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Omar YAD, Lipel ZG, Mandadapu KK. (2+δ)-dimensional theory of the electromechanics of lipid membranes: Electrostatics. Phys Rev E 2024; 109:054401. [PMID: 38907464 DOI: 10.1103/physreve.109.054401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/13/2024] [Indexed: 06/24/2024]
Abstract
The coupling of electric fields to the mechanics of lipid membranes gives rise to intriguing electromechanical behavior, as, for example, evidenced by the deformation of lipid vesicles in external electric fields. Electromechanical effects are relevant for many biological processes, such as the propagation of action potentials in axons and the activation of mechanically gated ion channels. Currently, a theoretical framework describing the electromechanical behavior of arbitrarily curved and deforming lipid membranes does not exist. Purely mechanical models commonly treat lipid membranes as two-dimensional surfaces, ignoring their finite thickness. While holding analytical and numerical merit, this approach cannot describe the coupling of lipid membranes to electric fields and is thus unsuitable for electromechanical models. In a sequence of articles, we derive an effective surface theory of the electromechanics of lipid membranes, called the (2+δ)-dimensional theory, which has the advantages of surface descriptions while accounting for finite thickness effects. The present article proposes a generic dimension reduction procedure relying on low-order spectral expansions. This procedure is applied to the electrostatics of lipid membranes to obtain the (2+δ)-dimensional theory that captures potential differences across and electric fields within lipid membranes. This model is tested on different geometries relevant for lipid membranes, showing good agreement with the corresponding three-dimensional electrostatics theory.
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Affiliation(s)
- Yannick A D Omar
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Zachary G Lipel
- Department of Chemical & Biomolecular Engineering, University of California, Berkeley, California 94720, USA
| | - Kranthi K Mandadapu
- Department of Chemical & Biomolecular Engineering, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, California 94720, 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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Nuñez-Magos L, Lira-Escobedo J, Rodríguez-López R, Muñoz-Navia M, Castillo-Rivera F, Viveros-Méndez PX, Araujo E, Encinas A, Saucedo-Anaya SA, Aranda-Espinoza S. Effects of DC Magnetic Fields on Magnetoliposomes. Front Mol Biosci 2021; 8:703417. [PMID: 34589517 PMCID: PMC8473709 DOI: 10.3389/fmolb.2021.703417] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/21/2021] [Indexed: 02/04/2023] Open
Abstract
The potential use of magnetic nanoparticles (MNPs) in biomedicine as magnetic resonance, drug delivery, imagenology, hyperthermia, biosensors, and biological separation has been studied in different laboratories. One of the challenges on MNP elaboration for biological applications is the size, biocompatibility, heat efficiency, stabilization in physiological conditions, and surface coating. Magnetoliposome (ML), a lipid bilayer of phospholipids encapsulating MNPs, is a system used to reduce toxicity. Encapsulated MNPs can be used as a potential drug and a gene delivery system, and in the presence of magnetic fields, MLs can be accumulated in a target tissue by a strong gradient magnetic field. Here, we present a study of the effects of DC magnetic fields on encapsulated MNPs inside liposomes. Despite their widespread applications in biotechnology and environmental, biomedical, and materials science, the effects of magnetic fields on MLs are unclear. We use a modified coprecipitation method to synthesize superparamagnetic nanoparticles (SNPs) in aqueous solutions. The SNPs are encapsulated inside phospholipid liposomes to study the interaction between phospholipids and SNPs. Material characterization of SNPs reveals round-shaped nanoparticles with an average size of 12 nm, mainly magnetite. MLs were prepared by the rehydration method. After formation, we found two types of MLs: one type is tense with SNPs encapsulated and the other is a floppy vesicle that does not show the presence of SNPs. To study the response of MLs to an applied DC magnetic field, we used a homemade chamber. Digitalized images show encapsulated SNPs assembled in chain formation when a DC magnetic field is applied. When the magnetic field is switched off, it completely disperses SNPs. Floppy MLs deform along the direction of the external applied magnetic field. Solving the relevant magnetostatic equations, we present a theoretical model to explain the ML deformations by analyzing the forces exerted by the magnetic field over the surface of the spheroidal liposome. Tangential magnetic forces acting on the ML surface result in a press force deforming MLs. The type of deformations will depend on the magnetic properties of the mediums inside and outside the MLs. The model predicts a coexistence region of oblate-prolate deformation in the zone where χ = 1. We can understand the chain formation in terms of a dipole-dipole interaction of SNP.
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Affiliation(s)
- L. Nuñez-Magos
- Laboratory of Biophysics and Soft Matter, Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - J. Lira-Escobedo
- Laboratory of Biophysics and Soft Matter, Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - R. Rodríguez-López
- Laboratory of Biophysics and Soft Matter, Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - M. Muñoz-Navia
- Ingeniería en Nanotecnología, Universidad de La Ciénega del Estado de Michoacán de Ocampo, Sahuayo, Mexico
| | - F. Castillo-Rivera
- CONACyT–Instituto de Geología de la Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - P. X. Viveros-Méndez
- Unidad Académica de Ciencia y Tecnología de la Luz y la Materia, Universidad Autónoma de Zacatecas, Zacatecas, Mexico
| | - E. Araujo
- Departamento de Matematicas y Física, Instituto Tecnológico y de Estudios Superiores de Occidente, San Pedro Tlaquepaque, Mexico
| | - A. Encinas
- Laboratory of Magnetism, División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica, San Luis Potosí, Mexico
| | - S. A. Saucedo-Anaya
- Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas, Zacatecas, Mexico
| | - S. Aranda-Espinoza
- Laboratory of Biophysics and Soft Matter, Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
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Samukhina YV, Matyushin DD, Polyakov PA, Buryak AK. On the Charge Instability and the Metastable Equilibrium State of a Conducting Droplet during Liquid Electrospraying. COLLOID JOURNAL 2021. [DOI: 10.1134/s1061933x21040098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Zhang R, Han Y, Zhang L, Chen Q, Ding M, Shi T. Migration and deformation of polyelectrolyte vesicle through a pore in electric field. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.125560] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kiełbik A, Szlasa W, Saczko J, Kulbacka J. Electroporation-Based Treatments in Urology. Cancers (Basel) 2020; 12:E2208. [PMID: 32784598 PMCID: PMC7465806 DOI: 10.3390/cancers12082208] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/03/2020] [Accepted: 08/05/2020] [Indexed: 02/06/2023] Open
Abstract
The observation that an application of a pulsed electric field (PEF) resulted in an increased permeability of the cell membrane has led to the discovery of the phenomenon called electroporation (EP). Depending on the parameters of the electric current and cell features, electroporation can be either reversible or irreversible. The irreversible electroporation (IRE) found its use in urology as a non-thermal ablative method of prostate and renal cancer. As its mechanism is based on the permeabilization of cell membrane phospholipids, IRE (as well as other treatments based on EP) provides selectivity sparing extracellular proteins and matrix. Reversible EP enables the transfer of genes, drugs, and small exogenous proteins. In clinical practice, reversible EP can locally increase the uptake of cytotoxic drugs such as cisplatin and bleomycin. This approach is known as electrochemotherapy (ECT). Few in vivo and in vitro trials of ECT have been performed on urological cancers. EP provides the possibility of transmission of genes across the cell membrane. As the protocols of gene electrotransfer (GET) over the last few years have improved, EP has become a well-known technique for non-viral cell transfection. GET involves DNA transfection directly to the cancer or the host skin and muscle tissue. Among urological cancers, the GET of several plasmids encoding prostate cancer antigens has been investigated in clinical trials. This review brings into discussion the underlying mechanism of EP and an overview of the latest progress and development perspectives of EP-based treatments in urology.
