Recent advances in pulsed power technology culminated in engineering of new devices capable of delivering high-voltage, nanosecond-duration electric pulses (nsEP) to low-impedance loads such as biological tissues and cell samples. We found that nsEP can be employed as a unique tool to modify physiology of the plasma membrane in living cells and alter cell function. The most remarkable effect of nsEP was opening of long-lived, voltage- and current-sensitive, rectifying, ion-selective, asymmetrical pores of nano- or sub- nanometer diameter ("nanopores"). These complex behaviors are normally expected only from sophisticated devices like protein ion channels and distinguish nanopores from conventional (larger) electropores. Once induced, nanopores oscillated between open and quasi-open (electrically silent) states for minutes, followed by either gradual resealing or abrupt breakdown into larger pores, with immediate loss of nanopore-specific properties. Nanopores appeared adequately equipped for certain functions that are traditionally ascribed to classic ion channels;we hypothesize that nanopores may form under physiological and pathological conditions to supplement ion channels as an additional ion transport pathway. Nanopores have previously been reported in synthetic foils and planar lipid bilayers, but our work is the first one to document the formation of nanopores and their properties in living cells. Furthermore, we have established both inhibitory and facilitatory responses of endogenous ion channels after nsEP treatment, as well as cytophysiological changes due to the osmotic imbalance. This Research Application is designed to explore the phenomenon of nanoelectroporation in living cells and to evaluate potential applications of this novel technique in research and medicine. The proposed study consists of four Specific Aims intended to characterize and improve the nanoelectroporation procedure;to reveal mechanisms that allow nanopores to perform their complex activities;and to elucidate mechanisms that underlie nsEP effects on plasma membrane barrier function and ion traffic:
Specific Aim 1 : Explore the dependence of nanopore formation on the physical parameters of electric pulses, optimize nanoelectroporation procedures and nanopore detection techniques.
Specific Aim 2 : Analyze structural and functional properties of nanopores (pore lifetime, opening diameter, ion selectivity, voltage and current sensitivity) and reveal mechanisms responsible for these properties.
Specific Aim 3 : Explore the impact of nanoelectroporation on the function of classic voltage-gated ion channels, and on the excitation and action potential propagation in nerve and muscle cells.
Specific Aim 4 : Explore mechanisms underlying nanoporation effect on plasma membrane water permeability and cell volume control.

Public Health Relevance

This study will be focused on the new phenomenon of nanoelectroporation, which is the formation of stable, voltage- and current-sensitive, nanometer-diameter membrane pores in living cells exposed to nanosecond- duration, high-voltage electric pulses (nsEP). We will focus on physico-chemical and physiological mechanisms that underlie and determine plasma membrane nanoelectroporation and nsEP effects on endogenous ion channels and water metabolism. Anticipated results will promote the development of new medical and research applications using nsEP for deliberate modification of cell functions, particularly in nerve and muscle tissues.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM088303-04
Application #
8500364
Study Section
Nanotechnology Study Section (NANO)
Program Officer
Lewis, Catherine D
Project Start
2010-07-01
Project End
2014-06-30
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
4
Fiscal Year
2013
Total Cost
$278,173
Indirect Cost
$91,880
Name
Old Dominion University
Department
None
Type
Organized Research Units
DUNS #
041448465
City
Norfolk
State
VA
Country
United States
Zip Code
23508
Muratori, Claudia; Pakhomov, Andrei G; Xiao, Shu et al. (2016) Electrosensitization assists cell ablation by nanosecond pulsed electric field in 3D cultures. Sci Rep 6:23225
Pakhomov, Andrei G; Gianulis, Elena; Vernier, P Thomas et al. (2015) Multiple nanosecond electric pulses increase the number but not the size of long-lived nanopores in the cell membrane. Biochim Biophys Acta 1848:958-66
Schoenbach, Karl H; Pakhomov, Andrei G; Semenov, Iurii et al. (2015) Ion transport into cells exposed to monopolar and bipolar nanosecond pulses. Bioelectrochemistry 103:44-51
Gianulis, Elena C; Pakhomov, Andrei G (2015) Gadolinium modifies the cell membrane to inhibit permeabilization by nanosecond electric pulses. Arch Biochem Biophys 570:1-7
Semenov, Iurii; Xiao, Shu; Kang, Dongkoo et al. (2015) Cell stimulation and calcium mobilization by picosecond electric pulses. Bioelectrochemistry 105:65-71
Semenov, Iurii; Zemlin, Christian; Pakhomova, Olga N et al. (2015) Diffuse, non-polar electropermeabilization and reduced propidium uptake distinguish the effect of nanosecond electric pulses. Biochim Biophys Acta 1848:2118-25
Gianulis, Elena C; Lee, Jimo; Jiang, Chunqi et al. (2015) Electroporation of mammalian cells by nanosecond electric field oscillations and its inhibition by the electric field reversal. Sci Rep 5:13818
Pakhomov, Andrei G; Semenov, Iurii; Xiao, Shu et al. (2014) Cancellation of cellular responses to nanoelectroporation by reversing the stimulus polarity. Cell Mol Life Sci 71:4431-41
Pakhomova, Olga N; Gregory, Betsy; Semenov, Iurii et al. (2014) Calcium-mediated pore expansion and cell death following nanoelectroporation. Biochim Biophys Acta 1838:2547-54
Pakhomov, Andrei G; Xiao, Shu; Pakhomova, Olga N et al. (2014) Disassembly of actin structures by nanosecond pulsed electric field is a downstream effect of cell swelling. Bioelectrochemistry 100:88-95

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