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de Caro A, Talmont F, Rols MP, Golzio M, Kolosnjaj-Tabi J. Therapeutic perspectives of high pulse repetition rate electroporation. Bioelectrochemistry 2024; 156:108629. [PMID: 38159429 DOI: 10.1016/j.bioelechem.2023.108629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 12/15/2023] [Accepted: 12/16/2023] [Indexed: 01/03/2024]
Abstract
Electroporation, a technique that uses electrical pulses to temporarily or permanently destabilize cell membranes, is increasingly used in cancer treatment, gene therapy, and cardiac tissue ablation. Although the technique is efficient, patients report discomfort and pain. Current strategies that aim to minimize pain and muscle contraction rely on the use of pharmacological agents. Nevertheless, technical improvements might be a valuable tool to minimize adverse events, which occur during the application of standard electroporation protocols. One recent technological strategy involves the use of high pulse repetition rate. The emerging technique, also referred as "high frequency" electroporation, employs short (micro to nanosecond) mono or bipolar pulses at repetition rate ranging from a few kHz to a few MHz. This review provides an overview of the historical background of electric field use and its development in therapies over time. With the aim to understand the rationale for novel electroporation protocols development, we briefly describe the physiological background of neuromuscular stimulation and pain caused by exposure to pulsed electric fields. Then, we summarize the current knowledge on electroporation protocols based on high pulse repetition rates. The advantages and limitations of these protocols are described from the perspective of their therapeutic application.
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Affiliation(s)
- Alexia de Caro
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Franck Talmont
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Marie-Pierre Rols
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Muriel Golzio
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France.
| | - Jelena Kolosnjaj-Tabi
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France.
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2
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Cvetkoska A, Maček-Lebar A, Polajžer T, Reberšek M, Upchurch W, Iaizzo PA, Sigg DC, Miklavčič D. The Effects of Interphase and Interpulse Delays and Pulse Widths on Induced Muscle Contractions, Pain and Therapeutic Efficacy in Electroporation-Based Therapies. J Cardiovasc Dev Dis 2023; 10:490. [PMID: 38132658 PMCID: PMC10744272 DOI: 10.3390/jcdd10120490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 11/29/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023] Open
Abstract
Electroporation is used in medicine for drug and gene delivery, and as a nonthermal ablation method in tumor treatment and cardiac ablation. Electroporation involves delivering high-voltage electric pulses to target tissue; however, this can cause effects beyond the intended target tissue like nerve stimulation, muscle contractions and pain, requiring use of sedatives or anesthetics. It was previously shown that adjusting pulse parameters may mitigate some of these effects, but not how these adjustments would affect electroporation's efficacy. We investigated the effect of varying pulse parameters such as interphase and interpulse delay while keeping the duration and number of pulses constant on nerve stimulation, muscle contraction and assessing pain and electroporation efficacy, conducting experiments on human volunteers, tissue samples and cell lines in vitro. Our results show that using specific pulse parameters, particularly short high-frequency biphasic pulses with short interphase and long interpulse delays, reduces muscle contractions and pain sensations in healthy individuals. Higher stimulation thresholds were also observed in experiments on isolated swine phrenic nerves and human esophagus tissues. However, changes in the interphase and interpulse delays did not affect the cell permeability and survival, suggesting that modifying the pulse parameters could minimize adverse effects while preserving therapeutic goals in electroporation.
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Affiliation(s)
- Aleksandra Cvetkoska
- Faculty of Electrical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.C.); (A.M.-L.); (T.P.); (M.R.)
| | - Alenka Maček-Lebar
- Faculty of Electrical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.C.); (A.M.-L.); (T.P.); (M.R.)
| | - Tamara Polajžer
- Faculty of Electrical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.C.); (A.M.-L.); (T.P.); (M.R.)
| | - Matej Reberšek
- Faculty of Electrical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.C.); (A.M.-L.); (T.P.); (M.R.)
| | - Weston Upchurch
- Visible Heart® Laboratories, Department of Surgery and the Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN 55455, USA; (W.U.); (P.A.I.)
| | - Paul A. Iaizzo
- Visible Heart® Laboratories, Department of Surgery and the Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN 55455, USA; (W.U.); (P.A.I.)
| | - Daniel C. Sigg
- Cardiac Ablation Solutions, Medtronic, Inc., Minneapolis, MN 55432, USA;
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.C.); (A.M.-L.); (T.P.); (M.R.)
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Tabaja C, Younis A, Hussein AA, Taigen TL, Nakagawa H, Saliba WI, Sroubek J, Santangeli P, Wazni OM. Catheter-Based Electroporation: A Novel Technique for Catheter Ablation of Cardiac Arrhythmias. JACC Clin Electrophysiol 2023; 9:2008-2023. [PMID: 37354168 DOI: 10.1016/j.jacep.2023.03.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/17/2023] [Accepted: 03/23/2023] [Indexed: 06/26/2023]
Abstract
Catheter ablation of arrhythmias is now standard of care in invasive electrophysiology. Current ablation strategies are based on the use of thermal energy. With continuous efforts to optimize thermal energy delivery, effectiveness has greatly improved; however, safety concerns persist. This review focuses on a novel ablation technology, irreversible electroporation (IRE), also known as pulsed-field ablation which may be a safer alternative for arrhythmia management. Pulsed-field ablation is thought to be a nonthermal ablation that applies short-duration high-voltage electrical fields to ablate myocardial tissue with high selectivity and durability while sparing important neighboring structures such as the esophagus and phrenic nerves. There are multiple ongoing studies investigating the potential superior outcomes of IRE compared to radiofrequency ablation in treating patients with atrial and ventricular arrhythmias. In this review, we describe the current evidence of preclinical and clinical trials that have shown promising results of catheter-based IRE.
