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Awasthi K, Wu TE, Hsu HY, Ohta N. Application of Nanosecond Pulsed Electric Field and Autofluorescence Lifetime Microscopy of FAD in Lung Cells. J Phys Chem B 2023. [PMID: 37319427 DOI: 10.1021/acs.jpcb.3c01148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Exposure of nanosecond pulsed electric fields (nsPEFs) to live cells is an increasing research interest in biology and medicine. Despite extensive studies, a question still remains as to how effects of application of nsPEF on intracellular functions are different between cancerous cells and normal cells and how the difference can be detected. Herein, we have presented an approach of autofluorescence lifetime (AFL) microscopy of flavin adenine dinucleotide (FAD) to detect effects of application of nsPEF having 50 ns of a pulse width, nsPEF(50), on intracellular function in lung cancerous cells, A549 and H661, which show nsPEF(50)-induced apoptosis, and normal cells, MRC-5, in which the field effect is less or not induced. Then, the application of nsPEF(50) is shown to increase the lifetime of FAD autofluorescence in lung cancerous cells, whereas the electric field effects on the autofluorescence of FAD was not significant in normal healthy cells, which indicates that the lifetime measurements of FAD autofluorescence are applicable to detect the field-induced change in intracellular functions. Lifetime and intensity microscopic images of FAD autofluorescence in these lung cells were also acquired after exposure to the apoptosis-inducer staurosporine (STS). Then, it was found that the AFL of FAD became longer after exposure not only in the cancerous cells but also in the normal cells. These results indicate that nsPEF(50) applied to lung cells induced apoptotic cell death only in lung cancerous cells (H661 and A549) but not in lung normal cells (MRC-5), whereas STS induced apoptotic cell death both in lung cancerous cells and in lung normal cells. The lifetime microscopy of FAD autofluorescence is suggested to be very useful as a sensitive detection method of nsPEF-induced apoptotic cell death.
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Affiliation(s)
- Kamlesh Awasthi
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300093, Taiwan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300093, Taiwan
| | - Tsai-En Wu
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300093, Taiwan
| | - Hsin-Yun Hsu
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300093, Taiwan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300093, Taiwan
| | - Nobuhiro Ohta
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300093, Taiwan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300093, Taiwan
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2
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Łapińska Z, Novickij V, Rembiałkowska N, Szewczyk A, Dubińska-Magiera M, Kulbacka J, Saczko J. The influence of asymmetrical bipolar pulses and interphase intervals on the bipolar cancellation phenomenon in the ovarian cancer cell line. Bioelectrochemistry 2023; 153:108483. [PMID: 37301162 DOI: 10.1016/j.bioelechem.2023.108483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 05/24/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023]
Abstract
The application of negative polarity electrical pulse (↓) following positive polarity pulses (↑) may induce bipolar cancellation (BPC), a unique physiological response believed to be specific to nanosecond electroporation (nsEP). The literature lacks analysis of bipolar electroporation (BP EP) involving asymmetrical sequences composed of nanosecond and microsecond pulses. Moreover, the impact of interphase interval on BPC caused by such asymmetrical pulse needs consideration. In this study, the authors utilized the ovarian clear carcinoma cell line (OvBH-1) model to investigate the BPC with asymmetrical sequences. Cells were exposed to pulses delivered in 10-pulse bursts but as uni- or bipolar, symmetrical, or asymmetrical sequences with a duration of 600 ns or 10 µs and electric field strength equal to 7.0 or 1.8 kV/cm, respectively. It was shown that the asymmetry of pulses influences BPC. The obtained results have also been investigated in the context of calcium electrochemotherapy. The reduction of cell membrane poration, and cell survival have been observed following Ca2+ electrochemotherapy. The effects of interphase delays (1 and 10 µs) on the BPC phenomenon were reported. Our findings show that the BPC phenomenon can be controlled using pulse asymmetry or delay between the positive and negative polarity of the pulse.
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Affiliation(s)
- Zofia Łapińska
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland.
| | - Vitalij Novickij
- Institute of High Magnetic Fields, Vilnius Gediminas Technical University, LT-03227 Vilnius, Lithuania; Department of Immunology, State Research Institute Centre for Innovative Medicine, Santariškių 5, 08410 Vilnius, Lithuania
| | - Nina Rembiałkowska
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland
| | - Anna Szewczyk
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland
| | - Magdalena Dubińska-Magiera
- Department of Animal Developmental Biology, Faculty of Biological Science, University of Wroclaw, Sienkiewicza 21, 50-335 Wroclaw, Poland
| | - Julita Kulbacka
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; Department of Immunology, State Research Institute Centre for Innovative Medicine, Santariškių 5, 08410 Vilnius, Lithuania.
