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Silkunas M, Silkuniene G, Pakhomov AG. Real-time imaging of individual electropores proves their longevity in cells. Biochem Biophys Res Commun 2024; 695:149408. [PMID: 38157631 PMCID: PMC10842338 DOI: 10.1016/j.bbrc.2023.149408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 12/18/2023] [Indexed: 01/03/2024]
Abstract
With over 50 years of electroporation research, the nature of cell membrane permeabilization remains elusive. The lifetime of electropores in molecular models is limited to nano- or microseconds, whereas the permeabilization of electroporated cells can last minutes. This study aimed at resolving a longstanding debate on whether the prolonged permeabilization is due to the formation of long-lived pores in cells. We developed a method for dynamic monitoring and conductance measurements of individual electropores. This was accomplished by time-lapse total internal reflection fluorescence (TIRF) imaging in HEK cells loaded with CAL-520 dye and placed on an indium tin oxide (ITO) surface. Applying a 1-ms, 0 to -400 mV pulse between the patch pipette and ITO evoked focal Ca2+ transients that identified individual electropores. Some transients disappeared in milliseconds but others persisted for over a minute. Persistent transients ("Ca2+ plumes") faded over time to a stable or a randomly fluctuating level that could include periods of full quiescence. Single pore conductance, measured by 0 to -50 mV, 50 ms steps at 30 and 60 s after the electroporation, ranged from 80 to 200 pS. These experiments proved electropore longevity in cells, in stark contrast to molecular simulations and many findings in lipid bilayers.
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Affiliation(s)
- Mantas Silkunas
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA; Institute for Digestive System Research, Lithuanian University of Health Sciences, 44307, Kaunas, Lithuania
| | - Giedre Silkuniene
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA; Institute for Digestive System Research, Lithuanian University of Health Sciences, 44307, Kaunas, Lithuania
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA.
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2
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Ángeles-Robles G, Ortiz-Dosal LC, Aranda-Espinoza H, Olivares-Illana V, Arauz-Lara JL, Aranda-Espinoza S. Actin protein inside DMPC GUVs and its mechanical response to AC electric fields. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183883. [PMID: 35181295 DOI: 10.1016/j.bbamem.2022.183883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/10/2022] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Cells are dynamic systems with complex mechanical properties, regulated by the presence of different species of proteins capable to assemble (and disassemble) into filamentous forms as required by different cells functions. Giant unilamellar vesicles (GUVs) of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) are systems frequently used as a simplified model of cells because they offer the possibility of assaying separately different stimuli, which is no possible in living cells. Here we present a study of the effect of acting protein on mechanical properties of GUVs, when the protein is inside the vesicles in either monomeric G-actin or filamentous F-actin. For this, rabbit skeletal muscle G-actin is introduced inside GUVs by the electroformation method. Protein polymerization inside the GUVs is promoted by adding to the solution MgCl2 and the ion carrier A23187 to allow the transport of Mg+2 ions into the GUVs. To determine how the presence of actin changes the mechanical properties of GUVs, the vesicles are deformed by the application of an AC electric field in both cases with G-actin and with polymerized F-actin. The changes in shape of the vesicles are characterized by optical microscopy and from them the bending stiffness of the membrane are determined. It is found that G-actin has no appreciable effect on the bending stiffness of DMPC GUVs, but the polymerized actin makes the vesicles more rigid and therefore more resistant to deformations. This result is supported by evidence that actin filaments tend to accumulate near the membrane.
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Affiliation(s)
- Gabriela Ángeles-Robles
- Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, S. L. P., Mexico
| | - Luis Carlos Ortiz-Dosal
- Unidad Académica de Ingeniería I, Universidad Autónoma de Zacatecas, Zacatecas, Zac., Mexico
| | - H Aranda-Espinoza
- Fischell Department of Bioengineering, University of Maryland, College Park, United States of America
| | - Vanesa Olivares-Illana
- Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, S. L. P., Mexico
| | - José Luis Arauz-Lara
- Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, S. L. P., Mexico
| | - S Aranda-Espinoza
- Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, S. L. P., Mexico.
