Editing Electroporation

{{Short description|Method in molecular biology to make pores in cell membranes}}
[[Image:Electroporation Cuvettes.jpg|thumb|right|230px|Cuvettes for in-vitro electroporation. These are [[plastic]] with aluminium [[electrodes]] and a blue lid. They hold a maximum of 400 μ'''L.''']]

'''Electroporation''', also known as '''electropermeabilization''', is a [[Microbiology|microbiological]] and [[Biotechnology|biotechnological]] technique in which an [[electric field]] is applied to [[Cell (biology)|cells]] to briefly increase the [[Permeability (porous media)|permeability]] of the [[cell membrane]].<ref>{{Cite journal |last=Gehl |first=J. |date=April 2003 |title=Electroporation: theory and methods, perspectives for drug delivery, gene therapy and research |url=https://pubmed.ncbi.nlm.nih.gov/12648161 |journal=Acta Physiologica Scandinavica |volume=177 |issue=4 |pages=437–447 |doi=10.1046/j.1365-201X.2003.01093.x |issn=0001-6772 |pmid=12648161}}</ref> The application of a high-[[voltage]] electric field induces a temporary destabilization of the [[lipid bilayer]], resulting in the formation of nanoscale pores that permit the entry or exit of [[Macromolecule|macromolecules]].<ref name="Potter_2003">{{cite book |title=Current Protocols in Molecular Biology |vauthors=Potter H |date=May 2003 |isbn=978-0471142720 |volume=Chapter 9 |pages=Unit 9.3 |chapter=Chapter 9: Transfection by electroporation |doi=10.1002/0471142727.mb0903s62 |pmc=2975437 |pmid=18265334}}</ref> 

This method is widely employed to introduce molecules—including [[small molecule]]s, [[DNA]], [[RNA]], and [[protein]]s—into cells. Electroporation can be performed on cells in suspension using electroporation [[Cuvette|cuvettes]], or directly on adherent cells ''[[in situ]]'' within their culture vessels.<ref>{{Cite journal |title=CORP: Gene delivery into murine skeletal muscle using in vivo electroporation |journal=Journal of Applied Physiology |last1=Hughes |first1=David C |date=2022-05-05 |volume=133 |issue=1 |pages=41–59 |author-link1=Carver College of Medicine |last2=Hardee |first2=Justin P |author-link2=University of Melbourne |last3=Waddell |first3=David S |author-link3=University of North Florida |last4=Goodman |first4=Craig A |author-link4=University of Melbourne |doi=10.1152/japplphysiol.00088.2022 |pmc=9236869 |pmid=35511722}}</ref>

In microbiology, electroporation is frequently utilized for the [[Genetic transformation|transformation]] of [[bacteria]] or [[yeast]] cells,<ref>{{Cite journal |title=An improved yeast transformation method for the generation of very large human antibody libraries |journal=[[Protein Engineering Design & Selection]] |last1=Benatuil |first1=Lorenzo |date=2010-02-03 |url=https://academic.oup.com/peds/article-abstract/23/4/155/1591574?redirectedFrom=fulltext |volume=23 |issue=4 |pages=155–159 |via=Oxford Academic |last2=Perez |first2=Jennifer M |last3=Belk |first3=Jonathan |last4=Hsieh |first4=Chung-Ming |doi=10.1093/protein/gzq002|pmid=20130105 }}</ref> often with [[plasmid]] DNA.<ref>{{Cite journal |title=A Critical Review of Electroporation as A Plasmid Delivery System in Mouse Skeletal Muscle |journal=[[International Journal of Molecular Sciences]] |last1=Sokołowska |first1=Emilia |author-link1=Medical University of Białystok|author-link2=Medical University of Białystok|date=2019-06-06 |volume=20 |issue=11 |pages=2776 |last2=Błachnio-Zabielska |first2=Agnieszka Urszula |doi=10.3390/ijms20112776 |doi-access=free |pmc=6600476 |pmid=31174257}}</ref> It is also used in the [[transfection]] of plant [[Protoplast|protoplasts]] and [[Mammal|mammalian]] cells.<ref>{{Cite book |title=Transfection by Electroporation |journal=Current Protocols in Molecular Biology |last1=Potter |first1=Huntington |date= 2001|last2=Heller |first2=Richard |editor-first1=Frederick M. |editor-first2=Roger |editor-first3=Robert E. |editor-first4=David D. |editor-first5=J.G. |editor-first6=John A. |editor-first7=Kevin |editor-last1=Ausubel |editor-last2=Brent |editor-last3=Kingston |editor-last4=Moore |editor-last5=Seidman |editor-last6=Smith |editor-last7=Struhl |chapter=9 |volume=Chapter 9 |pages=Unit 9.3 |doi=10.1002/0471142727 |pmc=2975437 |pmid=18265334|isbn=978-0-471-14272-0 }}</ref> Notably, electroporation plays a critical role in the ''[[ex vivo]]'' manipulation of immune cells for the development of cell-based therapies, such as [[CAR T cell|CAR T-cell]] therapy.<ref>{{Cite journal |title=Car T-Cell Production Using Nonviral Approaches |journal=Journal of Immunology Research |editor-last=Ponce-Soto|editor-first=Luis Alberto|last1=Lukjanov |first1=Victor |date=2021-03-27 |last2=Koutná |first2=Irena |last3=Šimara |first3=Pavel |pages=1–9 |doi=10.1155/2021/6644685 |doi-access=free |pmid=33855089|pmc=8019376 }}</ref><ref>{{Cite journal |title=Non-viral, specifically targeted CAR-T cells achieve high safety and efficacy in B-NHL |journal=[[Nature (journal)|Nature]] |last1=Zhang |first1=Jiqin |date=2022-08-31 |url=https://www.nature.com/articles/s41586-022-05140-y |volume=609 |pages=369–374 |last2=Hu |first2=Yongxian |last3=Yang |first3=Jiaxuan |last4=Li |first4=Wei |last5=Zhang |first5=Mingming |last6=Wang |first6=Qingcan |last7=Zhang |first7=Linjie |last8=Wei |first8=Guoqing |last9=Tian |first9=Yue |last10=Zhao |first10=Kui |last11=Chen |first11=Ang |last12=Tan |first12=Binghe |last13=Cui |first13=Jiazhen |last14=Li |first14=Deqi |last15=Li |first15=Yi |display-authors=3 |doi=10.1038/s41586-022-015140-y|doi-broken-date=17 April 2025 |pmid=36045296 }}</ref> Moreover, ''[[in vivo]]'' applications of electroporation have been successfully demonstrated in various tissue types.<ref>{{Cite journal |title=In vivo electroporation: a powerful and convenient means of nonviral gene transfer to tissues of living animals (Review) |journal=[[International Journal of Molecular Medicine]] |last1=Muramatsu |first1=T |date=1998-01-01 |url=https://pubmed.ncbi.nlm.nih.gov/9852198/ |volume=1 |issue=1 |pages=55–62 |via=[[PubMed]] |author-link1=Nagoya University |last2=Nakamura |first2=A |last3=Park |first3=H M |doi=10.3892/ijmm.1.1.55 |pmid=9852198}}</ref>

