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Zamuner A, Dettin M, Dall'Olmo L, Campana LG, Mognaschi ME, Conconi MT, Sieni E. Development of 3D melanoma cultures on a hyaluronic acid-based scaffold with synthetic self-assembling peptides: Electroporation enhancement. Bioelectrochemistry 2024; 156:108624. [PMID: 38104458 DOI: 10.1016/j.bioelechem.2023.108624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 11/30/2023] [Accepted: 12/03/2023] [Indexed: 12/19/2023]
Abstract
Electrochemotherapy (ECT) with bleomycin is an effective antitumor treatment. Still, researchers are investigating new drugs and electroporation conditions to improve its efficacy. To this aim, in vivo assays are accurate but expensive and ethically questionable. Conversely, in vitro assays, although cheaper and straightforward, do not reflect the architecture of the biological tissue because they lack a tridimensional (3D) structure (as in the case of two-dimensional [2D] in vitro assays) or do not include all the extracellular matrix components (as in the case of 3D in vitro scaffolds). To address this issue, 3D in vitro models have been proposed, including spheroids and hydrogel-based cultures, which require a suitable low-conductive medium to allow cell membrane electroporation. In this study, a synthetic scaffold based on hyaluronic acid (HA) and self-assembling peptides (SAPs; EAbuK), condensed with a Laminin-derived adhesive sequence (IKVAV), is proposed as a reliable alternative. We compare SKMEL28 cells cultured in the HA-EAbuK-IKVAV scaffold to the control (HA only scaffold). Three days after seeding, the culture on the HA-EAbuK-IKVAV scaffold showed collagen production. SKMEL28 cells cultured on the HA-EAbuK-IKVAV scaffold started to be electroporated at 400 V/cm, whereas, at the same electric field intensity, those cultured on HA were not. As a reference, 2D experiments showed that electroporation of SKMEL28 cells starts at 600 V/cm using an electroporation buffer and at 800 V/cm in a culture medium, but with very low efficiency (<50 % of cells electroporated). 3D cultures on HA-EAbuK-IKVAV allowed the simulation of a more reliable microenvironment and may represent a valuable tool for studying electroporation conditions. Using Finite Element Analysis (FEA) to compute the transmembrane potential, we detected the influence of inhomogeneity of the extracellular matrix on electroporation effect. Our 3D cell culture electroporation simulations showed that the transmembrane potential increased when collagen surrounded the cells. Of note, in the collagen-enriched HA-EAbuK-IKVAV scaffold, EP was already improved at lower electric field intensities. This study shows the influence of the extracellular matrix on electric conductivity and electric field distribution on cell membrane electroporation and supports the adoption of more reliable 3D scaffolds in experimental electroporation studies.
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Affiliation(s)
- Annj Zamuner
- Padova University, Department of Civil, Environmental, and Architectural Engineering, via Marzolo, 9, 35131 Padova, Italy; Padova University, Department of Industrial Engineering, via Marzolo, 9, 35131 Padova, Italy
| | - Monica Dettin
- Padova University, Department of Industrial Engineering, via Marzolo, 9, 35131 Padova, Italy
| | - Luigi Dall'Olmo
- Padova University, Department of Surgery Oncology and Gastroenterology, DISCOG. Via Giustiniani 2, 35128 Padova, Italy; Surgical Oncology Unit, Veneto Institute of Oncology (IOV-IRCCS), via Gattamelata 64, 35128 Padova, Italy
| | - Luca Giovanni Campana
- Department of Surgery, Manchester University NHS Foundation Trust, Oxford Rd, M13 9WL, Manchester, UK
| | - Maria Evelina Mognaschi
- Pavia University, Department of Electrical, Computer and Biomedical Engineering, via Ferrata, 5, 21100 Padova, Italy
| | - Maria Teresa Conconi
- Padova University, Department of Pharmaceutical and Pharmacological Sciences, via Marzolo, 5, 35131 Padova, Italy
| | - Elisabetta Sieni
- University of Insubria, Department of theoretical and applied sciences, via Dunant, 3, 21100 Varese, Italy.
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2
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Sieni E, Dettin M, Zamuner A, Conconi MT, Bazzolo B, Balducci C, Di Barba P, Forzan M, Lamberti P, Mognaschi ME. Finite Element Evaluation of the Electric Field Distribution in a Non-Homogeneous Environment. Bioengineering (Basel) 2023; 10:1062. [PMID: 37760163 PMCID: PMC10525744 DOI: 10.3390/bioengineering10091062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023] Open
Abstract
Finite element analysis is used in this study to investigate the effect of media inhomogeneity on the electric field distribution in a sample composed of cells and their extracellular matrix. The sample is supposed to be subjected to very high pulsed electric field. Numerically computed electric field distribution and transmembrane potential at the cell membrane in electroporation conditions are considered in order to study cell behavior at different degrees of inhomogeneity. The different inhomogeneity grade is locally obtained using a representative model of fixed volume with cell-cell distance varying in the range of 1-283 um. The conductivity of the extracellular medium was varied between plain collagen and a gel-like myxoid matrix through combinations of the two, i.e., collagen and myxoid. An increase in the transmembrane potential was shown in the case of higher aggregate. The results obtained in this study show the effect of the presence of the cell aggregates and collagen on the transmembrane potential. In particular, by increasing the cell aggregation in the two cases, the transmembrane potential increased. Finally, the simulation results were compared to experimental data obtained by culturing HCC1954 cells in a hyaluronic acid-based scaffold. The experimental validation confirmed the behavior of the transmembrane potential in presence of the collagen: an increase in electroporation at a lower electric field intensity was found for the cells cultured in the scaffolds where there is the formation of collagen areas.
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Affiliation(s)
- Elisabetta Sieni
- Department of Theoretical and Applied Sciences, University of Insubria, Via Dunant 3, 21100 Varese, Italy
- Italian Interuniversity Center ICEMB (Interaction between Electromagnetic Fields and Biosystems), DIET University of Genoa, 16145 Genoa, Italy; (P.L.); (M.E.M.)
| | - Monica Dettin
- Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35131 Padua, Italy; (M.D.); (C.B.); (M.F.)
| | - Annj Zamuner
- Department of Civil Environmental and Architectural Engineering, University of Padua, Via Marzolo 9, 35131 Padua, Italy;
| | - Maria Teresa Conconi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy; (M.T.C.); (B.B.)
| | - Bianca Bazzolo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy; (M.T.C.); (B.B.)
| | - Cristian Balducci
- Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35131 Padua, Italy; (M.D.); (C.B.); (M.F.)
| | - Paolo Di Barba
- Department of Electrical, Computer and Biomedical Engineering, Pavia University, Via Ferrata 5, 21100 Pavia, Italy;
| | - Michele Forzan
- Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35131 Padua, Italy; (M.D.); (C.B.); (M.F.)
| | - Patrizia Lamberti
- Italian Interuniversity Center ICEMB (Interaction between Electromagnetic Fields and Biosystems), DIET University of Genoa, 16145 Genoa, Italy; (P.L.); (M.E.M.)
- Department of Information and Electrical Engineering and Applied Mathematics, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy
| | - Maria Evelina Mognaschi
- Italian Interuniversity Center ICEMB (Interaction between Electromagnetic Fields and Biosystems), DIET University of Genoa, 16145 Genoa, Italy; (P.L.); (M.E.M.)
- Department of Electrical, Computer and Biomedical Engineering, Pavia University, Via Ferrata 5, 21100 Pavia, Italy;
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Kos B, Mattison L, Ramirez D, Cindrič H, Sigg DC, Iaizzo PA, Stewart MT, Miklavčič D. Determination of lethal electric field threshold for pulsed field ablation in ex vivo perfused porcine and human hearts. Front Cardiovasc Med 2023; 10:1160231. [PMID: 37424913 PMCID: PMC10326317 DOI: 10.3389/fcvm.2023.1160231] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 05/31/2023] [Indexed: 07/11/2023] Open
Abstract
Introduction Pulsed field ablation is an emerging modality for catheter-based cardiac ablation. The main mechanism of action is irreversible electroporation (IRE), a threshold-based phenomenon in which cells die after exposure to intense pulsed electric fields. Lethal electric field threshold for IRE is a tissue property that determines treatment feasibility and enables the development of new devices and therapeutic applications, but it is greatly dependent on the number of pulses and their duration. Methods In the study, lesions were generated by applying IRE in porcine and human left ventricles using a pair of parallel needle electrodes at different voltages (500-1500 V) and two different pulse waveforms: a proprietary biphasic waveform (Medtronic) and monophasic 48 × 100 μs pulses. The lethal electric field threshold, anisotropy ratio, and conductivity increase by electroporation were determined by numerical modeling, comparing the model outputs with segmented lesion images. Results The median threshold was 535 V/cm in porcine ((N = 51 lesions in n = 6 hearts) and 416 V/cm in the human donor hearts ((N = 21 lesions in n = 3 hearts) for the biphasic waveform. The median threshold value was 368 V/cm in porcine hearts ((N = 35 lesions in n = 9 hearts) cm for 48 × 100 μs pulses. Discussion The values obtained are compared with an extensive literature review of published lethal electric field thresholds in other tissues and were found to be lower than most other tissues, except for skeletal muscle. These findings, albeit preliminary, from a limited number of hearts suggest that treatments in humans with parameters optimized in pigs should result in equal or greater lesions.
