1
|
Sözer EB, Semenov I, Thomas Vernier P. Dihydroethidium-derived fluorescence in electrically stressed cells indicates intracellular microenvironment modifications independent of ROS. Bioelectrochemistry 2024; 160:108751. [PMID: 38851174 DOI: 10.1016/j.bioelechem.2024.108751] [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: 01/03/2024] [Revised: 05/15/2024] [Accepted: 05/27/2024] [Indexed: 06/10/2024]
Abstract
Intracellular reactive oxygen species (ROS) generation is widely suggested as a trigger for biological consequences of electric field exposures, such as those in electroporation applications. ROS are linked with membrane barrier function degradation, genetic damage, and complex events like immunological cell death. Dihydroethidium (DHE) is commonly used to monitor ROS in cells. DHE is linked to intracellular ROS by a primary oxidation product, Ethidium (Eth+), that shows increased fluorescence upon binding to polynucleotides. We observed changes in DHE-derived fluorescence in Chinese hamster ovary (CHO) cells post 300-ns electric pulse exposures, comparing them to tert-butyl-hydroperoxide (t-BHP) induced oxidative stress. Immediate intracellular fluorescence changes were noted in both cases, but with distinct localization patterns. After electrical stress, cytosolic DHE-derived fluorescence intensity decreases, and nucleolar intensity increases. Conversely, t-BHP exposure increases DHE-derived fluorescence uniformly across the cell. Surprisingly, fluorescence patterns after electrical stress in Eth+-loaded cells is identical to those in DHE-loaded cells, in kinetics and localization patterns. These findings indicate that DHE-derived fluorescence changes after pulsed electric field stress are not due to intracellular ROS generation leading to DHE oxidation, but rather indicate stress-induced intracellular microenvironment alterations affecting Eth+ fluorescence.
Collapse
Affiliation(s)
- Esin B Sözer
- Old Dominion University, Frank Reidy Research Center for Bioelectrics, Norfolk, VA, USA.
| | - Iurii Semenov
- Old Dominion University, Frank Reidy Research Center for Bioelectrics, Norfolk, VA, USA
| | - P Thomas Vernier
- Old Dominion University, Frank Reidy Research Center for Bioelectrics, Norfolk, VA, USA.
| |
Collapse
|
2
|
Polajžer T, Peng W, Yao C, Miklavčič D. Changes in Mitochondrial Membrane Potential in In Vitro Electroporation with Nano- and Microsecond Pulses. Bioelectricity 2024; 6:97-107. [PMID: 39119574 PMCID: PMC11305006 DOI: 10.1089/bioe.2024.0007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024] Open
Abstract
With the introduction of nanosecond (ns) pulses, it was suggested that such pulses could be used to permeabilize intracellular membranes, including the mitochondrial membrane. The results presented thus far, however, are not conclusive. Interestingly, the effect of longer microsecond (μs) pulses on changes in mitochondria has never been investigated. We, therefore, investigated the changes in mitochondrial membrane permeability through changes in mitochondrial membrane potential (MMP) in CHO and H9c2 cells after electroporation with 4 ns, 200 ns, and 100 μs pulses. In the range of reversible electroporation, the decrease in MMP generally depended on the cell line. In CHO, ns pulses decreased MMP at lower electroporation intensities than μs. In H9c2, ns and μs were equally effective. In the range of irreversible electroporation, MMP decreased even further, regardless of pulse duration and cell type. The analysis at different time points showed that the changes in MMP within the first hour after pulse treatment are dynamic. Our results on the efficacy of ns pulses are consistent with published data, but with this study we show that μs pulses cause similar changes in MMP as ns pulses, demonstrating that electroporation affects MMP regardless of pulse duration. At the same time, however, differences in MMP changes were observed between different cell lines, indicating some dependence of MMP changes on cell type.
Collapse
Affiliation(s)
- Tamara Polajžer
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Wencheng Peng
- The State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Electrical Engineering, Chongqing University, Chongqing, Republic of China
| | - Chenguo Yao
- The State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Electrical Engineering, Chongqing University, Chongqing, Republic of China
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
3
|
Sachdev S, Potočnik T, Rems L, Miklavčič D. Revisiting the role of pulsed electric fields in overcoming the barriers to in vivo gene electrotransfer. Bioelectrochemistry 2022; 144:107994. [PMID: 34930678 DOI: 10.1016/j.bioelechem.2021.107994] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/15/2021] [Accepted: 11/02/2021] [Indexed: 12/21/2022]
Abstract
Gene therapies are revolutionizing medicine by providing a way to cure hitherto incurable diseases. The scientific and technological advances have enabled the first gene therapies to become clinically approved. In addition, with the ongoing COVID-19 pandemic, we are witnessing record speeds in the development and distribution of gene-based vaccines. For gene therapy to take effect, the therapeutic nucleic acids (RNA or DNA) need to overcome several barriers before they can execute their function of producing a protein or silencing a defective or overexpressing gene. This includes the barriers of the interstitium, the cell membrane, the cytoplasmic barriers and (in case of DNA) the nuclear envelope. Gene electrotransfer (GET), i.e., transfection by means of pulsed electric fields, is a non-viral technique that can overcome these barriers in a safe and effective manner. GET has reached the clinical stage of investigations where it is currently being evaluated for its therapeutic benefits across a wide variety of indications. In this review, we formalize our current understanding of GET from a biophysical perspective and critically discuss the mechanisms by which electric field can aid in overcoming the barriers. We also identify the gaps in knowledge that are hindering optimization of GET in vivo.
Collapse
Affiliation(s)
- Shaurya Sachdev
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia
| | - Tjaša Potočnik
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia
| | - Lea Rems
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia
| | - Damijan Miklavčič
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia.
| |
Collapse
|
4
|
Pulse Duration Dependent Asymmetry in Molecular Transmembrane Transport Due to Electroporation in H9c2 Rat Cardiac Myoblast Cells In Vitro. Molecules 2021; 26:molecules26216571. [PMID: 34770979 PMCID: PMC8588460 DOI: 10.3390/molecules26216571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/09/2021] [Accepted: 10/22/2021] [Indexed: 11/17/2022] Open
Abstract
Electroporation (EP) is one of the successful physical methods for intracellular drug delivery, which temporarily permeabilizes plasma membrane by exposing cells to electric pulses. Orientation of cells in electric field is important for electroporation and, consequently, for transport of molecules through permeabilized plasma membrane. Uptake of molecules after electroporation are the greatest at poles of cells facing electrodes and is often asymmetrical. However, asymmetry reported was inconsistent and inconclusive-in different reports it was either preferentially anodal or cathodal. We investigated the asymmetry of polar uptake of calcium ions after electroporation with electric pulses of different durations, as the orientation of elongated cells affects electroporation to a different extent when using electric pulses of different durations in the range of 100 ns to 100 µs. The results show that with 1, 10, and 100 µs pulses, the uptake of calcium ions is greater at the pole closer to the cathode than at the pole closer to the anode. With shorter 100 ns pulses, the asymmetry is not observed. A different extent of electroporation at different parts of elongated cells, such as muscle or cardiac cells, may have an impact on electroporation-based treatments such as drug delivery, pulse-field ablation, and gene electrotransfection.