| | - Jolanta Saczko
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland
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Huang JJ, Ma RW, Li DZ, Yin SY, Liu Z, Zhou L, Yan KP, Zheng SS. Ultrasound-guided in vivo porcine liver ablation with nanosecond pulsed electric fields. Hepatobiliary Pancreat Dis Int 2022; 21:503-507. [PMID: 36038451 DOI: 10.1016/j.hbpd.2022.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/04/2022] [Indexed: 02/05/2023]
Affiliation(s)
- Jun-Jie Huang
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; NHC Key Laboratory of Combined Multi-organ Transplantation, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Rong-Wei Ma
- Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310028, China
| | - Da-Zhi Li
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; NHC Key Laboratory of Combined Multi-organ Transplantation, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Sheng-Yong Yin
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; NHC Key Laboratory of Combined Multi-organ Transplantation, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Zhen Liu
- Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310028, China
| | - Lin Zhou
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; NHC Key Laboratory of Combined Multi-organ Transplantation, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Ke-Ping Yan
- Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310028, China
| | - Shu-Sen Zheng
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; NHC Key Laboratory of Combined Multi-organ Transplantation, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
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4
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Steelman ZA, Coker ZN, Kiester A, Noojin G, Ibey BL, Bixler JN. Quantitative phase microscopy monitors subcellular dynamics in single cells exposed to nanosecond pulsed electric fields. JOURNAL OF BIOPHOTONICS 2021; 14:e202100125. [PMID: 34291579 DOI: 10.1002/jbio.202100125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/11/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
A substantial body of literature exists to study the dynamics of single cells exposed to short duration (<1 μs), high peak power (~1 MV/m) transient electric fields. Much of this research is limited to traditional fluorescence-based microscopy techniques, which introduce exogenous agents to the culture and are only sensitive to a single molecular target. Quantitative phase imaging (QPI) is a coherent imaging modality which uses optical path length as a label-free contrast mechanism, and has proven highly effective for the study of single-cell dynamics. In this work, we introduce QPI as a useful imaging tool for the study of cells undergoing cytoskeletal remodeling after nanosecond pulsed electric field (nsPEF) exposure. In particular, we use cell swelling, dry mass and disorder strength measurements derived from QPI phase images to monitor the cellular response to nsPEFs. We hope this demonstration of QPI's utility will lead to a further adoption of the technique for the study of directed energy bioeffects.
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Affiliation(s)
- Zachary A Steelman
- National Research Council Research Associateship Program, Washington, District of Columbia, USA
| | - Zachary N Coker
- Department of Physics and Astronomy, Texas A&M University, College Station, Texas, USA
- SAIC, San Antonio, Texas, USA
| | - Allen Kiester
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, JBSA Fort Sam Houston, San Antonio, Texas, USA
| | | | - Bennett L Ibey
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, JBSA Fort Sam Houston, San Antonio, Texas, USA
| | - Joel N Bixler
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, JBSA Fort Sam Houston, San Antonio, Texas, USA
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Liu H, Zhao Y, Yao C, Schmelz EM, Davalos RV. Differential effects of nanosecond pulsed electric fields on cells representing progressive ovarian cancer. Bioelectrochemistry 2021; 142:107942. [PMID: 34509872 DOI: 10.1016/j.bioelechem.2021.107942] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 12/12/2022]
Abstract
Nanosecond pulsed electric fields (nsPEFs) may induce differential effects on tumor cells from different disease stages and could be suitable for treating tumors by preferentially targeting the late-stage/highly aggressive tumor cells. In this study, we investigated the nsPEF responses of mouse ovarian surface epithelial (MOSE) cells representing progressive ovarian cancer from benign to malignant stages and highly aggressive tumor-initiating-like cells. We established the cell-seeded 3D collagen scaffolds cultured with or without Nocodazole (eliminating the influence of cell proliferation on ablation outcome) to observe the ablation effects at 3 h and 24 h after treatment and compared the corresponding thresholds obtained by numerically calculated electric field distribution. The results showed that nsPEFs induced larger ablation areas with lower thresholds as the cell progress from benign, malignant to a highly aggressive phenotype. This differential effect was not affected by the different doubling times of the cells, as apparent by similar ablation induction after a synergistic treatment of nsPEFs and Nocodazole. The result suggests that nsPEFs could induce preferential ablation effects on highly aggressive and malignant ovarian cancer cells than their benign counterparts. This study provides an experimental basis for the research on killing malignant tumor cells via electrical treatments and may have clinical implications for treating tumors and preventing tumor recurrence after treatment.
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Affiliation(s)
- Hongmei Liu
- School of Electrical Engineering, Chongqing University, Chongqing 400033, China; Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
| | - Yajun Zhao
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; College of Electrical Engineering and Control Science, Nanjing Tech. University, Nanjing 211816, China
| | - Chenguo Yao
- School of Electrical Engineering, Chongqing University, Chongqing 400033, China.
| | - Eva M Schmelz
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Rafael V Davalos
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA.
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Choromańska A, Chwiłkowska A, Kulbacka J, Baczyńska D, Rembiałkowska N, Szewczyk A, Michel O, Gajewska-Naryniecka A, Przystupski D, Saczko J. Modifications of Plasma Membrane Organization in Cancer Cells for Targeted Therapy. Molecules 2021; 26:1850. [PMID: 33806009 PMCID: PMC8037978 DOI: 10.3390/molecules26071850] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 12/11/2022] Open
Abstract
Modifications of the composition or organization of the cancer cell membrane seem to be a promising targeted therapy. This approach can significantly enhance drug uptake or intensify the response of cancer cells to chemotherapeutics. There are several methods enabling lipid bilayer modifications, e.g., pharmacological, physical, and mechanical. It is crucial to keep in mind the significance of drug resistance phenomenon, ion channel and specific receptor impact, and lipid bilayer organization in planning the cell membrane-targeted treatment. In this review, strategies based on cell membrane modulation or reorganization are presented as an alternative tool for future therapeutic protocols.