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Affiliation(s)
- Bor Kos
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Lars Mattison
- Cardiac Ablation Solutions, Medtronic, Inc., Minneapolis, MN, United States
| | - David Ramirez
- Department of Surgery, Visible Heart® Laboratories, University of Minnesota, Minneapolis, MN, United States
| | - Helena Cindrič
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Daniel C. Sigg
- Cardiac Ablation Solutions, Medtronic, Inc., Minneapolis, MN, United States
| | - Paul A. Iaizzo
- Department of Surgery, Visible Heart® Laboratories, University of Minnesota, Minneapolis, MN, United States
| | - Mark T. Stewart
- Cardiac Ablation Solutions, Medtronic, Inc., Minneapolis, MN, United States
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
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Colombani T, Haudebourg T, Pitard B. 704/DNA vaccines leverage cytoplasmic DNA stimulation to promote anti-HIV neutralizing antibody production in mice and strong immune response against alpha-fetoprotein in non-human primates. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 32:743-757. [PMID: 37251693 PMCID: PMC10213191 DOI: 10.1016/j.omtn.2023.04.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 04/28/2023] [Indexed: 05/31/2023]
Abstract
Genetic immunization is an attractive approach for prophylactic and therapeutic vaccination using synthetic vectors to deliver antigen-encoding nucleic acids. Recently, DNA delivered by a physical means or RNA by liposomes consisting of four different lipids demonstrated good protection in human phase III clinical trials and received Drugs Controller General of India and US FDA approval to protect against COVID-19, respectively. However, the development of a system allowing for efficient and simple delivery of nucleic acids while improving immune response priming has the potential to unleash the full therapeutic potential of genetic immunization. DNA-based gene therapies and vaccines have the potential for rapid development, as exemplified by the recent approval of Collategene, a gene therapy to treat human critical limb ischemia, and ZyCoV, a DNA vaccine delivered by spring-powered jet injector to protect against SARS-CoV2 infection. Recently, we reported amphiphilic block copolymer 704 as a promising synthetic vector for DNA vaccination in various models of human diseases. This vector allows dose sparing of antigen-encoding plasmid DNA. Here, we report the capacity of 704-mediated HIV and anti-hepatocellular carcinoma DNA vaccines to induce the production of specific antibodies against gp120 HIV envelope proteins in mice and against alpha-fetoprotein antigen in non-human primates, respectively. An investigation of the underlying mechanisms showed that 704-mediated vaccination did trigger a strong immune response by (1) allowing a direct DNA delivery into the cytosol, (2) promoting an intracytoplasmic DNA sensing leading to both interferon and NF-κB cascade stimulation, and (3) inducing antigen expression by muscle cells and presentation by antigen-presenting cells, leading to the induction of a robust adaptive response. Overall, our findings suggest that the 704-mediated DNA vaccination platform is an attractive method to develop both prophylactic and therapeutic vaccines.
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Affiliation(s)
- Thibault Colombani
- Nantes Université, University of Angers, INSERM, CNRS, Immunology and New Concepts in Immunotherapy, INSERM UMR1302, CNRS EMR6001, 44000 Nantes, France
| | - Thomas Haudebourg
- Nantes Université, University of Angers, INSERM, CNRS, Immunology and New Concepts in Immunotherapy, INSERM UMR1302, CNRS EMR6001, 44000 Nantes, France
| | - Bruno Pitard
- Nantes Université, University of Angers, INSERM, CNRS, Immunology and New Concepts in Immunotherapy, INSERM UMR1302, CNRS EMR6001, 44000 Nantes, France
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5
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Sugrue A, Maor E, Del-Carpio Munoz F, Killu AM, Asirvatham SJ. Cardiac ablation with pulsed electric fields: principles and biophysics. Europace 2022; 24:1213-1222. [PMID: 35426908 DOI: 10.1093/europace/euac033] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 02/24/2022] [Indexed: 01/04/2023] Open
Abstract
Pulsed electric fields (PEFs) have emerged as an ideal cardiac ablation modality. At present numerous clinical trials in humans are exploring PEF as an ablation strategy for both atrial and ventricular arrhythmias, with early data showing significant promise. As this is a relatively new technology there is limited understanding of its principles and biophysics. Importantly, PEF biophysics and principles are starkly different to current energy modalities (radiofrequency and cryoballoon). Given the relatively novel nature of PEFs, this review aims to provide an understanding of the principles and biophysics of PEF ablation. The goal is to enhance academic research and ultimately enable optimization of ablation parameters to maximize procedure success and minimize risk.
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Affiliation(s)
- Alan Sugrue
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
- Division of Cardiovascular Medicine, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elad Maor
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
- Chaim Sheba Medical Center and Sackler School of Medicine, Tel Aviv University, Israel
| | - Freddy Del-Carpio Munoz
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Ammar M Killu
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Samuel J Asirvatham
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
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6
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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: 15] [Impact Index Per Article: 7.5] [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.
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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.
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7
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Arpaia P, Crauso F, Frosolone M, Mariconda M, Minucci S, Moccaldi N. A personalized FEM model for reproducible measurement of anti-inflammatory drugs in transdermal administration to knee. Sci Rep 2022; 12:673. [PMID: 35027630 PMCID: PMC8758660 DOI: 10.1038/s41598-021-04718-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 11/08/2021] [Indexed: 11/09/2022] Open
Abstract
A personalized model of the human knee for enhancing the inter-individual reproducibility of a measurement method for monitoring Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) after transdermal delivery is proposed. The model is based on the solution of Maxwell Equations in the electric-quasi-stationary limit via Finite Element Analysis. The dimensions of the custom geometry are estimated on the basis of knee circumference at the patella, body mass index, and sex of each individual. An optimization algorithm allows to find out the electrical parameters of each subject by experimental impedance spectroscopy data. Muscular tissues were characterized anisotropically, by extracting Cole-Cole equation parameters from experimental data acquired with twofold excitation, both transversal and parallel to tissue fibers. A sensitivity and optimization analysis aiming at reducing computational burden in model customization achieved a worst-case reconstruction error lower than 5%. The personalized knee model and the optimization algorithm were validated in vivo by an experimental campaign on thirty volunteers, 67% healthy and 33% affected by knee osteoarthritis (Kellgren-Lawrence grade ranging in [1,4]), with an average error of 3%.
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Affiliation(s)
- Pasquale Arpaia
- Laboratory of Augmented Reality for Health Monitoring (ARHeMLab), Department of Electrical Engineering and Information Technology, University of Naples Federico II, Naples, Italy.,Interdepartmental Center for Research in Health Management and Innovation in Health (CIRMIS), University of Naples Federico II, Naples, Italy
| | - Federica Crauso
- Laboratory of Augmented Reality for Health Monitoring (ARHeMLab), Department of Electrical Engineering and Information Technology, University of Naples Federico II, Naples, Italy.,Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy
| | - Mirco Frosolone
- Laboratory of Augmented Reality for Health Monitoring (ARHeMLab), Department of Electrical Engineering and Information Technology, University of Naples Federico II, Naples, Italy.,Department of Public Health, University of Naples Federico II, Naples, Italy
| | - Massimo Mariconda
- Department of Public Health, University of Naples Federico II, Naples, Italy
| | - Simone Minucci
- Laboratory of Augmented Reality for Health Monitoring (ARHeMLab), Department of Electrical Engineering and Information Technology, University of Naples Federico II, Naples, Italy. .,Department of Economics, Engineering, Society and Business Organization (DEIM), University of Tuscia, Viterbo, Italy.
| | - Nicola Moccaldi
- Laboratory of Augmented Reality for Health Monitoring (ARHeMLab), Department of Electrical Engineering and Information Technology, University of Naples Federico II, Naples, Italy
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Caluori G, Odehnalova E, Jadczyk T, Pesl M, Pavlova I, Valikova L, Holzinger S, Novotna V, Rotrekl V, Hampl A, Crha M, Cervinka D, Starek Z. AC Pulsed Field Ablation Is Feasible and Safe in Atrial and Ventricular Settings: A Proof-of-Concept Chronic Animal Study. Front Bioeng Biotechnol 2020; 8:552357. [PMID: 33344428 PMCID: PMC7744788 DOI: 10.3389/fbioe.2020.552357] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 11/09/2020] [Indexed: 12/18/2022] Open
Abstract
Introduction Pulsed field ablation (PFA) exploits the delivery of short high-voltage shocks to induce cells death via irreversible electroporation. The therapy offers a potential paradigm shift for catheter ablation of cardiac arrhythmia. We designed an AC-burst generator and therapeutic strategy, based on the existing knowledge between efficacy and safety among different pulses. We performed a proof-of-concept chronic animal trial to test the feasibility and safety of our method and technology. Methods We employed 6 female swine - weight 53.75 ± 4.77 kg - in this study. With fluoroscopic and electroanatomical mapping assistance, we performed ECG-gated AC-PFA in the following settings: in the left atrium with a decapolar loop catheter with electrodes connected in bipolar fashion; across the interventricular septum applying energy between the distal electrodes of two tip catheters. After procedure and 4-week follow-up, the animals were euthanized, and the hearts were inspected for tissue changes and characterized. We perform finite element method simulation of our AC-PFA scenarios to corroborate our method and better interpret our findings. Results We applied square, 50% duty cycle, AC bursts of 100 μs duration, 100 kHz internal frequency, 900 V for 60 pulses in the atrium and 1500 V for 120 pulses in the septum. The inter-burst interval was determined by the native heart rhythm - 69 ± 9 bpm. Acute changes in the atrial and ventricular electrograms were immediately visible at the sites of AC-PFA - signals were elongated and reduced in amplitude (p < 0.0001) and tissue impedance dropped (p = 0.011). No adverse event (e.g., esophageal temperature rises or gas bubble streams) was observed - while twitching was avoided by addition of electrosurgical return electrodes. The implemented numerical simulations confirmed the non-thermal nature of our AC-PFA and provided specific information on the estimated treated area and need of pulse trains. The postmortem chest inspection showed no peripheral damage, but epicardial and endocardial discolorations at sites of ablation. T1-weighted scans revealed specific tissue changes in atria and ventricles, confirmed to be fibrotic scars via trichrome staining. We found isolated, transmural and continuous scars. A surviving cardiomyocyte core was visible in basal ventricular lesions. Conclusion We proved that our method and technology of AC-PFA is feasible and safe for atrial and ventricular myocardial ablation, supporting their systematic investigation into effectiveness evaluation for the treatment of cardiac arrhythmia. Further optimization, with energy titration or longer follow-up, is required for a robust atrial and ventricular AC-PFA.