Collapse
|
5
|
Vižintin A, Marković S, Ščančar J, Miklavčič D. Electroporation with nanosecond pulses and bleomycin or cisplatin results in efficient cell kill and low metal release from electrodes. Bioelectrochemistry 2021; 140:107798. [PMID: 33743336 DOI: 10.1016/j.bioelechem.2021.107798] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 02/19/2021] [Accepted: 03/01/2021] [Indexed: 12/21/2022]
Abstract
Nanosecond electric pulses have several potential advantages in electroporation-based procedures over the conventional micro- and millisecond pulses including low level of heating, reduced electrochemical reactions and reduced muscle contractions making them alluring for use in biomedicine and food industry. The aim of this study was to evaluate if nanosecond pulses can enhance the cytotoxicity of chemotherapeutics bleomycin and cisplatin in vitro and to quantify metal release from electrodes in comparison to 100 μs pulses commonly used in electrochemotherapy. The effects of nanosecond pulse parameters (voltage, pulse duration, number of pulses) on cell membrane permeabilization, resealing and on cell survival after electroporation only and after electrochemotherapy with bleomycin and cisplatin were evaluated on Chinese hamster ovary cells. Application of permeabilizing nanosecond pulses in combination with chemotherapeutics resulted in successful cell kill. Higher extracellular concentrations of bleomycin - but not cisplatin - were needed to achieve the same decrease in cell survival with nanosecond pulses as with eight 100 μs pulses, however, the tested bleomycin concentrations were still considerably lower compared to doses used in clinical practice. Decreasing the pulse duration from microseconds to nanoseconds and concomitantly increasing the amplitude to achieve the same biological effect resulted in reduced release of aluminum ions from electroporation cuvettes.
Collapse
Affiliation(s)
- Angelika Vižintin
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia
| | - Stefan Marković
- Jožef Stefan Institute, Department of Environmental Sciences, Jamova cesta 39, 1000 Ljubljana, Slovenia
| | - Janez Ščančar
- Jožef Stefan Institute, Department of Environmental Sciences, Jamova cesta 39, 1000 Ljubljana, Slovenia
| | - Damijan Miklavčič
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia.
| |
Collapse
|
6
|
Nonlinear dispersive cell model for microdosimetry of nanosecond pulsed electric fields. Sci Rep 2020; 10:19456. [PMID: 33173132 PMCID: PMC7655951 DOI: 10.1038/s41598-020-76642-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 10/30/2020] [Indexed: 01/07/2023] Open
Abstract
For applications based on nanosecond pulsed electric fields (nsPEFs), the underlying transmembrane potential (TMP) distribution on the plasma membrane is influenced by electroporation (EP) of the plasma membrane and dielectric dispersion (DP) of all cell compartments which is important for predicting the bioelectric effects. In this study, the temporal and spatial distribution of TMP on the plasma membrane induced by nsPEFs of various pulse durations (3 ns, 5 ns unipolar, 5 ns bipolar, and 10 ns) is investigated with the inclusion of both DP and EP. Based on the double-shelled dielectric spherical cell model, the Debye equation describing DP is transformed into the time-domain form with the introduction of polarization vector, and then we obtain the time course of TMP by solving the combination of Laplace equation and time-domain Debye equation. Next, the asymptotic version of the Smoluchowski equation is included to characterize the EP of plasma membrane in order to observe more profound electroporation effects with larger pore density and electroporated areas in consideration of both DP and EP. Through the simulation, it is clearer to understand the relationship between the applied nsPEFs and the induced bioelectric effects.
Collapse
|
7
|
Dermol-Černe J, Batista Napotnik T, Reberšek M, Miklavčič D. Short microsecond pulses achieve homogeneous electroporation of elongated biological cells irrespective of their orientation in electric field. Sci Rep 2020; 10:9149. [PMID: 32499601 PMCID: PMC7272635 DOI: 10.1038/s41598-020-65830-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 04/27/2020] [Indexed: 12/21/2022] Open
Abstract
In gene electrotransfer and cardiac ablation with irreversible electroporation, treated muscle cells are typically of elongated shape and their orientation may vary. Orientation of cells in electric field has been reported to affect electroporation, and hence electrodes placement and pulse parameters choice in treatments for achieving homogeneous effect in tissue is important. We investigated how cell orientation influences electroporation with respect to different pulse durations (ns to ms range), both experimentally and numerically. Experimentally detected electroporation (evaluated separately for cells parallel and perpendicular to electric field) via Ca2+ uptake in H9c2 and AC16 cardiomyocytes was numerically modeled using the asymptotic pore equation. Results showed that cell orientation affects electroporation extent: using short, nanosecond pulses, cells perpendicular to electric field are significantly more electroporated than parallel (up to 100-times more pores formed), and with long, millisecond pulses, cells parallel to electric field are more electroporated than perpendicular (up to 1000-times more pores formed). In the range of a few microseconds, cells of both orientations were electroporated to the same extent. Using pulses of a few microseconds lends itself as a new possible strategy in achieving homogeneous electroporation in tissue with elongated cells of different orientation (e.g. electroporation-based cardiac ablation).
Collapse
Affiliation(s)
- Janja Dermol-Černe
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000, Ljubljana, Slovenia
| | - Tina Batista Napotnik
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000, Ljubljana, Slovenia
| | - Matej Reberšek
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000, Ljubljana, Slovenia
| | - Damijan Miklavčič
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000, Ljubljana, Slovenia.
| |
Collapse
|
8
|
Kryukov AI, Kunelskaya NL, Shershunova EA, Rebrov IE, Yamshchikov VA, Garov EV, Tsarapkin GY, Mishchenko VV. [Topical drug administration to the inner ear. Modern state of the problem and development perspectives]. Vestn Otorinolaringol 2019; 84:6-14. [PMID: 31793520 DOI: 10.17116/otorino2019840516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The work assessed modern methods of drug delivery through biological barriers to the lesion, in particular, through the most studied - skin. The main advantages and disadvantages of the existing methods for the topical administration of drugs into the inner ear - intra-imperial and intra-labyrinth delivery are analyzed. A brief review of medicinal substances for topical administration to the inner ear, both widely used (for example, aminoglycosides, steroid drugs) and undergoing clinical trials, is given. An assessment is made of the prospects for the use of transmembrane drug delivery to the inner ear using an electric field, which has a combined electro-creative and iontophoretic effect.
Collapse
Affiliation(s)
- A I Kryukov
- The Sverzhevskiy's Otorhinolaryngology Healthcare Research Institute, Moscow, Russia, 117152
| | - N L Kunelskaya
- The Sverzhevskiy's Otorhinolaryngology Healthcare Research Institute, Moscow, Russia, 117152
| | - E A Shershunova
- The Institute for Electrophysics and Electric Power of the Russian Academy of Sciences, Sanct-Petersburg, Russia, 191186
| | - I E Rebrov
- The Institute for Electrophysics and Electric Power of the Russian Academy of Sciences, Sanct-Petersburg, Russia, 191186
| | - V A Yamshchikov
- The Institute for Electrophysics and Electric Power of the Russian Academy of Sciences, Sanct-Petersburg, Russia, 191186
| | - E V Garov
- The Sverzhevskiy's Otorhinolaryngology Healthcare Research Institute, Moscow, Russia, 117152
| | - G Yu Tsarapkin
- The Sverzhevskiy's Otorhinolaryngology Healthcare Research Institute, Moscow, Russia, 117152
| | - V V Mishchenko
- The Sverzhevskiy's Otorhinolaryngology Healthcare Research Institute, Moscow, Russia, 117152
| |
Collapse
|
9
|
Kotnik T, Rems L, Tarek M, Miklavčič D. Membrane Electroporation and Electropermeabilization: Mechanisms and Models. Annu Rev Biophys 2019; 48:63-91. [PMID: 30786231 DOI: 10.1146/annurev-biophys-052118-115451] [Citation(s) in RCA: 339] [Impact Index Per Article: 67.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Exposure of biological cells to high-voltage, short-duration electric pulses causes a transient increase in their plasma membrane permeability, allowing transmembrane transport of otherwise impermeant molecules. In recent years, large steps were made in the understanding of underlying events. Formation of aqueous pores in the lipid bilayer is now a widely recognized mechanism, but evidence is growing that changes to individual membrane lipids and proteins also contribute, substantiating the need for terminological distinction between electroporation and electropermeabilization. We first revisit experimental evidence for electrically induced membrane permeability, its correlation with transmembrane voltage, and continuum models of electropermeabilization that disregard the molecular-level structure and events. We then present insights from molecular-level modeling, particularly atomistic simulations that enhance understanding of pore formation, and evidence of chemical modifications of membrane lipids and functional modulation of membrane proteins affecting membrane permeability. Finally, we discuss the remaining challenges to our full understanding of electroporation and electropermeabilization.
