, either the pore diameter or the number of pores created, or both, increase with increasing pulse counts. But the prevention of cell swelling by PEG 1000 even after 2000 pulses suggests that 5 ns, 10 MV/m pulses cannot produce pores with a diameter larger than 1.9 nm.
authors.affiliation: Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way. STE 300, Norfolk, VA, USA. esozer@odu.edu.
authors.forename: Esin B
authors.initials: EB
authors.lastname: Sözer
authors.affiliation: Mork Family Department of Chemical Engineering and Materials Science, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA.
authors.forename: Yu-Hsuan
authors.initials: YH
authors.lastname: Wu
authors.affiliation: CNR - Institute for Electromagnetic Sensing of the Environment (IREA), Via Diocleziano 328, 80124, Naples, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Romeo
authors.affiliation: Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way. STE 300, Norfolk, VA, USA.
authors.forename: P Thomas
authors.initials: PT
authors.lastname: Vernier
mesh_terms: D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000502:physiology*; D002463:Cell Membrane Permeability; D048429:Cell Size; D003102:Colloids; D055724:Electrophysiological Phenomena; D006801:Humans; D007294:Inositol / Q000737:chemistry; D009995:Osmosis; D013395:Sucrose / Q000737:chemistry
chemical_list: D003102:Colloids; D007294:Inositol; D013395:Sucrose
keywords: Electroporation/electropermeabilization; Nanosecond pulsed electric field; Osmotic swelling