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Affiliation(s)
- Chadi Tabaja
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Arwa Younis
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Ayman A Hussein
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Tyler L Taigen
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Hiroshi Nakagawa
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Walid I Saliba
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Jakub Sroubek
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Pasquale Santangeli
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Oussama M Wazni
- Cardiac Electrophysiology and Pacing Section, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA.
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4
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O'Brien B, Reilly J, Coffey K, González-Suárez A, Quinlan L, van Zyl M. Cardioneuroablation Using Epicardial Pulsed Field Ablation for the Treatment of Atrial Fibrillation. J Cardiovasc Dev Dis 2023; 10:238. [PMID: 37367403 DOI: 10.3390/jcdd10060238] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 06/28/2023] Open
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting millions of people worldwide. The cardiac autonomic nervous system (ANS) is widely recognized as playing a key role in both the initiation and propagation of AF. This paper reviews the background and development of a unique cardioneuroablation technique for the modulation of the cardiac ANS as a potential treatment for AF. The treatment uses pulsed electric field energy to selectively electroporate ANS structures on the epicardial surface of the heart. Insights from in vitro studies and electric field models are presented as well as data from both pre-clinical and early clinical studies.
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Affiliation(s)
- Barry O'Brien
- AtriAN Medical Ltd., Unit 204, Business Innovation Centre, Upper Newcastle, H91 W60E Galway, Ireland
| | - John Reilly
- AtriAN Medical Ltd., Unit 204, Business Innovation Centre, Upper Newcastle, H91 W60E Galway, Ireland
| | - Ken Coffey
- AtriAN Medical Ltd., Unit 204, Business Innovation Centre, Upper Newcastle, H91 W60E Galway, Ireland
| | - Ana González-Suárez
- School of Engineering, University of Galway, H91 TK33 Galway, Ireland
- Translational Medical Device Lab, University of Galway, H91 YR71 Galway, Ireland
| | - Leo Quinlan
- Physiology and Cellular Physiology Research Laboratory, CURAM SFI Centre for Research in Medical Device, University of Galway, H91 TK33 Galway, Ireland
| | - Martin van Zyl
- Cardiac Electrophysiology, Royal Jubilee Hospital, Victoria, BC V8R 1J8, Canada
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5
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Polajžer T, Miklavčič D. Immunogenic Cell Death in Electroporation-Based Therapies Depends on Pulse Waveform Characteristics. Vaccines (Basel) 2023; 11:1036. [PMID: 37376425 DOI: 10.3390/vaccines11061036] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/26/2023] [Accepted: 05/27/2023] [Indexed: 06/29/2023] Open
Abstract
Traditionally, electroporation-based therapies such as electrochemotherapy (ECT), gene electrotransfer (GET) and irreversible electroporation (IRE) are performed with different but typical pulse durations-100 microseconds and 1-50 milliseconds. However, recent in vitro studies have shown that ECT, GET and IRE can be achieved with virtually any pulse duration (millisecond, microsecond, nanosecond) and pulse type (monopolar, bipolar-HFIRE), although with different efficiency. In electroporation-based therapies, immune response activation can affect treatment outcome, and the possibility of controlling and predicting immune response could improve the treatment. In this study, we investigated if different pulse durations and pulse types cause different or similar activations of the immune system by assessing DAMP release (ATP, HMGB1, calreticulin). Results show that DAMP release can be different when different pulse durations and pulse types are used. Nanosecond pulses seems to be the most immunogenic, as they can induce the release of all three main DAMP molecules-ATP, HMGB1 and calreticulin. The least immunogenic seem to be millisecond pulses, as only ATP release was detected and even that assumingly occurs due to increased permeability of the cell membrane. Overall, it seems that DAMP release and immune response in electroporation-based therapies can be controlled though pulse duration.
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Affiliation(s)
- Tamara Polajžer
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
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Potočnik T, Maček Lebar A, Kos Š, Reberšek M, Pirc E, Serša G, Miklavčič D. Effect of Experimental Electrical and Biological Parameters on Gene Transfer by Electroporation: A Systematic Review and Meta-Analysis. Pharmaceutics 2022; 14:pharmaceutics14122700. [PMID: 36559197 PMCID: PMC9786189 DOI: 10.3390/pharmaceutics14122700] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
The exact mechanisms of nucleic acid (NA) delivery with gene electrotransfer (GET) are still unknown, which represents a limitation for its broader use. Further, not knowing the effects that different experimental electrical and biological parameters have on GET additionally hinders GET optimization, resulting in the majority of research being performed using a trial-and-error approach. To explore the current state of knowledge, we conducted a systematic literature review of GET papers in in vitro conditions and performed meta-analyses of the reported GET efficiency. For now, there is no universal GET strategy that would be appropriate for all experimental aims. Apart from the availability of the required electroporation device and electrodes, the choice of an optimal GET approach depends on parameters such as the electroporation medium; type and origin of cells; and the size, concentration, promoter, and type of the NA to be transfected. Equally important are appropriate controls and the measurement or evaluation of the output pulses to allow a fair and unbiased evaluation of the experimental results. Since many experimental electrical and biological parameters can affect GET, it is important that all used parameters are adequately reported to enable the comparison of results, as well as potentially faster and more efficient experiment planning and optimization.