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Affiliation(s)
- Guido Caluori
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,IHU LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac, France.,Univ. Bordeaux, INSERM, UMR 1045, Cardiothoracic Research Center of Bordeaux, Pessac, France
| | - Eva Odehnalova
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia
| | - Tomasz Jadczyk
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
| | - Martin Pesl
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia.,First Department of Internal Medicine-Cardioangiology, St. Anne's University Hospital, Masaryk University, Brno, Czechia
| | - Iveta Pavlova
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czechia
| | - Lucia Valikova
- Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czechia
| | | | - Veronika Novotna
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Power Electrical and Electronic Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Vladimir Rotrekl
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Ales Hampl
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Michal Crha
- Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czechia
| | - Dalibor Cervinka
- Department of Power Electrical and Electronic Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Zdenek Starek
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,First Department of Internal Medicine-Cardioangiology, St. Anne's University Hospital, Masaryk University, Brno, Czechia
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9
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Kiełbik A, Szlasa W, Saczko J, Kulbacka J. Electroporation-Based Treatments in Urology. Cancers (Basel) 2020; 12:E2208. [PMID: 32784598 PMCID: PMC7465806 DOI: 10.3390/cancers12082208] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/03/2020] [Accepted: 08/05/2020] [Indexed: 02/06/2023] Open
Abstract
The observation that an application of a pulsed electric field (PEF) resulted in an increased permeability of the cell membrane has led to the discovery of the phenomenon called electroporation (EP). Depending on the parameters of the electric current and cell features, electroporation can be either reversible or irreversible. The irreversible electroporation (IRE) found its use in urology as a non-thermal ablative method of prostate and renal cancer. As its mechanism is based on the permeabilization of cell membrane phospholipids, IRE (as well as other treatments based on EP) provides selectivity sparing extracellular proteins and matrix. Reversible EP enables the transfer of genes, drugs, and small exogenous proteins. In clinical practice, reversible EP can locally increase the uptake of cytotoxic drugs such as cisplatin and bleomycin. This approach is known as electrochemotherapy (ECT). Few in vivo and in vitro trials of ECT have been performed on urological cancers. EP provides the possibility of transmission of genes across the cell membrane. As the protocols of gene electrotransfer (GET) over the last few years have improved, EP has become a well-known technique for non-viral cell transfection. GET involves DNA transfection directly to the cancer or the host skin and muscle tissue. Among urological cancers, the GET of several plasmids encoding prostate cancer antigens has been investigated in clinical trials. This review brings into discussion the underlying mechanism of EP and an overview of the latest progress and development perspectives of EP-based treatments in urology.
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Affiliation(s)
- Aleksander Kiełbik
- Faculty of Medicine, Wroclaw Medical University, 50-367 Wroclaw, Poland; (A.K.); (W.S.)
| | - Wojciech Szlasa
- Faculty of Medicine, Wroclaw Medical University, 50-367 Wroclaw, Poland; (A.K.); (W.S.)
| | - Jolanta Saczko
- Department of Molecular and Cellular Biology, Wroclaw Medical University, 50-556 Wroclaw, Poland;
| | - Julita Kulbacka
- Department of Molecular and Cellular Biology, Wroclaw Medical University, 50-556 Wroclaw, Poland;
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10
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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).
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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.
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11
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Sieni E, Dettin M, De Robertis M, Bazzolo B, Conconi MT, Zamuner A, Marino R, Keller F, Campana LG, Signori E. The Efficiency of Gene Electrotransfer in Breast-Cancer Cell Lines Cultured on a Novel Collagen-Free 3D Scaffold. Cancers (Basel) 2020; 12:cancers12041043. [PMID: 32340405 PMCID: PMC7226458 DOI: 10.3390/cancers12041043] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/08/2020] [Accepted: 04/21/2020] [Indexed: 12/15/2022] Open
Abstract
Gene Electro-Transfer (GET) is a powerful method of DNA delivery with great potential for medical applications. Although GET has been extensively studied in vitro and in vivo, the optimal parameters remain controversial. 2D cell cultures have been widely used to investigate GET protocols, but have intrinsic limitations, whereas 3D cultures may represent a more reliable model thanks to the capacity of reproducing the tumor architecture. Here we applied two GET protocols, using a plate or linear electrode, on 3D-cultured HCC1954 and MDA-MB231 breast cancer cell lines grown on a novel collagen-free 3D scaffold and compared results with conventional 2D cultures. To evaluate the electrotransfer efficiency, we used the plasmid pEGFP-C3 encoding the enhanced green fluorescent protein (EGFP) reporter gene. The novel 3D scaffold promoted extracellular matrix deposition, which particularly influences cell behavior in both in vitro cell cultures and in vivo tumor tissue. While the transfection efficiency was similar in the 2D-cultures, we observed significant differences in the 3D-model. The transfection efficiency in the 3D vs 2D model was 44% versus 15% (p < 0.01) and 24% versus 17% (p < 0.01) in HCC1954 and MDA-MB231 cell cultures, respectively. These findings suggest that the novel 3D scaffold allows reproducing, at least partially, the peculiar morphology of the original tumor tissues, thus allowing us to detect meaningful differences between the two cell lines. Following GET with plate electrodes, cell viability was higher in 3D-cultured HCC1954 (66%) and MDA-MB231 (96%) cell lines compared to their 2D counterpart (53% and 63%, respectively, p < 0.001). Based on these results, we propose the novel 3D scaffold as a reliable support for the preparation of cell cultures in GET studies. It may increase the reliability of in vitro assays and allow the optimization of GET parameters of in vivo protocols.
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Affiliation(s)
- Elisabetta Sieni
- Department of Theoretical and Applied Sciences, University of Insubria, 21100 Varese, Italy
- Correspondence: (E.S.); (E.S.); Tel.: +39-0332-421405 (E.S.); Tel.: +39-0-649-934-232 (E.S.)
| | - Monica Dettin
- Department of Industrial Engineering, University of Padova, 35131 Padova, Italy; (M.D.); (A.Z.)
| | - Mariangela De Robertis
- CNR-Institute of Biomembrane, Bioenergetics and Molecular Biotechnology, 70126 Bari, Italy;
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari, 70126 Bari, Itay
| | - Bianca Bazzolo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy; (B.B.); (M.T.C.)
| | - Maria Teresa Conconi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy; (B.B.); (M.T.C.)
| | - Annj Zamuner
- Department of Industrial Engineering, University of Padova, 35131 Padova, Italy; (M.D.); (A.Z.)
| | - Ramona Marino
- Campus Bio-Medico University of Rome, 00128 Roma, Italy; (R.M.); (F.K.)
| | - Flavio Keller
- Campus Bio-Medico University of Rome, 00128 Roma, Italy; (R.M.); (F.K.)
| | - Luca Giovanni Campana
- Department of Surgical Oncological and Gastroenterological Sciences DISCOG, University of Padova, 35124 Padova, Italy;
| | - Emanuela Signori
- Campus Bio-Medico University of Rome, 00128 Roma, Italy; (R.M.); (F.K.)
- CNR-Institute of Translational Pharmacology, 00133 Roma, Italy
- Correspondence: (E.S.); (E.S.); Tel.: +39-0332-421405 (E.S.); Tel.: +39-0-649-934-232 (E.S.)
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12
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A Novel 3D Scaffold for Cell Growth to Asses Electroporation Efficacy. Cells 2019; 8:cells8111470. [PMID: 31752448 PMCID: PMC6912677 DOI: 10.3390/cells8111470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/07/2019] [Accepted: 11/16/2019] [Indexed: 12/15/2022] Open
Abstract
Tumor electroporation (EP) refers to the permeabilization of the cell membrane by means of short electric pulses thus allowing the potentiation of chemotherapeutic drugs. Standard plate adhesion 2D cell cultures can simulate the in vivo environment only partially due to lack of cell–cell interaction and extracellular matrix (ECM). In this study, we assessed a novel 3D scaffold for cell cultures based on hyaluronic acid and ionic-complementary self-assembling peptides (SAPs), by studying the growth patterns of two different breast carcinoma cell lines (HCC1569 and MDA-MB231). This 3D scaffold modulates cell shape and induces extracellular matrix deposit around cells. In the MDA-MB 231 cell line, it allows three-dimensional growth of structures known as spheroids, while in HCC1569 it achieves a cell organization similar to that observed in vivo. Interestingly, we were able to visualize the electroporation effect on the cells seeded in the new scaffold by means of standard propidium iodide assay and fluorescence microscopy. Thanks to the presence of cell–cell and cell–ECM interactions, the new 3D scaffold may represent a more reliable support for EP studies than 2D cancer cell cultures and may be used to test new EP-delivered drugs and novel EP protocols.
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A Laboratory IGBT-Based High-voltage Pulsed Electric Field Generator for Effective Water Diffusivity Enhancement in Chicken Meat. FOOD BIOPROCESS TECH 2019. [DOI: 10.1007/s11947-019-02360-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Effects of electrically-induced constant tension on giant unilamellar vesicles using irreversible electroporation. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2019; 48:731-741. [PMID: 31552440 DOI: 10.1007/s00249-019-01398-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/12/2019] [Accepted: 09/16/2019] [Indexed: 01/16/2023]
Abstract
Stretching in membranes of cells and vesicles plays important roles in various physiological and physicochemical phenomena. Irreversible electroporation (IRE) is the irreversible permeabilization of the membrane through the application of a series of electrical field pulses of micro- to millisecond duration. IRE induces lateral tension due to stretching in the membranes of giant unilamellar vesicles (GUVs). However, the effects of electrically induced (i.e., IRE) constant tension in the membranes of GUVs have not been investigated yet in detail. To explore the effects of electrically induced tension on GUVs, firstly a microcontroller-based IRE technique is developed which produces electric field pulses (332 V/cm) with pulse width 200 µs. Then the electrodeformation, electrofusion and membrane rupture of GUVs are investigated at various constant tensions in which the membranes of GUVs are composed of dioleoylphosphatidylglycerol (DOPG) and dioleoylphosphatidylcholine (DOPC). Stochastic electropore formation is observed in the membranes at an electrically induced constant tension in which the probability of pore formation is increased with the increase of tension from 2.5 to 7.0 mN/m. The results of pore formation at different electrically-induced constant tensions are in agreement with those reported for mechanically-induced constant tension. The decrease in the energy barrier of the pre-pore state due to the increase of electrically-induced tension is the main factor increasing the probability of electropore formation. These investigations help to provide an understanding of the complex behavior of cells/vesicles in electric field pulses and can form the basis for practical applications in biomedical technology.
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15
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Cell-seeded 3D scaffolds as in vitro models for electroporation. Bioelectrochemistry 2019; 125:15-24. [DOI: 10.1016/j.bioelechem.2018.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 07/19/2018] [Accepted: 08/24/2018] [Indexed: 12/12/2022]
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16
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Campana LG, Bullo M, Di Barba P, Dughiero F, Forzan M, Mognaschi ME, Sgarbossa P, Tosi AL, Bernardis A, Sieni E. Effect of Tissue Inhomogeneity in Soft Tissue Sarcomas: From Real Cases to Numerical and Experimental Models. Technol Cancer Res Treat 2018; 17:1533033818789693. [PMID: 30045667 PMCID: PMC6071161 DOI: 10.1177/1533033818789693] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Electrochemotherapy is an established treatment option for patients with superficially
metastatic tumors, mainly malignant melanoma and breast cancer. Based on preliminary
experiences, electrochemotherapy has the potential to be translated in the treatment of
larger and deeper neoplasms, such as soft tissue sarcomas. However, soft tissue sarcomas
are characterized by tissue inhomogeneity and, consequently, by variable electrical
characteristic of tumor tissue. The inhomogeneity in conductivity represents the cause of
local variations in the electric field intensity. Crucially, this fact may hamper the
achievement of the electroporation threshold during the electrochemotherapy procedure. In
order to evaluate the effect of tissue inhomogeneity on the electric field distribution,
we first performed ex vivo analysis of some clinical cases to quantify
the inhomogeneity area. Subsequently, we performed some simulations where the electric
field intensity was evaluated by means of finite element analysis. The results of the
simulation models are finally compared to an experimental model based on potato and tissue
mimic materials. Tissue mimic materials are materials where the conductivity can be
suitably designed. The coupling of computation and experimental results could be helpful
to show the effect of the inhomogeneity in terms of variation in electric field
distribution and characteristics.
