scholarly journals Liposomes Under Real Cell Conditions Behave Like Real Cells with a Single Pulsed Electric Field

2019 ◽  
Author(s):  
Gen Urabe ◽  
Masaharu Shimada ◽  
Takumi Ogata ◽  
Sunao Katsuki
Keyword(s):  
Electric Field ◽  
Red Blood Cells ◽  
Physical Model ◽  
Electric Fields ◽  
Blood Cells ◽  
Pulsed Electric Fields ◽  
Molar Ratio ◽  
Real Cell ◽  
Almost All ◽  
Phosphate Buffered Saline

AbstractLiposomes are widely assumed to present a straightforward physical model of cells. However, almost all previous liposome experiments with pulsed electric fields (PEFs) have been conducted in low-conductivity liquids, a condition that differs significantly from that of cells in medium. Here, we prepared liposomes consisting of soy bean lecithin and cholesterol, at a molar ratio of 1:1, in higher-conductivity liquid that approximated the conditions of red blood cells in phosphate-buffered saline, with inner and outer liquid conductivities of 0.6 and 1.6 S/m, respectively. We found that a single 1.1 kV/cm, 400 μs PEF promoted cell-like spontaneous division of liposomes.

Membrane Fusion and Deformation of Red Blood Cells by Electric Fields

1980 ◽  
Vol 35 (11-12) ◽  
pp. 1081-1085 ◽  
Author(s):  
Peter Scheurich ◽  
Ulrich Zimmermann ◽  
Maja Mischel ◽  
Ingolf Lamprecht
Keyword(s):  
Electric Field ◽  
Red Blood Cells ◽  
Membrane Fusion ◽  
Electric Fields ◽  
Blood Cells ◽  
Electrical Breakdown ◽  
Osmotic Shock ◽  
Sine Wave ◽  
Hypotonic Solution ◽  
Alternating Electric Field

Abstract Human red blood cells suspended in a slightly hypotonic solution of low electric conductivity were exposed to an inhomogeneous and alternating electric field (sine wave, 30 V peak-to-peak value, electrode distance 120 μm, 0.5 to 2 MHz). Due to the dielectrophoretic effect the cells align parallel to the field lines under the formation of pearl chains. At high voltages (10 V amplitude) membrane fusion is observed between the adhered red blood cells in the pearl chains, whereby the chains become attached to the electrodes. In contrast to the pearl chains observed at voltages of up to 5 V amplitude the resulting fused and uniform aggregates which exhibit no recognisable individual cells under the light microscope, remain stable, even after the alternating electric field has been switched off or after haemolysis in response to osmotic shock. The fused aggregates are highly elastic. If the field strength of the applied alternating electric field is further increased they are stretched in the direction of the opposite electrode. Frequently, bridges are formed between the two electrodes. The uniform bridges remain stable for some time even in the absence of an electric field. The possibility of cell fusion and its initiation by electrical breakdown of the cell membranes are discussed.

scholarly journals Integrating flexible electronics for pulsed electric field delivery in a vascularized 3D glioblastoma model

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Marie C. Lefevre ◽  
Gerwin Dijk ◽  
Attila Kaszas ◽  
Martin Baca ◽  
David Moreau ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Flexible Electronics ◽  
Soft Tissues ◽  
Multiphoton Microscopy ◽  
Membrane Integrity ◽  
Tumor Model ◽  
Pulsed Electric Fields ◽  
In Ovo ◽  
Cell Membrane Integrity

AbstractGlioblastoma is a highly aggressive brain tumor, very invasive and thus difficult to eradicate with standard oncology therapies. Bioelectric treatments based on pulsed electric fields have proven to be a successful method to treat cancerous tissues. However, they rely on stiff electrodes, which cause acute and chronic injuries, especially in soft tissues like the brain. Here we demonstrate the feasibility of delivering pulsed electric fields with flexible electronics using an in ovo vascularized tumor model. We show with fluorescence widefield and multiphoton microscopy that pulsed electric fields induce vasoconstriction of blood vessels and evoke calcium signals in vascularized glioblastoma spheroids stably expressing a genetically encoded fluorescence reporter. Simulations of the electric field delivery are compared with the measured influence of electric field effects on cell membrane integrity in exposed tumor cells. Our results confirm the feasibility of flexible electronics as a means of delivering intense pulsed electric fields to tumors in an intravital 3D vascularized model of human glioblastoma.