Collapse
Affiliation(s)
- Tadej Kotnik
- Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia; ,
| | - Lea Rems
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 17165 Solna, Sweden;
| | - Mounir Tarek
- Université de Lorraine, CNRS, LPCT, F-54000 Nancy, France;
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia; ,
| |
Collapse
|
10
|
Batista Napotnik T, Miklavčič D. In vitro electroporation detection methods – An overview. Bioelectrochemistry 2018; 120:166-182. [DOI: 10.1016/j.bioelechem.2017.12.005] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 12/22/2022]
|
11
|
Schoenbach KH. From the basic science of biological effects of ultrashort electrical pulses to medical therapies. Bioelectromagnetics 2018. [DOI: 10.1002/bem.22117] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Karl H. Schoenbach
- Frank Reidy Research Center for Bioelectrics; Old Dominion University; Norfolk Virginia
| |
Collapse
|
12
|
Perrier DL, Rems L, Boukany PE. Lipid vesicles in pulsed electric fields: Fundamental principles of the membrane response and its biomedical applications. Adv Colloid Interface Sci 2017; 249:248-271. [PMID: 28499600 DOI: 10.1016/j.cis.2017.04.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/24/2017] [Accepted: 04/25/2017] [Indexed: 01/04/2023]
Abstract
The present review focuses on the effects of pulsed electric fields on lipid vesicles ranging from giant unilamellar vesicles (GUVs) to small unilamellar vesicles (SUVs), from both fundamental and applicative perspectives. Lipid vesicles are the most popular model membrane systems for studying biophysical and biological processes in living cells. Furthermore, as vesicles are made from biocompatible and biodegradable materials, they provide a strategy to create safe and functionalized drug delivery systems in health-care applications. Exposure of lipid vesicles to pulsed electric fields is a common physical method to transiently increase the permeability of the lipid membrane. This method, termed electroporation, has shown many advantages for delivering exogenous molecules including drugs and genetic material into vesicles and living cells. In addition, electroporation can be applied to induce fusion between vesicles and/or cells. First, we discuss in detail how research on cell-size GUVs as model cell systems has provided novel insight into the basic mechanisms of cell electroporation and associated phenomena. Afterwards, we continue with a thorough overview how electroporation and electrofusion have been used as versatile methods to manipulate vesicles of all sizes in different biomedical applications. We conclude by summarizing the open questions in the field of electroporation and possible future directions for vesicles in the biomedical field.
Collapse
|
13
|
Adrenal Chromaffin Cells Exposed to 5-ns Pulses Require Higher Electric Fields to Porate Intracellular Membranes than the Plasma Membrane: An Experimental and Modeling Study. J Membr Biol 2017; 250:535-552. [PMID: 28840286 DOI: 10.1007/s00232-017-9983-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 08/19/2017] [Indexed: 12/17/2022]
Abstract
Nanosecond-duration electric pulses (NEPs) can permeabilize the endoplasmic reticulum (ER), causing release of Ca2+ into the cytoplasm. This study used experimentation coupled with numerical modeling to understand the lack of Ca2+ mobilization from Ca2+-storing organelles in catecholamine-secreting adrenal chromaffin cells exposed to 5-ns pulses. Fluorescence imaging determined a threshold electric (E) field of 8 MV/m for mobilizing intracellular Ca2+ whereas whole-cell recordings of membrane conductance determined a threshold E-field of 3 MV/m for causing plasma membrane permeabilization. In contrast, a 2D numerical model of a chromaffin cell, which was constructed with internal structures representing a nucleus, mitochondrion, ER, and secretory granule, predicted that exposing the cell to the same 5-ns pulse electroporated the plasma and ER membranes at the same E-field amplitude, 3-4 MV/m. Agreement of the numerical simulations with the experimental results was obtained only when the ER interior conductivity was 30-fold lower than that of the cytoplasm and the ER membrane permittivity was twice that of the plasma membrane. A more realistic intracellular geometry for chromaffin cells in which structures representing multiple secretory granules and an ER showed slight differences in the thresholds necessary to porate the membranes of the secretory granules. We conclude that more sophisticated cell models together with knowledge of accurate dielectric properties are needed to understand the effects of NEPs on intracellular membranes in chromaffin cells, information that will be important for elucidating how NEPs porate organelle membranes in other cell types having a similarly complex cytoplasmic ultrastructure.
Collapse
|
14
|
Batista Napotnik T, Bello G, Sinner EK, Miklavčič D. The Effect of Nanosecond, High-Voltage Electric Pulses on the Shape and Permeability of Polymersome GUVs. J Membr Biol 2017; 250:441-453. [PMID: 28735341 DOI: 10.1007/s00232-017-9968-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 07/06/2017] [Indexed: 11/27/2022]
Abstract
Polymersomes, vesicles composed of block copolymers, are promising candidates as membrane alternatives and functional containers, e.g., as potential carriers for functional molecules because of their stability and tunable membrane properties. In the scope of possible use for membrane protein delivery to cells by electrofusion, we investigated the cytotoxicity of such polymersomes as well as the effects of nanosecond electric pulses with variable repetition rate on the shape and permeability of polymersomes in buffers with different conductivities. The polymersomes did not show cytotoxic effects to CHO and B16-F1 cells in vitro in concentrations up to 250 µg/mL (for 48 h) or 1.35 mg/mL (for 60 min), which renders them suitable for interacting with living cells. We observed a significant effect of the pulse repetition rate on electrodeformation of the polymersomes. The electrodeformation was most pronounced in low conductivity buffer, which is favorable for performing electrofusion with cells. However, despite more pronounced deformation at higher pulse repetition rate, the electroporation performance of polymersomes was unaffected and remained in similar ranges both at 10 Hz and 10 kHz. This phenomenon is possibly due to the higher stability and rigidity of polymer vesicles, compared to liposomes, and can serve as an advantage (or disadvantage) depending on the aim in employing polymersomes such as stable membrane alternative architectures or drug vehicles.