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Affiliation(s)
- Tjaša Potočnik
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
| | - Alenka Maček Lebar
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
| | - Špela Kos
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia
| | - Matej Reberšek
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
| | - Eva Pirc
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
| | - Gregor Serša
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
- Correspondence:
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7
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Di Gregorio E, Israel S, Staelens M, Tankel G, Shankar K, Tuszyński JA. The distinguishing electrical properties of cancer cells. Phys Life Rev 2022; 43:139-188. [PMID: 36265200 DOI: 10.1016/j.plrev.2022.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 09/30/2022] [Indexed: 11/07/2022]
Abstract
In recent decades, medical research has been primarily focused on the inherited aspect of cancers, despite the reality that only 5-10% of tumours discovered are derived from genetic causes. Cancer is a broad term, and therefore it is inaccurate to address it as a purely genetic disease. Understanding cancer cells' behaviour is the first step in countering them. Behind the scenes, there is a complicated network of environmental factors, DNA errors, metabolic shifts, and electrostatic alterations that build over time and lead to the illness's development. This latter aspect has been analyzed in previous studies, but how the different electrical changes integrate and affect each other is rarely examined. Every cell in the human body possesses electrical properties that are essential for proper behaviour both within and outside of the cell itself. It is not yet clear whether these changes correlate with cell mutation in cancer cells, or only with their subsequent development. Either way, these aspects merit further investigation, especially with regards to their causes and consequences. Trying to block changes at various levels of occurrence or assisting in their prevention could be the key to stopping cells from becoming cancerous. Therefore, a comprehensive understanding of the current knowledge regarding the electrical landscape of cells is much needed. We review four essential electrical characteristics of cells, providing a deep understanding of the electrostatic changes in cancer cells compared to their normal counterparts. In particular, we provide an overview of intracellular and extracellular pH modifications, differences in ionic concentrations in the cytoplasm, transmembrane potential variations, and changes within mitochondria. New therapies targeting or exploiting the electrical properties of cells are developed and tested every year, such as pH-dependent carriers and tumour-treating fields. A brief section regarding the state-of-the-art of these therapies can be found at the end of this review. Finally, we highlight how these alterations integrate and potentially yield indications of cells' malignancy or metastatic index.
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Affiliation(s)
- Elisabetta Di Gregorio
- Dipartimento di Ingegneria Meccanica e Aerospaziale (DIMEAS), Politecnico di Torino, Corso Duca degli Abruzzi, 24, Torino, 10129, TO, Italy; Autem Therapeutics, 35 South Main Street, Hanover, 03755, NH, USA
| | - Simone Israel
- Dipartimento di Ingegneria Meccanica e Aerospaziale (DIMEAS), Politecnico di Torino, Corso Duca degli Abruzzi, 24, Torino, 10129, TO, Italy; Autem Therapeutics, 35 South Main Street, Hanover, 03755, NH, USA
| | - Michael Staelens
- Department of Physics, University of Alberta, 11335 Saskatchewan Drive NW, Edmonton, T6G 2E1, AB, Canada
| | - Gabriella Tankel
- Department of Mathematics & Statistics, McMaster University, 1280 Main Street West, Hamilton, L8S 4K1, ON, Canada
| | - Karthik Shankar
- Department of Electrical & Computer Engineering, University of Alberta, 9211 116 Street NW, Edmonton, T6G 1H9, AB, Canada
| | - Jack A Tuszyński
- Dipartimento di Ingegneria Meccanica e Aerospaziale (DIMEAS), Politecnico di Torino, Corso Duca degli Abruzzi, 24, Torino, 10129, TO, Italy; Department of Physics, University of Alberta, 11335 Saskatchewan Drive NW, Edmonton, T6G 2E1, AB, Canada; Department of Oncology, University of Alberta, 11560 University Avenue, Edmonton, T6G 1Z2, AB, Canada.