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Affiliation(s)
- Aleksander Kiełbik
- Faculty of Medicine, Wroclaw Medical University, 50-367 Wroclaw, Poland; (A.K.); (W.S.)
| | - Wojciech Szlasa
- Faculty of Medicine, Wroclaw Medical University, 50-367 Wroclaw, Poland; (A.K.); (W.S.)
| | - Jolanta Saczko
- Department of Molecular and Cellular Biology, Wroclaw Medical University, 50-556 Wroclaw, Poland;
| | - Julita Kulbacka
- Department of Molecular and Cellular Biology, Wroclaw Medical University, 50-556 Wroclaw, Poland;
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7
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Robinson T, Dittrich PS. Observations of Membrane Domain Reorganization in Mechanically Compressed Artificial Cells. Chembiochem 2019; 20:2666-2673. [PMID: 31087814 PMCID: PMC7612542 DOI: 10.1002/cbic.201900167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Indexed: 01/01/2023]
Abstract
Giant unilamellar vesicles (GUVs) are considered to be the gold standard for assembling artificial cells from the bottom up. In this study, we investigated the behavior of such biomimetic vesicles as they were subjected to mechanical compression. A microfluidic device is presented that comprises a trap to capture GUVs and a microstamp that is deflected downwards to mechanically compress the trapped vesicle. After characterization of the device, we show that single-phase GUVs can be controllably compressed to a high degree of deformation (D=0.40) depending on the pressure applied to the microstamp. A permeation assay was implemented to show that vesicle bursting is prevented by water efflux. Next, we mechanically compressed GUVs with co-existing liquid-ordered and liquid-disordered membrane phases. Upon compression, we observed that the normally stable lipid domains reorganized themselves across the surface and fused into larger domains. This phenomenon, observed here in a model membrane system, not only gives us insights into how the multicomponent membranes of artificial cells behave, but might also have interesting consequences for the role of lipid rafts in biological cells that are subjected to compressive forces in a natural environment.
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Affiliation(s)
- Tom Robinson
- ETH Zurich, Department of Biosystems Science and Engineering, Mattenstrasse 26, 4058, Basel, Switzerland
- Present address: Department of Theory, Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424, Potsdam, Germany
| | - Petra S Dittrich
- ETH Zurich, Department of Biosystems Science and Engineering, Mattenstrasse 26, 4058, Basel, Switzerland
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8
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Biophysical implications of Maxwell stress in electric field stimulated cellular microenvironment on biomaterial substrates. Biomaterials 2019; 209:54-66. [DOI: 10.1016/j.biomaterials.2019.04.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 04/05/2019] [Accepted: 04/06/2019] [Indexed: 01/09/2023]
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9
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Morshed A, Dutta P, Hossan MR, Dillon R. Electrodeformation of Vesicles Suspended in a Liquid Medium. PHYSICAL REVIEW FLUIDS 2018; 3:103702. [PMID: 32864538 PMCID: PMC7451073 DOI: 10.1103/physrevfluids.3.103702] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Deformation of flexible vesicles suspended in a fluid medium due to an applied electric field can provide valuable insight into deformation dynamics at a very small scale. In an electric field, the response of the vesicle membrane is strongly influenced by the conductivity of surrounding fluid, vesicle size and shape, and the magnitude of applied field. We studied the electrodeformation of vesicles immersed in a fluid media under a DC electric field. An immersed interface method is used to solve the electric field over the domain with conductive or non-conductive vesicles while an immersed boundary method is employed to solve fluid flow, fluid-solid interaction, membrane mechanics and vesicle deformation. Initial force analysis on the membrane surface reveals almost linear influence of vesicle size, but the vesicle size does not affect the long-term deformation which is consistent with experimental evidence. Highly nonlinear effect of the applied field as well as the conductivity ratios inside and outside of the vesicle are observed. Results also point towards an early linear deformation regime followed by an equilibrium stage for the membranes. Modeling results suggest that electrodeforming vesicles can create unique external flows for different conductivity ratios. Moreover, significant influence of the initial aspect ratio of the vesicle on the force distribution is observed across a range of conductivity ratios.