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Affiliation(s)
- Luca Giovanni Campana
- 1 Surgical Oncology Unit, Veneto Institute of Oncology IOV-IRCCS, Padova, Italy.,2 Department of Surgery Oncology and Gastroenterology, University of Padova, Padova, Italy
| | - Marco Bullo
- 3 Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Paolo Di Barba
- 4 Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy
| | - Fabrizio Dughiero
- 3 Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Michele Forzan
- 3 Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Maria Evelina Mognaschi
- 4 Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy
| | - Paolo Sgarbossa
- 3 Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Anna Lisa Tosi
- 5 Melanoma and Sarcoma Pathology Unit, Veneto Institute of Oncology IOV-IRCCS, Padova, Italy
| | - Alessia Bernardis
- 3 Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Elisabetta Sieni
- 3 Department of Industrial Engineering, University of Padova, Padova, Italy
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17
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Ongaro A, Campana LG, De Mattei M, Di Barba P, Dughiero F, Forzan M, Mognaschi ME, Pellati A, Rossi CR, Bernardello C, Sieni E. Effect of Electrode Distance in Grid Electrode: Numerical Models and In Vitro Tests. Technol Cancer Res Treat 2018; 17:1533033818764498. [PMID: 29558871 PMCID: PMC5863864 DOI: 10.1177/1533033818764498] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Electrochemotherapy is an emerging local treatment for the management of superficial tumors and, among these, also chest wall recurrences from breast cancer. Generally, the treatment of this peculiar type of tumor requires the coverage of large skin areas. In these cases, electrochemotherapy treatment by means of standard small size needle electrodes (an array of 0.73 cm spaced needles, which covers an area of 1.5 cm2) is time-consuming and can allow an inhomogeneous coverage of the target area. We have previously designed grid devices suitable for treating an area ranging from 12 to 200 cm2. In this study, we propose different approaches to study advantages and drawbacks of a grid device with needles positioned 2 cm apart. The described approach includes a numerical evaluation to estimate electric field intensity, followed by an experimental quantification of electroporation on a cell culture. The electric field generated in a conductive medium has been studied by means of 3-dimensional numerical models with varying needle pair distance from 1 to 2 cm. In particular, the electric field evaluation shows that the electric field intensity with varying needle distance is comparable in the area in the middle of the 2 electrodes. Differently, near needles, the electric field intensity increases with the increasing electrode distance and supply voltage. The computational results have been correlated with experimental ones obtained in vitro on cell culture. In particular, electroporation effect has been assessed on human breast cancer cell line MCF7, cultured in monolayer. The use of 2-cm distant needles, supplied by 2000 V, produced an electroporation effect in the whole area comprised between the electrodes. Areas of cell culture where reversible and irreversible electroporation occurred were identified under microscope by using fluorescent dyes. The coupling of computation and experimental results could be helpful to evaluate the effect of the needle distance on the electric field intensity in cell cultures in terms of reversible or irreversible electroporation.
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Affiliation(s)
- Alessia Ongaro
- 1 Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Luca Giovanni Campana
- 2 Surgical Oncology Unit, Veneto Institute of Oncology IOV-IRCCS, Padova, Italy.,3 Department of Surgery Oncology and Gastroenterology, University of Padova, Padova, Italy
| | - Monica De Mattei
- 1 Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Paolo Di Barba
- 4 Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy
| | - Fabrizio Dughiero
- 5 Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Michele Forzan
- 5 Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Maria Evelina Mognaschi
- 4 Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy
| | - Agnese Pellati
- 1 Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Carlo Riccardo Rossi
- 2 Surgical Oncology Unit, Veneto Institute of Oncology IOV-IRCCS, Padova, Italy.,3 Department of Surgery Oncology and Gastroenterology, University of Padova, Padova, Italy
| | - Clara Bernardello
- 5 Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Elisabetta Sieni
- 5 Department of Industrial Engineering, University of Padova, Padova, Italy
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18
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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]
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19
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Cemazar M, Sersa G, Frey W, Miklavcic D, Teissié J. Recommendations and requirements for reporting on applications of electric pulse delivery for electroporation of biological samples. Bioelectrochemistry 2018; 122:69-76. [PMID: 29571034 DOI: 10.1016/j.bioelechem.2018.03.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/09/2018] [Accepted: 03/10/2018] [Indexed: 01/26/2023]
Abstract
Electric field-induced membrane changes are an important approach in the life sciences. However, the developments in knowledge and translational applications face problems of reproducibility. Indeed, a quick survey of the literature reveals a lack of transparent and comprehensive reporting of essential technical information in many papers. Too many of the published scientific papers do not contain sufficient information for proper assessment of the presented results. The general rule/guidance in reporting experimental data should require details on exposure conditions such that other researchers are able to evaluate, judge and reproduce the experiments and data obtained. To enhance dissemination of information and reproducibility of protocols, it is important to agree upon nomenclature and reach a consensus on documentation of experimental methods and procedures. This paper offers recommendations and requirements for reporting on applications of electric pulse delivery for electroporation of biological samples in life science.
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Affiliation(s)
- M Cemazar
- Department of Experimental Oncology, Institute of Oncology, Ljubljana, Zaloska 2, 1000 Ljubljana, Slovenia; Faculty of Health Sciences, University of Primorska, Polje, 42, 6310 Izola, Slovenia
| | - G Sersa
- Department of Experimental Oncology, Institute of Oncology, Ljubljana, Zaloska 2, 1000 Ljubljana, Slovenia
| | - W Frey
- Karlsruhe Institute of Technology (KIT), Institute for Pulsed Power and Microwave Technology (IHM), 76344 Eggenstein-Leopoldshafen, Germany
| | - D Miklavcic
- University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, 1000 Ljubljana, Slovenia
| | - J Teissié
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.
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20
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Suzuki DOH, Berkenbrock JA, de Oliveira KD, Freytag JO, Rangel MMM. Novel application for electrochemotherapy: Immersion of nasal cavity in dog. Artif Organs 2016; 41:767-773. [PMID: 28028827 DOI: 10.1111/aor.12858] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 07/19/2016] [Accepted: 08/17/2016] [Indexed: 12/11/2022]
Abstract
Electrochemotherapy is a new modality of local cancer treatment that increases the delivery of chemotherapy drugs into tumor cells by applying intense electric fields. This novel electrochemotherapy application was applied as an adjuvant to surgery and eliminated intranasal tumors in dog. The treatment challenges are the surgery limitations due to anatomy and residual tumor in the bone cavity. Most of the tumoral mass on nasal cavity was surgically removed. The internal nasal cavity was immersed in liquid and bleomycin before applying electric field. The solution was necessary to increase the superficial contact between plate electrodes and residual tumor. The numerical study demonstrated electrochemotherapy efficiency in different clinical situations. The proximity between electrodes and bone (<3 mm) and bone irregularities affect the electric field distribution on tumoral tissue. The tumoral tissue around bone protuberances tends to be eliminated. Electrochemotherapy with plate electrodes inside the cavity might not be effective. Different values of electric conductivity solution were studied; the ideal value was 0.5 S/m. The numerical and experimental results confirm the successful application of electrochemotherapy on dog nasal cavity.
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Affiliation(s)
- Daniela O H Suzuki
- Institute of Biomedical Engineering, Federal University of Santa Catarina (UFSC), Florianópolis-SC
| | - José A Berkenbrock
- Institute of Biomedical Engineering, Federal University of Santa Catarina (UFSC), Florianópolis-SC
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21
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Microscopic histological characteristics of soft tissue sarcomas: analysis of tissue features and electrical resistance. Med Biol Eng Comput 2016; 55:1097-1108. [DOI: 10.1007/s11517-016-1573-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 09/15/2016] [Indexed: 12/21/2022]
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22
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Ghazikhanlou-Sani K, Firoozabadi SMP, Agha-Ghazvini L, Mahmoodzadeh H. Evaluation of Soft Tissue Sarcoma Tumors Electrical Conductivity Anisotropy Using Diffusion Tensor Imaging for Numerical Modeling on Electroporation. J Biomed Phys Eng 2016; 6:71-80. [PMID: 27672627 PMCID: PMC5022757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 04/06/2015] [Indexed: 06/06/2023]
Abstract
INTRODUCTION There is many ways to assessing the electrical conductivity anisotropy of a tumor. Applying the values of tissue electrical conductivity anisotropy is crucial in numerical modeling of the electric and thermal field distribution in electroporation treatments. This study aims to calculate the tissues electrical conductivity anisotropy in patients with sarcoma tumors using diffusion tensor imaging technique. MATERIALS AND METHOD A total of 3 subjects were involved in this study. All of patients had clinically apparent sarcoma tumors at the extremities. The T1, T2 and DTI images were performed using a 3-Tesla multi-coil, multi-channel MRI system. The fractional anisotropy (FA) maps were performed using the FSL (FMRI software library) software regarding the DTI images. The 3D matrix of the FA maps of each area (tumor, normal soft tissue and bone/s) was reconstructed and the anisotropy matrix was calculated regarding to the FA values. RESULT The mean FA values in direction of main axis in sarcoma tumors were ranged between 0.475-0.690. With assumption of isotropy of the electrical conductivity, the FA value of electrical conductivity at each X, Y and Z coordinate axes would be equal to 0.577. The gathered results showed that there is a mean error band of 20% in electrical conductivity, if the electrical conductivity anisotropy not concluded at the calculations. The comparison of FA values showed that there is a significant statistical difference between the mean FA value of tumor and normal soft tissues (P<0.05). CONCLUSION DTI is a feasible technique for the assessment of electrical conductivity anisotropy of tissues. It is crucial to quantify the electrical conductivity anisotropy data of tissues for numerical modeling of electroporation treatments.