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8
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Poderyte M, Ramanavicius A, Valiūnienė A. Scanning electrochemical microscopy based irreversible destruction of living cells. Biosens Bioelectron 2022; 216:114621. [PMID: 36007410 DOI: 10.1016/j.bios.2022.114621] [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: 06/10/2022] [Revised: 07/18/2022] [Accepted: 08/02/2022] [Indexed: 11/02/2022]
Abstract
In this research, scanning electrochemical microscopy combined with electrochemical impedance spectroscopy has been applied to irreversible electroporation of active yeast cells by causing cell death. This finding is important for the development of irreversible electroporation technique, which could be suitable for the curing of cancerous tissues, because during this research cell death has been achieved using relatively low ultramicro-electrode (UME) voltage, precisely of 2.0 V vs Ag/AgCl,Cl-sat. It was determined that the irreversibly electroporated area of immobilized yeast cells was located directly below the UME and was of approximately 20 times larger width than the diameter of the UME, leaving undamaged cells out of this area. The ability of SECM to move the UME with high accuracy in x, y, and z directions and the ability to use electrodes of various diameters as well as the fact that the diameter of the electroporated area depends on the diameter of the UME and on the distance between the UME and the surface, what offers the possibility to establish targeted electroporation systems for selective treatment of tissues.
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Affiliation(s)
- Margarita Poderyte
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Naugarduko 24, Vilnius, LT, 03225, Lithuania
| | - Arunas Ramanavicius
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Naugarduko 24, Vilnius, LT, 03225, Lithuania
| | - Aušra Valiūnienė
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Naugarduko 24, Vilnius, LT, 03225, Lithuania.
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9
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Aycock KN, Campelo SN, Salameh ZS, Vadlamani RA, Lorenzo MF, Davalos RV. Extended interpulse delays improve therapeutic efficacy of microsecond-duration pulsed electric fields. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2022; 2022:5021-5024. [PMID: 36086570 DOI: 10.1109/embc48229.2022.9871737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Irreversible electroporation (IRE), or pulsed field ablation, employs microsecond-duration pulsed electric fields to generate targeted cellular damage without injury to the underlying tissue architecture. Biphasic, burst-type waveforms (termed high-frequency IRE, or H-FIRE) have garnered attention for their ability to elicit clinically relevant ablation volumes while reducing several undesirable side effects (muscle contractions/electrochemical effects) seen with monophasic pulses. Pulse width is generally the main (or only) parameter considered during burst construction, with little attention given to the delays within the burst. In this work, we tested the hypothesis that H-FIRE waveforms could be further optimized by manipulating only the interpulse delay between biphasic pulses within each burst. Using benchtop, ex vivo, and in vivo models, we demonstrate that extended interpulse delays (i.e., ~100 μs) reduce the severity of induced muscle contractions, alleviate mechanical tissue destruction, and minimize the chances of electrical arcing. Clinical Relevance- This proof-of-concept study shows that H-FIRE waveforms with extended interpulse delays provide several therapeutic benefits over conventional waveforms.
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10
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Ji X, Zhang H, Zang L, Yan S, Wu X. The Effect of Discharge Mode on the Distribution of Myocardial Pulsed Electric Field—A Simulation Study for Pulsed Field Ablation of Atrial Fibrillation. J Cardiovasc Dev Dis 2022; 9:jcdd9040095. [PMID: 35448071 PMCID: PMC9031694 DOI: 10.3390/jcdd9040095] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 01/05/2023] Open
Abstract
Background: At present, the effects of discharge modes of multielectrode catheters on the distribution of pulsed electric fields have not been completely clarified. Therefore, the control of the distribution of the pulsed electric field by selecting the discharge mode remains one of the key technical problems to be solved. Methods: We constructed a model including myocardium, blood, and a flower catheter. Subsequently, by setting different positive and ground electrodes, we simulated the electric field distribution in the myocardium of four discharge modes (A, B, C, and D) before and after the catheter rotation and analyzed their mechanisms. Results: Modes B, C, and D formed a continuous circumferential ablation lesion without the rotation of the catheter, with depths of 1.6 mm, 2.7 mm, and 0.7 mm, respectively. After the catheter rotation, the four modes could form a continuous circumferential ablation lesion with widths of 10.8 mm, 10.6 mm, 11.8 mm, and 11.5 mm, respectively, and depths of 5.2 mm, 2.7 mm, 4.7 mm, and 4.0 mm, respectively. Conclusions: The discharge mode directly affects the electric field distribution in the myocardium. Our results can help improve PFA procedures and provide enlightenment for the design of the discharge mode with multielectrode catheters.
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Affiliation(s)
- Xingkai Ji
- Centre for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; (X.J.); (H.Z.); (L.Z.)
| | - Hao Zhang
- Centre for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; (X.J.); (H.Z.); (L.Z.)
| | - Lianru Zang
- Centre for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; (X.J.); (H.Z.); (L.Z.)
| | - Shengjie Yan
- Centre for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; (X.J.); (H.Z.); (L.Z.)
- Correspondence: (S.Y.); (X.W.); Tel.: +86-21-6564-3709-801 or +86-0579-85507181 (X.W.)
| | - Xiaomei Wu
- Centre for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; (X.J.); (H.Z.); (L.Z.)
- Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
- Key Laboratory of Medical Imaging Computing and Computer-Assisted Intervention (MICCAI) of Shanghai, Fudan University, Shanghai 200433, China
- Shanghai Engineering Research Centre of Assistive Devices, Shanghai 200433, China
- Yiwu Research Institute, Fudan University, Chengbei Road, Yiwu City 322000, China
- Correspondence: (S.Y.); (X.W.); Tel.: +86-21-6564-3709-801 or +86-0579-85507181 (X.W.)
