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Silkuniene G, Mangalanathan UM, Pakhomov AG, Pakhomova ON. Silencing of ATP1A1 attenuates cell membrane disruption by nanosecond electric pulses. Biochem Biophys Res Commun 2023; 677:93-97. [PMID: 37566922 DOI: 10.1016/j.bbrc.2023.08.011] [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: 07/27/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023]
Abstract
This study explored the role of the Na/K-ATPase (NKA) in membrane permeabilization induced by nanosecond electric pulses. Using CRISPR/Cas9 and shRNA, we silenced the ATP1A1 gene, which encodes α1 NKA subunit in U937 human monocytes. Silencing reduced the rate and the cumulative uptake of YoPro-1 dye after electroporation by 300-ns, 7-10 kV/cm pulses, while ouabain, a specific NKA inhibitor, enhanced YoPro-1 entry. We conclude that the α1 subunit supports the electropermeabilized membrane state, by forming or stabilizing electropores or by hindering repair mechanisms, and this role is independent of NKA's ion pump function.
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Affiliation(s)
- Giedre Silkuniene
- 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
| | - Uma M Mangalanathan
- 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
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA.
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2
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SARIAN MN, ZULKEFLI N, CHE ZAIN MS, MANIAM S, FAKURAZI S. A review with updated perspectives on in vitro and in vivo wound healing models. Turk J Biol 2023; 47:236-246. [PMID: 38152620 PMCID: PMC10751087 DOI: 10.55730/1300-0152.2659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 08/31/2023] [Accepted: 08/10/2023] [Indexed: 12/29/2023] Open
Abstract
A skin wound or perforation triggers a series of homeostatic reactions to safeguard internal organs from invasion by pathogens or other substances that could damage body tissues. An injury may occasionally heal quickly, leading to the closure of the skin's structure. Healing from chronic wounds takes a long time. Although many treatment options are available to manage wound healing, an unmet therapy need remains because of the complexity of the processes and the other factors involved. It is crucial to conduct consistent research on novel therapeutic approaches to find an effective healing agent. Therefore, this work aims to cover various in vitro and in vivo methodologies that could be utilised to examine wound recovery. Before deciding on the optimal course of action, several techniques' benefits, drawbacks, and factors need to be reviewed.
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Affiliation(s)
- Murni Nazira SARIAN
- Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (National University of Malaysia), 43600, Bandar Baru Bangi, Selangor,
Malaysia
| | - Nabilah ZULKEFLI
- Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (National University of Malaysia), 43600, Bandar Baru Bangi, Selangor,
Malaysia
| | - Mohamad Shazeli CHE ZAIN
- Bioresource Technology Division, School of Industrial Technology, Universiti Sains Malaysia (Science University of Malaysia), 11800, Pulau Pinang,
Malaysia
| | - Sandra MANIAM
- Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (University of Putra Malaysia), Serdang 43400, Selangor,
Malaysia
| | - Sharida FAKURAZI
- Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (University of Putra Malaysia), Serdang 43400, Selangor,
Malaysia
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Ibrahimi N, Vallet L, Andre FM, Rivaletto M, Novac BM, Mir LM, Pécastaing L. An Overview of Subnanosecond Pulsed Electric Field Biological Effects: Toward Contactless Technologies for Cancer Treatment. Bioelectricity 2023. [DOI: 10.1089/bioe.2022.0031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023] Open
Affiliation(s)
- Njomza Ibrahimi
- Laboratoire des Sciences de l'Ingénieur Appliquées à la Mécanique et au Génie Électrique–Fédération IPRA, EA4581, Université de Pau et des Pays de l'Adour/E2S UPPA, Pau, France
| | - Leslie Vallet
- Université Paris-Saclay, CNRS, Gustave Roussy, UMR 9018, Metabolic and Systemic Aspects of Oncogenesis (METSY), Villejuif, France
| | - Franck M. Andre
- Université Paris-Saclay, CNRS, Gustave Roussy, UMR 9018, Metabolic and Systemic Aspects of Oncogenesis (METSY), Villejuif, France