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Affiliation(s)
- Adnan Morshed
- School of Mechanical and Materials Engineering Washington State University, Pullman, WA 99164
| | - Prashanta Dutta
- School of Mechanical and Materials Engineering Washington State University, Pullman, WA 99164
| | | | - Robert Dillon
- Department of Mathematics and Statistics Washington State University, Pullman, WA 99164
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10
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Das S, Thaokar RM. Large deformation electrohydrodynamics of a Skalak elastic capsule in AC electric field. SOFT MATTER 2018; 14:1719-1736. [PMID: 29431817 DOI: 10.1039/c7sm02297b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The axisymmetric electrohydrodynamic deformation of an elastic capsule with a capacitive membrane obeying the Skalak law under a uniform AC electric field is investigated using analytical and boundary integral theory. The low capillary number (the ratio of destabilizing shear or electric force to the stabilizing elastic force) regime shows that time-averaged prolate and oblate spheroid deformations, and the time-periodic prolate-sphere, oblate-sphere breathing modes are commensurate with the time averaged-deformation. A novel prolate-oblate breathing mode is observed due to an interplay of finite membrane charging time and the field reversal of the AC field. The study, when extended to high capillary numbers, shows new breathing modes of cylinder-prolate, cylinder-oblate, and biconcave-prolate deformation. These are the results of highly compressive normal Maxwell stress at the poles and are aided by a weak compressive equatorial stress, characteristic of a capacitive membrane. The findings of this work should form the basis for the understanding of more complex biological cells and synthetic capsules for industrial applications.
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Affiliation(s)
- Sudip Das
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India.
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11
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Numerical study of the effect of soft layer properties on bacterial electroporation. Bioelectrochemistry 2017; 123:261-272. [PMID: 29146422 DOI: 10.1016/j.bioelechem.2017.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 09/07/2017] [Accepted: 09/07/2017] [Indexed: 11/24/2022]
Abstract
We present a numerical model of electroporation in a gram-positive bacterium, which accounts for the presence of a negatively charged soft polyelectrolyte layer (which may include a periplasmic space, peptidoglycan layer, cilia, flagella, and other surface appendages) surrounding its plasma membrane. We model the ion transport within and outside the soft layer using the soft layer electrokinetics-based Poisson-Nernst-Planck formalism. Additionally, we model the electroporation dynamics on the plasma membrane using the pore nucleation-based electroporation formalism developed by Krassowska and Filev. We find that ion transport within the soft layer (surface conduction), which depends on the relative importance of the soft layer charged group concentration compared to the buffer concentration, significantly alters the transmembrane voltage across the plasma membrane and hence the pore characteristics. Our numerical simulations suggest that surface conduction significantly lowers the pore number in the plasma membrane. This observation is consistent with experimental studies that show that gram-positive bacteria, in general, have lower transformation efficiencies compared to gram-negative bacteria. Our studies highlight a strong dependence of bacterial electroporation on cell envelope properties and buffer conditions, which need to be taken into consideration when designing electroporation protocols.
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12
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Mikkelsen A, Dommersnes P, Rozynek Z, Gholamipour-Shirazi A, Carvalho MDS, Fossum JO. Mechanics of Pickering Drops Probed by Electric Field-Induced Stress. MATERIALS 2017; 10:ma10040436. [PMID: 28772796 PMCID: PMC5506933 DOI: 10.3390/ma10040436] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 03/26/2017] [Accepted: 04/13/2017] [Indexed: 01/08/2023]
Abstract
Fluid drops coated with particles, so-called Pickering drops, play an important role in emulsion and capsule applications. In this context, knowledge of mechanical properties and stability of Pickering drops are essential. Here we prepare Pickering drops via electric field-driven self-assembly. We use direct current (DC) electric fields to induce mechanical stress on these drops, as a possible alternative to the use of, for example, fluid flow fields. Drop deformation is monitored as a function of the applied electric field strength. The deformation of pure silicone oil drops is enhanced when covered by insulating polyethylene (PE) particles, whereas drops covered by conductive clay particles can also change shape from oblate to prolate. We attribute these results to changes in the electric conductivity of the drop interface after adding particles, and have developed a fluid shell description to estimate the conductivity of Pickering particle layers that are assumed to be non-jammed and fluid-like. Retraction experiments in the absence of electric fields are also performed. Particle-covered drops retract slower than particle-free drops, caused by increased viscous dissipation due to the presence of the Pickering particle layer.
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Affiliation(s)
- Alexander Mikkelsen
- Department of Physics, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491 Trondheim, Norway.
- Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland.
| | - Paul Dommersnes
- Department of Physics, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491 Trondheim, Norway.
| | - Zbigniew Rozynek
- Department of Physics, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491 Trondheim, Norway.
- Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland.
| | - Azarmidokht Gholamipour-Shirazi
- Department of Mechanical Engineering, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente, 225, Rio de Janeiro, Brazil.
| | - Marcio da Silveira Carvalho
- Department of Mechanical Engineering, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente, 225, Rio de Janeiro, Brazil.
| | - Jon Otto Fossum
- Department of Physics, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491 Trondheim, Norway.
- Department of Mechanical Engineering, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente, 225, Rio de Janeiro, Brazil.
- Institut Pierre-Gilles de Gennes, 6-12 rue Jean Calvin, Paris 75005, France.
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Antonova K, Vitkova V, Meyer C. Membrane tubulation from giant lipid vesicles in alternating electric fields. Phys Rev E 2016; 93:012413. [PMID: 26871107 DOI: 10.1103/physreve.93.012413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Indexed: 06/05/2023]
Abstract
We report on the formation of tubular membrane protrusions from giant unilamellar vesicles in alternating electric fields. The construction of the experimental chamber permitted the application of external AC fields with strength of dozens of V/mm and kHz frequency during relatively long time periods (several minutes). Besides the vesicle electrodeformation from quasispherical to prolate ellipsoidal shape, the formation of long tubular membrane protrusions with length of up to several vesicle diameters, arising from the vesicular surface in the field direction, was registered and analyzed. The threshold electric field at which the electro-induced protrusions appeared was lower than the field strengths inducing membrane electroporation.