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Affiliation(s)
- K Ghazikhanlou-Sani
- PhD student of Medical Physics, Tarbiat Modares University, Medical Physics Department, Tehran, Iran
| | - S M P Firoozabadi
- Professor of Biomedical Engineering, Tarbiat Modares University, Medical Physics Department, Tehran, Iran
| | - L Agha-Ghazvini
- Assistant Professor of Radiology, Department of Radiology, School of Medicine and Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - H Mahmoodzadeh
- Assistant Professor of General Surgery, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
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23
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Qiang B, Brigham JC, McGough RJ, Greenleaf JF, Urban MW. Mapped Chebyshev pseudo-spectral method for simulating the shear wave propagation in the plane of symmetry of a transversely isotropic viscoelastic medium. Med Biol Eng Comput 2016; 55:389-401. [PMID: 27221812 DOI: 10.1007/s11517-016-1522-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 05/06/2016] [Indexed: 11/26/2022]
Abstract
Shear wave elastography is a versatile technique that is being applied to many organs. However, in tissues that exhibit anisotropic material properties, special care must be taken to estimate shear wave propagation accurately and efficiently. A two-dimensional simulation method is implemented to simulate the shear wave propagation in the plane of symmetry in transversely isotropic viscoelastic media. The method uses a mapped Chebyshev pseudo-spectral method to calculate the spatial derivatives and an Adams-Bashforth-Moulton integrator with variable step sizes for time marching. The boundaries of the two-dimensional domain are surrounded by perfectly matched layers to approximate an infinite domain and minimize reflection errors. In an earlier work, we proposed a solution for estimating the apparent shear wave elasticity and viscosity of the spatial group velocity as a function of rotation angle through a low-frequency approximation by a Taylor expansion. With the solver implemented in MATLAB, the simulated results in this paper match well with the theory. Compared to the finite element method simulations we used before, the pseudo-spectral solver consumes less memory and is faster and achieves better accuracy.
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Affiliation(s)
- Bo Qiang
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA.
- The Nielsen Company, Oldsmar, FL, 34677, USA.
| | - John C Brigham
- Department of Civil and Environmental Engineering, Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- School of Engineering and Computing Sciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Robert J McGough
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, 48824, USA
| | - James F Greenleaf
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Matthew W Urban
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
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Langus J, Kranjc M, Kos B, Šuštar T, Miklavčič D. Dynamic finite-element model for efficient modelling of electric currents in electroporated tissue. Sci Rep 2016; 6:26409. [PMID: 27211822 PMCID: PMC4876422 DOI: 10.1038/srep26409] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 05/03/2016] [Indexed: 12/18/2022] Open
Abstract
In silico experiments (numerical simulations) are a valuable tool for non-invasive research of the influences of tissue properties, electrode placement and electric pulse delivery scenarios in the process of electroporation. The work described in this article was aimed at introducing time dependent effects into a finite element model developed specifically for electroporation. Reference measurements were made ex vivo on beef liver samples and experimental data were used both as an initial condition for simulation (applied pulse voltage) and as a reference value for numerical model calibration (measured pulse current). The developed numerical model is able to predict the time evolution of an electric pulse current within a 5% error over a broad range of applied pulse voltages, pulse durations and pulse repetition frequencies. Given the good agreement of the current flowing between the electrodes, we are confident that the results of our numerical model can be used both for detailed in silico research of electroporation mechanisms (giving researchers insight into time domain effects) and better treatment planning algorithms, which predict the outcome of treatment based on both spatial and temporal distributions of applied electric pulses.
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Affiliation(s)
- J Langus
- C3M d.o.o., Technology park 21, SI-1000 Ljubljana, Slovenia
| | - M Kranjc
- University of Ljubljana, Faculty of Electrical Engineering, Laboratory of Biocybernetics, Tržaška 25, 1000 Ljubljana, Slovenia
| | - B Kos
- University of Ljubljana, Faculty of Electrical Engineering, Laboratory of Biocybernetics, Tržaška 25, 1000 Ljubljana, Slovenia
| | - T Šuštar
- C3M d.o.o., Technology park 21, SI-1000 Ljubljana, Slovenia
| | - D Miklavčič
- University of Ljubljana, Faculty of Electrical Engineering, Laboratory of Biocybernetics, Tržaška 25, 1000 Ljubljana, Slovenia
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Čorović S, Mahnič-Kalamiza S, Miklavčič D. Education on electrical phenomena involved in electroporation-based therapies and treatments: a blended learning approach. Biomed Eng Online 2016; 15:36. [PMID: 27056369 PMCID: PMC4823865 DOI: 10.1186/s12938-016-0152-7] [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: 01/31/2016] [Accepted: 03/30/2016] [Indexed: 11/28/2022] Open
Abstract
Background Electroporation-based applications require multidisciplinary expertise and collaboration of experts with different professional backgrounds in engineering and science. Beginning in 2003, an international scientific workshop and postgraduate course electroporation based technologies and treatments (EBTT) has been organized at the University of Ljubljana to facilitate transfer of knowledge from leading experts to researches, students and newcomers in the field of electroporation. In this paper we present one of the integral parts of EBTT: an e-learning practical work we developed to complement delivery of knowledge via lectures and laboratory work, thus providing a blended learning approach on electrical phenomena involved in electroporation-based therapies and treatments. Methods The learning effect was assessed via a pre- and post e-learning examination test composed of 10 multiple choice questions (i.e. items). The e-learning practical work session and both of the e-learning examination tests were carried out after the live EBTT lectures and other laboratory work. Statistical analysis was performed to compare and evaluate the learning effect measured in two groups of students: (1) electrical engineers and (2) natural scientists (i.e. medical doctors, biologists and chemists) undergoing the e-learning practical work in 2011–2014 academic years. Item analysis was performed to assess the difficulty of each item of the examination test. Results The results of our study show that the total score on the post examination test significantly improved and the item difficulty in both experimental groups decreased. The natural scientists reached the same level of knowledge (no statistical difference in total post-examination test score) on the post-course test take, as do electrical engineers, although the engineers started with statistically higher total pre-test examination score, as expected. Conclusions The main objective of this study was to investigate whether the educational content the e-learning practical work presented to the students with different professional backgrounds enhanced their knowledge acquired via lectures during EBTT. We compared the learning effect assessed in two experimental groups undergoing the e-learning practical work: electrical engineers and natural scientists. The same level of knowledge on the post-course examination was reached in both groups. The results indicate that our e-learning platform supported by blended learning approach provides an effective learning tool for populations with mixed professional backgrounds and thus plays an important role in bridging the gap between scientific domains involved in electroporation-based technologies and treatments. Electronic supplementary material The online version of this article (doi:10.1186/s12938-016-0152-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Selma Čorović
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška c. 25, 1000, Ljubljana, Slovenia.
| | - Samo Mahnič-Kalamiza
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška c. 25, 1000, Ljubljana, Slovenia
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška c. 25, 1000, Ljubljana, Slovenia
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Rosazza C, Meglic SH, Zumbusch A, Rols MP, Miklavcic D. Gene Electrotransfer: A Mechanistic Perspective. Curr Gene Ther 2016; 16:98-129. [PMID: 27029943 PMCID: PMC5412002 DOI: 10.2174/1566523216666160331130040] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 11/22/2022]
Abstract
Gene electrotransfer is a powerful method of DNA delivery offering several medical applications, among the most promising of which are DNA vaccination and gene therapy for cancer treatment. Electroporation entails the application of electric fields to cells which then experience a local and transient change of membrane permeability. Although gene electrotransfer has been extensively studied in in vitro and in vivo environments, the mechanisms by which DNA enters and navigates through cells are not fully understood. Here we present a comprehensive review of the body of knowledge concerning gene electrotransfer that has been accumulated over the last three decades. For that purpose, after briefly reviewing the medical applications that gene electrotransfer can provide, we outline membrane electropermeabilization, a key process for the delivery of DNA and smaller molecules. Since gene electrotransfer is a multipart process, we proceed our review in describing step by step our current understanding, with particular emphasis on DNA internalization and intracellular trafficking. Finally, we turn our attention to in vivo testing and methodology for gene electrotransfer.
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Affiliation(s)
| | | | | | - Marie-Pierre Rols
- Institute of Pharmacology and Structural Biology (IPBS), CNRS UMR5089, 205 route de Narbonne, 31077 Toulouse, France.
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Suzuki DO, Marques CM, Rangel MM. Conductive Gel Increases the Small Tumor Treatment With Electrochemotherapy Using Needle Electrodes. Artif Organs 2015; 40:705-11. [DOI: 10.1111/aor.12631] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Daniela O.H. Suzuki
- Institute of Biomedical Engineering, Federal University of Santa Catarina (UFSC); Florianópolis Santa Catarina Brazil
| | - Claudia M.G. Marques
- Center for Health Sciences and Sports; State University of Santa Catarina (UDESC); Florianópolis Santa Catarina Brazil
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Bonakdar M, Latouche EL, Mahajan RL, Davalos RV. The Feasibility of a Smart Surgical Probe for Verification of IRE Treatments Using Electrical Impedance Spectroscopy. IEEE Trans Biomed Eng 2015; 62:2674-84. [PMID: 26057529 DOI: 10.1109/tbme.2015.2441636] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
SIGNIFICANCE Irreversible electroporation (IRE) is gaining popularity as a focal ablation modality for the treatment of unresectable tumors. One clinical limitation of IRE is the absence of methods for real-time treatment evaluation, namely actively monitoring the dimensions of the induced lesion. This information is critical to ensure a complete treatment and minimize collateral damage to the surrounding healthy tissue. GOAL In this study, we are taking advantage of the biophysical properties of living tissues to address this critical demand. METHODS Using advanced microfabrication techniques, we have developed an electrical impedance microsensor to collect impedance data along the length of a bipolar IRE probe for treatment verification. For probe characterization and interpretation of the readings, we used potato tuber, which is a suitable platform for IRE experiments without having the complexities of in vivo or ex vivo models. We used the impedance spectra, along with an electrical model of the tissue, to obtain critical parameters such as the conductivity of the tissue before, during, and after completion of treatment. To validate our results, we used a finite element model to simulate the electric field distribution during treatments in each potato. RESULTS It is shown that electrical impedance spectroscopy could be used as a technique for treatment verification, and when combined with appropriate FEM modeling can determine the lesion dimensions. CONCLUSIONS This technique has the potential to be readily translated for use with other ablation modalities already being used in clinical settings for the treatment of malignancies.