| | - Marc Rivaletto
- Laboratoire des Sciences de l'Ingénieur Appliquées à la Mécanique et au Génie Électrique–Fédération IPRA, EA4581, Université de Pau et des Pays de l'Adour/E2S UPPA, Pau, France
| | - Bucur M. Novac
- Laboratoire des Sciences de l'Ingénieur Appliquées à la Mécanique et au Génie Électrique–Fédération IPRA, EA4581, Université de Pau et des Pays de l'Adour/E2S UPPA, Pau, France
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom
| | - Lluis M. Mir
- Université Paris-Saclay, CNRS, Gustave Roussy, UMR 9018, Metabolic and Systemic Aspects of Oncogenesis (METSY), Villejuif, France
| | - Laurent Pécastaing
- Laboratoire des Sciences de l'Ingénieur Appliquées à la Mécanique et au Génie Électrique–Fédération IPRA, EA4581, Université de Pau et des Pays de l'Adour/E2S UPPA, Pau, France
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Petrov AA, Moraleva AA, Antipova NV, Amirov RK, Samoylov IS, Savinov SY. The Action of the Pulsed Electric Field of the Subnanosecond Range on Human Tumor Cells. Bioelectromagnetics 2022; 43:327-335. [PMID: 35535612 DOI: 10.1002/bem.22408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 02/20/2022] [Accepted: 04/21/2022] [Indexed: 11/11/2022]
Abstract
The action of the pulsed electric field of the subnanosecond range on Jurkat, HEK 293, and U-87 MG human cell lines was studied. The cells were treated in a waveguide in 0.18 ml electrodeless Teflon cuvettes. The electric field strength in the cell culture medium was ~2 kV/cm, the pulse duration was ~1 ns, the leading edge was 150 ps, the frequency was 100 Hz, and the treatment time was 5 min. According to estimates, the change of the transmembrane potential during the pulse was ~20 mV and we assume that it was insufficient for electroporation. Jurkat and HEK 293 cells appeared to be more resistant to the treatment than U-87 MG cells. We have observed that the impulses with the above-mentioned parameters can cause a noticeable change in the mitochondrial activity of U-87 MG cells. © 2022 Bioelectromagnetics Society.
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Affiliation(s)
| | - Anastasiya A Moraleva
- P. N. Lebedev Physical Institute of RAS, Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of RAS, Moscow, Russia
| | - Nadezhda V Antipova
- P. N. Lebedev Physical Institute of RAS, Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of RAS, Moscow, Russia.,National Research University Higher School of Economics, Moscow, Russia
| | - Ravil Kh Amirov
- Joint Institute for High Temperatures of RAS, Moscow, Russia
| | - Igor S Samoylov
- Joint Institute for High Temperatures of RAS, Moscow, Russia
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Pakhomov AG, Pakhomova ON. The interplay of excitation and electroporation in nanosecond pulse stimulation. Bioelectrochemistry 2020; 136:107598. [PMID: 32711366 DOI: 10.1016/j.bioelechem.2020.107598] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 12/11/2022]
Abstract
Conventional electric stimuli of micro- and millisecond duration excite or activate cells at voltages 10-100 times below the electroporation threshold. This ratio is remarkably different for nanosecond electric pulses (nsEP), which caused excitation and activation only at or above the electroporation threshold in diverse cell lines, primary cardiomyocytes, neurons, and chromaffin cells. Depolarization to the excitation threshold often results from (or is assisted by) the loss of the resting membrane potential due to ion leaks across the membrane permeabilized by nsEP. Slow membrane resealing and the build-up of electroporation damages prevent repetitive excitation by nsEP. However, peripheral nerves and muscles are exempt from this rule and withstand multiple cycles of excitation by nsEP without the loss of function or signs of electroporation. We show that the damage-free excitation by nsEP may be enabled by the membrane charging time constant sufficiently large to (1) cap the peak transmembrane voltage during nsEP below the electroporation threshold, and (2) extend the post-nsEP depolarization long enough to activate voltage-gated ion channels. The low excitatory efficacy of nsEP compared to longer pulses makes them advantageous for medical applications where the neuromuscular excitation is an unwanted side effect, such as electroporation-based cancer and tissue ablation.