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Affiliation(s)
- K Antonova
- Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko chaussee, Sofia 1784, Bulgaria
| | - V Vitkova
- Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko chaussee, Sofia 1784, Bulgaria
| | - C Meyer
- Laboratoire de Physique des Systèmes Complexes, Université de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens, France
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14
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Mauroy C, Rico-Lattes I, Teissié J, Rols MP. Electric Destabilization of Supramolecular Lipid Vesicles Subjected to Fast Electric Pulses. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12215-12222. [PMID: 26488925 DOI: 10.1021/acs.langmuir.5b03090] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Biological membranes are weakly permeable to hydrophilic molecules and ions and electric pulses can induce their transient permeabilization, but this process is not well characterized. We directly assay the electropermeabilization process, on the minimum model of lipid vesicles, by using a highly sensitive fluorescence method based on manganese ion transport. The approach gives access, at the single-lipid self-assembly level, to the transmembrane potential needed to detect divalent ion permeabilization on supramolecular giant unilamellar lipid vesicles. The critical values are strongly dependent on the lipid composition and are observed to vary from 10 to 150 mV. These values appear to be much lower than those previously reported in the literature for cells and vesicles. The detection method appears to be a decisive parameter as it is controlled by the transport of the reporter dye. We also provide evidence that the electropermeabilization process is a transient transition of the lipid self-organization due to the loss of assembly cohesion induced by bioelectrochemical perturbations of the zwitterionic interface with the solution.
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Affiliation(s)
- Chloé Mauroy
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, UMR 5089 and Université Paul Sabatier , 205 route de Narbonne, BP 64182, 31077 Toulouse, France
- Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique, UMR 5623 CNRS and Université Paul Sabatier , 118 route de Narbonne, 31062 Toulouse, France
| | - Isabelle Rico-Lattes
- Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique, UMR 5623 CNRS and Université Paul Sabatier , 118 route de Narbonne, 31062 Toulouse, France
| | - Justin Teissié
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, UMR 5089 and Université Paul Sabatier , 205 route de Narbonne, BP 64182, 31077 Toulouse, France
- Emeritus Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, UMR 5089 and Université Paul Sabatier, 205 route de Narbonne, BP 64182, 31077 Toulouse, France
| | - Marie-Pierre Rols
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, UMR 5089 and Université Paul Sabatier , 205 route de Narbonne, BP 64182, 31077 Toulouse, France
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15
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Murovec T, Brosseau C. Spectral fingerprint of electrostatic forces between biological cells. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:042717. [PMID: 26565282 DOI: 10.1103/physreve.92.042717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Indexed: 06/05/2023]
Abstract
The prediction of electrostatic forces (EFs) between biological cells still poses challenges of great scientific importance, e.g., cell recognition, electroporation (EP), and mechanosensing. Frequency-domain finite element simulations explore a variety of cell configurations in the range of parameters typical for eukaryotic cells. Here, by applying an electric field to a pair of layered concentric shells, a prototypical model of a biological cell, we provide numerical evidence that the instantaneous EF changes from repulsion to attraction as the drive frequency of the electric field is varied. We identify crossover frequencies and discuss their dependence as a function of field frequency, conductivity of the extracellular medium, and symmetry of the configuration of cells. We present findings which suggest that the spectrum of EFs depends sensitively on the configuration of cells. We discuss the signatures of the collective behavior of systems with many cells in the spectrum of the EF and highlight a few of the observational consequences that this behavior implies. By looking at different cell configurations, we are able to show that the repulsion-to-attraction transition phenomenon is largely associated with an asymmetric electrostatic screening at very small separation between cells. These findings pave the way for the experimental observation of the electromagnetic properties of efficient and simple models of biological tissues.
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Affiliation(s)
- T Murovec
- Université de Brest, Lab-STICC, CS 93837, 6 avenue Le Gorgeu, 29238 Brest Cedex 3, France
| | - C Brosseau
- Université de Brest, Lab-STICC, CS 93837, 6 avenue Le Gorgeu, 29238 Brest Cedex 3, France
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16
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Kolahdouz EM, Salac D. Dynamics of three-dimensional vesicles in dc electric fields. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:012302. [PMID: 26274157 DOI: 10.1103/physreve.92.012302] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 06/04/2023]
Abstract
A numerical and systematic parameter study of three-dimensional vesicle electrohydrodynamics is presented to investigate the effects of varying electric field strength and different fluid and membrane properties. The dynamics of vesicles in the presence of dc electric fields is considered, in both the presence and absence of linear shear flow. For suspended vesicles it is shown that the conductivity ratio and viscosity ratio between the interior and exterior fluids, as well as the vesicle membrane capacitance, substantially affect the minimum electric field strength required to induce a full prolate-oblate-prolate transition. In addition, there exists a critical electric field strength above which a vesicle will no longer tumble when exposed to linear shear flow.
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Affiliation(s)
- Ebrahim M Kolahdouz
- Department of Mechanical and Aerospace Engineering, State University of New York at Buffalo, Buffalo, New York 14226, USA
| | - David Salac
- Department of Mechanical and Aerospace Engineering, State University of New York at Buffalo, Buffalo, New York 14226, USA
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17
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Zhou C, Riehn R. Collapse of DNA under alternating electric fields. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:012714. [PMID: 26274209 PMCID: PMC5014398 DOI: 10.1103/physreve.92.012714] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Indexed: 05/04/2023]
Abstract
Recent studies have shown that double-stranded DNA can collapse in the presence of a strong electric field. Here we provide an in-depth study of the collapse of DNA under weak confinement in microchannels as a function of buffer strength, driving frequency, applied electric-field strength, and molecule size. We find that the critical electric field at which DNA molecules collapse (tens of kV/m) is strongly dependent on driving frequency (100-800 Hz) and molecular size (20-160 kbp), and weakly dependent on the ionic strength (8-60 mM). We argue that an apparent stretching at very high electric fields is an artifact of the finite frame time of video microscopy.
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Affiliation(s)
- Chunda Zhou
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202
| | - Robert Riehn
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202
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18
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Tang YG, Liu Y, Feng XQ. Deformation analysis of vesicles in an alternating-current electric field. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:022709. [PMID: 25215760 DOI: 10.1103/physreve.90.022709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Indexed: 06/03/2023]
Abstract
In this paper the shape equation for axisymmetric vesicles subjected to an ac electric field is derived on the basis of the liquid-crystal model. The equilibrium morphology of a lipid vesicle is determined by the minimization of its free energy in coupled mechanical and ac electric fields. Besides elastic bending, the effects of the osmotic pressure difference, surface tension, Maxwell pressure, and flexoelectric and dielectric properties of phospholipid membrane as well are taken into account. The influences of elastic bending, osmotic pressure difference, and surface tension on the frequency-dependent behavior of a vesicle membrane in an ac electric field are examined. The singularity of the ac electric field is also investigated. Our theoretical results of vesicle deformation agree well with previous experimental and numerical results. The present study provides insights into the physical mechanisms underpinning the frequency-dependent morphological evolution of vesicles in the electric and mechanical fields.
