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de Caro A, Talmont F, Rols MP, Golzio M, Kolosnjaj-Tabi J. Therapeutic perspectives of high pulse repetition rate electroporation. Bioelectrochemistry 2024; 156:108629. [PMID: 38159429 DOI: 10.1016/j.bioelechem.2023.108629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 12/15/2023] [Accepted: 12/16/2023] [Indexed: 01/03/2024]
Abstract
Electroporation, a technique that uses electrical pulses to temporarily or permanently destabilize cell membranes, is increasingly used in cancer treatment, gene therapy, and cardiac tissue ablation. Although the technique is efficient, patients report discomfort and pain. Current strategies that aim to minimize pain and muscle contraction rely on the use of pharmacological agents. Nevertheless, technical improvements might be a valuable tool to minimize adverse events, which occur during the application of standard electroporation protocols. One recent technological strategy involves the use of high pulse repetition rate. The emerging technique, also referred as "high frequency" electroporation, employs short (micro to nanosecond) mono or bipolar pulses at repetition rate ranging from a few kHz to a few MHz. This review provides an overview of the historical background of electric field use and its development in therapies over time. With the aim to understand the rationale for novel electroporation protocols development, we briefly describe the physiological background of neuromuscular stimulation and pain caused by exposure to pulsed electric fields. Then, we summarize the current knowledge on electroporation protocols based on high pulse repetition rates. The advantages and limitations of these protocols are described from the perspective of their therapeutic application.
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Affiliation(s)
- Alexia de Caro
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Franck Talmont
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Marie-Pierre Rols
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Muriel Golzio
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France.
| | - Jelena Kolosnjaj-Tabi
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France.
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Asadipour K, Zhou C, Yi V, Beebe SJ, Xiao S. Ultra-Low Intensity Post-Pulse Affects Cellular Responses Caused by Nanosecond Pulsed Electric Fields. Bioengineering (Basel) 2023; 10:1069. [PMID: 37760171 PMCID: PMC10525734 DOI: 10.3390/bioengineering10091069] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
High-intensity nanosecond pulse electric fields (nsPEF) can preferentially induce various effects, most notably regulated cell death and tumor elimination. These effects have almost exclusively been shown to be associated with nsPEF waveforms defined by pulse duration, rise time, amplitude (electric field), and pulse number. Other factors, such as low-intensity post-pulse waveform, have been completely overlooked. In this study, we show that post-pulse waveforms can alter the cell responses produced by the primary pulse waveform and can even elicit unique cellular responses, despite the primary pulse waveform being nearly identical. We employed two commonly used pulse generator designs, namely the Blumlein line (BL) and the pulse forming line (PFL), both featuring nearly identical 100 ns pulse durations, to investigate various cellular effects. Although the primary pulse waveforms were nearly identical in electric field and frequency distribution, the post-pulses differed between the two designs. The BL's post-pulse was relatively long-lasting (~50 µs) and had an opposite polarity to the main pulse, whereas the PFL's post-pulse was much shorter (~2 µs) and had the same polarity as the main pulse. Both post-pulse amplitudes were less than 5% of the main pulse, but the different post-pulses caused distinctly different cellular responses. The thresholds for dissipation of the mitochondrial membrane potential, loss of viability, and increase in plasma membrane PI permeability all occurred at lower pulsing numbers for the PFL than the BL, while mitochondrial reactive oxygen species generation occurred at similar pulsing numbers for both pulser designs. The PFL decreased spare respiratory capacity (SRC), whereas the BL increased SRC. Only the PFL caused a biphasic effect on trans-plasma membrane electron transport (tPMET). These studies demonstrate, for the first time, that conditions resulting from low post-pulse intensity charging have a significant impact on cell responses and should be considered when comparing the results from similar pulse waveforms.
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Affiliation(s)
- Kamal Asadipour
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529, USA;
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23529, USA; (C.Z.); (S.J.B.)
| | - Carol Zhou
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23529, USA; (C.Z.); (S.J.B.)
| | - Vincent Yi
- Ocean Lakes High School, Virginia Beach, VA 23454, USA;
| | - Stephen J. Beebe
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23529, USA; (C.Z.); (S.J.B.)
| | - Shu Xiao
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529, USA;
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23529, USA; (C.Z.); (S.J.B.)