Collapse
Affiliation(s)
- Tina Batista Napotnik
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000, Ljubljana, Slovenia
| | - Gianluca Bello
- Institute of Synthetic Bioarchitectures, University of Natural Resources and Life Sciences (BOKU), Muthgasse 11, 1190, Vienna, Austria
| | - Eva-Kathrin Sinner
- Institute of Synthetic Bioarchitectures, University of Natural Resources and Life Sciences (BOKU), Muthgasse 11, 1190, Vienna, Austria
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000, Ljubljana, Slovenia.
| |
Collapse
|
15
|
Delivery devices for exposure of biological cells to nanosecond pulsed electric fields. Med Biol Eng Comput 2017; 56:85-97. [PMID: 28674780 DOI: 10.1007/s11517-017-1676-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 06/25/2017] [Indexed: 12/11/2022]
Abstract
In this paper, delivery devices for nanosecond pulsed electric field exposure of biological samples in direct contact with electrodes or isolated are presented and characterized. They are based on a modified electroporation cuvette and two transverse electromagnetic cells (TEM cells). The devices were used to apply pulses with high intensity (4.5 kV) and short durations (3 and 13 ns). The delivery devices were electromagnetically characterized in the frequency and time domains. Field intensities of around 5, 0.5, and 12 MV m-1 were obtained by numerical simulations of the biological sample positioned in the three delivery devices. Two delivery systems had a homogenous electric field spatial distribution, and one was adapted to permit a highly localized exposure in the vicinity of a needle. Experimental biological investigations were carried out at different field intensities for five cancer cell lines. The results using flow cytometry showed that cells kept polarized mitochondrial membrane but lost plasma membrane integrity following a dose-response trend after exposure to different electric field intensities. Certain cell types (U87, MCF7) showed higher sensitivities to nsPEFs than other lines tested.
Collapse
|
16
|
Investigation of the morphological transition of a phospholipid bilayer membrane in an external electric field via molecular dynamics simulation. J Mol Model 2017; 23:113. [PMID: 28289956 DOI: 10.1007/s00894-017-3292-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/20/2017] [Indexed: 12/12/2022]
Abstract
Elucidating the mechanisms for morphological transitions of the phospholipid bilayer membrane during cellular activity should lead to greater understanding of these membrane transitions and allow us to optimize biotechnologies such as drug delivery systems in organisms. To investigate the mechanism for and the dynamics of morphological changes in the phospholipid membrane, we performed molecular dynamics simulation of a phospholipid membrane with and without membrane protein under the influence of electric fields with different strengths. In the absence of membrane protein, it was possible to control the transition from one lamellar membrane morphology to another by applying a strong electric field. The strong electric field initially disordered the lipid molecules in the membrane, leading to the formation of a hydrophilic pore. The lipid molecules then spontaneously fused into a new lamellar membrane morphology. In the presence of membrane protein, a morphological transition from lamellar membrane to vesicle under the influence of a strong electric field was observed. Studying the complex transition dynamics associated with these changes in membrane morphology allowed us to gain deep insight into the electrofusion and electroporation that occur in the presence or absence of membrane protein, and the results obtained here should prove useful in work aimed at controlling membrane morphology. Graphical Abstract Memebrane morphological transition under the electric field of 0.6 V/nm with the membrane protein (down) and without membrane protein (up).
Collapse
|
17
|
Rems L. Applicative Use of Electroporation Models. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2017. [DOI: 10.1016/bs.abl.2017.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
18
|
Effects of high voltage nanosecond electric pulses on eukaryotic cells (in vitro): A systematic review. Bioelectrochemistry 2016; 110:1-12. [PMID: 26946156 DOI: 10.1016/j.bioelechem.2016.02.011] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 02/23/2016] [Accepted: 02/23/2016] [Indexed: 01/04/2023]
Abstract
For this systematic review, 203 published reports on effects of electroporation using nanosecond high-voltage electric pulses (nsEP) on eukaryotic cells (human, animal, plant) in vitro were analyzed. A field synopsis summarizes current published data in the field with respect to publication year, cell types, exposure configuration, and pulse duration. Published data were analyzed for effects observed in eight main target areas (plasma membrane, intracellular, apoptosis, calcium level and distribution, survival, nucleus, mitochondria, stress) and an additional 107 detailed outcomes. We statistically analyzed effects of nsEP with respect to three pulse duration groups: A: 1-10ns, B: 11-100ns and C: 101-999ns. The analysis confirmed that the plasma membrane is more affected with longer pulses than with short pulses, seen best in uptake of dye molecules after applying single pulses. Additionally, we have reviewed measurements of nsEP and evaluations of the electric fields to which cells were exposed in these reports, and we provide recommendations for assessing nanosecond pulsed electric field effects in electroporation studies.
Collapse
|
19
|
Majhi AK, Kanchi S, Venkataraman V, Ayappa KG, Maiti PK. Estimation of activation energy for electroporation and pore growth rate in liquid crystalline and gel phases of lipid bilayers using molecular dynamics simulations. SOFT MATTER 2015; 11:8632-8640. [PMID: 26372335 DOI: 10.1039/c5sm02029h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Molecular dynamics simulations of electroporation in POPC and DPPC lipid bilayers have been carried out at different temperatures ranging from 230 K to 350 K for varying electric fields. The dynamics of pore formation, including threshold field, pore initiation time, pore growth rate, and pore closure rate after the field is switched off, was studied in both the gel and liquid crystalline (Lα) phases of the bilayers. Using an Arrhenius model of pore initiation kinetics, the activation energy for pore opening was estimated to be 25.6 kJ mol(-1) and 32.6 kJ mol(-1) in the Lα phase of POPC and DPPC lipids respectively at a field strength of 0.32 V nm(-1). The activation energy decreases to 24.2 kJ mol(-1) and 23.7 kJ mol(-1) respectively at a higher field strength of 1.1 V nm(-1). At temperatures below the melting point, the activation energy in the gel phase of POPC and DPPC increases to 28.8 kJ mol(-1) and 34.4 kJ mol(-1) respectively at the same field of 1.1 V nm(-1). The pore closing time was found to be higher in the gel than in the Lα phase. The pore growth rate increases linearly with temperature and quadratically with field, consistent with viscosity limited growth models.
Collapse
Affiliation(s)
- Amit Kumar Majhi
- Department of Physics, Indian Institute of Science, Bangalore, India.
| | - Subbarao Kanchi
- Department of Physics, Indian Institute of Science, Bangalore, India.
| | - V Venkataraman
- Department of Physics, Indian Institute of Science, Bangalore, India.
| | - K G Ayappa
- Department of Chemical Engineering, Center for Biosystems Science and Engineering, Bangalore, India.
| | - Prabal K Maiti
- Department of Physics, Indian Institute of Science, Bangalore, India.
| |
Collapse
|
20
|
Chopinet L, Rols MP. Nanosecond electric pulses: A mini-review of the present state of the art. Bioelectrochemistry 2015; 103:2-6. [DOI: 10.1016/j.bioelechem.2014.07.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 07/20/2014] [Accepted: 07/24/2014] [Indexed: 01/08/2023]
|
21
|
Vernier PT, Levine ZA, Ho MC, Xiao S, Semenov I, Pakhomov AG. Picosecond and Terahertz Perturbation of Interfacial Water and Electropermeabilization of Biological Membranes. J Membr Biol 2015; 248:837-47. [PMID: 25796485 DOI: 10.1007/s00232-015-9788-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 03/10/2015] [Indexed: 01/19/2023]
Abstract
Non-thermal probing and stimulation with subnanosecond electric pulses and terahertz electromagnetic radiation may lead to new, minimally invasive diagnostic and therapeutic procedures and to methods for remote monitoring and analysis of biological systems, including plants, animals, and humans. To effectively engineer these still-emerging tools, we need an understanding of the biophysical mechanisms underlying the responses that have been reported to these novel stimuli. We show here that subnanosecond (≤500 ps) electric pulses induce action potentials in neurons and cause calcium transients in neuroblastoma-glioma hybrid cells, and we report complementary molecular dynamics simulations of phospholipid bilayers in electric fields in which membrane permeabilization occurs in less than 1 ns. Water dipoles in the interior of these model membranes respond in less than 1 ps to permeabilizing electric potentials by aligning in the direction of the field, and they re-orient at terahertz frequencies to field reversals. The mechanism for subnanosecond lipid electropore formation is similar to that observed on longer time scales-energy-minimizing intrusions of interfacial water into the membrane interior and subsequent reorganization of the bilayer into hydrophilic, conductive structures.