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Affiliation(s)
- Yu-Gang Tang
- Department of Mechanics, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, People's Republic of China
| | - Ying Liu
- Department of Mechanics, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, People's Republic of China
| | - Xi-Qiao Feng
- AML and CNMM, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, People's Republic of China
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19
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Winterhalter M. Lipid membranes in external electric fields: kinetics of large pore formation causing rupture. Adv Colloid Interface Sci 2014; 208:121-8. [PMID: 24485595 DOI: 10.1016/j.cis.2014.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/06/2014] [Accepted: 01/10/2014] [Indexed: 10/25/2022]
Abstract
About 40 years ago, Helfrich introduced an elastic model to explain shapes and shape transitions of cells (Z Naturforsch C, 1973; 28:693). This seminal article stimulated numerous theoretical as well as experimental investigations and created new research fields. In particular, the predictive power of his approach was demonstrated in a large variety of lipid model system. Here in this review, we focus on the development with respect to planar lipid membranes in external electric fields. Stimulated by the early work of Helfrich on electric field forces acting on liposomes, we extended his early approach to understand the kinetics of lipid membrane rupture. First, we revisit the main forces determining the kinetics of membrane rupture followed by an overview on various experiments. Knowledge on the kinetics of defect formation may help to design stable membranes or serve for novel mechanism for controlled release.
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20
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Dimova R. Recent developments in the field of bending rigidity measurements on membranes. Adv Colloid Interface Sci 2014; 208:225-34. [PMID: 24666592 DOI: 10.1016/j.cis.2014.03.003] [Citation(s) in RCA: 333] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 02/28/2014] [Accepted: 03/02/2014] [Indexed: 12/19/2022]
Abstract
This review gives a brief overview of experimental approaches used to assess the bending rigidity of membranes. Emphasis is placed on techniques based on the use of giant unilamellar vesicles. We summarize the effect on the bending rigidity of membranes as a function of membrane composition, presence of various inclusions in the bilayer and molecules and ions in the bathing solutions. Examples for the impact of temperature, cholesterol, some peptides and proteins, sugars and salts are provided and the literature data are discussed critically. Future directions, open questions and possible developments in this research field are also included.
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Affiliation(s)
- Rumiana Dimova
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany.
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21
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Bassereau P, Sorre B, Lévy A. Bending lipid membranes: experiments after W. Helfrich's model. Adv Colloid Interface Sci 2014; 208:47-57. [PMID: 24630341 DOI: 10.1016/j.cis.2014.02.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 02/02/2014] [Accepted: 02/03/2014] [Indexed: 10/25/2022]
Abstract
Current description of biomembrane mechanics originates for a large part from W. Helfrich's model. Based on his continuum theory, many experiments have been performed in the past four decades on simplified membranes in order to characterize the mechanical properties of lipid membranes and the contribution of polymers or proteins. The long-term goal was to develop a better understanding of the mechanical properties of cell membranes. In this paper, we will review representative experimental approaches that were developed during this period and the main results that were obtained.
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22
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Iwamoto M, Ou-Yang ZC. Anharmonic magnetic deformation of spherical vesicle: Field-induced tension and swelling effects. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.10.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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23
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Nganguia H, Young YN. Equilibrium electrodeformation of a spheroidal vesicle in an ac electric field. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:052718. [PMID: 24329307 DOI: 10.1103/physreve.88.052718] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Indexed: 06/03/2023]
Abstract
In this work, we develop a theoretical model to explain the equilibrium spheroidal deformation of a giant unilamellar vesicle (GUV) under an alternating (ac) electric field. Suspended in a leaky dielectric fluid, the vesicle membrane is modeled as a thin capacitive spheroidal shell. The equilibrium vesicle shape results from the balance between mechanical forces from the viscous fluid, the restoring elastic membrane forces, and the externally imposed electric forces. Our spheroidal model predicts a deformation-dependent transmembrane potential, and is able to capture large deformation of a vesicle under an electric field. A detailed comparison against both experiments and small-deformation (quasispherical) theory showed that the spheroidal model gives better agreement with experiments in terms of the dependence on fluid conductivity ratio, permittivity ratio, vesicle size, electric field strength, and frequency. The spheroidal model also allows for an asymptotic analysis on the crossover frequency where the equilibrium vesicle shape crosses over between prolate and oblate shapes. Comparisons show that the spheroidal model gives better agreement with experimental observations.
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Affiliation(s)
- H Nganguia
- Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102, USA
| | - Y-N Young
- Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102, USA
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24
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25
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Destabilizing giant vesicles with electric fields: an overview of current applications. J Membr Biol 2012; 245:555-64. [PMID: 22864479 DOI: 10.1007/s00232-012-9467-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 06/24/2012] [Indexed: 10/28/2022]
Abstract
This review presents an overview of the effects of electric fields on giant unilamellar vesicles. The application of electrical fields leads to three basic phenomena: shape changes, membrane breakdown, and uptake of molecules. We describe how some of these observations can be used to measure a variety of physical properties of lipid membranes or to advance our understanding of the phenomena of electropermeabilization. We also present results on how electropermeabilization and other liposome responses to applied fields are affected by lipid composition and by the presence of molecules of therapeutic interest in the surrounding solution.