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Affiliation(s)
- Anna Choromańska
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
| | - Agnieszka Chwiłkowska
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
| | - Julita Kulbacka
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
| | - Dagmara Baczyńska
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
| | - Nina Rembiałkowska
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
| | - Anna Szewczyk
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
| | - Olga Michel
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
| | - Agnieszka Gajewska-Naryniecka
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
| | - Dawid Przystupski
- Department of Paediatric Bone Marrow Transplantation, Oncology and Haematology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland;
| | - Jolanta Saczko
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland; (J.K.); (D.B.); (N.R.); (A.S.); (O.M.); (A.G.-N.); (J.S.)
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7
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Poudel A, Oludiran A, Sözer EB, Casciola M, Purcell EB, Muratori C. Growth in a biofilm sensitizes Cutibacterium acnes to nanosecond pulsed electric fields. Bioelectrochemistry 2021; 140:107797. [PMID: 33773215 DOI: 10.1016/j.bioelechem.2021.107797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
The Gram-positive anaerobic bacterium Cutibacterium acnes (C. acnes) is a commensal of the human skin, but also an opportunistic pathogen that contributes to the pathophysiology of the skin disease acne vulgaris. C. acnes can form biofilms; cells in biofilms are more resilient to antimicrobial stresses. Acne therapeutic options such as topical or systemic antimicrobial treatments often show incomplete responses. In this study we measured the efficacy of nanosecond pulsed electric fields (nsPEF), a new promising cell and tissue ablation technology, to inactivate C. acnes. Our results show that all tested nsPEF doses (250 to 2000 pulses, 280 ns pulses, 28 kV/cm, 5 Hz; 0.5 to 4 kJ/ml) failed to inactivate planktonic C. acnes and that pretreatment with lysozyme, a naturally occurring cell-wall-weakening enzyme, increased C. acnes vulnerability to nsPEF. Surprisingly, growth in a biofilm appears to sensitize C. acnes to nsPEF-induced stress, as C. acnes biofilm-derived cells showed increased cell death after nsPEF treatments that did not affect planktonic cells. Biofilm inactivation by nsPEF was confirmed by treating intact biofilms grown on glass coverslips with an indium oxide conductive layer. Altogether our results show that, contrary to other antimicrobial agents, nsPEF kill more efficiently bacteria in biofilms than planktonic cells.
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Affiliation(s)
- Asia Poudel
- Old Dominion University, Department of Chemistry and Biochemistry, USA
| | - Adenrele Oludiran
- Old Dominion University, Department of Chemistry and Biochemistry, USA
| | - Esin B Sözer
- Old Dominion University, Frank Reidy Research Center for Bioelectrics, USA
| | - Maura Casciola
- Old Dominion University, Frank Reidy Research Center for Bioelectrics, USA; Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Erin B Purcell
- Old Dominion University, Department of Chemistry and Biochemistry, USA.
| | - Claudia Muratori
- Old Dominion University, Frank Reidy Research Center for Bioelectrics, USA.
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Liu H, Yao C, Zhao Y, Chen X, Dong S, Wang L, Davalos RV. In Vitro Experimental and Numerical Studies on the Preferential Ablation of Chemo-Resistant Tumor Cells Induced by High-Voltage Nanosecond Pulsed Electric Fields. IEEE Trans Biomed Eng 2020; 68:2400-2411. [PMID: 33232222 DOI: 10.1109/tbme.2020.3040337] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Chemoresistance causes tumor recurrence and metastasis, resulting in poor clinical outcomes and low survival, and has been considered an obstacle to tumor therapy. The development of novel therapeutic approaches that can effectively kill chemoresistant tumor cells (CRTCs) is therefore critical to overcoming these obstacles. OBJECTIVE Here, we introduce an emerging physical feature-based therapeutic approach based on nanosecond pulsed electric fields (nsPEFs). The goal of this study is to investigate the effect of nsPEFs on CRTCs. METHODS The cell viability, ablation effects on a 3D-cultured scaffold, and lethal thresholds of nsPEFs were evaluated according to fluorescence staining assays. RESULTS nsPEF treatment preferentially affected chemoresistant cells (A549/CDDP) with a higher cell viability inhibition ability/cell death rate, larger ablation area, and lower ablation threshold compared to their respective homologous tumor cells (A549). The experimental and theoretical studies suggested that nsPEFs displayed selective behavior toward intracellular structures. With this selective character, nsPEFs can induce higher electroporation effects (e.g., higher pore number, larger electroporation area, and faster fluorescence dissipation on the nuclear envelope) on CRTCs due to their larger nuclear size and cell membrane capacitance. CONCLUSION These findings demonstrated that nsPEFs induced preferential ablation of CRTCs over their respective homologous tumor cells. SIGNIFICANCE This study provides an experimental and theoretical basis for the study of killing CRTCs by electrical treatments and suggests potential applications in the optimization of novel anti-chemoresistance methods.
