title: Characterization of Pressure Transients Generated by Nanosecond Electrical Pulse (nsEP) Exposure.
abstract: The mechanism(s) responsible for the breakdown (nanoporation) of cell plasma membranes after nanosecond pulse (nsEP) exposure remains poorly understood. Current theories focus exclusively on the electrical field, citing electrostriction, water dipole alignment and/or electrodeformation as the primary mechanisms for pore formation. However, the delivery of a high-voltage nsEP to cells by tungsten electrodes creates a multitude of biophysical phenomena, including electrohydraulic cavitation, electrochemical interactions, thermoelastic expansion, and others. To date, very limited research has investigated non-electric phenomena occurring during nsEP exposures and their potential effect on cell nanoporation. Of primary interest is the production of acoustic shock waves during nsEP exposure, as it is known that acoustic shock waves can cause membrane poration (sonoporation). Based on these observations, our group characterized the acoustic pressure transients generated by nsEP and determined if such transients played any role in nanoporation. In this paper, we show that nsEP exposures, equivalent to those used in cellular studies, are capable of generating high-frequency (2.5 MHz), high-intensity (>13 kPa) pressure transients. Using confocal microscopy to measure cell uptake of YO-PRO®-1 (indicator of nanoporation of the plasma membrane) and changing the electrode geometry, we determined that acoustic waves alone are not responsible for poration of the membrane.
authors.affiliation: School of Medicine, Dept. of Radiological Sciences, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas, USA 78229.
authors.forename: Caleb C
authors.initials: CC
authors.lastname: Roth
authors.affiliation: Dept. of Electrical Engineering, University of Texas San Antonio, 1 UTSA Circle, San Antonio, Texas, USA 78249.
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Barnes
authors.affiliation: Radio Frequency Bioeffects Branch, Bioeffects Division, Human Effectiveness Directorate, 711th Human Performance Wing, Air Force Research Laboratory, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas, USA 78234.
authors.forename: Bennett L
authors.initials: BL
authors.lastname: Ibey
authors.affiliation: Optical Radiation Bioeffects Branch, Bioeffects Division, Human Effectiveness Directorate, 711th Human Performance Wing, Air Force Research Laboratory, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas, USA 78234.
authors.forename: Hope T
authors.initials: HT
authors.lastname: Beier
authors.affiliation: Dept. of Physics, University of Texas San Antonio, 1 UTSA Circle, San Antonio, Texas, USA 78249.
authors.forename: L
authors.initials: L
authors.lastname: Christopher Mimun
authors.affiliation: Dept. of Electrical Engineering, University of Texas San Antonio, 1 UTSA Circle, San Antonio, Texas, USA 78249.
authors.forename: Saher M
authors.initials: SM
authors.lastname: Maswadi
authors.affiliation: Dept. of Electrical Engineering, University of Texas San Antonio, 1 UTSA Circle, San Antonio, Texas, USA 78249.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Shadaram
authors.affiliation: School of Medicine, Dept. of Ophthalmology, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas, USA 78229.
authors.forename: Randolph D
authors.initials: RD
authors.lastname: Glickman
mesh_terms: D000818:Animals; D001583:Benzoxazoles / Q000378:metabolism / Q000493:pharmacokinetics; D016466:CHO Cells; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D002463:Cell Membrane Permeability; D006224:Cricetinae; D003412:Cricetulus; D004560:Electricity; D018274:Electroporation / Q000295:instrumentation* / Q000379:methods*; D005456:Fluorescent Dyes / Q000378:metabolism / Q000493:pharmacokinetics; D005583:Fourier Analysis; D018613:Microscopy, Confocal; D016062:Porosity; D011312:Pressure; D011806:Quinolinium Compounds / Q000378:metabolism / Q000493:pharmacokinetics; D013997:Time Factors
chemical_list: D001583:Benzoxazoles; D005456:Fluorescent Dyes; D011806:Quinolinium Compounds; C089813:YO-PRO 1