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11
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Comparison of analysis methods for determination of dynamic tissue conductivity during microseconds-long pulsed electric fields. Biomed Signal Process Control 2022. [DOI: 10.1016/j.bspc.2021.103305] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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12
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Aycock KN, Vadlamani RA, Jacobs EJ, Imran KM, Verbridge S, Allen IC, Manuchehrabadi N, Davalos RV. Experimental and Numerical Investigation of Parameters Affecting High-frequency Irreversible Electroporation for Prostate Cancer Ablation. J Biomech Eng 2022; 144:1131491. [PMID: 35044426 DOI: 10.1115/1.4053595] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Indexed: 11/09/2022]
Abstract
While the primary goal of focal therapy for prostate cancer (PCa) is conserving patient quality of life by reducing oncological burden, available modalities use thermal energy or whole-gland radiation which can damage critical neurovascular structures within the prostate and increase risk of genitourinary dysfunction. High-frequency irreversible electroporation (H-FIRE) is a promising alternative ablation modality that utilizes bursts of pulsed electric fields (PEFs) to destroy aberrant cells via targeted membrane damage. Due to its non-thermal mechanism, H-FIRE offers several advantages over state-of-the-art treatments, but waveforms have not been optimized for treatment of PCa. In this study, we characterize lethal electric field thresholds (EFTs) for H-FIRE waveforms with three different pulse widths as well as three interpulse delays in vitro and compare them to conventional IRE. Experiments were performed in non-neoplastic and malignant prostate cells to determine the effect of waveforms on both targeted (malignant) and adjacent (non-neoplastic) tissue. A numerical modeling approach was developed to estimate the clinical effects of each waveform including extent of non-thermal ablation, undesired thermal damage, and nerve excitation. Our findings indicate that H-FIRE waveforms with pulse durations of 5 and 10 µs provide large ablations comparable to IRE with tolerable levels of thermal damage and minimized muscle contractions. Lower duration (2 µs) H-FIRE waveforms exhibit the least amount of muscle contractions but require increased voltages which may be accompanied by unwanted thermal damage.
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Affiliation(s)
- Kenneth N Aycock
- Virginia Tech, Department of Biomedical Engineering and Mechanics, 325 Stanger St, Blacksburg, VA 24061
| | - Ram Anand Vadlamani
- Virginia Tech, Department of Biomedical Engineering and Mechanics, 325 Stanger St, Blacksburg, VA 24061
| | - Edward J Jacobs
- Virginia Tech, Department of Biomedical Engineering and Mechanics, 325 Stanger St, Blacksburg, VA 24061
| | - Khan Mohammad Imran
- Virginia-Maryland College of Veterinary Medicine, Department of Biomedical Sciences and Pathobiology, 205 Duck Pond Dr, Blacksburg, VA 24061
| | - Scott Verbridge
- Virginia Tech, Department of Biomedical Engineering and Mechanics, 325 Stanger St, Blacksburg, VA 24061
| | - Irving C Allen
- Virginia-Maryland College of Veterinary Medicine, Department of Biomedical Sciences and Pathobiology, 205 Duck Pond Dr, Blacksburg, VA 24061
| | | | - Rafael V Davalos
- Virginia Tech, Department of Biomedical Engineering and Mechanics, 325 Stanger St, Blacksburg, VA 24061
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13
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Lorenzo MF, Campelo SN, Arroyo JP, Aycock KN, Hinckley J, Arena CB, Rossmeisl JH, Davalos RV. An Investigation for Large Volume, Focal Blood-Brain Barrier Disruption with High-Frequency Pulsed Electric Fields. Pharmaceuticals (Basel) 2021; 14:1333. [PMID: 34959733 PMCID: PMC8715747 DOI: 10.3390/ph14121333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 01/28/2023] Open
Abstract
The treatment of CNS disorders suffers from the inability to deliver large therapeutic agents to the brain parenchyma due to protection from the blood-brain barrier (BBB). Herein, we investigated high-frequency pulsed electric field (HF-PEF) therapy of various pulse widths and interphase delays for BBB disruption while selectively minimizing cell ablation. Eighteen male Fisher rats underwent craniectomy procedures and two blunt-tipped electrodes were advanced into the brain for pulsing. BBB disruption was verified with contrast T1W MRI and pathologically with Evans blue dye. High-frequency irreversible electroporation cell death of healthy rodent astrocytes was investigated in vitro using a collagen hydrogel tissue mimic. Numerical analysis was conducted to determine the electric fields in which BBB disruption and cell ablation occur. Differences between the BBB disruption and ablation thresholds for each waveform are as follows: 2-2-2 μs (1028 V/cm), 5-2-5 μs (721 V/cm), 10-1-10 μs (547 V/cm), 2-5-2 μs (1043 V/cm), and 5-5-5 μs (751 V/cm). These data suggest that HF-PEFs can be fine-tuned to modulate the extent of cell death while maximizing peri-ablative BBB disruption. Furthermore, numerical modeling elucidated the diffuse field gradients of a single-needle grounding pad configuration to favor large-volume BBB disruption, while the monopolar probe configuration is more amenable to ablation and reversible electroporation effects.