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Affiliation(s)
- Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
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Probing Nanoelectroporation and Resealing of the Cell Membrane by the Entry of Ca 2+ and Ba 2+ Ions. Int J Mol Sci 2020; 21:ijms21093386. [PMID: 32403282 PMCID: PMC7247012 DOI: 10.3390/ijms21093386] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 12/11/2022] Open
Abstract
The principal bioeffect of the nanosecond pulsed electric field (nsPEF) is a lasting cell membrane permeabilization, which is often attributed to the formation of nanometer-sized pores. Such pores may be too small for detection by the uptake of fluorescent dyes. We tested if Ca2+, Cd2+, Zn2+, and Ba2+ ions can be used as nanoporation markers. Time-lapse imaging was performed in CHO, BPAE, and HEK cells loaded with Fluo-4, Calbryte, or Fluo-8 dyes. Ca2+ and Ba2+ did not change fluorescence in intact cells, whereas their entry after nsPEF increased fluorescence within <1 ms. The threshold for one 300-ns pulse was at 1.5–2 kV/cm, much lower than >7 kV/cm for the formation of larger pores that admitted YO-PRO-1, TO-PRO-3, or propidium dye into the cells. Ba2+ entry caused a gradual emission rise, which reached a stable level in 2 min or, with more intense nsPEF, kept rising steadily for at least 30 min. Ca2+ entry could elicit calcium-induced calcium release (CICR) followed by Ca2+ removal from the cytosol, which markedly affected the time course, polarity, amplitude, and the dose-dependence of fluorescence change. Both Ca2+ and Ba2+ proved as sensitive nanoporation markers, with Ba2+ being more reliable for monitoring membrane damage and resealing.
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7
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Recent advances in micro/nanoscale intracellular delivery. NANOTECHNOLOGY AND PRECISION ENGINEERING 2020. [DOI: 10.1016/j.npe.2019.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Casciola M, Xiao S, Apollonio F, Paffi A, Liberti M, Muratori C, Pakhomov AG. Cancellation of nerve excitation by the reversal of nanosecond stimulus polarity and its relevance to the gating time of sodium channels. Cell Mol Life Sci 2019; 76:4539-4550. [PMID: 31055644 PMCID: PMC11105181 DOI: 10.1007/s00018-019-03126-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/19/2019] [Accepted: 04/30/2019] [Indexed: 12/30/2022]
Abstract
The initiation of action potentials (APs) by membrane depolarization occurs after a brief vulnerability period, during which excitation can be abolished by the reversal of the stimulus polarity. This vulnerability period is determined by the time needed for gating of voltage-gated sodium channels (VGSC). We compared nerve excitation by ultra-short uni- and bipolar stimuli to define the time frame of bipolar cancellation and of AP initiation. Propagating APs in isolated frog sciatic nerve were elicited by cathodic pulses (200 ns-300 µs), followed by an anodic (canceling) pulse of the same duration after a 0-200-µs delay. We found that the earliest and the latest boundaries for opening the critical number of VGSC needed to initiate AP are, respectively, between 11 and 20 µs and between 100 and 200 µs after the onset of depolarization. Stronger depolarization accelerated AP initiation, apparently due to faster VGSC opening, but not beyond the 11-µs limit. Bipolar cancellation was augmented by reducing pulse duration, shortening the delay between pulses, decreasing the amplitude of the cathodic pulse, and increasing the amplitude of the anodic one. Some of these characteristics contrasted the bipolar cancellation of cell membrane electroporation (Pakhomov et al. in Bioelectrochemistry 122:123-133, 2018; Gianulis et al. in Bioelectrochemistry 119:10-19, 2017), suggesting different mechanisms. The ratio of nerve excitation thresholds for a unipolar cathodic pulse and a symmetrical bipolar pulse increased as a power function as the pulse duration decreased, in remarkable agreement with the predictions of SENN model of nerve excitation (Reilly and Diamant in Health Phys 83(3):356-365, 2002).