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3
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Kramar P, Miklavčič D. Effect of the cholesterol on electroporation of planar lipid bilayer. Bioelectrochemistry 2022; 144:108004. [PMID: 34864271 DOI: 10.1016/j.bioelechem.2021.108004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 11/18/2021] [Accepted: 11/21/2021] [Indexed: 11/21/2022]
Abstract
Electroporation threshold depends on the membrane composition, with cholesterol being one of its key components already studied in the past, but the results were inconclusive. The aim of our study was to determine behaviour of planar lipid bilayers with varying cholesterol concentrations under electric field. This would give us a better insight into cholesterol effect on membrane properties during electroporation process, since cholesterol is one of the major components of biological membranes and plays a crucial role in membrane organisation, dynamics, and function. Planar lipid bilayers were prepared from phosphatidylcholine lipids with 0, 20, 30, 50 and 80 mol% cholesterol. Capacitance was measured using the discharge method. Results show no statistical difference of cBLM between the cholesterol concentrations. Breakdown voltage Ubr of planar lipid bilayers was measured by means of linear rising voltage with seven different slopes. Obtained results were fitted to a strength-duration curve, where parameter Ubrmin represents minimal breakdown voltage, and parameter τRC represents the inclination of the strength-duration curve. Adding cholesterol to planar lipid bilayer gradually increased its Ubrmin until 50 mol% cholesterol concentration. Afterwards at 80 mol% Ubrmin does not further increase, in fact it reduces by 20% of the Ubrmin at 50 mol% cholesterol concentration.
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Affiliation(s)
- Peter Kramar
- University of Ljubljana, Faculty of Electrical Engineering, Slovenia.
| | - Damijan Miklavčič
- University of Ljubljana, Faculty of Electrical Engineering, Slovenia
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4
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Ultrastructural changes in hepatocellular carcinoma cells induced by exponential pulses of nanosecond duration delivered via a transmission line. Bioelectrochemistry 2020; 135:107548. [PMID: 32408094 DOI: 10.1016/j.bioelechem.2020.107548] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 04/30/2020] [Accepted: 04/30/2020] [Indexed: 12/21/2022]
Abstract
Clinical applications of high-intensity pulsed electric fields have proven useful in ablating solid tumors. However, novel ideas for the development of an effective tumor ablation device are urgently needed. Here, we studied cellular effects of the nanosecond exponential pulse, which is generated by a capacitor-discharging circuit and delivered via a transmission line. Pulses of peak voltage boosted by transmission line oscillation possess high capability to induce swelling and to cause loss of viability in cells. The appropriate parameter of the pulse was selected to investigate the ultrastructural changes in swollen cells, which present smoothened plasma membrane, loss of microvilli, and lowered cytoplasm electron density. We propose the equivalent force field hypothesis to understand the mechanism underlying cell swelling induced by pulsing. Wrinkles on the plasma membrane might indicate recovery from cell swelling, and this was verified by co-culture of pulsed PKH26-Cells with sham-treated PKH67-Cells. We concluded that the ultrastructural changes, such as irregular pores formed on the plasma membrane, were mainly induced by the effect of electric pulse applied on the charged molecules in the membrane.
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Stewart S, He X. Intracellular Delivery of Trehalose for Cell Banking. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7414-7422. [PMID: 30078320 PMCID: PMC6382607 DOI: 10.1021/acs.langmuir.8b02015] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Advances in stem cell technology and regenerative medicine have underscored the need for effective banking of living cells. Cryopreservation, using very low temperatures to achieve suspended animation, is widely used to store or bank cells for later use. This process requires the use of cryoprotective agents (CPAs) to protect cells against damage caused by the cooling and warming process. However, current popular CPAs like DMSO can be toxic to cells and must be thoroughly removed from cells before they can be used for research or clinical applications. Trehalose, a nontoxic sugar found in organisms capable of withstanding extreme cold or desiccation, has been explored as an alternative CPA. The disaccharide must be present on both sides of the cellular membrane to provide cryo-protection. However, trehalose is not synthesized by mammalian cells nor has the capability to diffuse through their plasma membranes. Therefore, it is crucial to achieve intracellular delivery of trehalose for utilizing the full potential of the sugar for cell banking. In this review, various methods that have been explored to deliver trehalose into mammalian cells for their banking at both cryogenic and ambient temperatures are surveyed. Among them, the nanoparticle-mediated approach is particularly exciting. Collectively, studies in the literature demonstrate the great potential of using trehalose as the sole CPA for cell banking, to facilitate the widespread use of living cells in modern medicine.