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Liu H, Shi F, Tang X, Zheng S, Kolb J, Yao C. Application of bioimpedance spectroscopy to characterize chemoresistant tumor cell selectivity of nanosecond pulse stimulation. Bioelectrochemistry 2020; 135:107570. [PMID: 32526679 DOI: 10.1016/j.bioelechem.2020.107570] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 02/08/2023]
Abstract
The discriminating effects of nanosecond pulsed electric fields (nsPEFs) between chemoresistant tumor cells (CRTCs) and their respective homologous chemosensitive tumor cells (CSTCs) were investigated based on bioimpedance spectroscopy (BIS). The electrical properties of individual untreated cells were determined by fitting the impedance spectra to an equivalent circuit model and then using aided simulations to calculate the nuclear envelope transmembrane potential (nTMP) and electroporation area on the nuclear envelope. Additionally, fluorescence staining assays of cell monolayers after nanopulse stimulation (80 pulses, 200 ns, 3 kV) were conducted to validate the simulation results. The staining results indicated that CRTCs showed a larger ablation area and lower lethal threshold compared to CSTCs after exposure to the same nsPEF energy, which was in accordance with the higher nTMP and larger electroporation area calculated for CRTCs. The increase in the lethal effects of nsPEFs on CRTCs compared to CSTCs mainly resulted from the superposition of the changes in the electrical properties and nuclear size. The work shows that BIS can distinguish CRTCs and CSTCs and the corresponding nsPEF effects, suggesting potential applications for the optimization of novel anti-chemoresistance methods, including nsPEF-treatments.
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Affiliation(s)
- Hongmei Liu
- School of Electrical Engineering, Chongqing University, Chongqing 400033, China; State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing 400033, China
| | - Fukun Shi
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, 215163 Suzhou, China; Leibniz Institute for Plasma Science and Technology (INP), Greifswald 17489, Germany; Institute of Physics, University of Rostock, Rostock 18059, Germany
| | - Xiao Tang
- School of Electrical Engineering, Chongqing University, Chongqing 400033, China; State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing 400033, China
| | - Shuang Zheng
- School of Electrical Engineering, Chongqing University, Chongqing 400033, China; State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing 400033, China
| | - Juergen Kolb
- Leibniz Institute for Plasma Science and Technology (INP), Greifswald 17489, Germany; Institute of Physics, University of Rostock, Rostock 18059, Germany
| | - Chenguo Yao
- School of Electrical Engineering, Chongqing University, Chongqing 400033, China; State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing 400033, China.
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Graybill PM, Davalos RV. Cytoskeletal Disruption after Electroporation and Its Significance to Pulsed Electric Field Therapies. Cancers (Basel) 2020; 12:E1132. [PMID: 32366043 PMCID: PMC7281591 DOI: 10.3390/cancers12051132] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/18/2022] Open
Abstract
Pulsed electric fields (PEFs) have become clinically important through the success of Irreversible Electroporation (IRE), Electrochemotherapy (ECT), and nanosecond PEFs (nsPEFs) for the treatment of tumors. PEFs increase the permeability of cell membranes, a phenomenon known as electroporation. In addition to well-known membrane effects, PEFs can cause profound cytoskeletal disruption. In this review, we summarize the current understanding of cytoskeletal disruption after PEFs. Compiling available studies, we describe PEF-induced cytoskeletal disruption and possible mechanisms of disruption. Additionally, we consider how cytoskeletal alterations contribute to cell-cell and cell-substrate disruption. We conclude with a discussion of cytoskeletal disruption-induced anti-vascular effects of PEFs and consider how a better understanding of cytoskeletal disruption after PEFs may lead to more effective therapies.
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Affiliation(s)
- Philip M. Graybill
- BEMS Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA;
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Rafael V. Davalos
- BEMS Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA;
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA
- Virginia Tech–Wake Forest University, School of Biomedical Engineering and Sciences, Blacksburg, VA 24061, USA
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Nuccitelli R, McDaniel A, Connolly R, Zelickson B, Hartman H. Nano-Pulse Stimulation Induces Changes in the Intracellular Organelles in Rat Liver Tumors Treated In Situ. Lasers Surg Med 2020; 52:882-889. [PMID: 32220023 PMCID: PMC7586959 DOI: 10.1002/lsm.23239] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2020] [Indexed: 12/19/2022]
Abstract
Background and Objectives Nano‐pulse stimulation (NPS) therapy is the application of ultrafast pulses of high amplitude electrical energy to tissues to influence cell function. Unique characteristics of these pulses enable electric field penetration into the interior of cells and organelles to generate transient nanopores in both organelle and plasma membranes. The purpose of this study is to document the temporal and physical changes in intracellular organelles following NPS therapy using electron microscopy. Study Design/Materials and Methods Liver tumors were induced in five buffalo rats by implanting syngeneic McA‐RH7777 hepatocellular carcinoma cells into the surgically exposed livers. Tumors were allowed to grow for 1 week and then the surgically exposed livers were treated in situ with NPS energy delivered at a sufficient level to trigger regulated cell death in the tumor. Samples of NPS‐treated and control tissue were removed and fixed for electron microscopy at 1 minute, 5 minutes, 30 minutes, 2 hours and 4 hours after exposure. Results Measurements of cellular organelles indicate strong swelling following NPS therapy exposure compared with untreated controls. The mean diameter of the mitochondria increased by 55% within 1 minute and then by 2.5‐fold by 2 hours post‐NPS therapy. The rough endoplasmic reticulum (RER) cisternae swelled immediately after NPS therapy with reduced swelling by 30 minutes and loss of structural integrity by 2 hours. The Golgi apparatus appears swollen in images collected 1 and 5 minutes after NPS therapy and was no longer detected at 30 minutes and 2 hours post‐NPS therapy. By 4 hours after NPS therapy, a nascent Golgi apparatus was detected in many of the images. The plasma membrane lost its well‐defined morphology and became less linear, exhibiting discontinuities as early as 1 minute post‐NPS energy exposure and the nuclear envelope became subjectively less distinct over time. Conclusions NPS therapy at sufficient energy levels causes the rapid swelling of organelles, disintegration of the RER, breaks in the plasma membrane and blurs the borders of the nuclear envelope. These changes in the mitochondria and RER are indicative of a regulated cell death process. These immediate physical changes to vital cell organelles are likely to trigger subsequent regulated cell death mechanisms observed in other studies of NPS therapy. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.