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Affiliation(s)
- Maura Casciola
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA, 23508, USA
| | - Shu Xiao
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA, 23508, USA
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, USA
| | - Francesca Apollonio
- Department of Information Engineering, Electronics and Telecommunications (D.I.E.T.), Sapienza University of Rome, Rome, Italy
| | - Alessandra Paffi
- Department of Information Engineering, Electronics and Telecommunications (D.I.E.T.), Sapienza University of Rome, Rome, Italy
| | - Micaela Liberti
- Department of Information Engineering, Electronics and Telecommunications (D.I.E.T.), Sapienza University of Rome, Rome, Italy
| | - Claudia Muratori
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA, 23508, USA
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA, 23508, USA.
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Hirata M, Tanihara F, Wittayarat M, Hirano T, Nguyen NT, Le QA, Namula Z, Nii M, Otoi T. Genome mutation after introduction of the gene editing by electroporation of Cas9 protein (GEEP) system in matured oocytes and putative zygotes. In Vitro Cell Dev Biol Anim 2019; 55:237-242. [PMID: 30820813 DOI: 10.1007/s11626-019-00338-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 02/13/2019] [Indexed: 11/30/2022]
Abstract
The application of CRISPR/Cas9 strategy promises to rapidly increase the production of genetically engineered animals since it yields stably integrated transgenes. In the present study, we investigated the efficiency of target mutations after electroporation with the CRISPR/Cas9 system using sgRNAs to target the MSTN or FGF10 genes in porcine-matured oocytes and putative zygotes. Effects of pulse number (3-7 pulse repetitions) during electroporation on the embryonic development and mutation efficiency were also investigated. Our results showed that the cleavage rate of matured oocytes with electroporation treatment significantly decreased as compared with electroporated putative zygotes (p < 0.05). Moreover, the rates of blastocyst formation from oocytes/zygotes electroporated with more than 5 pulses decreased. Mutation efficiency was then assessed after sequencing the target sites in individual blastocysts derived from oocytes/zygotes electroporated by 3 and 5 pulses. No bi-allelic mutations in all examined blastocysts were observed in this study. There were no differences in the mutation rates (50-60%) between blastocysts derived from matured oocytes electroporated by 3 and 5 pulses, irrespective of targeting gene. In the targeting MSTN gene, however, the mutation rate (12.5%) of blastocysts derived from putative zygotes electroporated by 3 pulses tended to be lower than that (60%) from 5-pulsed electroporated putative zygotes. These data indicate that the type of eggs may influence not only their development after electroporation treatment but also the mutation rate in the resulting blastocysts.
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Affiliation(s)
- Maki Hirata
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Fuminori Tanihara
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan.
| | - Manita Wittayarat
- Faculty of Veterinary Science, Prince of Songkla University, Songkhla, Thailand
| | - Takayuki Hirano
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Nhien Thi Nguyen
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Quynh Anh Le
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Zhao Namula
- Faculty of Veterinary Science, Guangdong Ocean University, Zhanjiang, China
| | - Masahiro Nii
- Tokushima Prefectural Livestock Research Institute, Tokushima, Japan
| | - Takeshige Otoi
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
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Lamberti P, Compitiello M, Romeo S, Lamberti P, Compitiello M, Romeo S, Lamberti P, Romeo S, Compitiello M. ns Pulsed Electric Field-Induced Action Potentials in the Circuital Model of an Axon. IEEE Trans Nanobioscience 2019; 17:110-116. [PMID: 29870334 DOI: 10.1109/tnb.2018.2822840] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pulsed electric fields with duration in the sub- and ns time scale (nsPEFs) increase the permeability of cell membranes, enabling the transport of normally impermeant molecules into or out of the cell (electroporation). Such effect is associated to intracellular alterations and indicates nsPEFs as a new stimulus to modulate cell functions. In particular, studies dealing with the application of nsPEFs to excitable cells suggest their use for the stimulation/inhibition of cell excitation. In this paper, the circuital model per surface unit of the plasma membrane of an axon was developed to implement the Hodgkin and Huxley equations, describing the action potential activation process. For the first time, a power electronics circuital simulator was adopted. The model was first validated with conventional microsecond stimuli, and then it was employed to identify the conditions for cell excitation by nsPEFs. The results demonstrated the possibility of electrostimulation by nsPEFs at depolarization levels far below those required for inducing electroporation, and with ionic current dynamics similar to that induced by conventional stimuli, confirming recent experimental findings. Moreover, by using a power electronics tool, easier integration of the cell modeling with the design and optimization of pulse generation systems can be gained.