Bulk electroporation confers advantages over other physical delivery methods, including [[microinjection]] and [[gene gun]] techniques. However, it is limited by reduced cell [[viability assay|viability]]. To address these issues, researchers have developed [[miniaturization|miniaturized]] approaches such as micro-electroporation<ref>{{Cite journal |title=Micro-electroporation in mesenchymal stem cells with alternating electrical current pulses |journal=[[Biomedical Microdevices]] |last1=Ziv |first1=Roee |date=2009-02-11 |url=https://pubmed.ncbi.nlm.nih.gov/18815886/ |volume=11 |issue=1 |pages=95–101 |author-link1=Hebrew University of Jerusalem |last2=Steinhardt |first2=Yair |last3=Pelled |first3=Gadi |last4=Gazit |first4=Dan |last5=Rubinsky |first5=Boris |doi=10.1007/s10544-008-9213-4 |pmid=18815886}}</ref> and [[tissue nanotransfection|nanotransfection]].<ref>{{Cite book |title=Tissue Nanotransfection in Regenerative Medicine |journal=MicroRNA in Regenerative Medicine |last1=Xuan |first1=Yi |date=2023-05-12 |chapter-url=https://www.sciencedirect.com/science/article/abs/pii/B9780128207192000387 |pages=1051–1074 |author-link1=Indiana University School of Medicine |last2=Li |first2=Zhigang |author-link2=Purdue University |last3=Ghatak |first3=Subhadip |author-link3=McGowan Institute for Regenerative Medicine |last4=Sen |first4=Chandan K |author-link4=McGowan Institute for Regenerative Medicine |chapter=37 |doi=10.1016/B978-0-12-820719-2.00038-7 |isbn=978-0-12-820719-2}}</ref> These techniques utilize nanochannel-mediated electroporation to deliver molecular cargo to cells in a more controlled and less invasive manner. 

Alternative methods for intracellular delivery include the use of cell-penetrating [[peptide]]s,<ref>{{Cite journal |title=Peptide-mediated delivery of CRISPR enzymes for the efficient editing of primary human lymphocytes |journal=[[Nature Biomedical Engineering]] |last1=Foss |first1=Dana |date=2023-04-25 |url=https://www.nature.com/articles/s41551-023-01032-2 |volume=7 |pages=640–660 |last2=Muldoon |first2=Joseph J |last3=Nguyen |first3=David N |last4=Carr |first4=Daniel |last5=Sahu |first5=Srishti U |last6=Hunsinger |first6=John M |last7=Wyman |first7=Stacia K |last8=Krishnappa |first8=Netravathi |last9=Mendonsa |first9=Rima |last10=Schanzer |first10=Elaine V |last11=Shy |first11=Brian R |last12=Vykunta |first12=Vivasvan S |last13=Allain |first13=Vincent |last14=Li |first14=Zhongmei |last15=Marson |first15=Alexander |issue=5 |display-authors=3 |doi=10.1038/s41551-023-01032-2}}</ref> cell squeezing techniques,<ref>{{Cite journal |title=Microfluidic cell squeeze-based vaccine comes into clinical investigation |journal=npj Vaccines |last1=Wang |first1=Shuhang |date=2023-05-04 |volume=8 |issue=65 |last2=Yang |first2=Yuqi |last3=Zha |first3=Yan |last4=Li |first4=Ning |page=65 |doi=10.1038/s41541-023-00641-x|pmid=37142615 |pmc=10160095 }}</ref> and [[Calcium chloride transformation|chemical transformation]],<ref>{{Cite book |chapter=Transformation of E. coli Via Electroporation |last=Lessard |first=Julia C |title=Laboratory Methods in Enzymology: DNA |date=2013 |chapter-url=https://www.sciencedirect.com/science/article/abs/pii/B9780124186873000276 |volume=529 |pages=321–327 |author-link=Johns Hopkins Bloomberg School of Public Health |doi=10.1016/B978-0-12-418687-3.00027-6|pmid=24011058 |isbn=978-0-12-418687-3 }}</ref> with selection depending on the specific cell type and cargo characteristics.