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Affiliation(s)
| | - Amanda McDaniel
- Pulse Biosciences, 3957 Point Eden Way, Hayward, California, 94545
| | - Richard Connolly
- Pulse Biosciences, 3957 Point Eden Way, Hayward, California, 94545
| | - Brian Zelickson
- Zel Skin and Laser Specialists, 4100 W 50th St, Edina, Minnesota, 55424
| | - Holly Hartman
- Pulse Biosciences, 3957 Point Eden Way, Hayward, California, 94545
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12
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Martens SL, Klein S, Barnes RA, TrejoSanchez P, Roth CC, Ibey BL. 600-ns pulsed electric fields affect inactivation and antibiotic susceptibilities of Escherichia coli and Lactobacillus acidophilus. AMB Express 2020; 10:55. [PMID: 32189137 PMCID: PMC7080936 DOI: 10.1186/s13568-020-00991-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/10/2020] [Indexed: 12/23/2022] Open
Abstract
Cell suspensions of Escherichia coli and Lactobacillus acidophilus were exposed to 600-ns pulsed electric fields (nsPEFs) at varying amplitudes (Low-13.5, Mid-18.5 or High-23.5 kV cm−1) and pulse numbers (0 (sham), 1, 5, 10, 100 or 1000) at a 1 hertz (Hz) repetition rate. The induced temperature rise generated at these exposure parameters, hereafter termed thermal gradient, was measured and applied independently to cell suspensions in order to differentiate inactivation triggered by electric field (E-field) from heating. Treated cell suspensions were plated and cellular inactivation was quantified by colony counts after a 24-hour (h) incubation period. Additionally, cells from both exposure conditions were incubated with various antibiotic-soaked discs to determine if nsPEF exposure would induce changes in antibiotic susceptibility. Results indicate that, for both species, the total delivered energy (amplitude, pulse number and pulse duration) determined the magnitude of cell inactivation. Specifically, for 18.5 and 23.5 kV cm−1 exposures, L. acidophilus was more sensitive to the inactivation effects of nsPEF than E. coli, however, for the 13.5 kV cm−1 exposures E. coli was more sensitive, suggesting that L. acidophilus may need to meet an E-field threshold before significant inactivation can occur. Results also indicate that antibiotic susceptibility was enhanced by multiple nsPEF exposures, as observed by increased zones of growth inhibition. Moreover, for both species, a temperature increase of ≤ 20 °C (89% of exposures) was not sufficient to significantly alter cell inactivation, whereas none of the thermal equivalent exposures were sufficient to change antibiotic susceptibility categories.
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13
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Mao Z, Zhang Y, Lu N, Cheng S, Hong R, Liu QH. Carbon Nanotubes Enabling Highly Efficient Cell Apoptosis by Low-Intensity Nanosecond Electric Pulses via Perturbing Calcium Handling. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1904047. [PMID: 31799810 DOI: 10.1002/smll.201904047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/06/2019] [Indexed: 06/10/2023]
Abstract
Effective induction of targeted cancer cells apoptosis with minimum side effects has always been the primary objective for anti-tumor therapy. In this study, carbon nanotubes (CNTs) are employed for their unique ability to target tumors and amplify the localized electric field due to the high aspect ratio. Highly efficient and cancer cell specific apoptosis is finally achieved by combining carbon nanotubes with low intensity nanosecond electric pulses (nsEPs). The underlying mechanism may be as follows: the electric field produced by nsEPs is amplified by CNTs, causing an enhanced plasma membrane permeabilization and Ca2+ influx, simultaneously triggering Ca2+ release from intracellular storages to cytoplasm in a direct/indirect manner. All the changes above lead to excessive mitochondrial Ca2+ uptake. Substructural damage and obvious mitochondria membrane potential depolarization are caused subsequently with the combined action of numerously reactive oxygen species production, ultimately initiating the apoptotic process through the translocation of cytochrome c to the cytoplasm and activating apoptotic markers including caspase-9 and -3. Thus, the combination of nanosecond electric field with carbon nanotubes can actually promote HCT116 cell death via mitochondrial signaling pathway-mediated cell apoptosis. These results may provide a new and highly efficient strategy for cancer therapy.
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Affiliation(s)
- Zheng Mao
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, 361005, China
| | - Youyu Zhang
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, 361005, China
- Shenzhen Research Institute of Xiamen University, Shenzhen, 518000, China
| | - Nan Lu
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, 361005, China
| | - Shun Cheng
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, 361005, China
| | - Ronghan Hong
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, 361005, China
| | - Qing Huo Liu
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA
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14
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Abstract
This review covers the use of pulsed electric fields in cancer therapy. It is organized into three sections based on pulse length, millisecond domain, microsecond domain, and nanosecond domain. The predominant application of pulsed electric fields is the modification of the permeability of cellular membranes, sometimes referred to as electroporation. This has been used in many different ways for cancer treatment. These include introducing genes into the tumor cells to activate an immune response, introducing poisons into the tumor cells, initiating necrosis using irreversible electroporation, and initiating immunogenic cell death with nanopulse stimulation.