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Affiliation(s)
- Melvin F. Lorenzo
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.N.C.); (J.P.A.); (K.N.A.); (C.B.A.); (R.V.D.)
| | - Sabrina N. Campelo
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.N.C.); (J.P.A.); (K.N.A.); (C.B.A.); (R.V.D.)
| | - Julio P. Arroyo
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.N.C.); (J.P.A.); (K.N.A.); (C.B.A.); (R.V.D.)
| | - Kenneth N. Aycock
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.N.C.); (J.P.A.); (K.N.A.); (C.B.A.); (R.V.D.)
| | - Jonathan Hinckley
- Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA 24061, USA; (J.H.); (J.H.R.J.)
| | - Christopher B. Arena
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.N.C.); (J.P.A.); (K.N.A.); (C.B.A.); (R.V.D.)
| | - John H. Rossmeisl
- Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA 24061, USA; (J.H.); (J.H.R.J.)
| | - Rafael V. Davalos
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.N.C.); (J.P.A.); (K.N.A.); (C.B.A.); (R.V.D.)
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14
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Jenkins EPW, Finch A, Gerigk M, Triantis IF, Watts C, Malliaras GG. Electrotherapies for Glioblastoma. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100978. [PMID: 34292672 PMCID: PMC8456216 DOI: 10.1002/advs.202100978] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/20/2021] [Indexed: 05/08/2023]
Abstract
Non-thermal, intermediate frequency (100-500 kHz) electrotherapies present a unique therapeutic strategy to treat malignant neoplasms. Here, pulsed electric fields (PEFs) which induce reversible or irreversible electroporation (IRE) and tumour-treating fields (TTFs) are reviewed highlighting the foundations, advances, and considerations of each method when applied to glioblastoma (GBM). Several biological aspects of GBM that contribute to treatment complexity (heterogeneity, recurrence, resistance, and blood-brain barrier(BBB)) and electrophysiological traits which are suggested to promote glioma progression are described. Particularly, the biological responses at the cellular and molecular level to specific parameters of the electrical stimuli are discussed offering ways to compare these parameters despite the lack of a universally adopted physical description. Reviewing the literature, a disconnect is found between electrotherapy techniques and how they target the biological complexities of GBM that make treatment difficult in the first place. An attempt is made to bridge the interdisciplinary gap by mapping biological characteristics to different methods of electrotherapy, suggesting important future research topics and directions in both understanding and treating GBM. To the authors' knowledge, this is the first paper that attempts an in-tandem assessment of the biological effects of different aspects of intermediate frequency electrotherapy methods, thus offering possible strategies toward GBM treatment.
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Affiliation(s)
- Elise P. W. Jenkins
- Division of Electrical EngineeringDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Alina Finch
- Institute of Cancer and Genomic ScienceUniversity of BirminghamBirminghamB15 2TTUK
| | - Magda Gerigk
- Division of Electrical EngineeringDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Iasonas F. Triantis
- Department of Electrical and Electronic EngineeringCity, University of LondonLondonEC1V 0HBUK
| | - Colin Watts
- Institute of Cancer and Genomic ScienceUniversity of BirminghamBirminghamB15 2TTUK
| | - George G. Malliaras
- Division of Electrical EngineeringDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
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15
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Guo F, Qian K, Zhang L, Liu X, Peng H. Multiphysics modelling of electroporation under uni- or bipolar nanosecond pulse sequences. Bioelectrochemistry 2021; 141:107878. [PMID: 34198114 DOI: 10.1016/j.bioelechem.2021.107878] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 06/11/2021] [Accepted: 06/14/2021] [Indexed: 12/16/2022]
Abstract
A nonlinear dispersive multiphysics model of single-cell electroporation was proposed in this paper. The time-domain Debye model was utilised to describe the membrane dispersion while the dynamic pore radius function was deployed to modify the plasma membrane conductivity. The dynamic spatial distributions of the ion concentration were dominated by the Nernst-Planck function. First, a single nanosecond pulsed electric field was applied to verify our model and to explore the effects of dispersion and dynamic pore radius on the redistribution of the electric field. The dispersive membrane was found to increase the transmembrane potential, expedite the electroporation process, and weaken the membrane permeability; however, adding the dynamic pore radius function had the opposite effect on transmembrane potential and membrane permeability. The responses of the cells exposed to unipolar and bipolar nanosecond pulse sequences were subsequently simulated. During the application of unipolar pulse sequences, the pore radius and perforation area showed a step-like accumulation, and significant increases in the perforation area and intracellular ion concentration were observed with higher frequency pulse sequences and wider subpulse intervals. The bipolar cancellation effect was also observed in terms of membrane permeability and pore radius.