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Cell Fragmentation and Permeabilization by a 1 ns Pulse Driven Triple-Point Electrode. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4072983. [PMID: 29744357 PMCID: PMC5878903 DOI: 10.1155/2018/4072983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 01/25/2018] [Accepted: 02/07/2018] [Indexed: 01/09/2023]
Abstract
Ultrashort electric pulses (ns-ps) are useful in gaining understanding as to how pulsed electric fields act upon biological cells, but the electric field intensity to induce biological responses is typically higher than longer pulses and therefore a high voltage ultrashort pulse generator is required. To deliver 1 ns pulses with sufficient electric field but at a relatively low voltage, we used a glass-encapsulated tungsten wire triple-point electrode (TPE) at the interface among glass, tungsten wire, and water when it is immersed in water. A high electric field (2 MV/cm) can be created when pulses are applied. However, such a high electric field was found to cause bubble emission and temperature rise in the water near the electrode. They can be attributed to Joule heating near the electrode. Adherent cells on a cover slip treated by the combination of these stimuli showed two major effects: (1) cells in a crater (<100 μm from electrode) were fragmented and the debris was blown away. The principal mechanism for the damage is presumed to be shear forces due to bubble collapse; and (2) cells in the periphery of the crater were permeabilized, which was due to the combination of bubble movement and microstreaming as well as pulsed electric fields. These results show that ultrashort electric fields assisted by microbubbles can cause significant cell response and therefore a triple-point electrode is a useful ablation tool for applications that require submillimeter precision.
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Damage-free peripheral nerve stimulation by 12-ns pulsed electric field. Sci Rep 2017; 7:10453. [PMID: 28874684 PMCID: PMC5585227 DOI: 10.1038/s41598-017-10282-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/07/2017] [Indexed: 12/15/2022] Open
Abstract
Modern technologies enable deep tissue focusing of nanosecond pulsed electric field (nsPEF) for non-invasive nerve and muscle stimulation. However, it is not known if PEF orders of magnitude shorter than the activation time of voltage-gated sodium channels (VGSC) would evoke action potentials (APs). One plausible scenario requires the loss of membrane integrity (electroporation) and resulting depolarization as an intermediate step. We report, for the first time, that the excitation of a peripheral nerve can be accomplished by 12-ns PEF without electroporation. 12-ns stimuli at 4.1-11 kV (3.3-8.8 kV/cm) evoked APs similarly to conventional stimuli (100-250 μs, 1-5 V, 103-515 V/m), except for having higher selectivity for the faster nerve fibers. Nerves sustained repeated tetanic stimulations (50 Hz or 100 Hz for 1 min) alternately by 12-ns PEF and by conventional pulses. Such tetani caused a modest AP decrease, to a similar extent for both types of stimuli. Nerve refractory properties were not affected. The lack of cumulative damages even from tens of thousands of 12-ns stimuli and the similarities with the conventional stimulation prove VGSC activation by nsPEF without nerve membrane damage.