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15
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Zhang Y, Mao Z, Wang B, Zhang J, Lu N, Hong R, Dong S, Yao C, Liu QH. Enhanced Antitumor Efficacy Achieved Through Combination of nsPEFs and Low-Dosage Paclitaxel. IEEE Trans Biomed Eng 2019; 66:3129-3135. [PMID: 30794505 DOI: 10.1109/tbme.2019.2900720] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Looking for a safe and effective cancer therapy for patients is becoming an important and promising research direction. Nanosecond pulsed electric field (nsPEF) has been found to be a potential non-thermal therapeutic technique with few side effects in pre-clinical studies. On the other hand, paclitaxel (PTX), as a common chemotherapeutic agent, shows full anti-tumor activities and is used to treat a wide variety of cancers. However, the delivery of PTX is challenging due to its poor aqueous solubility. Hence, high dosages of PTX have been used to achieve effective treatment, which creates some side effects. In this study, nsPEF was combined with low-level PTX, in order to validate if this combined treatment could bring about enhanced efficacy and allow reduced doses of PTX in clinical application. Cell proliferation, apoptosis, and cell cycle distribution were examined using MTT and flow cytometry assay, respectively. Results showed that combination treatments of nsPEF and PTX exhibited significant synergistic effects in vitro. The underlying mechanism might be that these two agents acted at different targets and coordinately enhanced MDA-MB-231 cell death.
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16
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Lustig M, Feng Q, Payan Y, Gefen A, Benayahu D. Noninvasive Continuous Monitoring of Adipocyte Differentiation: From Macro to Micro Scales. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2019; 25:119-128. [PMID: 30712528 DOI: 10.1017/s1431927618015520] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
3T3-L1 cells serve as model systems for studying adipogenesis and research of adipose tissue-related diseases, e.g. obesity and diabetes. Here, we present two novel and complementary nondestructive methods for adipogenesis analysis of living cells which facilitate continuous monitoring of the same culture over extended periods of time, and are applied in parallel at the macro- and micro-scales. At the macro-scale, we developed visual differences mapping (VDM), a novel method which allows to determine level of adipogenesis (LOA)-a numerical index which quantitatively describes the extent of differentiation in the whole culture, and percentage area populated by adipocytes (PAPBA) across a whole culture, based on the apparent morphological differences between preadipocytes and adipocytes. At the micro-scale, we developed an improved version of our previously published image-processing algorithm, which now provides data regarding single-cell morphology and lipid contents. Both methods were applied here synergistically for measuring differentiation levels in cultures over multiple weeks. VDM revealed that the mean LOA value reached 1.11 ± 0.06 and the mean PAPBA value reached >60%. Micro-scale analysis revealed that during differentiation, the cells transformed from a fibroblast-like shape to a circular shape with a build-up of lipid droplets. We predict a vast potential for implementation of these methods in adipose-related pharmacological research, such as in metabolic-syndrome studies.
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Affiliation(s)
- Maayan Lustig
- Department of Biomedical Engineering, Faculty of Engineering,Tel Aviv University,Tel Aviv 6997801,Israel
| | - Qingling Feng
- Key Laboratory of Advanced Materials of Ministry of Education of China,School of Materials Science and Engineering, Tsinghua University,Beijing 100084,China
| | - Yohan Payan
- CNRS, Grenoble INP, TIMC-IMAG, University of Grenoble Alpes,Grenoble F-38000,France
| | - Amit Gefen
- Department of Biomedical Engineering, Faculty of Engineering,Tel Aviv University,Tel Aviv 6997801,Israel
| | - Dafna Benayahu
- Department of Cell and Developmental Biology,Sackler School of Medicine, Tel Aviv University,Tel Aviv 6997801,Israel
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17
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Martens SL, Roth CC, Ibey BL. Nanosecond pulsed electric field exposure does not induce the unfolded protein response in adult human dermal fibroblasts. Bioelectromagnetics 2018; 39:491-499. [PMID: 29984845 DOI: 10.1002/bem.22131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 04/21/2018] [Indexed: 02/03/2023]
Abstract
Cell-circuit models have suggested that nanosecond pulsed electric fields (nsPEFs) can disrupt intracellular membranes including endoplasmic reticulum (ER), mitochondria, and/or nucleus thereby inducing intrinsic apoptotic pathways. Therefore, we hypothesized that the unfolded protein response (UPR) would be activated, due to the fluctuations of ionic concentrations, upon poration of the ER membrane. Quantitative real-time polymerase chain reaction was utilized to measure changes in messenger RNA (mRNA) expression of specific ER stress genes in adult human dermal fibroblast (HDFa) cells treated with tunicamycin (TM) (known ER stress inducer) and cells exposed to nsPEFs (100, 10-ns pulses at 150 kV/cm delivered at a repetition rate of 1 Hz). For HDFa cells, results showed time-dependent UPR activation to TM; however, when HDFa cells were exposed to nsPEFs, no significant changes in mRNA expression of ER stress genes, and/or caspase gene were observed. These results indicate that although cell death can be observed under these exposure parameters, it is most likely not initiated through activation of the UPR. Bioelectromagnetics. 2018;39:491-499, 2018. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Stacey L Martens