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Silkunas M, Gudvangen E, Novickij V, Pakhomov AG. Sub-MHz bursts of nanosecond pulses excite neurons at paradoxically low electric field thresholds without membrane damage. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184034. [PMID: 35981654 DOI: 10.1016/j.bbamem.2022.184034] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/29/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Neuromodulation applications of nanosecond electric pulses (nsEP) are hindered by their low potency to elicit action potentials in neurons. Excitation by a single nsEP requires a strong electric field which injures neurons by electroporation. We bypassed the high electric field requirement by replacing single nsEP stimuli with high-frequency brief nsEP bursts. In hippocampal neurons, excitation thresholds progressively decreased at nsEP frequencies above 20-200 kHz, with up to 20-30-fold reduction at sub-MHz and MHz rates. For a fixed burst duration, thresholds were determined by the duty cycle, irrespective of the specific nsEP duration, rate, or number of pulses per burst. For 100-μs bursts of 100-, 400-, or 800-ns pulses, the threshold decreased as a power function when the duty cycle exceeded 3-5 %. nsEP bursts were compared with single "long" pulses whose duration and amplitude matched the duration and the time-average amplitude of the burst. Such pulses deliver the same electric charge as bursts, within the same time interval. High-frequency nsEP bursts excited neurons at the time-average electric field 2-3 times below the threshold for a single long pulse. For example, the excitation threshold of 139 ± 14 V/cm for a single 100-μs pulse decreased to 57 ± 8 V/cm for a 100-μs burst of 100-ns, 0.25-MHz pulses (p < 0.001). Applying nsEP in bursts reduced or prevented the loss of excitability in multiple stimulation attempts. Stimulation by high-frequency nsEP bursts is a powerful novel approach to excite neurons at paradoxically low electric charge while also avoiding the electroporative membrane damage.
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Affiliation(s)
- Mantas Silkunas
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; Institute for Digestive System Research, Lithuanian University of Health Sciences, 44307 Kaunas, Lithuania
| | - Emily Gudvangen
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | | | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
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Merla C, Nardoni M, Scherman M, Petralito S, Caramazza L, Apollonio F, Liberti M, Paolicelli P, Attal-Tretout B, Mir LM. Changes in hydration of liposome membranes exposed to nanosecond electric pulses detected by wide-field Coherent anti-Stokes Raman microspectroscopy. Bioelectrochemistry 2022; 147:108218. [DOI: 10.1016/j.bioelechem.2022.108218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/25/2022] [Accepted: 07/28/2022] [Indexed: 11/02/2022]
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Kiełbik A, Szlasa W, Novickij V, Szewczyk A, Maciejewska M, Saczko J, Kulbacka J. Effects of high-frequency nanosecond pulses on prostate cancer cells. Sci Rep 2021; 11:15835. [PMID: 34349171 PMCID: PMC8339066 DOI: 10.1038/s41598-021-95180-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 07/21/2021] [Indexed: 02/07/2023] Open
Abstract
Electroporation with pulsed electric fields show a potential to be applied as an experimental focal therapy of tumors. Sub-microsecond regime of electric pulses displays unique electrophysical features operative in cells and membranes. Recently, MHz compression of nanosecond pulses electric fields (nsPEFs) bursts proved to enhance the effectiveness of the therapy. High morbidity of prostate cancer (PCa) and risk of overtreatment associated with this malignancy call for new minimal-invasive treatment alternative. Herein we present the in vitro study for developing applications based on this new technology. In this study, we used flow cytometric analysis, cell viability assay, caspase activity analysis, wound healing assay, confocal microscopy study, and immunofluorescence to investigate the biological effect of high-frequency nsPEFs on PCa cells. Our results show that high-frequency nsPEFs induces the permeabilization and cell death of PCa cells. The cytotoxicity is significantly enhanced in MHz compression of pulses and with the presence of extracellular Ca2+. High-frequency nsPEFs trigger changes in PCa cells' cytoskeleton and their mobility. The presented data show a therapeutic potential of high-frequency nsPEFs in a PCa setting. The sub-microsecond regime of pulses can potentially be applied in nanosecond electroporation protocols for PCa treatment.