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Sersa G, Teissie J, Cemazar M, Signori E, Kamensek U, Marshall G, Miklavcic D. Electrochemotherapy of tumors as in situ vaccination boosted by immunogene electrotransfer. Cancer Immunol Immunother 2015; 64:1315-27. [PMID: 26067277 PMCID: PMC4554735 DOI: 10.1007/s00262-015-1724-2] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 05/26/2015] [Indexed: 12/21/2022]
Abstract
Electroporation is a platform technology for drug and gene delivery. When applied to cell in vitro or tissues in vivo, it leads to an increase in membrane permeability for molecules which otherwise cannot enter the cell (e.g., siRNA, plasmid DNA, and some chemotherapeutic drugs). The therapeutic effectiveness of delivered chemotherapeutics or nucleic acids depends greatly on their successful and efficient delivery to the target tissue. Therefore, the understanding of different principles of drug and gene delivery is necessary and needs to be taken into account according to the specificity of their delivery to tumors and/or normal tissues. Based on the current knowledge, electrochemotherapy (a combination of drug and electric pulses) is used for tumor treatment and has shown great potential. Its local effectiveness is up to 80 % of local tumor control, however, without noticeable effect on metastases. In an attempt to increase systemic antitumor effectiveness of electrochemotherapy, electrotransfer of genes with immunomodulatory effect (immunogene electrotransfer) could be used as adjuvant treatment. Since electrochemotherapy can induce immunogenic cell death, adjuvant immunogene electrotransfer to peritumoral tissue could lead to locoregional effect as well as the abscopal effect on distant untreated metastases. Therefore, we propose a combination of electrochemotherapy with peritumoral IL-12 electrotransfer, as a proof of principle, using electrochemotherapy boosted with immunogene electrotransfer as in situ vaccination for successful tumor treatment.
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Affiliation(s)
- Gregor Sersa
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, 1000, Ljubljana, Slovenia,
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Campana LG, Cesari M, Dughiero F, Forzan M, Rastrelli M, Rossi CR, Sieni E, Tosi AL. Electrical resistance of human soft tissue sarcomas: an ex vivo study on surgical specimens. Med Biol Eng Comput 2015; 54:773-87. [PMID: 26324245 DOI: 10.1007/s11517-015-1368-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 08/07/2015] [Indexed: 12/17/2022]
Abstract
This paper presents a study about electrical resistance, which using fixed electrode geometry could be correlated to the tissue resistivity, of different histological types of human soft tissue sarcomas measured during electroporation. The same voltage pulse sequence was applied to the tumor mass shortly after surgical resection by means of a voltage pulse generator currently used in clinical practice for electrochemotherapy that uses reversible electroporation. The voltage pulses were applied by means of a standard hexagonal electrode composed by seven, 20-mm-long equispaced needles. Irrespective of tumor size, the electrode applies electric pulses to the same volume of tissue. The resistance value was computed from the voltage and current recorded by the pulse generator, and it was correlated with the histological characteristics of the tumor tissue which was assessed by a dedicated pathologist. Some differences in resistance values, which could be correlated to a difference in tissue resistivity, were noticed according to sarcoma histotype. Lipomatous tumors (i.e., those rich in adipose tissue) displayed the highest resistance values (up to 1700 Ω), whereas in the other soft tissue sarcomas, such as those originating from muscle, nerve sheath, or fibrous tissue, the electrical resistance measured was between 40 and 110 Ω. A variability in resistance was found also within the same histotype. Among lipomatous tumors, the presence of myxoid tissue between adipocytes reduced the electrical resistance (e.g., 50-100 Ω). This work represents the first step in order to explore the difference in tissue electrical properties of STS. These results may be used to verify whether tuning electric field intensity according to the specific STS histotype could improve tissue electroporation and ultimately treatment efficacy.
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Affiliation(s)
- L G Campana
- Sarcoma and Melanoma Unit, Veneto Institute of Oncology IOV IRCCS, Via Gattamelata, 64, 35128, Padua, Italy
| | - M Cesari
- Department of Industrial Engineering, University of Padova, Via Gradenigo, 6/a, 35131, Padua, Italy
| | - F Dughiero
- Department of Industrial Engineering, University of Padova, Via Gradenigo, 6/a, 35131, Padua, Italy
| | - M Forzan
- Department of Industrial Engineering, University of Padova, Via Gradenigo, 6/a, 35131, Padua, Italy
| | - M Rastrelli
- Sarcoma and Melanoma Unit, Veneto Institute of Oncology IOV IRCCS, Via Gattamelata, 64, 35128, Padua, Italy
| | - C R Rossi
- Sarcoma and Melanoma Unit, Veneto Institute of Oncology IOV IRCCS, Via Gattamelata, 64, 35128, Padua, Italy
| | - E Sieni
- Department of Industrial Engineering, University of Padova, Via Gradenigo, 6/a, 35131, Padua, Italy.
| | - A L Tosi
- Melanoma and Sarcoma Pathology Unit, Veneto Institute of Oncology IOV IRCCS, Via Gattamelata, 64, 35128, Padua, Italy
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Golberg A, Rubinsky B. Towards electroporation based treatment planning considering electric field induced muscle contractions. Technol Cancer Res Treat 2015; 11:189-201. [PMID: 22335414 DOI: 10.7785/tcrt.2012.500249] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The electric field threshold for muscle contraction is two orders of magnitudes lower than that for electroporation. Current electroporation treatment planning and electrode design studies focus on optimizing the delivery of electroporation electric fields to the targeted tissue. The goal of one part of this study was to investigate the relation between the volumes of tissue that experience electroporation electric fields in a targeted tissue volume and the volumes of tissue that experience muscle contraction inducing electric fields around the electroporated tissue volume, (V(MC)), during standard electroporation procedures and for various electroporation electrodes designs. The numerical analysis shows that conventional electroporation protocols and electrode design can generate muscle contraction inducing electric fields in surprisingly large volumes of non-target tissue, around the electroporation treated tissue. In studying various electrode configurations, we found that electrode placement in a structure we refer to as a "Current Cage" can substantially reduce the volume of non-target tissue exposed to electric fields above the muscle contraction threshold. In an experimental study on a tissue phantom we compare a commercial two parallel needle electroporation system with the Current Cage design. While tissue electroporated volumes were similar, V(MC) of tissue treated using the Current Cage design electrodes was an order of magnitude smaller than that using a commercially available system. An important aspect of the entire study is that it suggests the benefit of including the calculations of V(MC) for planning of electroporation based treatments such as DNA vaccination, electrochemotherapy and irreversible electroporation.
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Affiliation(s)
- Alex Golberg
- Department of Mechanical Engineering, Etcheverry Hall, 6124, University of California at Berkeley, Berkeley, CA 94720, USA.
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Dermol J, Miklavčič D. Mathematical Models Describing Chinese Hamster Ovary Cell Death Due to Electroporation In Vitro. J Membr Biol 2015. [PMID: 26223863 DOI: 10.1007/s00232-015-9825-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Electroporation is a phenomenon used in the treatment of tumors by electrochemotherapy, non-thermal ablation with irreversible electroporation, and gene therapy. When treating patients, either predefined or variable electrode geometry is used. Optimal pulse parameters are predetermined for predefined electrode geometry, while they must be calculated for each specific case for variable electrode geometry. The position and number of electrodes are also determined for each patient. It is currently assumed that above a certain experimentally determined value of electric field, all cells are permeabilized/destroyed and under it they are unaffected. In this paper, mathematical models of survival in which the probability of cell death is continuously distributed from 0 to 100 % are proposed and evaluated. Experiments were performed on cell suspensions using electrical parameters similar to standard electrochemotherapy and irreversible electroporation parameters. The proportion of surviving cells was determined using clonogenic assay for assessing the ability of a cell to grow into a colony. Various mathematical models (first-order kinetics, Hülsheger, Peleg-Fermi, Weibull, logistic, adapted Gompertz, Geeraerd) were fitted to experimental data using a non-linear least-squares method. The fit was evaluated by calculating goodness of fit and by observing the trend of values of models' parameters. The most appropriate models of cell survival as a function of treatment time were the adapted Gompertz and the Geeraerd models and, as a function of the electric field, the logistic, adapted Gompertz and Peleg-Fermi models. The next steps to be performed are validation of the most appropriate models on tissues and determination of the models' predictive power.
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Affiliation(s)
- Janja Dermol
- Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000, Ljubljana, Slovenia
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Dymek K, Rems L, Zorec B, Dejmek P, Galindo FG, Miklavčič D. Modeling electroporation of the non-treated and vacuum impregnated heterogeneous tissue of spinach leaves. INNOV FOOD SCI EMERG 2015. [DOI: 10.1016/j.ifset.2014.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Phillips M. The effect of small intestine heterogeneity on irreversible electroporation treatment planning. J Biomech Eng 2015; 136:091009. [PMID: 24907451 DOI: 10.1115/1.4027815] [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: 02/19/2014] [Accepted: 06/09/2014] [Indexed: 11/08/2022]
Abstract
Nonthermal irreversible electroporation (NTIRE) is an ablation modality that utilizes microsecond electric fields to produce nanoscale defects in the cell membrane. This results in selective cell death while preserving all other molecules, including the extracellular matrix. Here, finite element analysis and experimental results are utilized to examine the effect of NTIRE on the small intestine due to concern over collateral damage to this organ during NTIRE treatment of abdominal cancers. During previous studies, the electrical treatment parameters were chosen based on a simplified homogeneous tissue model. The small intestine, however, has very distinct layers, and a more realistic model is needed to further develop this technology for precise clinical applications. This study uses a two-dimensional finite element solution of the Laplace and heat conduction equations to investigate how small intestine heterogeneities affect the electric field and temperature distribution. Experimental results obtained by applying NTIRE to the rat small intestine in vivo support the heterogeneous effect of NTIRE on the tissue. The numerical modeling indicates that the electroporation parameters chosen for this study avoid thermal damage to the tissue. This is supported by histology obtained from the in vivo study, which showed preservation of extracellular structures. The finite element model also indicates that the heterogeneous structure of the small intestine has a significant effect on the electric field and volume of cell ablation during electroporation and could have a large impact on the extent of treatment. The heterogeneous nature of the tissue should be accounted for in clinical treatment planning.