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Affiliation(s)
| | - Xiaoming He
- Correspondence should be addressed to: Xiaoming He, Ph.D., Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States.,
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Ruzgys P, Jakutavičiūtė M, Šatkauskienė I, Čepurnienė K, Šatkauskas S. Effect of electroporation medium conductivity on exogenous molecule transfer to cells in vitro. Sci Rep 2019; 9:1436. [PMID: 30723286 PMCID: PMC6363740 DOI: 10.1038/s41598-018-38287-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 12/21/2018] [Indexed: 12/02/2022] Open
Abstract
In this study we evaluated the influence of medium conductivity to propidium iodide (PI) and bleomycin (BLM) electroporation mediated transfer to cells. Inverse dependency between the extracellular conductivity and the efficiency of the transfer had been found. Using 1 high voltage (HV) pulse, the total molecule transfer efficiency decreased 4.67 times when external medium conductivity increased from 0.1 to 0.9 S/m. Similar results had been found using 2 HV and 3 HV pulses. The percentage of cells killed by BLM electroporation mediated transfer had also decreased with the conductivity increase, from 79% killed cells in 0.1 S/m conductivity medium to 28% killed cells in 0.9 S/m conductivity medium. We hypothesize that the effect of external medium conductivity on electroporation mediated transfer is triggered by cell deformation during electric field application. In high conductivity external medium cell assumes oblate shape, which causes a change of voltage distribution on the cell membrane, leading to lower electric field induced transmembrane potential. On the contrary, low conductivity external medium leads to prolate cell shape and increased transmembrane potential at the electrode facing cell poles.
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Affiliation(s)
- Paulius Ruzgys
- Vytautas Magnus University, Faculty of Natural Sciences, Vileikos 8, Kaunas, Lithuania
| | - Milda Jakutavičiūtė
- Vytautas Magnus University, Faculty of Natural Sciences, Vileikos 8, Kaunas, Lithuania
| | - Ingrida Šatkauskienė
- Vytautas Magnus University, Faculty of Natural Sciences, Vileikos 8, Kaunas, Lithuania
| | - Karolina Čepurnienė
- Vytautas Magnus University, Faculty of Natural Sciences, Vileikos 8, Kaunas, Lithuania
| | - Saulius Šatkauskas
- Vytautas Magnus University, Faculty of Natural Sciences, Vileikos 8, Kaunas, Lithuania.
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Morotomi-Yano K, Yano KI. Calcium-dependent activation of transglutaminase 2 by nanosecond pulsed electric fields. FEBS Open Bio 2017; 7:934-943. [PMID: 28680807 PMCID: PMC5494297 DOI: 10.1002/2211-5463.12227] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 04/06/2017] [Indexed: 12/17/2022] Open
Abstract
Exposure of cultured human cells to nanosecond pulsed electric fields (nsPEFs) elicits various cellular events, including Ca2+ influx and cell death. Recently, nsPEFs have been regarded as a novel physical treatment useful for biology and medicine, but the underlying mechanism of action remains to be fully elucidated. In this study, we investigated the effect of nsPEFs on transglutaminases (TGs), enzymes that catalyze covalent protein modifications such as protein-protein crosslinking. Cellular TG activity was monitored by conjugation of cellular proteins with biotin-cadaverine, a cell-permeable pseudosubstrate for TGs. We applied nsPEFs to HeLa S3 cells and found that overall catalytic activity of cellular TGs was greatly increased in a Ca2+-dependent manner. The Ca2+ ionophore ionomycin significantly augmented nsPEF-induced TG activation, further supporting the importance of Ca2+. Among human TG family members, TG2 is known to be the most ubiquitously expressed, and its catalytic activity requires elevated intracellular Ca2+. Given the requirement of Ca2+ for TG activation by nsPEFs, we performed depletion of TG2 by RNA interference (RNAi). We observed that TG2 RNAi suppressed the nsPEF-induced TG activation and partially alleviated the cytotoxic effects of nsPEFs. These findings demonstrate that TG2 activation is a Ca2+-dependent event in nsPEF-exposed cells and exerts negative effects on cell physiology.