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Affiliation(s)
- Fei Guo
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China.
| | - Kun Qian
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Lin Zhang
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Xin Liu
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Hao Peng
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
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16
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McBride S, Avazzadeh S, Wheatley AM, O’Brien B, Coffey K, Elahi A, O’Halloran M, Quinlan LR. Ablation Modalities for Therapeutic Intervention in Arrhythmia-Related Cardiovascular Disease: Focus on Electroporation. J Clin Med 2021; 10:jcm10122657. [PMID: 34208708 PMCID: PMC8235263 DOI: 10.3390/jcm10122657] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 02/06/2023] Open
Abstract
Targeted cellular ablation is being increasingly used in the treatment of arrhythmias and structural heart disease. Catheter-based ablation for atrial fibrillation (AF) is considered a safe and effective approach for patients who are medication refractory. Electroporation (EPo) employs electrical energy to disrupt cell membranes which has a minimally thermal effect. The nanopores that arise from EPo can be temporary or permanent. Reversible electroporation is transitory in nature and cell viability is maintained, whereas irreversible electroporation causes permanent pore formation, leading to loss of cellular homeostasis and cell death. Several studies report that EPo displays a degree of specificity in terms of the lethal threshold required to induce cell death in different tissues. However, significantly more research is required to scope the profile of EPo thresholds for specific cell types within complex tissues. Irreversible electroporation (IRE) as an ablative approach appears to overcome the significant negative effects associated with thermal based techniques, particularly collateral damage to surrounding structures. With further fine-tuning of parameters and longer and larger clinical trials, EPo may lead the way of adapting a safer and efficient ablation modality for the treatment of persistent AF.
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Affiliation(s)
- Shauna McBride
- Physiology and Cellular Physiology Laboratory, CÚRAM SFI Centre for Research in Medical Devices, School of Medicine, Human Biology Building, National University of Ireland (NUI) Galway, H91 W5P7 Galway, Ireland; (S.M.); (S.A.); (A.M.W.)
| | - Sahar Avazzadeh
- Physiology and Cellular Physiology Laboratory, CÚRAM SFI Centre for Research in Medical Devices, School of Medicine, Human Biology Building, National University of Ireland (NUI) Galway, H91 W5P7 Galway, Ireland; (S.M.); (S.A.); (A.M.W.)
| | - Antony M. Wheatley
- Physiology and Cellular Physiology Laboratory, CÚRAM SFI Centre for Research in Medical Devices, School of Medicine, Human Biology Building, National University of Ireland (NUI) Galway, H91 W5P7 Galway, Ireland; (S.M.); (S.A.); (A.M.W.)
| | - Barry O’Brien
- AtriAN Medical Limited, Unit 204, NUIG Business Innovation Centre, Upper Newcastle, H91 R6W6 Galway, Ireland; (B.O.); (K.C.)
| | - Ken Coffey
- AtriAN Medical Limited, Unit 204, NUIG Business Innovation Centre, Upper Newcastle, H91 R6W6 Galway, Ireland; (B.O.); (K.C.)
| | - Adnan Elahi
- Translational Medical Device Lab (TMDL), Lamb Translational Research Facility, University College Hospital Galway, H91 V4AY Galway, Ireland; (A.E.); (M.O.)
- Electrical & Electronic Engineering, School of Engineering, National University of Ireland Galway, H91 HX31 Galway, Ireland
| | - Martin O’Halloran
- Translational Medical Device Lab (TMDL), Lamb Translational Research Facility, University College Hospital Galway, H91 V4AY Galway, Ireland; (A.E.); (M.O.)
| | - Leo R. Quinlan
- Physiology and Cellular Physiology Laboratory, CÚRAM SFI Centre for Research in Medical Devices, School of Medicine, Human Biology Building, National University of Ireland (NUI) Galway, H91 W5P7 Galway, Ireland; (S.M.); (S.A.); (A.M.W.)
- CÚRAM, SFI Research Centre for Medical Devices, National University of Ireland Galway, H92 W2TY Galway, Ireland
- Correspondence:
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17
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Aycock KN, Zhao Y, Lorenzo MF, Davalos RV. A Theoretical Argument for Extended Interpulse Delays in Therapeutic High-Frequency Irreversible Electroporation Treatments. IEEE Trans Biomed Eng 2021; 68:1999-2010. [PMID: 33400646 PMCID: PMC8291206 DOI: 10.1109/tbme.2021.3049221] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
High-frequency irreversible electroporation (H-FIRE) is a tissue ablation modality employing bursts of electrical pulses in a positive phase-interphase delay (d1)-negative phase-interpulse delay (d2) pattern. Despite accumulating evidence suggesting the significance of these delays, their effects on therapeutic outcomes from clinically-relevant H-FIRE waveforms have not been studied extensively. OBJECTIVE We sought to determine whether modifications to the delays within H-FIRE bursts could yield a more desirable clinical outcome in terms of ablation volume versus extent of tissue excitation. METHODS We used a modified spatially extended nonlinear node (SENN) nerve fiber model to evaluate excitation thresholds for H-FIRE bursts with varying delays. We then calculated non-thermal tissue ablation, thermal damage, and excitation in a clinically relevant numerical model. RESULTS Excitation thresholds were maximized by shortening d1, and extension of d2 up to 1,000 μs increased excitation thresholds by at least 60% versus symmetric bursts. In the ablation model, long interpulse delays lowered the effective frequency of burst waveforms, modulating field redistribution and reducing heat production. Finally, we demonstrate mathematically that variable delays allow for increased voltages and larger ablations with similar extents of excitation as symmetric waveforms. CONCLUSION Interphase and interpulse delays play a significant role in outcomes resulting from H-FIRE treatment. SIGNIFICANCE Waveforms with short interphase delays (d1) and extended interpulse delays (d2) may improve therapeutic efficacy of H-FIRE as it emerges as a clinical tissue ablation modality.