- Radio Frequency Bioeffects Branch, Bioeffects Division, Airman Systems Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, Texas
| | - Caleb C Roth
- Radio Frequency Bioeffects Branch, Bioeffects Division, Airman Systems Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, Texas
| | - Bennett L Ibey
- Radio Frequency Bioeffects Branch, Bioeffects Division, Airman Systems Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, Texas
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18
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Merla C, Liberti M, Marracino P, Muscat A, Azan A, Apollonio F, Mir LM. A wide-band bio-chip for real-time optical detection of bioelectromagnetic interactions with cells. Sci Rep 2018; 8:5044. [PMID: 29568067 PMCID: PMC5864909 DOI: 10.1038/s41598-018-23301-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 03/07/2018] [Indexed: 01/01/2023] Open
Abstract
The analytical and numerical design, implementation, and experimental validation of a new grounded closed coplanar waveguide for wide-band electromagnetic exposures of cells and their optical detection in real-time is reported. The realized device fulfills high-quality requirements for novel bioelectromagnetic experiments, involving elevated temporal and spatial resolutions. Excellent performances in terms of matching bandwidth (less than -10 dB up to at least 3 GHz), emission (below 1 × 10-6 W/m2) and efficiency (around 1) have been obtained as revealed by both numerical simulations and experimental measurements. A low spatial electric field inhomogeneity (coefficient of variation of around 10 %) has been achieved within the cell solutions filling the polydimethylsiloxane reservoir of the conceived device. This original bio-chip based on the grounded closed coplanar waveguide concept opens new possibilities for the development of controlled experiments combining electromagnetic exposures and sophisticated imaging using optical spectroscopic techniques.
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Affiliation(s)
- Caterina Merla
- Laboratory of Vectorology and Anticancer Therapies, UMR 8203, CNRS, Univ. Paris-Sud, Gustave Roussy, Université Paris-Saclay, 114 rue E. Vaillant, 94805, Villejuif, France. .,National Italian Agency for New Technology Energy and Sustainable Economic Development (ENEA), Division of Health Protection Technologies, via Anguillarese 301, 00123, Rome, Italy.
| | - Micaela Liberti
- "Sapienza" University of Rome, Department of Information Engineering Electronics and Telecommunications, via Eudossiana 18, 00184, Rome, Italy
| | - Paolo Marracino
- "Sapienza" University of Rome, Department of Information Engineering Electronics and Telecommunications, via Eudossiana 18, 00184, Rome, Italy
| | - Adeline Muscat
- Laboratory of Vectorology and Anticancer Therapies, UMR 8203, CNRS, Univ. Paris-Sud, Gustave Roussy, Université Paris-Saclay, 114 rue E. Vaillant, 94805, Villejuif, France
| | - Antoine Azan
- Laboratory of Vectorology and Anticancer Therapies, UMR 8203, CNRS, Univ. Paris-Sud, Gustave Roussy, Université Paris-Saclay, 114 rue E. Vaillant, 94805, Villejuif, France
| | - Francesca Apollonio
- "Sapienza" University of Rome, Department of Information Engineering Electronics and Telecommunications, via Eudossiana 18, 00184, Rome, Italy
| | - Lluis M Mir
- Laboratory of Vectorology and Anticancer Therapies, UMR 8203, CNRS, Univ. Paris-Sud, Gustave Roussy, Université Paris-Saclay, 114 rue E. Vaillant, 94805, Villejuif, France
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19
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Enhancing Electrotransfection Efficiency through Improvement in Nuclear Entry of Plasmid DNA. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 11:263-271. [PMID: 29858061 PMCID: PMC5992438 DOI: 10.1016/j.omtn.2018.02.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 02/22/2018] [Accepted: 02/26/2018] [Indexed: 01/15/2023]
Abstract
The nuclear envelope is a physiological barrier to electrogene transfer. To understand different mechanisms of the nuclear entry for electrotransfected plasmid DNA (pDNA), the current study investigated how manipulation of the mechanisms could affect electrotransfection efficiency (eTE), transgene expression level (EL), and cell viability. In the investigation, cells were first synchronized at G2-M phase prior to electrotransfection so that the nuclear envelope breakdown (NEBD) occurred before pDNA entered the cells. The NEBD significantly increased the eTE and the EL while the cell viability was not compromised. In the second experiment, the cells were treated with a nuclear pore dilating agent (i.e., trans-1,2-cyclohexanediol). The treatment could increase the EL, but had only minor effects on eTE. Furthermore, the treatment was more cytotoxic, compared with the cell synchronization. In the third experiment, a nuclear targeting sequence (i.e., SV40) was incorporated into the pDNA prior to electrotransfection. The incorporation was more effective than the cell synchronization for enhancing the EL, but not the eTE, and the effectiveness was cell type dependent. Taken together, the data described above suggested that synchronization of the NEBD could be a practical approach to improving electrogene transfer in all dividing cells.