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Affiliation(s)
- Keiko Morotomi-Yano
- Department of Bioelectrics Institute of Pulsed Power Science Kumamoto University Japan
| | - Ken-Ichi Yano
- Department of Bioelectrics Institute of Pulsed Power Science Kumamoto University Japan
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Sözer EB, Pocetti CF, Vernier PT. Asymmetric Patterns of Small Molecule Transport After Nanosecond and Microsecond Electropermeabilization. J Membr Biol 2017; 251:197-210. [PMID: 28484798 PMCID: PMC5910485 DOI: 10.1007/s00232-017-9962-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 05/03/2017] [Indexed: 02/02/2023]
Abstract
Imaging of fluorescent small molecule transport into electropermeabilized cells reveals polarized patterns of entry, which must reflect in some way the mechanisms of the migration of these molecules across the compromised membrane barrier. In some reports, transport occurs primarily across the areas of the membrane nearest the positive electrode (anode), but in others cathode-facing entry dominates. Here we compare YO-PRO-1, propidium, and calcein uptake into U-937 cells after nanosecond (6 ns) and microsecond (220 µs) electric pulse exposures. Each of the three dyes exhibits a different pattern. Calcein shows no preference for anode- or cathode-facing entry that is detectable with our measurement system. Immediately after a microsecond pulse, YO-PRO-1 and propidium enter the cell roughly equally from the positive and negative poles, but transport through the cathode-facing side dominates in less than 1 s. After nanosecond pulse permeabilization, YO-PRO-1 and propidium enter primarily on the anode-facing side of the cell.
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Affiliation(s)
- Esin B Sözer
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Ste. 300, Norfolk, VA, 23508, USA
| | - C Florencia Pocetti
- Department of Bioengineering, Instituto Tecnológico de Buenos Aires, Buenos Aires, Argentina
| | - P Thomas Vernier
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Ste. 300, Norfolk, VA, 23508, USA.
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9
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Selective effect of irreversible electroporation on parenchyma of the pancreas and its vascular structures - an in vivo experiment on a porcine model. ACTA VET BRNO 2016. [DOI: 10.2754/avb201685020133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Irreversible electroporation is a local, non-thermal ablation method, where short electrical pulses of high voltage lead to changes in cell membrane permeability and cell death. Recent experimental studies have shown that it does not lead to damage of blood vessels, nerves, bile duct or ureters. The aim of our experimental study was to evaluate the negative effect of irreversible electroporation regarding damage to the vascular wall and porcine pancreatic tissue. Irreversible electroporation of the pancreas was performed in 6 pigs after medial laparotomy. Irreversible electroporation was applied to each pig to the splenic lobe of the pancreas in order to assess damage to the pancreatic tissue and to the duodenal lobe of the pancreas to assess damage to the vascular structure of the pancreatic tissue. Higher ablation electric intensity (minimum 500 V/cm – maximum 1,750 V/cm, step 250 V/cm) in 90 μs pulses was utilized on each pig. After 7 days, macroscopic and microscopic evaluations of en bloc resected specimen (pancreas with duodenum) were performed. During 7 post-ablation days, no deaths or clinical worsening occurred in any of the pigs. Necrotic changes in the pancreatic tissue were recorded at an electric intensity of 750 V/cm. Changes in the outer layers of the wall of the arteries and veins occurred at 1,000 V/cm. Transmural vascular wall damage was not recorded in any case. Irreversible electroporation allows for relatively efficient cell death in the target tissues. Our independent experimental work confirms the safety of this method towards vascular structures located in the ablation zone.
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Yin S, Chen X, Xie H, Zhou L, Guo D, Xu Y, Wu L, Zheng S. Nanosecond pulsed electric field (nsPEF) enhance cytotoxicity of cisplatin to hepatocellular cells by microdomain disruption on plasma membrane. Exp Cell Res 2016; 346:233-40. [PMID: 27375200 DOI: 10.1016/j.yexcr.2016.06.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/11/2016] [Accepted: 06/24/2016] [Indexed: 12/21/2022]
Abstract
Previous studies showed nanosecond pulsed electric field (nsPEF) can ablate solid tumors including hepatocellular carcinoma (HCC) but its effect on cell membrane is not fully understood. We hypothesized nsPEF disrupt the microdomains on outer-cellular membrane with direct mechanical force and as a result the plasma membrane permeability increases to facilitate the small molecule intake. Three HCC cells were pulsed one pulse per minute, an interval longer than nanopore resealing time. The cationized ferritin was used to mark up the electronegative microdomains, propidium iodide (PI) for membrane permeabilization, energy dispersive X-ray spectroscopy (EDS) for the negative cell surface charge and cisplatin for inner-cellular cytotoxicity. We demonstrated that the ferritin marked-microdomain and negative cell surface charge were disrupted by nsPEF caused-mechanical force. The cell uptake of propidium and cytotoxicity of DNA-targeted cisplatin increased with a dose effect. Cisplatin gains its maximum inner-cellular cytotoxicity when combining with nsPEF stimulation. We conclude that nsPEF disrupt the microdomains on the outer cellular membrane directly and increase the membrane permeabilization for PI and cisplatin. The microdomain disruption and membrane infiltration changes are caused by the mechanical force from the changes of negative cell surface charge.