Collapse
Affiliation(s)
- P Thomas Vernier
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Norfolk, VA, 23508, USA,
| | | | | | | | | | | |
Collapse
|
22
|
Pourmirjafari Firoozabadi T, Shankayi Z, Izadi A, Pourmirjafari Firoozabadi SM. Can Lucifer Yellow Indicate Correct Permeability of Biological Cell Membrane under An Electric and Magnetic Field? CELL JOURNAL 2015; 16:560-3. [PMID: 25685747 PMCID: PMC4297495 DOI: 10.22074/cellj.2015.501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 12/25/2013] [Indexed: 01/24/2023]
Abstract
The effect of external magnetic and electric fields, in the range of electroporation and
magnetoporation, on Lucifer Yellow (LY) fluorescence in the absence of cells is studied.
Electric-field-induced quenching and magnetic field-induced increase are observed for
fluorescence intensity of LY. Regard to the fact that the variation of field-induced fluorescence, even in the absence of cells, can be observed, the application of LY, as a marker,
is debatable in electroporation and magnetoporation techniques.
Collapse
Affiliation(s)
| | - Zeinab Shankayi
- Department of Medical Physics, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran
| | - Azam Izadi
- Department of Physics, Faculty of Science, K. N. Toosi University of Technology, Tehran, Iran
| | | |
Collapse
|
23
|
Polak A, Tarek M, Tomšič M, Valant J, Ulrih NP, Jamnik A, Kramar P, Miklavčič D. Electroporation of archaeal lipid membranes using MD simulations. Bioelectrochemistry 2014; 100:18-26. [DOI: 10.1016/j.bioelechem.2013.12.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/24/2013] [Accepted: 12/31/2013] [Indexed: 12/13/2022]
|
24
|
Pasquet L, Bellard E, Golzio M, Rols MP, Teissie J. A double-pulse approach for electrotransfection. J Membr Biol 2014; 247:1253-8. [PMID: 25135167 DOI: 10.1007/s00232-014-9720-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/07/2014] [Indexed: 11/26/2022]
Abstract
Gene transfer and expression can be obtained by delivering calibrated electric pulses on cells in the presence of plasmids coding for the activity of interest. The electric treatment affects the plasma membrane and induces the formation of a transient complex between nucleic acids and the plasma membrane. It results in a delivery of the plasmid in the cytoplasm. Expression is only obtained if the plasmid is translocated inside the nucleus. This is a key limit in the process. We previously showed that delivery of a high-field short-duration electric pulse was inducing a structural alteration of the nuclear envelope. This study investigates if the double-pulse approach (first pulse to transfer the plasmid to the cytoplasm, and second pulse to induce the structural alteration of the envelope) was a way to enhance the protein expression using the green fluorescent protein as a reporter. We observed that not only the double-pulse approach induced the transfection of a lower number of cells but moreover, these transfected cells were less fluorescent than the cells treated only with the first pulse.
Collapse
Affiliation(s)
- L Pasquet
- Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, BP64182, 205 route de Narbonne, 31077, Toulouse, France
| | | | | | | | | |
Collapse
|
25
|
Wasungu L, Pillet F, Bellard E, Rols MP, Teissié J. Shock waves associated with electric pulses affect cell electro-permeabilization. Bioelectrochemistry 2014; 100:36-43. [PMID: 25027311 DOI: 10.1016/j.bioelechem.2014.06.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 06/06/2014] [Accepted: 06/20/2014] [Indexed: 01/27/2023]
Abstract
New features of cell electro-permeabilization are obtained by using high field (several tens of kV/cm) with short (sub-microsecond, nanosecond) pulse duration. Arcing appears as a main safety problem when air gaps are present between electrodes. A new applicator design was chosen to obtain a closed chamber where high field pulses could be delivered in a safe way with very short pulse duration. The safety issue of the system was validated under millisecond, microsecond and nanosecond pulses. The closed chamber applicator was then checked for its use under classical electro-mediated permeabilization and electro-gene transfer (EGT). A 20 times decrease in gene expression was observed compared with classical open chambers. It was experimentally observed that shock waves were present under the closed chamber configuration of the applicator. This was not the case with an open chamber design. Electropulsation chamber design plays a role on pulsing conditions and in the efficiency of gene electro transfer.
Collapse
Affiliation(s)
- Luc Wasungu
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale);205 Route de Narbonne BP64182, F-31077 Toulouse, France; Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France
| | - Flavien Pillet
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale);205 Route de Narbonne BP64182, F-31077 Toulouse, France; Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France
| | - Elizabeth Bellard
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale);205 Route de Narbonne BP64182, F-31077 Toulouse, France; Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France
| | - Marie-Pierre Rols
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale);205 Route de Narbonne BP64182, F-31077 Toulouse, France; Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France
| | - Justin Teissié
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale);205 Route de Narbonne BP64182, F-31077 Toulouse, France; Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France.
| |
Collapse
|
26
|
Salomone F, Breton M, Leray I, Cardarelli F, Boccardi C, Bonhenry D, Tarek M, Mir LM, Beltram F. High-Yield Nontoxic Gene Transfer through Conjugation of the CM18-Tat11 Chimeric Peptide with Nanosecond Electric Pulses. Mol Pharm 2014; 11:2466-74. [DOI: 10.1021/mp500223t] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fabrizio Salomone
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
- Center
for Nanotechnology Innovation
@NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Marie Breton
- CNRS, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses,
UMR 8203, Orsay F-91405, France
| | - Isabelle Leray
- CNRS, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses,
UMR 8203, Orsay F-91405, France
- Université Paris-Sud, Laboratoire de Vectorologie et
Thérapeutiques
Anticancéreuses, UMR 8203, Orsay F-91405, France
- Institute Gustave-Roussy, Laboratoire de
Vectorologie et Thérapeutiques
Anticancéreuses, UMR 8203, Villejuif F-94805, France
| | - Francesco Cardarelli
- Center
for Nanotechnology Innovation
@NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Claudia Boccardi
- Center
for Nanotechnology Innovation
@NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Daniel Bonhenry
- Université de Lorraine, UMR 7565, Structure et Réactivité
des
Systèmes Moléculaires Complexes, CNRS, Nancy F-54003, France
| | - Mounir Tarek
- Université de Lorraine, UMR 7565, Structure et Réactivité
des
Systèmes Moléculaires Complexes, CNRS, Nancy F-54003, France
| | - Lluis M. Mir
- CNRS, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses,
UMR 8203, Orsay F-91405, France
- Université Paris-Sud, Laboratoire de Vectorologie et
Thérapeutiques
Anticancéreuses, UMR 8203, Orsay F-91405, France
- Institute Gustave-Roussy, Laboratoire de
Vectorologie et Thérapeutiques
Anticancéreuses, UMR 8203, Villejuif F-94805, France
| | - Fabio Beltram
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
- Center
for Nanotechnology Innovation
@NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| |
Collapse
|
27
|
Cell electrofusion using nanosecond electric pulses. Sci Rep 2013; 3:3382. [PMID: 24287643 PMCID: PMC3843160 DOI: 10.1038/srep03382] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 11/13/2013] [Indexed: 12/21/2022] Open
Abstract
Electrofusion is an efficient method for fusing cells using short-duration high-voltage electric pulses. However, electrofusion yields are very low when fusion partner cells differ considerably in their size, since the extent of electroporation (consequently membrane fusogenic state) with conventionally used microsecond pulses depends proportionally on the cell radius. We here propose a new and innovative approach to fuse cells with shorter, nanosecond (ns) pulses. Using numerical calculations we demonstrate that ns pulses can induce selective electroporation of the contact areas between cells (i.e. the target areas), regardless of the cell size. We then confirm experimentally on B16-F1 and CHO cell lines that electrofusion of cells with either equal or different size by using ns pulses is indeed feasible. Based on our results we expect that ns pulses can improve fusion yields in electrofusion of cells with different size, such as myeloma cells and B lymphocytes in hybridoma technology.