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20
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Gianulis EC, Casciola M, Xiao S, Pakhomova ON, Pakhomov AG. Electropermeabilization by uni- or bipolar nanosecond electric pulses: The impact of extracellular conductivity. Bioelectrochemistry 2017; 119:10-19. [PMID: 28865240 DOI: 10.1016/j.bioelechem.2017.08.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/05/2017] [Accepted: 08/15/2017] [Indexed: 02/03/2023]
Abstract
Cellular effects caused by nanosecond electric pulses (nsEP) can be reduced by an electric field reversal, a phenomenon known as bipolar cancellation. The reason for this cancellation effect remains unknown. We hypothesized that assisted membrane discharge is the mechanism for bipolar cancellation. CHO-K1 cells bathed in high (16.1mS/cm; HCS) or low (1.8mS/cm; LCS) conductivity solutions were exposed to either one unipolar (300-ns) or two opposite polarity (300+300-ns; bipolar) nsEP (4-40kV/cm) with increasing interpulse intervals (0.1-50μs). Time-lapse YO-PRO-1 (YP) uptake revealed enhanced membrane permeabilization in LCS compared to HCS at all tested voltages. The time-dependence of bipolar cancellation was similar in both solutions, using either identical (22kV/cm) or isoeffective nsEP treatments (12 and 32kV/cm for LCS and HCS, respectively). However, cancellation was significantly stronger in LCS when the bipolar nsEP had no, or very short (<1μs), interpulse intervals. Finally, bipolar cancellation was still present with interpulse intervals as long as 50μs, beyond the time expected for membrane discharge. Our findings do not support assisted membrane discharge as the mechanism for bipolar cancellation. Instead they exemplify the sustained action of nsEP that can be reversed long after the initial stimulus.
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Affiliation(s)
- Elena C Gianulis
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
| | - Maura Casciola
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Shu Xiao
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23508, USA
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
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21
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Gianulis EC, Labib C, Saulis G, Novickij V, Pakhomova ON, Pakhomov AG. Selective susceptibility to nanosecond pulsed electric field (nsPEF) across different human cell types. Cell Mol Life Sci 2016; 74:1741-1754. [PMID: 27986976 DOI: 10.1007/s00018-016-2434-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/27/2016] [Accepted: 12/05/2016] [Indexed: 12/18/2022]
Abstract
Tumor ablation by nanosecond pulsed electric fields (nsPEF) is an emerging therapeutic modality. We compared nsPEF cytotoxicity for human cell lines of cancerous (IMR-32, Hep G2, HT-1080, and HPAF-II) and non-cancerous origin (BJ and MRC-5) under strictly controlled and identical conditions. Adherent cells were uniformly treated by 300-ns PEF (0-2000 pulses, 1.8 kV/cm, 50 Hz) on indium tin oxide-covered glass coverslips, using the same media and serum. Cell survival plotted against the number of pulses displayed three distinct regions (initial resistivity, logarithmic survival decline, and residual resistivity) for all tested cell types, but with differences in LD50 spanning as much as nearly 80-fold. The non-cancerous cells were less sensitive than IMR-32 neuroblastoma cells but more vulnerable than the other cancers tested. The cytotoxic efficiency showed no apparent correlation with cell or nuclear size, cell morphology, metabolism level, or the extent of membrane disruption by nsPEF. Increasing pulse duration to 9 µs (0.75 kV/cm, 5 Hz) produced a different selectivity pattern, suggesting that manipulation of PEF parameters can, at least for certain cancers, overcome their resistance to nsPEF ablation. Identifying mechanisms and cell markers of differential nsPEF susceptibility will critically contribute to the proper choice and outcome of nsPEF ablation therapies.
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Affiliation(s)
- Elena C Gianulis
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA, 23508, USA.
| | - Chantelle Labib
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA, 23508, USA
| | - Gintautas Saulis
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Vitalij Novickij
- Magnetic Field Institute, Vilnius Gediminas Technical University, Vilnius, Lithuania
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA, 23508, USA
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA, 23508, USA
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22
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Muratori C, Pakhomov AG, Gianulis EC, Jensen SD, Pakhomova ON. The cytotoxic synergy of nanosecond electric pulses and low temperature leads to apoptosis. Sci Rep 2016; 6:36835. [PMID: 27833151 PMCID: PMC5104977 DOI: 10.1038/srep36835] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/18/2016] [Indexed: 12/20/2022] Open
Abstract
Electroporation by nanosecond electric pulses (nsEP) is an emerging modality for tumor ablation. Here we show the efficient induction of apoptosis even by a non-toxic nsEP exposure when it is followed by a 30-min chilling on ice. This chilling itself had no impact on the survival of U-937 or HPAF-II cells, but caused more than 75% lethality in nsEP-treated cells (300 ns, 1.8-7 kV/cm, 50-700 pulses). The cell death was largely delayed by 5-23 hr and was accompanied by a 5-fold activation of caspase 3/7 (compared to nsEP without chilling) and more than 60% cleavage of poly-ADP ribose polymerase (compared to less than 5% in controls or after nsEP or chilling applied separately). When nsEP caused a transient permeabilization of 83% of cells to propidium iodide, cells placed at 37 °C resealed in 10 min, whereas 60% of cells placed on ice remained propidium-permeable even in 30 min. The delayed membrane resealing caused cell swelling, which could be blocked by an isosmotic addition of a pore-impermeable solute (sucrose). However, the block of swelling did not prevent the delayed cell death by apoptosis. The potent enhancement of nsEP cytotoxicity by subsequent non-damaging chilling may find applications in tumor ablation therapies.
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Affiliation(s)
- Claudia Muratori
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Elena C Gianulis
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Sarah Damsbo Jensen
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
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