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26
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Giant Vesicles. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/b978-0-12-396534-9.00001-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
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27
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Dimova R. Membrane Electroporation in High Electric Fields. ADVANCES IN ELECTROCHEMICAL SCIENCES AND ENGINEERING 2011. [DOI: 10.1002/9783527644117.ch7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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28
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Sadik MM, Li J, Shan JW, Shreiber DI, Lin H. Vesicle deformation and poration under strong dc electric fields. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:066316. [PMID: 21797486 DOI: 10.1103/physreve.83.066316] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 01/17/2011] [Indexed: 05/31/2023]
Abstract
When subject to applied electric pulses, a lipid membrane exhibits complex responses including electrodeformation and electroporation. In this work, the electrodeformation of giant unilamellar vesicles under strong dc electric fields was investigated. Specifically, the degree of deformation was quantified as a function of the applied field strength and the electrical conductivity ratio of the fluids inside and outside of the vesicles. The vesicles were made from L-α-phosphatidylcholine with diameters ranging from 14 to 30 μm. Experiments were performed with field strengths ranging from 0.9 to 2.0 kV/cm, and intra-to-extra-vesicular conductivity ratios varying between 1.92 and 53.0. With these parametric configurations, the vesicles exhibited prolate elongations along the direction of the electric field. The degree of deformation was, in general, significant. In some cases, the aspect ratio of a deformed vesicle exceeded 10, representing a strong-deformation regime previously not explored. The aspect ratio scaled quadratically with the field strength, and increased asymptotically to a maximum value at high conductivity ratios. Appreciable area and volumetric changes were observed both during and after pulsation, indicating the concurrence of electroporation. A theoretical model is developed to predict these large deformations in the strongly permeabilized limit, and the results are compared with the experimental data. Both agreements and discrepancies are found, and the model limitations and possible extensions are discussed.
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Affiliation(s)
- Mohamed M Sadik
- Department of Mechanical and Aerospace Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854, USA
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29
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Peterlin P. Frequency-dependent electrodeformation of giant phospholipid vesicles in AC electric field. J Biol Phys 2010; 36:339-54. [PMID: 21886342 PMCID: PMC2923700 DOI: 10.1007/s10867-010-9187-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Accepted: 02/22/2010] [Indexed: 11/26/2022] Open
Abstract
A model of vesicle electrodeformation is described which obtains a parametrized vesicle shape by minimizing the sum of the membrane bending energy and the energy due to the electric field. Both the vesicle membrane and the aqueous media inside and outside the vesicle are treated as leaky dielectrics, and the vesicle itself is modeled as a nearly spherical shape enclosed within a thin membrane. It is demonstrated (a) that the model achieves a good quantitative agreement with the experimentally determined prolate-to-oblate transition frequencies in the kilohertz range and (b) that the model can explain a phase diagram of shapes of giant phospholipid vesicles with respect to two parameters: the frequency of the applied alternating current electric field and the ratio of the electrical conductivities of the aqueous media inside and outside the vesicle, explored in a recent paper (S. Aranda et al., Biophys J 95:L19-L21, 2008). A possible use of the frequency-dependent shape transitions of phospholipid vesicles in conductometry of microliter samples is discussed.
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Affiliation(s)
- Primož Peterlin
- Faculty of Medicine, Institute of Biophysics, University of Ljubljana, Lipičeva 2, 1000 Ljubljana, Slovenia
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30
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Yamamoto T, Aranda-Espinoza S, Dimova R, Lipowsky R. Stability of spherical vesicles in electric fields. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:12390-407. [PMID: 20575588 PMCID: PMC2903956 DOI: 10.1021/la1011132] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 05/26/2010] [Indexed: 05/16/2023]
Abstract
The stability of spherical vesicles in alternating (ac) electric fields is studied theoretically for asymmetric conductivity conditions across their membranes. The vesicle deformation is obtained from a balance between the curvature elastic energies and the work done by the Maxwell stresses. The present theory describes and clarifies the mechanisms for the four types of morphological transitions observed experimentally on vesicles exposed to ac fields in the frequency range from 500 to 2 x 10(7) Hz. The displacement currents across the membranes redirect the electric fields toward the membrane normal to accumulate electric charges by the Maxwell-Wagner mechanism. These accumulated electric charges provide the underlying molecular mechanism for the morphological transitions of vesicles as observed on the micrometer scale.
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Affiliation(s)
- Tetsuya Yamamoto
- Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany.
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31
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Kakorin S, Neumann E. Kinetics of the electroporative deformation of lipid vesicles and biological cells in an electric field. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19981020411] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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32
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33
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Sekine K, Takeda T, Nagaomo K, Matsushima E. Boundary-element calculations for amplification of effects of low-frequency electric fields in a doublet-shaped biological cell. Bioelectrochemistry 2010; 77:106-13. [DOI: 10.1016/j.bioelechem.2009.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 05/18/2009] [Accepted: 07/07/2009] [Indexed: 10/20/2022]
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34
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Vlahovska PM. Nonequilibrium Dynamics of Lipid Membranes: Deformation and Stability in Electric Fields. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/b978-0-12-381266-7.00005-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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35
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36
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Zhivkov AM, Gyurova AY. Influence of cytoplasm electrolyte concentration on Maxwell-Wagner polarizability of bacteria E. coli. J Phys Chem B 2009; 113:8375-82. [PMID: 19469565 DOI: 10.1021/jp810020p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electric polarizability of bacteria is considered in the literature to have a surface charge dependent (ChD) and a Maxwell-Wagner (MW) mechanism. We distinguish experimentally both the types of interface polarizability by the frequency of the electric field and the medium electrolyte concentration. It was shown in a previous work ( Zhivkov , A. M. ; Gyurova , A. Y. Colloids Surf., B 2008 , 66 , 201. ) that the ChD component is shown up on the outer bacteria surface even at megahertz frequencies. The MW polarizability is studied in the present work in the range from 20 kHz to 20 MHz by change in the inner (cytoplasm) electrolyte concentration. The ion transport through the cytoplasmic membrane of alive and fixed by formaldehyde E. coli K12 is accelerated by adding of ethanol in low concentration. The frequency dependence and the kinetics of the electric polarizability and the size of the bacteria are investigated by conservative electric dichroism, based on the alteration of the optical density at orientation of the cells in electric field. The conclusion is that the internal MW component has the main contribution to the change in the total bacteria polarizability, as well as the external MW and the internal ChD components are not shown up.