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Affiliation(s)
- Shengyong Yin
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou, China; Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Xinhua Chen
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou, China; Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Haiyang Xie
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou, China; Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Lin Zhou
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou, China; Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Danjing Guo
- Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Yuning Xu
- Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Liming Wu
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou, China; Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China.
| | - Shusen Zheng
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou, China; Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China.
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11
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Phillips M, Krishnan H, Raju N, Rubinsky B. Tissue Ablation by a Synergistic Combination of Electroporation and Electrolysis Delivered by a Single Pulse. Ann Biomed Eng 2016; 44:3144-3154. [DOI: 10.1007/s10439-016-1624-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 04/20/2016] [Indexed: 01/20/2023]
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12
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Synergistic Combination of Electrolysis and Electroporation for Tissue Ablation. PLoS One 2016; 11:e0148317. [PMID: 26866693 PMCID: PMC4750947 DOI: 10.1371/journal.pone.0148317] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 01/15/2016] [Indexed: 01/04/2023] Open
Abstract
Electrolysis, electrochemotherapy with reversible electroporation, nanosecond pulsed electric fields and irreversible electroporation are valuable non-thermal electricity based tissue ablation technologies. This paper reports results from the first large animal study of a new non-thermal tissue ablation technology that employs "Synergistic electrolysis and electroporation" (SEE). The goal of this pre-clinical study is to expand on earlier studies with small animals and use the pig liver to establish SEE treatment parameters of clinical utility. We examined two SEE methods. One of the methods employs multiple electrochemotherapy-type reversible electroporation magnitude pulses, designed in such a way that the charge delivered during the electroporation pulses generates the electrolytic products. The second SEE method combines the delivery of a small number of electrochemotherapy magnitude electroporation pulses with a low voltage electrolysis generating DC current in three different ways. We show that both methods can produce lesion with dimensions of clinical utility, without the need to inject drugs as in electrochemotherapy, faster than with conventional electrolysis and with lower electric fields than irreversible electroporation and nanosecond pulsed ablation.
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13
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Different Cell Viability Assays Reveal Inconsistent Results After Bleomycin Electrotransfer In Vitro. J Membr Biol 2015; 248:857-63. [PMID: 26077843 DOI: 10.1007/s00232-015-9813-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 06/06/2015] [Indexed: 12/21/2022]
Abstract
The aim of this study was to compare different and commonly used cell viability assays after CHO cells treatment with anticancer drug bleomycin (20 nM), high voltage (HV) electric pulses (4 pulses, 1200 V/cm, 100 µs, 1 Hz), and combination of bleomycin and HV electric pulses. Cell viability was measured using clonogenic assay, propidium iodide (PI) assay, MTT assay, and employing flow cytometry modality to precisely count cells in definite volume of the sample (flow cytometry assay). Results showed that although clonogenic cell viability drastically decreased correspondingly to 57 and 3 % after cell treatment either with HV pulses or combination of bleomycin and HV pulses (bleomycin electrotransfer), PI assay performed ~15 min after the treatments indicated nearly 100 % cell viability. MTT assay performed at 6-72 h time points after these treatments revealed that MTT cell viability is highly dependent on evaluation time point and decreased with later evaluation time points. Nevertheless, in comparison to clonogenic cell viability, MTT cell viability after bleomycin electrotransfer at all testing time points was significantly higher. Flow cytometry assay if used at later times, 2-3 days after the treatment, allowed reliable evaluation of cell viability. In overall, our results showed that in order to estimate cell viability after cell treatment with combination of the bleomycin and electroporation the most reliable method is clonogenic assay. Improper use of PI and MTT assays can lead to misinterpretation of the experimental results.