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Affiliation(s)
- Kenneth N. Aycock
- Department of Biomedical Engineering and Mechanics, Bioelectromechanical Systems Laboratory at Virginia Tech, Blacksburg, VA 24061 USA
| | - Yajun Zhao
- Department of Biomedical Engineering and Mechanics, Bioelectromechanical Systems Laboratory at Virginia Tech, Blacksburg, VA 24061 USA
| | - Melvin F. Lorenzo
- Department of Biomedical Engineering and Mechanics, Bioelectromechanical Systems Laboratory at Virginia Tech, Blacksburg, VA 24061 USA
| | - Rafael V. Davalos
- Department of Biomedical Engineering and Mechanics, Bioelectromechanical Systems Laboratory at Virginia Tech, Blacksburg, VA 24061 USA
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Lorenzo MF, Bhonsle SP, Arena CB, Davalos RV. Rapid Impedance Spectroscopy for Monitoring Tissue Impedance, Temperature, and Treatment Outcome During Electroporation-Based Therapies. IEEE Trans Biomed Eng 2021; 68:1536-1546. [PMID: 33156779 PMCID: PMC8127872 DOI: 10.1109/tbme.2020.3036535] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Electroporation-based therapies (EBTs) employ high voltage pulsed electric fields (PEFs) to permeabilize tumor tissue; this results in changes in electrical properties detectable using electrical impedance spectroscopy (EIS). Currently, commercial potentiostats for EIS are limited by impedance spectrum acquisition time ( ∼ 10 s); this timeframe is much larger than pulse periods used with EBTs ( ∼ 1 s). In this study, we utilize rapid EIS techniques to develop a methodology for characterizing electroporation (EP) and thermal effects associated with high-frequency irreversible EP (H-FIRE) in real-time by monitoring inter-burst impedance changes. METHODS A charge-balanced, bipolar rectangular chirp signal is proposed for rapid EIS. Validation of rapid EIS measurements against a commercial potentiostat was conducted in potato tissue using flat-plate electrodes and thereafter for the measurement of impedance changes throughout IRE treatment. Flat-plate electrodes were then utilized to uniformly heat potato tissue; throughout high-voltage H-FIRE treatment, low-voltage inter-burst impedance measurements were used to continually monitor impedance change and to identify a frequency at which thermal effects are delineated from EP effects. RESULTS Inter-burst impedance measurements (1.8 kHz - 4.93 MHz) were accomplished at 216 discrete frequencies. Impedance measurements at frequencies above ∼ 1 MHz served to delineate thermal and EP effects in measured impedance. CONCLUSION We demonstrate rapid-capture ( 1 s) EIS which enables monitoring of inter-burst impedance in real-time. For the first time, we show impedance analysis at high frequencies can delineate thermal effects from EP effects in measured impedance. SIGNIFICANCE The proposed waveform demonstrates the potential to perform inter-burst EIS using PEFs compatible with existing pulse generator topologies.
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19
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Potočnik T, Miklavčič D, Maček Lebar A. Gene transfer by electroporation with high frequency bipolar pulses in vitro. Bioelectrochemistry 2021; 140:107803. [PMID: 33975183 DOI: 10.1016/j.bioelechem.2021.107803] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 12/21/2022]
Abstract
High-frequency bipolar pulses (HF-BP) have been demonstrated to be efficient for membrane permeabilization and irreversible electroporation. Since membrane permeabilization has been achieved using HF-BP pulses we hypothesized that with these pulses we can also achieve successful gene electrotransfer (GET). Three variations of bursts of 2 µs bipolar pulses with 2 µs interphase delay were applied in HF-BP protocols. We compared transfection efficiency of monopolar micro and millisecond pulses and HF-BP protocols at various plasmid DNA (pDNA) concentrations on CHO - K1 cells. GET efficiency increased with increasing pDNA concentration. Overall GET obtained by HF-BP pulse protocols was comparable to overall GET obtained by longer monopolar pulse protocols. Our results, however, suggest that although we were able to achieve similar percent of transfected cells, the number of pDNA copies that were successfully transferred into cells seemed to be higher when longer monopolar pulses were used. Interestingly, we did not observe any direct correlation between fluorescence intensity of pDNA aggregates formed on cell membrane and transfection efficiency. The results of our study confirmed that we can achieve successful GET with bipolar microsecond i. e. HF-BP pulses, although at the expense of higher pDNA concentrations.
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Affiliation(s)
- Tjaša Potočnik
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška 25, 1000 Ljubljana, Slovenia
| | - Damijan Miklavčič
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška 25, 1000 Ljubljana, Slovenia
| | - Alenka Maček Lebar
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška 25, 1000 Ljubljana, Slovenia.
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20
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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: 25] [Impact Index Per Article: 8.3] [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.
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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.
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