Malaria

2019 ◽  
Author(s):  
Angelina Jayakumar ◽  
Zahir Osman Eltahir Babiker
Keyword(s):  
Southeast Asia ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Parasitic Infection ◽  
Sub Saharan Africa ◽  
Anopheline Mosquito ◽  
Sub Saharan ◽  
The Uk ◽  
Almost All ◽  
Human Infections

Malaria is a tropical parasitic infection of the red blood cells caused by the protozoal species Plasmodium falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi. It is transmitted through the bite of the female Anopheles mosquito. The average incubation period is twelve to fourteen days. Congenital and blood-borne transmissions can also occur. P. falciparum and P. vivax account for most human infections but almost all deaths are caused by P. falciparum, with children under five years of age bearing the brunt of morbidity and mortality in endemic countries. P. falciparum is dominant in sub-Saharan Africa whereas P. vivax predominates in Southeast Asia and the Western Pacific. P. ovalae and P. malaria are less common and are mainly found in sub-Saharan Africa. P. knowlesi primarily causes malaria in macaques and is geographically restricted to southeast Asia. While taking a blood meal, the female anopheline mosquito injects motile sporozoites into the bloodstream. Within half an hour, the sporozoites invade the hepatocytes and start dividing to form tissue schizonts. In P. vivax and P. ovale, some of the sporozoites that reach the liver develop into hypnozoites and stay dormant within the hepatocytes for months to years after the original infection. The schizonts eventually rupture releasing daughter merozoites into the bloodstream. The merozoites develop within the red blood cells into ring forms, trophozoites, and eventually mature schizont. This part of the life cycle takes twenty-four hours for P. knowlesi; forty-eight hours for P. falciparum, P. vivax, P. ovale; and seventy-two hours for P. malariae. In P. vivax and P. ovale, some of the sporozoites that reach the liver develop into hypnozoites and stay dormant within the hepatocytes for months to years after the original infection. The hallmark of malaria pathogenesis is parasite sequestration in major organs leading to cytoadherence, endothelial injury, coagulopathy, vascular leakage, pro-inflammatory cytokine production, and tissue inflammation. Malaria is the most frequently imported tropical disease in the UK with an annual case load of around 2000. P. falciparum is the predominant imported species, and failure to take chemoprophylaxis is the commonest risk factor.

Pulsed Electric Fields Versus Thermal Treatment: Equivalent Processes To Obtain Equally Acceptable Citrus Juices

2006 ◽  
Vol 69 (8) ◽  
pp. 2016-2018 ◽  
Author(s):  
E. SENTANDREU ◽  
L. CARBONELL ◽  
D. RODRIGO ◽  
J. V. CARBONELL
Keyword(s):  
Thermal Treatment ◽  
Electric Field ◽  
Electric Fields ◽  
Pulsed Electric Fields ◽  
Pectin Methylesterase ◽  
Pulsed Electric Field ◽  
Citrus Juices ◽  
Pulsed Electric Field Treatment ◽  
Electric Field Treatment

Pulsed electric field treatment has been claimed to produce more acceptable chilled citrus juices than those obtained by conventional thermal treatment. The pectin methylesterase activity and the acceptability of nine juices obtained from Clementine mandarins, Valencia oranges, and Ortanique fruits (hybrid of mandarin and orange), untreated, pasteurized (85°C for 10 s), and treated by pulsed electric fields (25 kV/cm for 330 μs), were evaluated. The treatments, selected to reach a similar level of pectin methylesterase inactivation, produced juices that did not differ in acceptability from each other for the three varieties and in all cases were less acceptable than the untreated juice.

scholarly journals Cytoskeletal Disruption after Electroporation and Its Significance to Pulsed Electric Field Therapies

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1132 ◽  
Author(s):  
Philip M. Graybill ◽  
Rafael V. Davalos
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Irreversible Electroporation ◽  
Pulsed Electric Fields ◽  
Pulsed Electric Field ◽  
Current Understanding ◽  
Vascular Effects ◽  
Cell Substrate ◽  
Membrane Effects ◽  
Cytoskeletal Disruption

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.