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Yarmush ML, Golberg A, Serša G, Kotnik T, Miklavčič D. Electroporation-Based Technologies for Medicine: Principles, Applications, and Challenges. Annu Rev Biomed Eng 2014; 16:295-320. [DOI: 10.1146/annurev-bioeng-071813-104622] [Citation(s) in RCA: 519] [Impact Index Per Article: 51.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Martin L. Yarmush
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, Harvard Medical School and Shriners Burn Hospital for Children, Boston, Massachusetts 02114; email (M.L.Y.):
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey 08854;
| | - Alexander Golberg
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, Harvard Medical School and Shriners Burn Hospital for Children, Boston, Massachusetts 02114; email (M.L.Y.):
| | - Gregor Serša
- Department of Experimental Oncology, Institute of Oncology Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Tadej Kotnik
- Department of Biomedical Engineering, Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia;
| | - Damijan Miklavčič
- Department of Biomedical Engineering, Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia;
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Suzuki DO, Anselmo J, de Oliveira KD, Freytag JO, Rangel MM, Marques JL, Ramos A. Numerical Model of Dog Mast Cell Tumor Treated by Electrochemotherapy. Artif Organs 2014; 39:192-7. [DOI: 10.1111/aor.12333] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Daniela O.H. Suzuki
- Institute of Biomedical Engineering; Federal University of Santa Catarina (UFSC); Florianopolis Santa Catarina Brazil
| | - Jânio Anselmo
- Institute of Biomedical Engineering; Federal University of Santa Catarina (UFSC); Florianopolis Santa Catarina Brazil
| | | | | | | | - Jefferson L.B. Marques
- Institute of Biomedical Engineering; Federal University of Santa Catarina (UFSC); Florianopolis Santa Catarina Brazil
| | - Airton Ramos
- Institute of Biomedical Engineering; Federal University of Santa Catarina (UFSC); Florianopolis Santa Catarina Brazil
- Department of Electrical Engineering; State University of Santa Catarina (UDESC); Joinville Santa Catarina Brazil
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Electroporation-based gene therapy: recent evolution in the mechanism description and technology developments. Methods Mol Biol 2014; 1121:3-23. [PMID: 24510808 DOI: 10.1007/978-1-4614-9632-8_1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Thirty years after the publication of the first report on gene electrotransfer in cultured cells by the delivery of delivering electric pulses, this technology is starting to be applied to humans. In 2008, at the time of the publication of the first edition of this book, reversible cell electroporation for gene transfer and gene therapy (nucleic acids electrotransfer) was at a cross roads in its development. In 5 years, basic and applied developments have brought gene electrotransfer into a new status. Present knowledge on the effects of cell exposure to appropriate electric field pulses, particularly at the level of the cell membrane, is reported here, as an introduction to the large range of applications described in this book. The importance of the models of electric field distribution in tissues and of the correct choice of electrodes and applied voltages is highlighted, as well as the large range of new specialized electrodes, developed also in the frame of the other electroporation-based treatments (electrochemotherapy). Indeed, electric pulses are now routinely applied for localized drug delivery in the treatment of solid tumors by electrochemotherapy. The mechanisms involved in DNA electrotransfer, which include cell electropermeabilization and DNA electrophoresis, are also surveyed: noticeably, the first molecular description of the crossing of a lipid membrane by a nucleic acid was reported in 2012. The progress in the understanding of cell electroporation as well as developments of technological aspects, in silico, in vitro and in vivo, have contributed to bring gene electrotransfer development to the clinical stage. However, spreading of the technology will require not only more clinical trials but also further homogenization of the protocols and the preparation and validation of Standard Operating Procedures.
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Corovic S, Lackovic I, Sustaric P, Sustar T, Rodic T, Miklavcic D. Modeling of electric field distribution in tissues during electroporation. Biomed Eng Online 2013; 12:16. [PMID: 23433433 PMCID: PMC3614452 DOI: 10.1186/1475-925x-12-16] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 12/10/2012] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Electroporation based therapies and treatments (e.g. electrochemotherapy, gene electrotransfer for gene therapy and DNA vaccination, tissue ablation with irreversible electroporation and transdermal drug delivery) require a precise prediction of the therapy or treatment outcome by a personalized treatment planning procedure. Numerical modeling of local electric field distribution within electroporated tissues has become an important tool in treatment planning procedure in both clinical and experimental settings. Recent studies have reported that the uncertainties in electrical properties (i.e. electric conductivity of the treated tissues and the rate of increase in electric conductivity due to electroporation) predefined in numerical models have large effect on electroporation based therapy and treatment effectiveness. The aim of our study was to investigate whether the increase in electric conductivity of tissues needs to be taken into account when modeling tissue response to the electroporation pulses and how it affects the local electric distribution within electroporated tissues. METHODS We built 3D numerical models for single tissue (one type of tissue, e.g. liver) and composite tissue (several types of tissues, e.g. subcutaneous tumor). Our computer simulations were performed by using three different modeling approaches that are based on finite element method: inverse analysis, nonlinear parametric and sequential analysis. We compared linear (i.e. tissue conductivity is constant) model and non-linear (i.e. tissue conductivity is electric field dependent) model. By calculating goodness of fit measure we compared the results of our numerical simulations to the results of in vivo measurements. RESULTS The results of our study show that the nonlinear models (i.e. tissue conductivity is electric field dependent: σ(E)) fit experimental data better than linear models (i.e. tissue conductivity is constant). This was found for both single tissue and composite tissue. Our results of electric field distribution modeling in linear model of composite tissue (i.e. in the subcutaneous tumor model that do not take into account the relationship σ(E)) showed that a very high electric field (above irreversible threshold value) was concentrated only in the stratum corneum while the target tumor tissue was not successfully treated. Furthermore, the calculated volume of the target tumor tissue exposed to the electric field above reversible threshold in the subcutaneous model was zero assuming constant conductivities of each tissue.Our results also show that the inverse analysis allows for identification of both baseline tissue conductivity (i.e. conductivity of non-electroporated tissue) and tissue conductivity vs. electric field (σ(E)) of electroporated tissue. CONCLUSION Our results of modeling of electric field distribution in tissues during electroporation show that the changes in electrical conductivity due to electroporation need to be taken into account when an electroporation based treatment is planned or investigated. We concluded that the model of electric field distribution that takes into account the increase in electric conductivity due to electroporation yields more precise prediction of successfully electroporated target tissue volume. The findings of our study can significantly contribute to the current development of individualized patient-specific electroporation based treatment planning.
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Affiliation(s)
- Selma Corovic
- University of Ljubljana, Faculty of Electrical Engineering, Trzaska cesta 25, SI-1000 Ljubljana Slovenia
| | - Igor Lackovic
- University of Zagreb, Faculty of Electrical Engineering and Computing, Unska 3, HR-10000, Zagreb, Croatia
| | - Primoz Sustaric
- C3M, d. o. o., Centre for Computational Continuum Mechanics, Technological Park 21, SI-1000 Ljubljana, Slovenia
| | - Tomaz Sustar
- C3M, d. o. o., Centre for Computational Continuum Mechanics, Technological Park 21, SI-1000 Ljubljana, Slovenia
| | - Tomaz Rodic
- C3M, d. o. o., Centre for Computational Continuum Mechanics, Technological Park 21, SI-1000 Ljubljana, Slovenia
| | - Damijan Miklavcic
- University of Ljubljana, Faculty of Electrical Engineering, Trzaska cesta 25, SI-1000 Ljubljana Slovenia
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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]
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Zupanic A, Kos B, Miklavcic D. Treatment planning of electroporation-based medical interventions: electrochemotherapy, gene electrotransfer and irreversible electroporation. Phys Med Biol 2012; 57:5425-40. [PMID: 22864181 DOI: 10.1088/0031-9155/57/17/5425] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In recent years, cancer electrochemotherapy (ECT), gene electrotransfer for gene therapy and DNA vaccination (GET) and tissue ablation with irreversible electroporation (IRE) have all entered clinical practice. We present a method for a personalized treatment planning procedure for ECT, GET and IRE, based on medical image analysis, numerical modelling of electroporation and optimization with the genetic algorithm, and several visualization tools for treatment plan assessment. Each treatment plan provides the attending physician with optimal positions of electrodes in the body and electric pulse parameters for optimal electroporation of the target tissues. For the studied case of a deep-seated tumour, the optimal treatment plans for ECT and IRE require at least two electrodes to be inserted into the target tissue, thus lowering the necessary voltage for electroporation and limiting damage to the surrounding healthy tissue. In GET, it is necessary to place the electrodes outside the target tissue to prevent damage to target cells intended to express the transfected genes. The presented treatment planning procedure is a valuable tool for clinical and experimental use and evaluation of electroporation-based treatments.
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Affiliation(s)
- Anze Zupanic
- University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, 1000, Ljubljana, Slovenia
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Ballyns JJ, Turo D, Otto P, Shah JP, Hammond J, Gebreab T, Gerber LH, Sikdar S. Office-based elastographic technique for quantifying mechanical properties of skeletal muscle. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2012; 31:1209-19. [PMID: 22837285 PMCID: PMC3493148 DOI: 10.7863/jum.2012.31.8.1209] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
OBJECTIVES Our objectives were to develop a new, efficient, and easy-to-administer approach to ultrasound elastography and assess its ability to provide quantitative characterization of viscoelastic properties of skeletal muscle in an outpatient clinical environment. We sought to show its validity and clinical utility in assessing myofascial trigger points, which are associated with myofascial pain syndrome. METHODS Ultrasound imaging was performed while the muscle was externally vibrated at frequencies in the range of 60 to 200 Hz using a handheld vibrator. The spatial gradient of the vibration phase yielded the shear wave speed, which is related to the viscoelastic properties of tissue. The method was validated using a calibrated experimental phantom, the biceps brachii muscle in healthy volunteers (n = 6), and the upper trapezius muscle in symptomatic patients with axial neck pain (n = 13) and asymptomatic (pain-free) control participants (n = 9). RESULTS Using the experimental phantom, our method was able to quantitatively measure the shear moduli with error rates of less than 20%. The mean shear modulus ± SD in the normal biceps brachii measured 12.5 ± 3.4 kPa, within the range of published values using more sophisticated methods. Shear wave speeds in active myofascial trigger points and the surrounding muscle tissue were significantly higher than those in normal tissue at high frequency excitations (>100 Hz; P < .05). CONCLUSIONS Off-the-shelf office-based equipment can be used to quantitatively characterize skeletal muscle viscoelastic properties with estimates comparable to those using more sophisticated methods. Our preliminary results using this method indicate that patients with spontaneous neck pain and symptomatic myofascial trigger points have increased tissue heterogeneity at the trigger point site and the surrounding muscle tissue.