Collapse
|
28
|
Chopinet L, Batista-Napotnik T, Montigny A, Rebersek M, Teissié J, Rols MP, Miklavčič D. Nanosecond electric pulse effects on gene expression. J Membr Biol 2013; 246:851-9. [PMID: 23831956 PMCID: PMC3825134 DOI: 10.1007/s00232-013-9579-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 06/22/2013] [Indexed: 01/25/2023]
Abstract
Gene electrotransfection using micro- or millisecond electric pulses is a well-established method for safe gene transfer. For efficient transfection, plasmid DNA has to reach the nucleus. Shorter, high-intensity nanosecond electric pulses (nsEPs) affect internal cell membranes and may contribute to an increased uptake of plasmid by the nucleus. In our study, nsEPs were applied to Chinese hamster ovary (CHO) cells after classical gene electrotransfer, using micro- or millisecond pulses with a plasmid coding the green fluorescent protein (GFP). Time gaps between classical gene electrotransfer and nsEPs were varied (0.5, 2, 6 and 24 h) and three different nsEP parameters were used: 18 ns-10 kV/cm, 10 ns-40 kV/cm and 15 ns-60 kV/cm. Results analyzed by either fluorescence microscopy or flow cytometry showed that neither the percentage of electrotransfected cells nor the amount of GFP expressed was increased by nsEP. All nsEP parameters also had no effects on GFP fluorescence intensity of human colorectal tumor cells (HCT-116) with constitutive expression of GFP. We thus conclude that nsEPs have no major contribution to gene electrotransfer in CHO cells and no effect on constitutive GFP expression in HCT-116 cells.
Collapse
Affiliation(s)
- Louise Chopinet
- CNRS, IPBS - UMR 5089, 205 route de Narbonne, BP 64182, 31077 Toulouse Cedex 4, France
- UT1, UTM, LAAS, ITAV, UPS, INSA, INP, ISAE, Université de Toulouse, 31077 Toulouse Cedex 4, France
| | | | - Audrey Montigny
- CNRS, IPBS - UMR 5089, 205 route de Narbonne, BP 64182, 31077 Toulouse Cedex 4, France
- UT1, UTM, LAAS, ITAV, UPS, INSA, INP, ISAE, Université de Toulouse, 31077 Toulouse Cedex 4, France
| | - Matej Rebersek
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Justin Teissié
- CNRS, IPBS - UMR 5089, 205 route de Narbonne, BP 64182, 31077 Toulouse Cedex 4, France
- UT1, UTM, LAAS, ITAV, UPS, INSA, INP, ISAE, Université de Toulouse, 31077 Toulouse Cedex 4, France
| | - Marie-Pierre Rols
- CNRS, IPBS - UMR 5089, 205 route de Narbonne, BP 64182, 31077 Toulouse Cedex 4, France
- UT1, UTM, LAAS, ITAV, UPS, INSA, INP, ISAE, Université de Toulouse, 31077 Toulouse Cedex 4, France
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
29
|
Polak A, Bonhenry D, Dehez F, Kramar P, Miklavčič D, Tarek M. On the electroporation thresholds of lipid bilayers: molecular dynamics simulation investigations. J Membr Biol 2013; 246:843-50. [PMID: 23780415 DOI: 10.1007/s00232-013-9570-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 05/31/2013] [Indexed: 10/26/2022]
Abstract
Electroporation relates to the cascade of events that follows the application of high electric fields and that leads to cell membrane permeabilization. Despite a wide range of applications, little is known about the electroporation threshold, which varies with membrane lipid composition. Here, using molecular dynamics simulations, we studied the response of dipalmitoyl-phosphatidylcholine, diphytanoyl-phosphocholine-ester and diphytanoyl-phosphocholine-ether lipid bilayers to an applied electric field. Comparing between lipids with acyl chains and methyl branched chains and between lipids with ether and ester linkages, which change drastically the membrane dipole potential, we found that in both cases the electroporation threshold differed substantially. We show, for the first time, that the electroporation threshold of a lipid bilayer depends not only on the "electrical" properties of the membrane, i.e., its dipole potential, but also on the properties of its component hydrophobic tails.
Collapse
Affiliation(s)
- Andraž Polak
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška cesta 25, 1000, Ljubljana, Slovenia,
| | | | | | | | | | | |
Collapse
|
30
|
Recruitment of the intracellular Ca2+ by ultrashort electric stimuli: the impact of pulse duration. Cell Calcium 2013; 54:145-50. [PMID: 23777980 DOI: 10.1016/j.ceca.2013.05.008] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 05/20/2013] [Accepted: 05/24/2013] [Indexed: 01/25/2023]
Abstract
Nanosecond-duration electric stimuli are distinguished by the ability to permeabilize intracellular membranes and recruit Ca2+ from intracellular stores. We quantified this effect in non-excitable cells (CHO) using ratiometric Ca2+ imaging with Fura-2. In a Ca(2+)-free medium, 10-, 60-, and 300-ns stimuli evoked Ca2+ transients by mobilization of Ca2+ from the endoplasmic reticulum. With 2 mM external Ca2+, the transients included both extra- and intracellular components. The recruitment of intracellular Ca2+ increased as the stimulus duration decreased. At the threshold of 200-300 nM, the transients were amplified by calcium-induced calcium release. We conclude that nanosecond stimuli mimic Ca2+ signaling while bypassing the usual receptor- and channels-mediated cascades. The recruitment of the intracellular Ca2+ can be controlled by the duration of the stimulus.
Collapse
|
31
|
Retelj L, Pucihar G, Miklavcic D. Electroporation of intracellular liposomes using nanosecond electric pulses--a theoretical study. IEEE Trans Biomed Eng 2013; 60:2624-35. [PMID: 23674414 DOI: 10.1109/tbme.2013.2262177] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nanosecond (ns) electric pulses of sufficient amplitude can provoke electroporation of intracellular organelles. This paper investigates whether such pulses could provide a method for controlled intracellular release of a content of small internalized artificial lipid vesicles (liposomes). To estimate the pulse parameters needed to selectively electroporate liposomes while keeping the plasma and nuclear membranes intact, we constructed a numerical model of a biological cell containing a nucleus and liposomes of different sizes (with radii from 50 to 500 nm), which were placed in various sites in the cytoplasm. Our results show that under physiological conditions selective electroporation is only possible for the largest liposomes and when using very short pulses (few ns). By increasing the liposome interior conductivity and/or decreasing the cytoplasmic conductivity, selective electroporation of even smaller liposomes could be achieved. The location of the liposomes inside the cell does not play a significant role, meaning that liposomes of similar size could all be electroporated simultaneously. Our results indicate the possibility of using ns pulse treatment for liposomal drug release.