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Affiliation(s)
- Alexandar M Zhivkov
- Institute of Physical Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, bl. 11, Sofia 1113, Bulgaria
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37
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Vlahovska PM, Gracià RS, Aranda-Espinoza S, Dimova R. Electrohydrodynamic model of vesicle deformation in alternating electric fields. Biophys J 2009; 96:4789-803. [PMID: 19527639 PMCID: PMC2712034 DOI: 10.1016/j.bpj.2009.03.054] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 03/12/2009] [Accepted: 03/18/2009] [Indexed: 11/29/2022] Open
Abstract
We develop an analytical theory to explain the experimentally observed morphological transitions of quasispherical giant vesicles induced by alternating electric fields. The model treats the inner and suspending media as lossy dielectrics, and the membrane as an impermeable flexible incompressible-fluid sheet. The vesicle shape is obtained by balancing electric, hydrodynamic, bending, and tension stresses exerted on the membrane. Our approach, which is based on force balance, also allows us to describe the time evolution of the vesicle deformation, in contrast to earlier works based on energy minimization, which are able to predict only stationary shapes. Our theoretical predictions for vesicle deformation are consistent with experiment. If the inner fluid is more conducting than the suspending medium, the vesicle always adopts a prolate shape. In the opposite case, the vesicle undergoes a transition from a prolate to oblate ellipsoid at a critical frequency, which the theory identifies with the inverse membrane charging time. At frequencies higher than the inverse Maxwell-Wagner polarization time, the electrohydrodynamic stresses become too small to alter the vesicle's quasispherical rest shape. The model can be used to rationalize the transient and steady deformation of biological cells in electric fields.
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Affiliation(s)
- Petia M Vlahovska
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire, USA.
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38
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Portet T, Camps i Febrer F, Escoffre JM, Favard C, Rols MP, Dean DS. Visualization of membrane loss during the shrinkage of giant vesicles under electropulsation. Biophys J 2009; 96:4109-21. [PMID: 19450482 PMCID: PMC2712208 DOI: 10.1016/j.bpj.2009.02.063] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 02/20/2009] [Accepted: 02/20/2009] [Indexed: 11/26/2022] Open
Abstract
We study the effect of permeabilizing electric fields applied to two different types of giant unilamellar vesicles, the first formed from EggPC lipids and the second formed from DOPC lipids. Experiments on vesicles of both lipid types show a decrease in vesicle radius, which is interpreted as being due to lipid loss during the permeabilization process. We show that the decrease in size can be qualitatively explained as a loss of lipid area, which is proportional to the area of the vesicle that is permeabilized. Three possible modes of membrane loss were directly observed: pore formation, vesicle formation, and tubule formation.
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Affiliation(s)
- Thomas Portet
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, UMR 5089
- Laboratoire de Physique Théorique, Centre National de la Recherche Scientifique, UMR 5152, Université Paul Sabatier, Toulouse, France
| | - Franc Camps i Febrer
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, UMR 5089
| | - Jean-Michel Escoffre
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, UMR 5089
| | - Cyril Favard
- Institut Fresnel, Centre National de la Recherche Scientifique, UMR 6133, Marseille, France
| | - Marie-Pierre Rols
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, UMR 5089
| | - David S. Dean
- Laboratoire de Physique Théorique, Centre National de la Recherche Scientifique, UMR 5152, Université Paul Sabatier, Toulouse, France
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39
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Castillo JA, Narciso DM, Hayes MA. Bionanotubule formation from surface-attached liposomes using electric fields. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:391-396. [PMID: 19063629 DOI: 10.1021/la8028897] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Spontaneous formation of long-range (millimeters) membrane-bound nanotubules from surface-immobilized liposomes is possible by application of modest electric fields (2 -20 V/cm), providing a novel fabrication strategy for these hollow cylindrical structures. Stable tubes generally aligned with the applied electric field were created from liposomes prepared with phosphatidylcholine (PC), phosphatidic acid (PA), phosphoethanolamine (PE), and cholesterol. The minimum voltage which causes nanotubular formation (the onset voltage) and the average number of tubules per liposome of varying composition was examined with fluorescent microscopy using labeled phospholipids. Generally, the onset voltages ranged between 4 and 15 V/cm and depended on the mother vesicle composition. The results of this study suggest that increasing the charged lipid content can decrease the onset voltage. Conversely, a cholesterol content of more than 30% (by mass) was found to hinder extension of lipid tubules. Basic calculations that assume lipid migration and domain formation on the mother liposome as a nucleating site for tubule extension are assessed and suggest this is a reasonable model to describe the mechanism of tubular growth from immobilized liposomes.
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Affiliation(s)
- Josemar A Castillo
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA
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40
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Abstract
When subjected to alternating electric fields in the frequency range 10(2)-10(8) Hz, giant lipid vesicles attain oblate, prolate, and spherical shapes and undergo morphological transitions between these shapes as one varies the field frequency and/or the conductivities lambda(in) and lambda(ex) of the aqueous solution inside and outside the vesicles. Four different transitions are observed with characteristic frequencies that depend primarily on the conductivity ratio lambda(in)/lambda(ex). The theoretical models that have been described in the literature are not able to describe all of these morphological transitions.
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41
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Knecht V, Risselada H, Mark A, Marrink S. Electrophoretic mobility does not always reflect the charge on an oil droplet. J Colloid Interface Sci 2008; 318:477-86. [DOI: 10.1016/j.jcis.2007.10.035] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 10/11/2007] [Accepted: 10/23/2007] [Indexed: 11/27/2022]
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42
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Teissie J, Golzio M, Rols MP. Mechanisms of cell membrane electropermeabilization: a minireview of our present (lack of ?) knowledge. Biochim Biophys Acta Gen Subj 2005; 1724:270-80. [PMID: 15951114 DOI: 10.1016/j.bbagen.2005.05.006] [Citation(s) in RCA: 353] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Accepted: 05/04/2005] [Indexed: 11/21/2022]
Abstract
Cell electropulsation is routinely used in cell Biology for protein, RNA or DNA transfer. Its clinical applications are under development for targeted drug delivery and gene therapy. Nevertheless, the molecular mechanisms supporting the induction of permeabilizing defects in the membrane assemblies remain poorly understood. This minireview describes the present state of the investigations concerning the different steps in the reversible electropermeabilization process. The different hypotheses, which were proposed to give a molecular description of the membrane events, are critically discussed. Other possibilities are then given. The need for more basic research on the associated loss of cohesion of the membrane appears as a conclusion.