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Affiliation(s)
- Aleksander Kiełbik
- grid.4495.c0000 0001 1090 049XMedical University Hospital, Borowska 213, 50-556 Wrocław, Poland ,grid.4495.c0000 0001 1090 049XDepartment of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Wrocław, Poland
| | - Wojciech Szlasa
- grid.4495.c0000 0001 1090 049XFaculty of Medicine, Wroclaw Medical University, Wrocław, Poland
| | - Vitalij Novickij
- grid.9424.b0000 0004 1937 1776Institute of High Magnetic Fields, Vilnius Gediminas Technical University, Vilnius, Lithuania
| | - Anna Szewczyk
- grid.4495.c0000 0001 1090 049XDepartment of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Wrocław, Poland ,grid.8505.80000 0001 1010 5103Department of Animal Developmental Biology, Institute of Experimental Biology, University of Wroclaw, 50-328 Wrocław, Poland
| | - Magdalena Maciejewska
- grid.413454.30000 0001 1958 0162Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland
| | - Jolanta Saczko
- grid.4495.c0000 0001 1090 049XDepartment of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Wrocław, Poland
| | - Julita Kulbacka
- grid.4495.c0000 0001 1090 049XDepartment of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Wrocław, Poland
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Zemlin CW. Safety factor for electrostimulation with nanosecond pulses. Bioelectrochemistry 2021; 141:107882. [PMID: 34274877 DOI: 10.1016/j.bioelechem.2021.107882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 06/08/2021] [Accepted: 06/28/2021] [Indexed: 11/19/2022]
Abstract
While electrical stimulation with pulses of milli- or microsecond duration is possible without electroporation, stimulation with nanosecond pulses typically entails electroporation, and nanosecond pulses can even cause electroporation without stimulation. A recently proposed explanation for this intriguing finding is that stimulation requires not only that a threshold membrane potential is reached, but also that it is sustained for a certain time tmin, while electroporation occurs almost immediately after a higher threshold potential is reached. Here we analytically derive stimulation and electroporation thresholds for membranes that satisfy these assumptions. We analyze the safety factor, i.e. the ratio between electroporation and stimulation threshold and its dependence on pulse duration, membrane charging time constant, and tmin. We find that the safety factor is sharply reduced if both the pulse duration and the membrane charging time constant are below tmin. We discuss different approaches to get models with varying tmin that could be used to experimentally test this theory and cardiac applications.
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Affiliation(s)
- Christian W Zemlin
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Campus Box 8234, 660 S Euclid Ave, St. Louis, MO 63110, USA.
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Kim V, Gudvangen E, Kondratiev O, Redondo L, Xiao S, Pakhomov AG. Peculiarities of Neurostimulation by Intense Nanosecond Pulsed Electric Fields: How to Avoid Firing in Peripheral Nerve Fibers. Int J Mol Sci 2021; 22:ijms22137051. [PMID: 34208945 PMCID: PMC8269031 DOI: 10.3390/ijms22137051] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 12/31/2022] Open
Abstract
Intense pulsed electric fields (PEF) are a novel modality for the efficient and targeted ablation of tumors by electroporation. The major adverse side effects of PEF therapies are strong involuntary muscle contractions and pain. Nanosecond-range PEF (nsPEF) are less efficient at neurostimulation and can be employed to minimize such side effects. We quantified the impact of the electrode configuration, PEF strength (up to 20 kV/cm), repetition rate (up to 3 MHz), bi- and triphasic pulse shapes, and pulse duration (down to 10 ns) on eliciting compound action potentials (CAPs) in nerve fibers. The excitation thresholds for single unipolar but not bipolar stimuli followed the classic strength–duration dependence. The addition of the opposite polarity phase for nsPEF increased the excitation threshold, with symmetrical bipolar nsPEF being the least efficient. Stimulation by nsPEF bursts decreased the excitation threshold as a power function above a critical duty cycle of 0.1%. The threshold reduction was much weaker for symmetrical bipolar nsPEF. Supramaximal stimulation by high-rate nsPEF bursts elicited only a single CAP as long as the burst duration did not exceed the nerve refractory period. Such brief bursts of bipolar nsPEF could be the best choice to minimize neuromuscular stimulation in ablation therapies.
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Affiliation(s)
- Vitalii Kim
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; (V.K.); (E.G.); (S.X.)
| | - Emily Gudvangen
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; (V.K.); (E.G.); (S.X.)
| | | | - Luis Redondo
- Lisbon Engineering Superior Institute, GIAAPP/ISEL, 1959-007 Lisbon, Portugal;
| | - Shu Xiao
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; (V.K.); (E.G.); (S.X.)
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23508, USA
| | - Andrei G. Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; (V.K.); (E.G.); (S.X.)
- Correspondence:
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