Collapse
Affiliation(s)
- Lea Retelj
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana SI-1000, Slovenia.
| | | | | |
Collapse
|
32
|
Napotnik T, Valant J, Gmajner D, Passamonti S, Miklavčič D, Ulrih NP. Cytotoxicity and uptake of archaeosomes prepared from Aeropyrum pernix lipids. Hum Exp Toxicol 2013; 32:950-9. [DOI: 10.1177/0960327113477875] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Archaeon Aeropyrum pernix K1 is an obligate aerobic hyperthermophilic organism with C25,25-archeol membrane lipids with head groups containing inositol. Interactions of archaeosomes, liposomes prepared from lipids of A. pernix, with mammalian cells in vitro were studied. In vitro cytotoxicity was tested on five different cell lines: rodent mouse melanoma cells (B16-F1) and Chinese hamster ovary (CHO) cells, and three human cell lines—epithelial colorectal adenocarcinoma cells (CACO-2), liver hepatocellular carcinoma cell line (Hep G2) and endothelial umbilical vein cell line (EA.hy926). Archaeosomes were nontoxic to human Hep G2, CACO-2 and mildly toxic to rodent CHO and B16-F1 cells but showed strong cytotoxic effect on EA.hy926 cells. Confocal microscopy revealed that archaeosomes are taken up by endocytosis. The uptake of archaeosomes and the release of loaded calcein are more prominent in EA.hy926 cells, which is in line with high toxicity toward these cells. The mechanisms of uptake, release and action in these cells as well as in vivo functioning have to be further studied for possible targeted drug delivery.
Collapse
Affiliation(s)
- T.B. Napotnik
- Department of Biomedical Engineering, Faculty of Electrical Engineering, University of Ljubljana, Tržaška, Ljubljana, Slovenia
| | - J. Valant
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva, Ljubljana, Slovenia
| | - D. Gmajner
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva, Ljubljana, Slovenia
| | - S. Passamonti
- Department of Life Sciences, University of Trieste, Via L. Giorgeri, Trieste, Italy
| | - D. Miklavčič
- Department of Biomedical Engineering, Faculty of Electrical Engineering, University of Ljubljana, Tržaška, Ljubljana, Slovenia
| | - N. P. Ulrih
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva, Ljubljana, Slovenia
| |
Collapse
|
33
|
Fifty years of publishing in biomedical engineering: reflections after 7-year editorship. Med Biol Eng Comput 2012. [DOI: 10.1007/s11517-012-1000-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
34
|
Pakhomova ON, Khorokhorina VA, Bowman AM, Rodaitė-Riševičienė R, Saulis G, Xiao S, Pakhomov AG. Oxidative effects of nanosecond pulsed electric field exposure in cells and cell-free media. Arch Biochem Biophys 2012; 527:55-64. [PMID: 22910297 PMCID: PMC3459148 DOI: 10.1016/j.abb.2012.08.004] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 08/04/2012] [Accepted: 08/07/2012] [Indexed: 02/03/2023]
Abstract
Nanosecond pulsed electric field (nsPEF) is a novel modality for permeabilization of membranous structures and intracellular delivery of xenobiotics. We hypothesized that oxidative effects of nsPEF could be a separate primary mechanism responsible for bioeffects. ROS production in cultured cells and media exposed to 300-ns PEF (1-13 kV/cm) was assessed by oxidation of 2',7'-dichlorodihydrofluoresein (H(2)DCF), dihidroethidium (DHE), or Amplex Red. When a suspension of H(2)DCF-loaded cells was subjected to nsPEF, the yield of fluorescent 2',7'-dichlorofluorescein (DCF) increased proportionally to the pulse number and cell density. DCF emission increased with time after exposure in nsPEF-sensitive Jurkat cells, but remained stable in nsPEF-resistant U937 cells. In cell-free media, nsPEF facilitated the conversion of H(2)DCF into DCF. This effect was not related to heating and was reduced by catalase, but not by mannitol or superoxide dismutase. Formation of H(2)O(2) in nsPEF-treated media was confirmed by increased oxidation of Amplex Red. ROS increase within individual cells exposed to nsPEF was visualized by oxidation of DHE. We conclude that nsPEF can generate both extracellular (electrochemical) and intracellular ROS, including H(2)O(2) and possibly other species. Therefore, bioeffects of nsPEF are not limited to electropermeabilization; concurrent ROS formation may lead to cell stimulation and/or oxidative cell damage.
Collapse
Affiliation(s)
- Olga N. Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA
| | - Vera A. Khorokhorina
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA
| | - Angela M. Bowman
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA
| | | | - Gintautas Saulis
- Department of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Shu Xiao
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA
- Dept. of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, USA
| | - Andrei G. Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA
| |
Collapse
|
35
|
Breton M, Delemotte L, Silve A, Mir LM, Tarek M. Transport of siRNA through Lipid Membranes Driven by Nanosecond Electric Pulses: An Experimental and Computational Study. J Am Chem Soc 2012; 134:13938-41. [DOI: 10.1021/ja3052365] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marie Breton
- Université Paris-Sud, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses, UMR 8203, Orsay F-91405, France
- CNRS,
Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses,
UMR 8203, Orsay F-91405, France
- Institut Gustave Roussy, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses, UMR 8203, Villejuif F-94805, France
| | - Lucie Delemotte
- Université de Lorraine, UMR Structure et Réactivité
des Systèmes Moléculaires Complexes, CNRS, Nancy 54003,
France
| | - Aude Silve
- Université Paris-Sud, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses, UMR 8203, Orsay F-91405, France
- CNRS,
Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses,
UMR 8203, Orsay F-91405, France
- Institut Gustave Roussy, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses, UMR 8203, Villejuif F-94805, France
| | - Lluis M. Mir
- Université Paris-Sud, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses, UMR 8203, Orsay F-91405, France
- CNRS,
Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses,
UMR 8203, Orsay F-91405, France
- Institut Gustave Roussy, Laboratoire de Vectorologie et Thérapeutiques
Anticancéreuses, UMR 8203, Villejuif F-94805, France
| | - Mounir Tarek
- Université de Lorraine, UMR Structure et Réactivité
des Systèmes Moléculaires Complexes, CNRS, Nancy 54003,
France
| |
Collapse
|
36
|
Beier HT, Roth CC, Tolstykh GP, Ibey BL. Resolving the spatial kinetics of electric pulse-induced ion release. Biochem Biophys Res Commun 2012; 423:863-6. [DOI: 10.1016/j.bbrc.2012.06.055] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 06/12/2012] [Indexed: 12/17/2022]
|
37
|
Vernier PT. Mitochondrial membrane permeabilization with nanosecond electric pulses. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2011:743-5. [PMID: 22254417 DOI: 10.1109/iembs.2011.6090169] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ultra-short, high-field electric pulses permeabilize plasma and intracellular membranes. We report here nanosecond pulse-induced permeabilization of mitochondrial membranes in living cells. Using four independent methods based on fluorescent dyes--JC-1, rhodamine 123, tetramethyl rhodamine ethyl ester, and cobalt-quenched calcein--we show that as few as five, 4 ns, 10 MV/m pulses delivered at 1 kHz cause an increase of the inner mitochondrial membrane permeability and an associated loss of mitochondrial membrane potential. The most likely interpretation of these results is a pulse-induced permeabilization of the inner mitochondrial membrane.