Electroporation is also employed to induce [[cell fusion]].<ref>{{Cite journal |title=Cell electrofusion using nanosecond electric pulses |journal=[[Scientific Reports]] |last1=Rems |first1=Lea |date=2013-11-29 |volume=3 |issue=3382 |last2=Ušaj |first2=Marko |last3=Kandušer |first3=Maša |last4=Reberšek |first4=Matej |last5=Miklavčič |first5=Damijan |last6=Pucihar |first6=Gorazd |page=3382 |doi=10.1038/srep03382|pmid=24287643 |pmc=3843160 |bibcode=2013NatSR...3.3382R }}</ref> A prominent application of cell fusion is [[hybridoma technology]], where antibody-producing [[B cell|B lymphocytes]] are fused with immortal [[Multiple myeloma|myeloma]] cell lines to produce [[Monoclonal antibody|monoclonal antibodies]].<ref>{{Cite journal |last1=Mitra |first1=Sanchita |author-link1=Manav Rachna International Institute of Research and Studies |last2=Chaudhary Tomar |first2=Pushpa |author-link2=Manav Rachna International Institute of Research and Studies |date=2021-10-18 |title=Hybridoma technology; advancements, clinical significance, and future aspects |journal=Journal of Genetic Engineering and Biotechnology |volume=19 |issue=1 |pages=159 |doi=10.1186/s43141-021-00264-6 |pmc=8521504 |pmid=34661773 |doi-access=free}}</ref><ref>{{Cite journal |last1=Smith |first1=Scott A |author-link1=Vanderbilt University Medical Center |last2=Crowe |first2=James E |author-link2=Vanderbilt University Medical Center |date=2021-05-28 |title=Use of Human Hybridoma Technology To Isolate Human Monoclonal Antibodies |journal=[[Microbiology Spectrum]] |volume=3 |issue=1 |pages=AID-0027-2014 |doi=10.1128/microbiolspec.AID-0027-2014 |pmc=8162739 |pmid=26104564}}</ref>

==Laboratory research==

Electroporation is widely utilized in laboratory settings due to its ability to achieve high [[Transformation efficiency|transformation efficiencies]], particularly for plasmid DNA, with reported yields approaching 10<sup>10</sup> [[Colony-forming unit|colony-forming units]] per microgram of DNA. Electroporation is generally more costly than chemical transformation methods due to the specialized equipment required. This includes electroporators—devices designed to generate controlled [[Electrostatic field|electrostatic fields]] for cell suspension<ref>{{Cite journal |last1=Pavlin |first1=Mojca |author-link1=University of Ljubljana |last2=Leben |first2=Vilko |last3=Miklavcic |first3=Damijan |date=2006-07-11 |title=Electroporation in dense cell suspension--theoretical and experimental analysis of ion diffusion and cell permeabilization |url=https://pubmed.ncbi.nlm.nih.gov/16935427/ |journal=[[Biochimica et Biophysica Acta]] |volume=1770 |issue=1 |pages=12–23 |doi=10.1016/j.bbagen.2006.06.014 |pmid=16935427}}</ref>—and electroporation cuvettes, which are typically constructed from glass or plastic and contain parallel aluminum [[Electrode|electrodes]].<ref>{{Cite web |title=Electroporation Cuvettes |url=https://www.thermofisher.com/us/en/home/life-science/cloning/competent-cells-for-transformation/electrocompetent-cells/electroporation-cuvettes.html |access-date=2025-04-17 |website=[[Thermo Fisher]]}}</ref><ref name="calvin1988">{{cite journal |vauthors=Calvin NM, Hanawalt PC |date=June 1988 |title=High-efficiency transformation of bacterial cells by electroporation |journal=Journal of Bacteriology |volume=170 |issue=6 |pages=2796–801 |doi=10.1128/jb.170.6.2796-2801.1988 |pmc=211205 |pmid=3286620}}</ref>

A standard bacterial transformation protocol involves several steps. First, electro-competent cells are prepared by washing to remove ions that could cause [[Electric arc|arcing]]. These cells are then mixed with [[plasmid]] DNA and transferred into an electroporation cuvette. A high-voltage electric pulse is applied, with specific [[parameter]]s such as voltage and [[pulse duration]] tailored to the particular cell type being used. Following electroporation, recovery medium is added, and the cells are incubated at an appropriate temperature to allow for outgrowth. Finally, the cells are plated onto selective [[agar plate]]s to assess transformation efficiency.<ref>{{Cite web|url=https://www.thermofisher.com/us/en/home/life-science/cloning/cloning-learning-center/invitrogen-school-of-molecular-biology/molecular-cloning/transformation/bacterial-transformation-workflow.html|title=Bacterial Transformation Workflow|access-date=2025-04-17|website=[[Thermo Fisher Scientific]]}}</ref>

The success of electroporation depends on several factors, including the purity of the plasmid DNA solution,<ref>{{Cite web |title=Plasmid DNA Purity Grades |url=https://www.thermofisher.com/us/en/home/life-science/dna-rna-purification-analysis/plasmid-isolation/transfection-grade-dna.html |access-date=2025-04-17 |website=[[Thermo Fisher]]}}</ref> salt concentration, and electroporation parameters.<ref>{{Cite web|url=https://www.sciencedirect.com/topics/neuroscience/electroporation|title=Electroporation - an overview|access-date=2025-04-17|website=[[ScienceDirect]]}}</ref> High salt concentrations can lead to arcing (electrical discharge), significantly reducing the viability of electroporated cells. Therefore, the electroporation conditions must be optimized for each cell type to achieve an effective balance between cell viability and DNA uptake.<ref>{{Cite journal|url=https://www.nature.com/articles/emm200237.pdf|title=Optimal salt concentration of vehicle for plasmid DNA enhances gene transfer mediated by electroporation|first1=Min-Jae|last1=Lee|author-link1=Seoul National University|first2=Soon-Shin|last2=Cho|author-link2=Seoul National University|journal=Experimental and Molecular Medicine|date=2002-07-22|volume=34|issue=4|pages=265–272|first3=Hyung-Suk|last3=Jang|author-link3=Samsung Medical Center|first4=Young Shin|last4=Lim|author-link4=Samsung Medical Center|first5=Ji-Ran|last5=You|author-link5=Samsung Medical Center|first6=Jangwon|last6=Park|author-link6=Samsung Medical Center|first7=Hearan|last7=Suh|author-link7=Seoul National University|first8=Jeong-a|last8=Kim|author-link8=Samsung Medical Center|first9=Jong-Sang|last9=Park|author-link9=Seoul National University|first10=Duk-Kyung|last10=Kim|doi=10.1038/emm.2002.37 |pmid=12515391 |author-link10=Samsung Medical Center|display-authors=3}}</ref>