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14
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Cutrera J, King G, Jones P, Kicenuik K, Gumpel E, Xia X, Li S. Safe and effective treatment of spontaneous neoplasms with interleukin 12 electro-chemo-gene therapy. J Cell Mol Med 2015; 19:664-75. [PMID: 25628149 PMCID: PMC4369822 DOI: 10.1111/jcmm.12382] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 07/07/2014] [Indexed: 01/01/2023] Open
Abstract
Electroporation improves the anti-tumour efficacy of chemotherapeutic and gene therapies. Combining electroporation-mediated chemotherapeutics with interleukin 12 (IL-12) plasmid DNA produces a strong yet safe anti-tumour effect for treating primary and refractory tumours. A previously published report demonstrated the efficacy of a single cycle of IL-12 plasmid DNA and bleomycin in canines, and, similarly, this study further demonstrates the safety and efficacy of repeated cycles of chemotherapy plus IL-12 gene therapy for long-term management of aggressive tumours. Thirteen canine patients were enrolled in this study and received multiple cycles of electro-chemo-gene therapy (ECGT) with IL-12 pDNA and either bleomycin or gemcitabine. ECGT treatments are very effective for inducing tumour regression via an antitumour immune response in all tested histotypes except for sarcomas, and these treatments can quickly eradicate or debulk large squamous cell carcinomas. The versatility of ECGT allows for response-based modifications which can overcome treatment resistance for affecting refractory lesions. Importantly, not a single severe adverse event was noted even in animals receiving the highest doses of chemotherapeutics and IL12 pDNA over multiple treatment cycles. This report highlights the safety, efficacy and versatility of this treatment strategy. The data reveal the importance of inducing a strong anti-tumour response for successfully affecting not only the treated tumours, but also non-treated metastatic tumours. ECGT with IL12 pDNA plus chemotherapy is an effective strategy for treating multiple types of spontaneous cancers including large, refractory and multiple tumour burdens.
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Affiliation(s)
- Jeffry Cutrera
- Department of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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15
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The photodynamic effect of far-red range phthalocyanines (AlPc and Pc green) supported by electropermeabilization in human gastric adenocarcinoma cells of sensitive and resistant type. Biomed Pharmacother 2014; 69:145-52. [PMID: 25661351 DOI: 10.1016/j.biopha.2014.11.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 11/12/2014] [Indexed: 01/25/2023] Open
Abstract
INTRODUCTION Electroporation (EP) is commonly applied for effective drug transport thorough cell membranes based on the application of electromagnetic field. When applied with cytostatics, it is called electrochemotherapy (ECT) - a quite new method of cancer treatment. A high-voltage pulse causes the formation of temporary pores in the cell membrane which create an additional way for the intracellular drug transport. In the current work, EP was effectively merged with the already known photodynamic therapy (PDT) to selective photosensitizers' delivery to diseased tissue. The application of electroporation can reduce the dose of applied drug. RESEARCH OBJECTIVE The aim of research was to evaluate the effectiveness of photodynamic reaction using two near infrared cyanines (AlPc and Pc green) combined with electroporation in two human gastric adenocarcinoma cell lines. MATERIALS AND METHODS Two human cell lines - EPG85-257P (parental) and EPG85-257RDB (resistant to daunorubicin) - of gastric cancer were used. The effect of two photosensitizers (aluminum 1,8,15,22-tetrakis(-phenylthio)-29H,31H-phthalocyanine chloride and Phthalocyanine green) was investigated. The efficiency of EP parameters was assessed by propidium iodide uptake. The viability assay was applied to analyse EP, PDT and EP-PDT effect. Cyanine localization was determined by confocal microscopy. Immunocytochemical evaluation of manganese superoxide dismutase and glutathione S-transferase-pi was determined after applied therapies. RESULTS PDT in combination with EP affected the viability of EPG85-257P and EPG85-257RDB cells negatively while both cyanine were used. The most evident changes were observed in the following concentrations: 15, 10 and 5μM. The optimal field strength for enhanced EP-PDT was 800 and 1200V/cm. AlPc distributed selectively in the lysosomes of parental cell line. CONCLUSIONS PDT, enhanced by EP, caused decreased viability when compared to the application of PDT alone. Both phthalocyanines found to be more effective after electroporation. Due to the low concentration of light-sensitive compounds and safety of electroporation itself, a treatment plan can be an alternative therapeutic modality against gastric adenocarcinomas.
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Gurtovenko AA, Lyulina AS. Electroporation of Asymmetric Phospholipid Membranes. J Phys Chem B 2014; 118:9909-18. [DOI: 10.1021/jp5028355] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrey A. Gurtovenko
- Institute
of Macromolecular Compounds, Russian Academy of Sciences, Bolshoi
Prospect V.O. 31, St. Petersburg, 199004 Russia
- Faculty
of Physics, St. Petersburg State University, Ulyanovskaya str. 1, Petrodvorets, St. Petersburg, 198504 Russia
| | - Anastasia S. Lyulina
- Institute
of Physics, Nanotechnology and Telecommunications, St. Petersburg State Polytechnical University, Polytechnicheskaya str. 29, St. Petersburg, 195251 Russia
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