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Affiliation(s)
- Jeffrey J Ballyns
- Department of Electrical and Computer Engineering, George Mason University, Fairfax, Virginia 22030, USA
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Čorović S, Mir LM, Miklavčič D. In vivo muscle electroporation threshold determination: realistic numerical models and in vivo experiments. J Membr Biol 2012; 245:509-20. [PMID: 22622286 DOI: 10.1007/s00232-012-9432-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 04/30/2012] [Indexed: 11/21/2022]
Abstract
In vivo electroporation is used as an effective technique for delivery of therapeutic agents such as chemotherapeutic drugs or DNA into target tissue cells for different biomedical purposes. In order to successfully electroporate a target tissue, it is essential to know the local electric field distribution produced by an application of electroporation voltage pulses. In this study three-dimensional finite element models were built in order to analyze local electric field distribution and corresponding tissue conductivity changes in rat muscle electroporated either transcutaneously or directly (i.e., two-plate electrodes were placed either on the skin or directly on the skeletal muscle after removing the skin). Numerical calculations of electroporation thresholds and conductivity changes in skin and muscle were validated with in vivo measurements. Our model of muscle with skin also confirms the in vivo findings of previous studies that electroporation "breaks" the skin barrier when the applied voltage is above 50 V.
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Affiliation(s)
- Selma Čorović
- University of Ljubljana, Trzaska 25, 1000 Ljubljana, Slovenia.
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43
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Bureau MF, Wasungu L, Jugé L, Scherman D, Rols MP, Mignet N. Investigating relationship between transfection and permeabilization by the electric field and/or the Pluronic® L64 in vitro and in vivo. J Gene Med 2012; 14:204-15. [DOI: 10.1002/jgm.2610] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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44
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Patient-specific treatment planning of electrochemotherapy: procedure design and possible pitfalls. Bioelectrochemistry 2012; 87:265-73. [PMID: 22341626 DOI: 10.1016/j.bioelechem.2012.01.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 01/06/2012] [Accepted: 01/20/2012] [Indexed: 01/25/2023]
Abstract
Electrochemotherapy uses electroporation for enhancing chemotherapy. Electrochemotherapy can be performed using standard operating procedures with predefined electrode geometries, or using patient-specific treatment planning to predict electroporation. The latter relies on realistic computer models to provide optimal results (i.e. electric field distribution as well as electrodes' position and number) and is suitable for treatment of deep-seated tumors. Since treatment planning for deep-seated tumors has been used in radiotherapy, we expose parallelisms with radiotherapy in order to establish the procedure for electrochemotherapy of deep-seated tumors. We partitioned electrochemotherapy in the following phases: the mathematical model of electroporation, treatment planning, set-up verification, treatment delivery and monitoring, and response assessment. We developed a conceptual treatment planning software that incorporates mathematical models of electroporation. Preprocessing and segmentation of the patient's medical images are performed, and a 3D model is constructed which allows placement of electrodes and implementation of the mathematical model of electroporation. We demonstrated the feasibility of electrochemotherapy of deep-seated tumors treatment planning within a clinical study where treatment planning contributed to the effective electrochemotherapy treatment of deep-seated colorectal metastases in the liver. The described procedure can provide medical practitioners with information on using electrochemotherapy in the clinical setting. The main aims of this paper are: 1) to present the procedure for treating deep-seated tumors by electrochemotherapy based on patient-specific treatment planning, and 2) to identify gaps in knowledge and possible pitfalls of such procedure.
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The Nightingale Prize 2011 for best MBEC paper in 2010. Med Biol Eng Comput 2011; 49:1353-4. [PMID: 22095317 PMCID: PMC3223592 DOI: 10.1007/s11517-011-0846-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 11/09/2011] [Indexed: 12/01/2022]
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Kazi AA, Hong-Brown L, Lang SM, Lang CH. Deptor knockdown enhances mTOR Activity and protein synthesis in myocytes and ameliorates disuse muscle atrophy. Mol Med 2011; 17:925-36. [PMID: 21607293 DOI: 10.2119/molmed.2011.00070] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 05/18/2011] [Indexed: 11/06/2022] Open
Abstract
Deptor is an mTOR binding protein that affects cell metabolism. We hypothesized that knockdown (KD) of Deptor in C2C12 myocytes will increase protein synthesis via stimulating mTOR-S6K1 signaling. Deptor KD was achieved using lentiviral particles containing short hairpin (sh)RNA targeting the mouse Deptor mRNA sequence, and control cells were transfected with a scrambled control shRNA. KD reduced Deptor mRNA and protein content by 90%, which increased phosphorylation of mTOR kinase substrates, 4E-BP1 and S6K1, and concomitantly increased protein synthesis. Deptor KD myoblasts were both larger in diameter and exhibited an increased mean cell volume. Deptor KD increased the percentage of cells in the S phase, coincident with an increased phosphorylation (S807/S811) of retinoblastoma protein (pRb) that is critical for the G(1) to S phase transition. Deptor KD did not appear to alter basal apoptosis or autophagy, as evidenced by the lack of change for cleaved caspase-3 and light chain (LC)3B, respectively. Deptor KD increased proliferation rate and enhanced myotube formation. Finally, in vivo Deptor KD (~50% reduction) by electroporation into gastrocnemius of C57/BL6 mice did not alter weight or protein synthesis in control muscle. However, Deptor KD prevented atrophy produced by 3 d of hindlimb immobilization, at least in part by increasing protein synthesis. Thus, our data support the hypothesis that Deptor is an important regulator of protein metabolism in myocytes and demonstrate that decreasing Deptor expression in vivo is sufficient to ameliorate muscle atrophy.
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Affiliation(s)
- Abid A Kazi
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
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Synergistic effects of local temperature enhancements on cellular responses in the context of high-intensity, ultrashort electric pulses. Med Biol Eng Comput 2011; 49:713-8. [PMID: 21340640 DOI: 10.1007/s11517-011-0745-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Accepted: 01/27/2011] [Indexed: 10/18/2022]
Abstract
Results of self-consistent analyses of cells show the possibility of temperature increases at membranes in response to a single nanosecond, high-voltage pulse, at least over small sections of the membrane. Molecular Dynamics simulations indicate that such a temperature increase could facilitate poration, which is one example of a bio-process at the plasma membrane. Our study thus suggests that the use of repetitive high-intensity voltage pulses could open up possibilities for a host of synergistic bio-responses involving both thermal and electrically driven phenomena.
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Zupanic A, Corovic S, Miklavcic D, Pavlin M. Numerical optimization of gene electrotransfer into muscle tissue. Biomed Eng Online 2010; 9:66. [PMID: 21050435 PMCID: PMC2990758 DOI: 10.1186/1475-925x-9-66] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 11/04/2010] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Electroporation-based gene therapy and DNA vaccination are promising medical applications that depend on transfer of pDNA into target tissues with use of electric pulses. Gene electrotransfer efficiency depends on electrode configuration and electric pulse parameters, which determine the electric field distribution. Numerical modeling represents a fast and convenient method for optimization of gene electrotransfer parameters. We used numerical modeling, parameterization and numerical optimization to determine the optimum parameters for gene electrotransfer in muscle tissue. METHODS We built a 3D geometry of muscle tissue with two or six needle electrodes (two rows of three needle electrodes) inserted. We performed a parametric study and optimization based on a genetic algorithm to analyze the effects of distances between the electrodes, depth of insertion, orientation of electrodes with respect to muscle fibers and applied voltage on the electric field distribution. The quality of solutions were evaluated in terms of volumes of reversibly (desired) and irreversibly (undesired) electroporated muscle tissue and total electric current through the tissue. RESULTS Large volumes of reversibly electroporated muscle with relatively little damage can be achieved by using large distances between electrodes and large electrode insertion depths. Orienting the electrodes perpendicular to muscle fibers is significantly better than the parallel orientation for six needle electrodes, while for two electrodes the effect of orientation is not so pronounced. For each set of geometrical parameters, the window of optimal voltages is quite narrow, with lower voltages resulting in low volumes of reversibly electroporated tissue and higher voltages in high volumes of irreversibly electroporated tissue. Furthermore, we determined which applied voltages are needed to achieve the optimal field distribution for different distances between electrodes. CONCLUSION The presented numerical study of gene electrotransfer is the first that demonstrates optimization of parameters for gene electrotransfer on tissue level. Our method of modeling and optimization is generic and can be applied to different electrode configurations, pulsing protocols and different tissues. Such numerical models, together with knowledge of tissue properties can provide useful guidelines for researchers and physicians in selecting optimal parameters for in vivo gene electrotransfer, thus reducing the number of animals used in studies of gene therapy and DNA vaccination.
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Affiliation(s)
- Anze Zupanic
- University of Ljubljana, Faculty of Electrical Engineering, Trzaska cesta 25, SI-1000 Ljubljana, Slovenia
| | - Selma Corovic
- University of Ljubljana, Faculty of Electrical Engineering, Trzaska cesta 25, SI-1000 Ljubljana, Slovenia
| | - Damijan Miklavcic
- University of Ljubljana, Faculty of Electrical Engineering, Trzaska cesta 25, SI-1000 Ljubljana, Slovenia
| | - Mojca Pavlin
- University of Ljubljana, Faculty of Electrical Engineering, Trzaska cesta 25, SI-1000 Ljubljana, Slovenia
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Kos B, Zupanic A, Kotnik T, Snoj M, Sersa G, Miklavcic D. Robustness of treatment planning for electrochemotherapy of deep-seated tumors. J Membr Biol 2010; 236:147-53. [PMID: 20596859 DOI: 10.1007/s00232-010-9274-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 06/11/2010] [Indexed: 01/10/2023]
Abstract
Treatment of cutaneous and subcutaneous tumors with electrochemotherapy has become a regular clinical method, while treatment of deep-seated tumors is still at an early stage of development. We present a method for preparing a dedicated patient-specific, computer-optimized treatment plan for electrochemotherapy of deep-seated tumors based on medical images. The treatment plan takes into account the patient's anatomy, tissue conductivity changes during electroporation and the constraints of the pulse generator. Analysis of the robustness of a treatment plan made with this method shows that the effectiveness of the treatment is not affected significantly by small single errors in electrode positioning. However, when many errors occur simultaneously, the resulting drop in effectiveness is larger, which means that it is necessary to be as accurate as possible in electrode positioning. The largest effect on treatment effectiveness stems from uncertainties in dielectric properties and electroporation thresholds of treated tumors and surrounding tissues, which emphasizes the need for more accurate measurements and more research. The presented methods for treatment planning and robustness analysis allow quantification of the treatment reproducibility and enable the setting of suitable safety margins to improve the likelihood of successful treatment of deep-seated tumors by electrochemotherapy.
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Affiliation(s)
- Bor Kos
- Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000, Ljubljana, Slovenia
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