In addition to ''[[in vitro]]'' applications, electroporation is employed ''in vivo'' to enhance cell membrane permeability during injections and surgical procedures. The effectiveness of ''in vivo'' electroporation depends greatly on selected parameters such as voltage, pulse duration, and number of pulses. Developing central [[Nervous system|nervous systems]] are particularly suitable for ''in vivo'' electroporation, as [[Ventricle (heart)|ventricles]] provide clear visibility for [[Cell nucleus|nucleic]] acid injections, and dividing cells exhibit increased [[Permeability (electromagnetism)|permeability]]. Electroporation of [[Embryo|embryos]] injected in utero is performed through the [[uterine wall]], often using [[forceps]]-type electrodes to minimize embryo damage.<ref>{{cite book | vauthors = Saito T |title=Guide to Techniques in Mouse Development, Part B: Mouse Molecular Genetics | edition = 2nd |chapter=Embryonic In Vivo Electroporation in the Mouse |date=2010 |chapter-url=https://linkinghub.elsevier.com/retrieve/pii/S0076687910770038 |series=Methods in Enzymology |volume=477 |pages=37–50 |publisher=Elsevier |language=en |doi=10.1016/s0076-6879(10)77003-8 |pmid=20699135 |isbn=978-0-12-384880-2 |access-date=2022-09-19}}</ref>

== History ==
Researchers in the 1960s discovered that applying an external [[electric field]] would create a large membrane potential at the two poles of a cell. In the 1970s, it was found that when a critical membrane potential is reached, the cellular membrane would break down and subsequently recover.<ref>{{Cite book |url=https://www.worldcat.org/oclc/817706277 |title=Guide to electroporation and electrofusion |date=1992 |publisher=Academic Press | vauthors = Chang DC |isbn=978-0-12-168041-1 |location=San Diego |oclc=817706277}}</ref> By the 1980s, this temporary membrane breakdown was exploited to introduce various molecules into cells.<ref name="neumann1982">{{cite journal | vauthors = Neumann E, Schaefer-Ridder M, Wang Y, Hofschneider PH | title = Gene transfer into mouse lyoma cells by electroporation in high electric fields | journal = The EMBO Journal | volume = 1 | issue = 7 | pages = 841–5 | date = 1982 | pmid = 6329708 | pmc = 553119 | doi = 10.1002/j.1460-2075.1982.tb01257.x}}</ref> 

''[[In vivo]]'' gene electroporation was first described in 1991.<ref name="pmid1703441">{{cite journal | vauthors = Titomirov AV, Sukharev S, Kistanova E | title = In vivo electroporation and stable transformation of skin cells of newborn mice by plasmid DNA | journal = Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression | volume = 1088 | issue = 1 | pages = 131–4 | date = January 1991 | pmid = 1703441 | doi = 10.1016/0167-4781(91)90162-F| url = https://zenodo.org/record/1258377}}</ref> This method delivers a large variety of [[therapeutic]] genes for the potential treatment of several diseases, including [[Immune disorder|immune disorders]], [[tumors]], [[Metabolic disorder|metabolic disorders]], monogenetic diseases, [[Cardiovascular disease|cardiovascular diseases]], and [[analgesia]].<ref name="heller2002">{{cite journal | vauthors = Heller LC, Coppola D | title = Electrically mediated delivery of vector plasmid DNA elicits an antitumor effect | journal = Gene Therapy | volume = 9 | issue = 19 | pages = 1321–5 | date = October 2002 | pmid = 12224015 | doi = 10.1038/sj.gt.3301802 | doi-access = free }}</ref><ref name="chuang2004">{{cite journal | vauthors = Chuang IC, Jhao CM, Yang CH, Chang HC, Wang CW, Lu CY, Chang YJ, Lin SH, Huang PL, Yang LC | title = Intramuscular electroporation with the pro-opiomelanocortin gene in rat adjuvant arthritis | journal = Arthritis Research & Therapy | volume = 6 | issue = 1 | pages = R7–R14 | date = 2004 | pmid = 14979933 | pmc = 400409 | doi = 10.1186/ar1014 | doi-access = free }}</ref><ref name="vilquin2001">{{cite journal | vauthors = Vilquin JT, Kennel PF, Paturneau-Jouas M, Chapdelaine P, Boissel N, Delaère P, Tremblay JP, Scherman D, Fiszman MY, Schwartz K | s2cid = 1081582 | title = Electrotransfer of naked DNA in the skeletal muscles of animal models of muscular dystrophies | journal = Gene Therapy | volume = 8 | issue = 14 | pages = 1097–107 | date = July 2001 | pmid = 11526457 | doi = 10.1038/sj.gt.3301484 }}</ref>

Regarding irreversible electroporation, the first successful treatment of malignant [[cutaneous]] tumors implanted in mice was accomplished in 2007 by a group of scientists who achieved complete tumor [[ablation]] in 12 of 13 mice. They accomplished this by sending 80 pulses of 100 [[Microsecond|microseconds]] at 0.3 Hz with an electrical field magnitude of 2500 V/cm to treat the cutaneous tumors.<ref>{{cite journal | vauthors = Al-Sakere B, André F, Bernat C, Connault E, Opolon P, Davalos RV, Rubinsky B, Mir LM | title = Tumor ablation with irreversible electroporation | journal = PLOS ONE | volume = 2 | issue = 11 | pages = e1135 | date = November 2007 | pmid = 17989772 | pmc = 2065844 | doi = 10.1371/journal.pone.0001135 | bibcode = 2007PLoSO...2.1135A | doi-access = free }}</ref>