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Affiliation(s)
- J Teissie
- IPBS UMR 5089 CNRS, 205 route de Narbonne, 31077 Toulouse, France.
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43
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Korlach J, Reichle C, Müller T, Schnelle T, Webb WW. Trapping, deformation, and rotation of giant unilamellar vesicles in octode dielectrophoretic field cages. Biophys J 2005; 89:554-62. [PMID: 15863477 PMCID: PMC1366554 DOI: 10.1529/biophysj.104.050401] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The behavior of freestanding lipid bilayer membranes under the influence of dielectric force potentials was studied by trapping, holding, and rotating individual giant unilamellar vesicles (GUVs) inside dielectrophoretic microfield cages. Using laser scanning confocal microscopy and three-dimensional image reconstructions of GUVs labeled with fluorescent membrane probes, field strength and frequency-dependent vesicle deformations were observed which are explained by calculations of the dielectric force potentials inside the cage. Dynamical membrane properties under the influence of the field cage were studied by fluorescence correlation spectroscopy, circumventing potential artifacts associated with measurements involving GUV immobilization on support surfaces. Lipid transport could be accelerated markedly by the applied fields, aided by hydrodynamic fluid streaming which was also studied by fluorescence correlation spectroscopy.
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Affiliation(s)
- J Korlach
- School of Applied & Engineering Physics, Clark Hall, Cornell University, Ithaca, New York, USA
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44
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Pysher MD, Hayes MA. Effects of deformability, uneven surface charge distributions, and multipole moments on biocolloid electrophoretic migration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:3572-3577. [PMID: 15807603 DOI: 10.1021/la0473097] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Liposomes have been widely used as cellular and bioparticle mimics due to their lipid bilayer structure and relative ease of production and manipulation. Such biocolloids are frequently characterized by capillary electrophoresis (CE), which promises a wealth of information about such properties as surface charge, composition, and rigidity. The applicability of this information is somewhat limited, however, since it is interpreted with colloidal theories that do not account for the unique properties of biocolloids. In this work, the effects of deformability, mobile surface charges, intrinsic polarizability, and uneven surface charge distributions are incorporated into colloidal theories in order to better model the electrophoretic behaviors of liposomes.
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Affiliation(s)
- Michele D Pysher
- Department of Chemistry and Biochemistry, Arizona Applied NanoSensors and The Center for Solid State Electronics Research, Arizona State University, P.O. Box 871604, Tempe, Arizona 85287-1604, USA
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45
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Peikov V, Schelly ZA. Modeling of the Electric Field-Induced Birefringence of Vesicles. J Phys Chem B 2004. [DOI: 10.1021/jp0369488] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Viktor Peikov
- Center for Colloidal and Interfacial Dynamics, Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019-0065
| | - Zoltan A. Schelly
- Center for Colloidal and Interfacial Dynamics, Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019-0065
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Pysher MD, Hayes MA. Examination of the electrophoretic behavior of liposomes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:4369-75. [PMID: 15969140 DOI: 10.1021/la0362730] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The electromigration of liposomes is a complex process resulting in many unexpected behaviors that are difficult to address with existing theories. In this study, the electrophoretic behaviors of liposome populations under various conditions were examined through the use of capillary electrophoresis and the results compared to classical electrokinetic, colloid, and spheroid theories. To elucidate the possible effects of applied field strength, bilayer rigidity, and surface charge on these behaviors, the electrophoretic mobilities of liposome populations were monitored while varying the applied potential, ionic strength of the medium, and the surface charge and cholesterol content of the liposomes. On the basis of comparisons made to the theoretical predictions, our results suggest that liposomal deformation and field-induced polarization may occur during electrophoresis and these mechanisms help to describe many of the observed behaviors.
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Affiliation(s)
- Michele D Pysher
- Department of Chemistry and Biochemistry, Arizona Applied NanoSensors, and The Center for Solid State Electronics Research, Arizona State University, P.O. Box 871604, Tempe, Arizona 85287-1604, , USA
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Kakorin S, Liese T, Neumann E. Membrane Curvature and High-Field Electroporation of Lipid Bilayer Vesicles. J Phys Chem B 2003. [DOI: 10.1021/jp022296w] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergej Kakorin
- Physical and Biophysical Chemistry, Faculty of Chemistry, University of Bielefeld, Germany
| | - Thomas Liese
- Physical and Biophysical Chemistry, Faculty of Chemistry, University of Bielefeld, Germany
| | - Eberhard Neumann
- Physical and Biophysical Chemistry, Faculty of Chemistry, University of Bielefeld, Germany
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48
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49
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Bellini T, Buscaglia M, Corti M, Mantegazza F, Rocca C. A laser interferometer for the study of electrically excited bubble capillary modes. Colloids Surf A Physicochem Eng Asp 2001. [DOI: 10.1016/s0927-7757(01)00541-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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50
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Kotnik T, Miklavcic D. Analytical description of transmembrane voltage induced by electric fields on spheroidal cells. Biophys J 2000; 79:670-9. [PMID: 10920001 PMCID: PMC1300967 DOI: 10.1016/s0006-3495(00)76325-9] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
An analytical description of transmembrane voltage induced on spherical cells was determined in the 1950s, and the tools for numerical assessment of transmembrane voltage induced on spheroidal cells were developed in the 1970s. However, it has often been claimed that an analytical description is unattainable for spheroidal cells, while others have asserted that even if attainable, it does not befit the reality due to the nonuniform membrane thickness, which is unrealistic but inevitable in spheroidal geometry. In this paper we show that for all spheroidal cells, membrane thickness is irrelevant to the induced transmembrane voltage under the assumption of a nonconductive membrane, which was also applied in the derivation of Schwan's equation. We then derive the analytical description of transmembrane voltage induced on prolate and oblate spheroidal cells. The final result, which we cast from spheroidal into more familiar spherical coordinates, represents a generalization of Schwan's equation to all spheroidal cells (of which spherical cells are a special case). The obtained expression is easy to apply, and we give a simple example of such application. We conclude the study by analyzing the variation of induced transmembrane voltage as a spheroidal cell is stretched by the field, performing one study at a constant membrane surface area, and another at a constant cell volume.
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Affiliation(s)
- T Kotnik
- Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
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