Collapse
Affiliation(s)
- P Thomas Vernier
- Ming Hsieh Department of Electrical Engineering and MOSIS, Information Science Institute, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA.
| |
Collapse
|
38
|
Nesin V, Bowman AM, Xiao S, Pakhomov AG. Cell permeabilization and inhibition of voltage-gated Ca(2+) and Na(+) channel currents by nanosecond pulsed electric field. Bioelectromagnetics 2011; 33:394-404. [PMID: 22213081 DOI: 10.1002/bem.21696] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 10/16/2011] [Indexed: 11/09/2022]
Abstract
Previous studies have found that nanosecond pulsed electric field (nsPEF) exposure causes long-term permeabilization of the cell plasma membrane. In this study, we utilized the whole-cell patch-clamp method to study the nsPEF effect on currents of voltage-gated (VG) Ca(2+) and Na(+) channels (I(Ca) and I(Na)) in cultured GH3 and NG108 cells. We found that a single 300 or 600 ns pulse at or above 1.5-2 kV/cm caused prolonged inhibition of I(Ca) and I(Na). Concurrently, nsPEF increased a non-inactivating "leak" current (I(leak)), presumably due to the formation of nanoelectropores or larger pores in the plasma membrane. The nsPEF effects were similar in cells that were exposed intact and subsequently brought into the whole-cell recording configuration, and in cells that were first brought into the whole-cell configuration and then exposed. Although both I(leak) and the inhibition of VG currents were enhanced at higher E-field levels, these two nsPEF effects showed relatively weak correlation with each other. In some cells, I(leak) increased 10-fold or more while VG currents remained unchanged. At longer time intervals after exposure (5-15 min), I(Ca) and I(Na) could remain inhibited although I(leak) had largely recovered. The causal relation of nsPEF inhibitory effects on VG currents and permeabilization of the plasma membrane is discussed.
Collapse
Affiliation(s)
- Vasyl Nesin
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | | | | | | |
Collapse
|
39
|
Napotnik TB, Wu YH, Gundersen MA, Miklavčič D, Vernier PT. Nanosecond electric pulses cause mitochondrial membrane permeabilization in Jurkat cells. Bioelectromagnetics 2011; 33:257-64. [DOI: 10.1002/bem.20707] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 09/01/2011] [Indexed: 12/22/2022]
|
40
|
Pucihar G, Krmelj J, Reberšek M, Napotnik TB, Miklavčič D. Equivalent pulse parameters for electroporation. IEEE Trans Biomed Eng 2011; 58:3279-88. [PMID: 21900067 DOI: 10.1109/tbme.2011.2167232] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Electroporation-based applications require the use of specific pulse parameters for a successful outcome. When recommended values of pulse parameters cannot be set, similar outcomes can be obtained by using equivalent pulse parameters. We determined the relations between the amplitude and duration/number of pulses resulting in the same fraction of electroporated cells. Pulse duration was varied from 150 ns to 100 ms, and the number of pulses from 1 to 128. Fura 2-AM was used to determine electroporation of cells to Ca(2+). With longer pulses or higher number of pulses, lower amplitudes are needed for the same fraction of electroporated cells. The expression derived from the model of electroporation could describe the measured data on the whole interval of pulse durations. In a narrower range (0.1-100 ms), less complex, logarithmic or power functions could be used instead. The relation between amplitude and number of pulses could best be described with a power function or an exponential function. We show that relatively simple two-parameter power or logarithmic functions are useful when equivalent pulse parameters for electroporation are sought. Such mathematical relations between pulse parameters can be important in planning of electroporation-based treatments, such as electrochemotherapy and nonthermal irreversible electroporation.
Collapse
Affiliation(s)
- Gorazd Pucihar
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
| | | | | | | | | |
Collapse
|
41
|
Breton M, Mir LM. Microsecond and nanosecond electric pulses in cancer treatments. Bioelectromagnetics 2011; 33:106-23. [PMID: 21812011 DOI: 10.1002/bem.20692] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 06/29/2011] [Indexed: 12/18/2022]
Abstract
New local treatments based on electromagnetic fields have been developed as non-surgical and minimally invasive treatments of tumors. In particular, short electric pulses can induce important non-thermal changes in cell physiology, especially the permeabilization of the cell membrane. The aim of this review is to summarize the present data on the electroporation-based techniques: electrochemotherapy (ECT), nanosecond pulsed electric fields (nsPEFs), and irreversible electroporation (IRE). ECT is a safe, easy, and efficient technique for the treatment of solid tumors that uses cell-permeabilizing electrical pulses to enhance the activity of a non-permeant (bleomycin) or low permeant (cisplatin) anticancer drug with a very high intrinsic cytotoxicity. The most interesting feature of ECT is its unique ability to selectively kill tumor cells without harming normal surrounding tissue. ECT is already used widely in the clinics in Europe. nsPEFs could represent a drug free, purely electrical cancer therapy. They allow the inhibition of tumor growth, and interestingly, nsPEF can target intracellular organelles. However, many questions remain on the mechanism of action of these pulses. Finally, IRE is a new ablation procedure using pulses that provoke the permanent permeabilization of the cells resulting in their death. This technique does not result in any thermal effect, which is its main advantage in current physical ablation technologies. For both the nsPEF and the IRE, the preservation of the normal tissue, which is characteristic of ECT, has not yet been shown and their safety and efficacy still have to be investigated thoroughly in vivo and in the clinics.
Collapse
Affiliation(s)
- Marie Breton
- Université Paris-Sud, Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203, Orsay, F-91405; CNRS, Orsay, Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203, F-91405; Institut Gustave Roussy, Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203, Villejuif 94805.
| | | |
Collapse
|
42
|
Shu Xiao, Siqi Guo, Nesin V, Heller R, Schoenbach KH. Subnanosecond Electric Pulses Cause Membrane Permeabilization and Cell Death. IEEE Trans Biomed Eng 2011; 58:1239-45. [DOI: 10.1109/tbme.2011.2112360] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
43
|
Nanosecond Electric Pulses: A Novel Stimulus for Triggering Ca2+ Influx into Chromaffin Cells Via Voltage-Gated Ca2+ Channels. Cell Mol Neurobiol 2010; 30:1259-65. [DOI: 10.1007/s10571-010-9573-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 09/02/2010] [Indexed: 12/15/2022]
|
44
|
Joshi RP, Hu Q. Analysis of cell membrane permeabilization mechanics and pore shape due to ultrashort electrical pulsing. Med Biol Eng Comput 2010; 48:837-44. [PMID: 20635223 DOI: 10.1007/s11517-010-0659-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 06/26/2010] [Indexed: 10/19/2022]
Abstract
Cell membrane permeabilization mechanics and the resulting shape of nanopores in response to electrical pulsing are probed based on a continuum approach. This has implications for electropermeabilization and cell membrane transport. It is argued that small pores resulting from high-intensity (approximately 100 kV/cm), nanosecond pulsing would have an initial asymmetric shape. This would lead to asymmetric membrane current-voltage characteristics, at least at early times. The role of the cytoskeleton is ignored here, but can be expected to additionally contribute to such asymmetries. Furthermore, we show that the pore shape and membrane conduction would be dynamic, and evolve toward a symmetric characteristic over time. This duration has been shown to be in the micro-second range.
Collapse
Affiliation(s)
- Ravindra P Joshi
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529, USA.
| | | |
Collapse
|