The first group to apply electroporation used a reversible procedure in conjunction with [[impermeable]] [[Macromolecule|macromolecules]]. The first research on how [[nanosecond]] pulses might be used on human cells was published in 2003.<ref>{{cite journal | vauthors = Beebe SJ, Fox PM, Rec LJ, Willis EL, Schoenbach KH | s2cid = 13189517 | title = Nanosecond, high-intensity pulsed electric fields induce apoptosis in human cells | journal = FASEB Journal | volume = 17 | issue = 11 | pages = 1493–5 | date = August 2003 | pmid = 12824299 | doi = 10.1096/fj.02-0859fje | doi-access = free }}</ref>

==Medical applications==
{{Main|Irreversible electroporation}}

The first medical application of electroporation was used for introducing poorly permeant anti-cancer drugs into tumor nodules.<ref name="pmid1723647">{{cite journal | vauthors = Mir LM, Belehradek M, Domenge C, Orlowski S, Poddevin B, Belehradek J, Schwaab G, Luboinski B, Paoletti C | title = [Electrochemotherapy, a new antitumor treatment: first clinical trial] | language = fr | journal = Comptes Rendus de l'Académie des Sciences, Série III  | volume = 313 | issue = 13 | pages = 613–8 | date = 1991 | pmid = 1723647 }}</ref> Gene electro-transfer soon became of interest because of its low cost, ease of implementation, and alleged safety. Viral vectors have since been found to have limitations in terms of immunogenicity and pathogenicity when used for DNA transfer.<ref name="pmid10636774">{{cite journal | vauthors = Marshall E | s2cid = 46362535 | title = Gene therapy death prompts review of adenovirus vector | journal = Science | volume = 286 | issue = 5448 | pages = 2244–5 | date = December 1999 | pmid = 10636774 | doi = 10.1126/science.286.5448.2244}}</ref>

[[Irreversible electroporation]] is being used and evaluated as [[Catheter ablation|cardiac ablation therapy]] to kill specific areas of heart muscle. This is done to treat [[Cardiac arrhythmia|irregularities of heart rhythm]]. A [[Cardiac catheterization|cardiac catheter]] delivers trains of high-voltage, ultra-rapid electrical pulses that form irreversible pores in cell membranes, resulting in cell death.<ref name="Tabaja_2023">{{cite journal |vauthors=Tabaja C, Younis A, Hussein AA, Taigen TL, Nakagawa H, Saliba WI, Sroubek J, Santangeli P, Wazni OM |date=September 2023 |title=Catheter-Based Electroporation: A Novel Technique for Catheter Ablation of Cardiac Arrhythmias |journal=JACC. Clinical Electrophysiology |volume=9 |issue=9 |pages=2008–2023 |doi=10.1016/j.jacep.2023.03.014 |pmid=37354168}}</ref>

===N-TIRE===
Non-thermal irreversible electroporation (N-TIRE) is a technique that treats many different types of tumors and other unwanted tissue. This procedure is done using small electrodes (about 1mm in diameter), placed either inside or surrounding the target tissue to apply short, repetitive bursts of electricity at a predetermined voltage and frequency. These bursts of electricity increase the resting transmembrane potential (TMP) so that nanopores form in the plasma membrane. When the electricity applied to the tissue is above the electric field threshold of the target tissue, the cells become permanently permeable from the formation of nanopores. As a result, the cells are unable to repair the damage and die due to a loss of homeostasis.<ref>{{cite book | vauthors = Garcia PA, Rossmeisl JH, Davalos RV | title = 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society | chapter = Electrical conductivity changes during irreversible electroporation treatment of brain cancer | s2cid = 4953213 | volume = 2011 | pages = 739–42 | year = 2011 | pmid = 22254416 | doi = 10.1109/IEMBS.2011.6090168 | isbn = 978-1-4577-1589-1 }}</ref> N-TIRE is unique to other tumor ablation techniques in that it does not create thermal damage to the tissue around it.

===Reversible electroporation===
In contrast, reversible electroporation occurs when the electricity applied with the [[Electrode|electrodes]] is below the target tissue's electric field threshold. Because the electricity applied is below the cells' threshold, it allows the cells to repair their [[phospholipid bilayer]] and continue with their normal cell functions. Reversible electroporation is typically done with treatments that involve inserting a drug or gene (or other molecule that is not normally permeable to the cell membrane) into the cell. Not all tissues have the same electric field threshold; therefore, to improve safety and efficacy, careful calculations need to be made prior to a treatment.<ref>{{cite book | vauthors = Garcia PA, Neal RE, Rossmeisl JH, Davalos RV | title = 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology | chapter = Non-thermal irreversible electroporation for deep intracranial disorders | s2cid = 9589956 | volume = 2010 | pages = 2743–6 | year = 2010 | pmid = 21095962 | doi = 10.1109/IEMBS.2010.5626371 | isbn = 978-1-4244-4123-5 }}</ref>

N-TIRE, when done correctly, only affects the target tissue. Proteins, the extracellular matrix, and critical structures such as blood vessels and nerves are all unaffected and left healthy by this treatment. This facilitates a more rapid replacement of dead tumor cells and a faster recovery.<ref>{{cite journal | vauthors = Garcia PA, Rossmeisl JH, Neal RE, Ellis TL, Olson JD, Henao-Guerrero N, Robertson J, Davalos RV | s2cid = 10958480 | title = Intracranial nonthermal irreversible electroporation: in vivo analysis | journal = The Journal of Membrane Biology | volume = 236 | issue = 1 | pages = 127–36 | date = July 2010 | pmid = 20668843 | doi = 10.1007/s00232-010-9284-z | citeseerx = 10.1.1.679.527 }}</ref>

Imaging technology such as [[CT scan|CT scans]] and [[Magnetic resonance imaging|MRIs]] are commonly used to create a 3D image of the tumor. Computed tomography is used to help with the placement of electrodes during the procedure, particularly when the electrodes are being used to treat tumors in the brain.<ref>{{cite book | vauthors = Neal RE, Garcia PA, Rossmeisl JH, Davalos RV | title = 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology | chapter = A study using irreversible electroporation to treat large, irregular tumors in a canine patient | s2cid = 24348785 | volume = 2010 | pages = 2747–50 | year = 2010 | pmid = 21095963 | doi = 10.1109/IEMBS.2010.5626372 | isbn = 978-1-4244-4123-5 }}</ref>