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Neuronal excitation and permeabilization by 200-ns pulsed electric field: An optical membrane potential study with FluoVolt dye. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1273-1281. [PMID: 28432032 DOI: 10.1016/j.bbamem.2017.04.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 03/28/2017] [Accepted: 04/15/2017] [Indexed: 11/24/2022]
Abstract
Electric field pulses of nano- and picosecond duration are a novel modality for neurostimulation, activation of Ca2+ signaling, and tissue ablation. However it is not known how such brief pulses activate voltage-gated ion channels. We studied excitation and electroporation of hippocampal neurons by 200-ns pulsed electric field (nsPEF), by means of time-lapse imaging of the optical membrane potential (OMP) with FluoVolt dye. Electroporation abruptly shifted OMP to a more depolarized level, which was reached within <1ms. The OMP recovery started rapidly (τ=8-12ms) but gradually slowed down (to τ>10s), so cells remained above the resting OMP level for at least 20-30s. Activation of voltage-gated sodium channels (VGSC) enhanced the depolarizing effect of electroporation, resulting in an additional tetrodotoxin-sensitive OMP peak in 4-5ms after nsPEF. Omitting Ca2+ in the extracellular solution did not reduce the depolarization, suggesting no contribution of voltage-gated calcium channels (VGCC). In 40% of neurons, nsPEF triggered a single action potential (AP), with the median threshold of 3kV/cm (range: 1.9-4kV/cm); no APs could be evoked by stimuli below the electroporation threshold (1.5-1.9kV/cm). VGSC opening could already be detected in 0.5ms after nsPEF, which is too fast to be mediated by the depolarizing effect of electroporation. The overlap of electroporation and AP thresholds does not necessarily reflect the causal relation, but suggests a low potency of nsPEF, as compared to conventional electrostimulation, for VGSC activation and AP induction.
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Min SH, Kwon O, Sattorov M, Baek IK, Kim S, Jeong JY, Hong D, Park S, Park GS. Miniaturized two-stack Blumlein pulser with a variable repetition-rate for non-thermal irreversible-electroporation experiments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:014704. [PMID: 28147680 DOI: 10.1063/1.4973768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Non-thermal irreversible electroporation (NTIRE) to avoid thermal damage to cells during intense DC ns pulsed electric fields (nsPEFs) is a recent modality for medical applications. This mechanism, related to bioelectrical dynamics of the cell, is linked to the effect of a DC electric field and a threshold effect with an electrically stimulated membrane for the charge distribution in the cell. To create the NTIRE condition, the pulse width of the nsPEF should be shorter than the charging time constant of the membrane related to the cell radius, membrane capacitance, cytoplasm resistivity, and medium resistivity. It is necessary to design and fabricate a very intense nanosecond DC electric field pulser that is capable of producing voltages up to the level of 100 kV/cm with an artificial pulse width (∼ns) with controllable repetition rates. Many devices to generate intense DC nsPEF using various pulse-forming line technologies have been introduced thus far. However, the previous Blumlein pulse-generating devices are clearly inefficient due to the energy loss between the input voltage and the output voltage. An improved two-stage stacked Blumlein pulse-forming line can overcome this limitation and decrease the energy loss from a DC power supply. A metal oxide silicon field-effect transistor switch with a fast rise and fall time would enable a high repetition rate (max. 100 kHz) and good endurance against very high voltages (DC ∼ 30 kV). The load is designed to match the sample for exposure to cell suspensions consisting of a 200 Ω resistor matched with a Blumlein circuit and two electrodes without the characteristic RC time effect of the circuit (capacitance =0.174 pF).
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Affiliation(s)
- Sun-Hong Min
- Korea Heavy Ion Medical Accelerator Project, Korea Institute of Radiological and Medical Science, Seoul 01812, South Korea
| | - Ohjoon Kwon
- Institute for Basic Science Center for Axion and Precision Physics Research, Daejeon 305-701, South Korea
| | - Matlabjon Sattorov
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
| | - In-Keun Baek
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
| | - Seontae Kim
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
| | - Jin-Young Jeong
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
| | - Dongpyo Hong
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
| | | | - Gun-Sik Park
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
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