Molecular Electronics Including Temperature Effects Based on Dyes Pigments

2019 ◽  
Vol 19 (6) ◽  
pp. 3631-3636
Author(s):  
Adriana T Amador ◽  
Abel F. G Neto ◽  
Jorddy N Cruz ◽  
Fatima N. B Magno ◽  
Francisco C Marques ◽  
...  
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Molecular Electronics ◽  
Electric Fields ◽  
Density Functional ◽  
Functional Theory ◽  
Degradation Temperature ◽  
Red Color ◽  
The Density Functional Theory ◽  
Almost All

In this work we used the Density Functional Theory to study the thermodynamic properties from Brazilein (BZE) and Brazilin (BZI) molecules, main pigments responsible for the red color from Brazil wood. We did a comparison between the two dyes to then know which dye has better resistance to temperature (T ) and external electric field (E) values, aiming their potential to possible applications in solar cells, as excitons trainers. We have found that the BZE molecule becomes less stable after a temperature known as degradation temperature, and therefore enters oxidation state. However, BZE is more stable and more resistant to high temperatures. With respect to the applied external electric field, we find that BZE is more reactive to almost all the applied electric fields, thus more easily converted into energy in the form of electrical work.

Critical Electric Field Strengths of Onion Tissues Treated by Pulsed Electric Fields

2010 ◽  
Vol 75 (7) ◽  
pp. E433-E443 ◽  
Author(s):  
Suvaluk Asavasanti ◽  
Seda Ersus ◽  
William Ristenpart ◽  
Pieter Stroeve ◽  
Diane M. Barrett
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Pulsed Electric Fields ◽  
Field Strengths

scholarly journals Review of the Dynamics of Coalescence and Demulsification by High-Voltage Pulsed Electric Fields

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ye Peng ◽  
Tao Liu ◽  
Haifeng Gong ◽  
Xianming Zhang
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
High Voltage ◽  
Industrial Application ◽  
Voltage Pulse ◽  
Pulse Electric Field ◽  
Pulsed Electric Fields ◽  
High Voltage Pulse ◽  
Technological Method ◽  
Pulse Electric

The coalescence of droplets in oil can be implemented rapidly by high-voltage pulse electric field, which is an effective demulsification dehydration technological method. At present, it is widely believed that the main reason of pulse electric field promoting droplets coalescence is the dipole coalescence and oscillation coalescence in pulse electric field, and the optimal coalescence pulse electric field parameters exist. Around the above content, the dynamics of high-voltage pulse electric field promoting the coalescence of emulsified droplets is studied by researchers domestically and abroad. By review, the progress of high-voltage pulse electric field demulsification technology can get a better understanding, which has an effect of throwing a sprat to catch a whale on promoting the industrial application.

Inactivation of Microorganisms in Cloudy Ginkgo (Ginkgo biloba Linn.) Juice by Pulsed Electric Fields

2007 ◽  
Vol 13 (2) ◽  
pp. 83-90 ◽  
Author(s):  
H. Zhang ◽  
Z. Wang ◽  
R.-J. Yang ◽  
S.-Y. Xu
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Fields ◽  
Treatment Time ◽  
Synergistic Effects ◽  
Pulsed Electric Fields ◽  
Bath Temperature ◽  
Microbial Inactivation ◽  
Plate Counts

Pulsed electric fields (PEF) were applied to neutral ginkgo cloudy juice to study the influence of the electric field strength, the treatment time and temperature on microbial inactivation. The results showed that microbial inactivation increased with the electric field strength, the treatment time and temperature. PEF treatment caused 3.39 and 4.44-log cycles reduction of coliforms and total plate counts, respectively, when pulse duration was 3 μs, the electric field strength 30 kV/cm, the treatment time 520 μs and the water bath temperature 15°C. Under the same conditions, the microbial shelf life of ginkgo cloudy juice was extended to 24 days at 4°C and 18 days at room temperature. A 3.7-log cycles reduction of the total yeast and mould counts was obtained by applying 390 μs of 30 kV/cm at 15°C.Yeast and mould cells were less resistant to PEF process than bacteria cells. The effect of heat generated during the PEF treatment was limited on microbial inactivation. Temperature and the induced heat by PEF had synergistic effects to microbial inactivation in cloudy ginkgo juice.

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