The procedure takes five minutes with a high success rate.<ref name = "Potter_2003" /> It may be used for future treatment in humans. One disadvantage of using N-TIRE is that the electricity delivered from the electrodes can stimulate muscle cells to contract, which could have lethal consequences, depending on the situation. Therefore, a paralytic agent must be used when performing the procedure. The paralytic agents that have been used in such research have risks<ref>{{Cite journal |last1=Deipolyi |first1=Amy R |last2=Golberg |first2=Alexander |last3=Yarmush |first3=Martin L |author-link3=Martin Yarmush |last4=Arellano |first4=Ronald S |last5=Oklu |first5=Rahmi |date=October 1, 2014 |title=Irreversible electroporation: evolution of a laboratory technique in interventional oncology |journal=Diagnostic and Interventional Radiology |volume=20 |issue=2 |pages=147–154 |doi=10.5152/dir.2013.13304 |pmc=4463294 |pmid=24412820 |doi-access=free}}</ref> when using anesthetics.

===H-FIRE===
High-frequency irreversible electroporation (H-FIRE) uses electrodes to apply bipolar bursts of electricity at a high frequency, as opposed to unipolar bursts of electricity at a low frequency. This type of procedure has the same tumor ablation success as N-TIRE. However, it has one distinct advantage: H-FIRE does not cause muscle contraction in the patient, and therefore, there is no need for a paralytic agent.<ref>{{cite journal | vauthors = Arena CB, Sano MB, Rossmeisl JH, Caldwell JL, Garcia PA, Rylander MN, Davalos RV | title = High-frequency irreversible electroporation (H-FIRE) for non-thermal ablation without muscle contraction | journal = BioMedical Engineering OnLine | volume = 10 | pages = 102 | date = November 2011 | pmid = 22104372 | pmc = 3258292 | doi = 10.1186/1475-925X-10-102 | doi-access = free }}</ref> Furthermore, H-FIRE has been demonstrated to produce more predictable ablations due to the lesser difference in the electrical properties of tissues at higher frequencies.<ref>{{cite journal | vauthors = Bhonsle SP, Arena CB, Sweeney DC, Davalos RV | title = Mitigation of impedance changes due to electroporation therapy using bursts of high-frequency bipolar pulses | journal = BioMedical Engineering OnLine | volume = 13 | pages = S3 | date = 27 August 2015 | issue = Suppl 3 | pmid = 26355870 | pmc =4565149 | doi = 10.1186/1475-925X-14-S3-S3 | doi-access = free }}</ref>

=== Drug and gene delivery ===
{{Further|Electrochemotherapy|gene electrotransfer}}
Electroporation can also be used to help deliver drugs or genes into the cell by applying short and intense electric pulses that transiently permeabilize cell membrane, thus allowing the transport of molecules otherwise not transported through a cellular membrane. This procedure is referred to as [[electrochemotherapy]] when the molecules to be transported are chemotherapeutic agents or [[gene electrotransfer]] when the molecule to be transported is DNA. Scientists from [[Karolinska Institute]] and the [[University of Oxford]] use electroporation of [[Exosome complex|exosomes]] to deliver [[SiRNA|siRNAs]], antisense oligonucleotides, chemotherapeutic agents, and proteins specifically to neurons after injecting them systemically (in blood). Because these exosomes can cross the [[blood brain barrier|blood-brain barrier]], this protocol could solve the problem of poor delivery of medications to the central nervous system and may potentially treat [[Alzheimer's disease]], [[Parkinson's disease]], and [[brain cancer]], among other conditions.<ref name="five2">{{cite journal | vauthors = El-Andaloussi S, Lee Y, Lakhal-Littleton S, Li J, Seow Y, Gardiner C, Alvarez-Erviti L, Sargent IL, Wood MJ | s2cid = 34413410 | title = Exosome-mediated delivery of siRNA in vitro and in vivo | journal = Nature Protocols | volume = 7 | issue = 12 | pages = 2112–26 | date = December 2012 | pmid = 23154783 | doi = 10.1038/nprot.2012.131 }}</ref>

Research has shown that shock waves could be used for pre-treating the cell membrane prior to electroporation.<ref>{{Cite journal| vauthors = Hu Q, Hossain S, Joshi RP |date=2018-06-25|title=Analysis of a dual shock-wave and ultrashort electric pulsing strategy for electro-manipulation of membrane nanopores|url=https://iopscience.iop.org/article/10.1088/1361-6463/aaca7a|journal=Journal of Physics D: Applied Physics|volume=51|issue=28|pages=285403|doi=10.1088/1361-6463/aaca7a|bibcode=2018JPhD...51B5403H|s2cid=125134522|issn=0022-3727}}</ref><ref>{{cite journal | vauthors = Hossain S, Abdelgawad A | title = Analysis of membrane permeability due to synergistic effect of controlled shock wave and electric field application | journal = Electromagnetic Biology and Medicine | volume = 39 | issue = 1 | pages = 20–29 | date = 2020-01-02 | pmid = 31868023 | doi = 10.1080/15368378.2019.1706553 | s2cid = 209446699 }}</ref> This synergistic strategy has shown to reduce external voltage requirement and create larger pores. Also, application of shock waves allow scope to target desired membrane site. This procedure allows to control the size of the pore.

==Physical mechanism==
[[Image:Pore schematic.svg|right|thumb|250px|Schematic cross-section showing the theoretical arrangement of lipids in a hydrophobic pore (top) and a hydrophilic pore (bottom).]]
{{further|Lipid bilayer mechanics}}
Electroporation allows cellular introduction of large highly charged molecules, such as [[DNA]], that cannot passively diffuse across the hydrophobic [[lipid bilayer|bilayer]] core.<ref name="pmid6329708">{{cite journal |vauthors=Neumann E, Schaefer-Ridder M, Wang Y, Hofschneider PH |year=1982 |title=Gene transfer into mouse lyoma cells by electroporation in high electric fields |journal=The EMBO Journal |volume=1 |issue=7 |pages=841–845 |doi=10.1002/j.1460-2075.1982.tb01257.x |pmc=553119 |pmid=6329708}}</ref> This phenomenon indicates that the mechanism is the creation of nm-scale water-filled holes in the membrane.<ref name="chang1990">{{cite journal | vauthors = Chang DC, Reese TS | title = Changes in membrane structure induced by electroporation as revealed by rapid-freezing electron microscopy | journal = Biophysical Journal | volume = 58 | issue = 1 | pages = 1–12 | date = July 1990 | pmid = 2383626 | pmc = 1280935 | doi = 10.1016/S0006-3495(90)82348-1 | bibcode = 1990BpJ....58....1C }}</ref> Electropores were optically imaged in lipid bilayer models like droplet interface bilayers<ref>{{cite journal | vauthors = Sengel JT, Wallace MI | title = Imaging the dynamics of individual electropores | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 113 | issue = 19 | pages = 5281–5286 | date = May 2016 | pmid = 27114528 | pmc = 4868429 | doi = 10.1073/pnas.1517437113 | doi-access = free | bibcode = 2016PNAS..113.5281S }}</ref> and giant unilamellar vesicles,<ref>{{cite journal | vauthors = Sachdev S, Muralidharan A, Choudhary DK, Perrier DL, Rems L, Kreutzer MT, Boukany PE | title = DNA translocation to giant unilamellar vesicles during electroporation is independent of DNA size | journal = Soft Matter | volume = 15 | issue = 45 | pages = 9187–9194 | date = December 2019 | pmid = 31595286 | doi = 10.1039/C9SM01274E | hdl-access = free | doi-access = free | bibcode = 2019SMat...15.9187S | hdl = 1887/85963 }}</ref> while addition of cytoskeleton proteins such as actin networks to the giant unilamellar vesicles seem to prevent the formation of visible electropores.<ref>{{cite journal | vauthors = Perrier DL, Vahid A, Kathavi V, Stam L, Rems L, Mulla Y, Muralidharan A, Koenderink GH, Kreutzer MT, Boukany PE | title = Response of an actin network in vesicles under electric pulses | journal = Scientific Reports | volume = 9 | issue = 1 | pages = 8151 | date = May 2019 | pmid = 31148577 | pmc = 6544639 | doi = 10.1038/s41598-019-44613-5 | author8-link = Gijsje Koenderink | bibcode = 2019NatSR...9.8151P }}</ref> Experimental evidences for actin networks in regulating the cell membrane permeability has also emerged.<ref>{{cite journal | vauthors = Muralidharan A, Rems L, Kreutzer MT, Boukany PE | title = Actin networks regulate the cell membrane permeability during electroporation | journal = Biochimica et Biophysica Acta (BBA) - Biomembranes | volume = 1863 | issue = 1 | pages = 183468 | date = January 2021 | pmid = 32882211 | doi = 10.1016/j.bbamem.2020.183468 | doi-access = free }}</ref> Although electroporation and [[dielectric breakdown]] both result from application of an electric field, the mechanisms involved are fundamentally different. In dielectric breakdown the barrier material is ionized, creating a conductive pathway. The material alteration is thus chemical in nature. In contrast, during electroporation the lipid molecules are not chemically altered but simply shift position, opening up a pore which acts as the conductive pathway through the bilayer as it is filled with water.

Electroporation is a dynamic phenomenon that depends on the local transmembrane voltage at each point on the cell membrane. It is generally accepted that for a given pulse duration and shape, a specific transmembrane voltage threshold exists for the manifestation of the electroporation phenomenon (from 0.5 V to 1 V). This leads to the definition of an electric field magnitude threshold for electroporation (E<sub>th</sub>). That is, only the cells within areas where E≧E<sub>th</sub> are electroporated. If a second threshold (E<sub>ir</sub>) is reached or surpassed, electroporation will compromise the viability of the cells, ''i.e.'', irreversible electroporation (IRE).<ref>{{cite web |url=http://www.freshpatents.com/Gels-with-predetermined-conductivity-used-in-electroporation-of-tissue-dt20080904ptan20080214986.php |title=Gels with predetermined conductivity used in electroporation of tissue USPTO Application #: 20080214986 — Class: 604 21 (USPTO) | vauthors = Ivorra A, Rubinsky B |access-date=2008-11-21 |archive-url=https://web.archive.org/web/20141022224315/http://www.freshpatents.com/Gels-with-predetermined-conductivity-used-in-electroporation-of-tissue-dt20080904ptan20080214986.php |archive-date=2014-10-22 |url-status=dead }}</ref>

Electroporation is a process with several distinct phases.<ref name="Weaver1996">{{cite journal | vauthors = Ho SY, Mittal GS | title = Electroporation of cell membranes: a review | journal = Critical Reviews in Biotechnology | volume = 16 | issue = 4 | pages = 349–62 | year = 1996 | pmid = 8989868 | doi = 10.3109/07388559609147426 }}</ref><ref name="Scuderi12022">{{cite journal | vauthors = Scuderi M, Dermol-Cerne J, Amaral C, Muralidharan A, Boukany PE, Rems L| title = Models of electroporation and the associated transmembrane molecular transport should be revisited | journal = Bioelectrochemistry | volume = 147| pages = 108216 | year = 2022 | doi = 10.1016/j.bioelechem.2022.108216| pmid = 35932533 | doi-access = free }}</ref> First, a short electrical pulse is applied. Typical parameters would be 300–400 mV for &lt; 1 ms across the membrane (note- the voltages used in cell experiments are typically much larger because they are being applied across large distances to the bulk solution so the resulting field across the actual membrane is only a small fraction of the applied bias). Application of this potential causes migration of ions from the surrounding solution to the membrane which charges like a [[capacitor]].  Rapid localized rearrangements in lipid morphology occur once the critical level is achieved. The resulting structure is believed to be a "pre-pore" since it is not electrically conductive but leads rapidly to the creation of a conductive pore.<ref>{{cite journal | vauthors = Becker SM, Kuznetsov AV | title = Local temperature rises influence in vivo electroporation pore development: a numerical stratum corneum lipid phase transition model | journal = Journal of Biomechanical Engineering | volume = 129 | issue = 5 | pages = 712–21 | date = October 2007 | pmid = 17887897 | doi = 10.1115/1.2768380 }}</ref> Evidence for the existence of such pre-pores comes mostly from the "flickering" of pores, which suggests a transition between conductive and insulating states.<ref name="Melikov2001">{{cite journal | vauthors = Melikov KC, Frolov VA, Shcherbakov A, Samsonov AV, Chizmadzhev YA, Chernomordik LV | title = Voltage-induced nonconductive pre-pores and metastable single pores in unmodified planar lipid bilayer | journal = Biophysical Journal | volume = 80 | issue = 4 | pages = 1829–36 | date = April 2001 | pmid = 11259296 | pmc = 1301372 | doi = 10.1016/S0006-3495(01)76153-X | bibcode = 2001BpJ....80.1829M }}</ref> It has been suggested that these pre-pores are small (~3 Å) hydrophobic defects. If this theory is correct, then the transition to a conductive state could be explained by a rearrangement at the pore edge, in which the lipid heads fold over to create a hydrophilic interface.{{Cn|date=April 2025}} Finally, these conductive pores can either heal, resealing the bilayer or expand, eventually rupturing it. The resultant fate depends on whether the critical defect size was exceeded<ref name="Joshi2000">{{cite journal | vauthors = Joshi RP, Schoenbach KH | title = Electroporation dynamics in biological cells subjected to ultrafast electrical pulses: a numerical simulation study | journal = Physical Review E | volume = 62 | issue = 1 Pt B | pages = 1025–33 | date = July 2000 | pmid = 11088559 | doi = 10.1103/PhysRevE.62.1025 | bibcode = 2000PhRvE..62.1025J | url = https://digitalcommons.odu.edu/bioelectrics_pubs/254 }}</ref> which in turn depends on the applied field, local mechanical stress and bilayer edge energy.

=== Gene electroporation ===
[[Image:Electrogenetransfer.JPG|thumb|500x500px]]
Application of electric pulses of sufficient strength to the cell causes an increase in the trans-membrane potential difference, which provokes the membrane destabilization. Cell membrane permeability is increased, and otherwise non-permeant molecules enter the cell.<ref name="kotnik2000">{{cite journal | vauthors = Kotnik T, Miklavcic D | title = Analytical description of transmembrane voltage induced by electric fields on spheroidal cells | journal = Biophysical Journal | volume = 79 | issue = 2 | pages = 670–679 | date = August 2000 | pmid = 10920001 | pmc = 1300967 | doi = 10.1016/S0006-3495(00)76325-9 | bibcode = 2000BpJ....79..670K }}</ref><ref name="sweeney2018">{{cite journal | vauthors = Sweeney DC, Weaver JC, Davalos RV | title = Characterization of Cell Membrane Permeability In Vitro Part I: Transport Behavior Induced by Single-Pulse Electric Fields | journal = Technology in Cancer Research & Treatment | volume = 17 | pages = 1533033818792491 | date = January 2018 | pmid = 30236040 | pmc = 6154305 | doi = 10.1177/1533033818792491 }}</ref> Although the mechanisms of gene electrotransfer are not yet fully understood, it was shown that the introduction of DNA only occurs in the part of the membrane facing the cathode and that several steps are needed for successful transfection: electrophoretic migration of DNA towards the cell, DNA insertion into the membrane, translocation across the  spoke membrane, migration of DNA towards the nucleus, transfer of DNA across the nuclear envelope and finally gene expression.<ref name="satkauskas2002">{{cite journal | vauthors = Satkauskas S, Bureau MF, Puc M, Mahfoudi A, Scherman D, Miklavcic D, Mir LM | title = Mechanisms of in vivo DNA electrotransfer: respective contributions of cell electropermeabilization and DNA electrophoresis | journal = Molecular Therapy | volume = 5 | issue = 2 | pages = 133–40 | date = February 2002 | pmid = 11829520 | doi = 10.1006/mthe.2002.0526 | doi-access = free }}</ref> There are a number of factors that can influence the efficiency of gene electrotransfer, such as: temperature, parameters of electric pulses, DNA concentration, electroporation buffer used, cell size and the ability of cells to express transfected genes.<ref name="gehl2003">{{cite journal | vauthors = Gehl J | s2cid = 16742681 | title = Electroporation: theory and methods, perspectives for drug delivery, gene therapy and research | journal = Acta Physiologica Scandinavica | volume = 177 | issue = 4 | pages = 437–47 | date = April 2003 | pmid = 12648161 | doi = 10.1046/j.1365-201X.2003.01093.x }}</ref> In ''[[in vivo]]'' gene electrotransfer, DNA diffusion through extracellular matrix, properties of tissue, and overall tissue conductivity may be crucial.<ref name="miklavcic1998">{{cite journal | vauthors = Miklavcic D, Beravs K, Semrov D, Cemazar M, Demsar F, Sersa G | title = The importance of electric field distribution for effective in vivo electroporation of tissues | journal = Biophysical Journal | volume = 74 | issue = 5 | pages = 2152–8 | date = May 1998 | pmid = 9591642 | pmc = 1299558 | doi = 10.1016/S0006-3495(98)77924-X | bibcode = 1998BpJ....74.2152M }}</ref>

== References ==
{{Reflist}}

{{Genetic engineering}}
{{Authority control}}

[[Category:Biotechnology]]
[[Category:Microbiology]]
[[Category:Molecular biology]]
[[Category:Gene delivery]]
[[Category:Laboratory techniques]]