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Akenuwa OH, Abel SM. Organization and dynamics of cross-linked actin filaments in confined environments. Biophys J 2023; 122:30-42. [PMID: 36461638 PMCID: PMC9822838 DOI: 10.1016/j.bpj.2022.11.2944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/02/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
The organization of the actin cytoskeleton is impacted by the interplay between physical confinement, features of cross-linking proteins, and deformations of semiflexible actin filaments. Some cross-linking proteins preferentially bind filaments in parallel, although others bind more indiscriminately. However, a quantitative understanding of how the mode of binding influences the assembly of actin networks in confined environments is lacking. Here we employ coarse-grained computer simulations to study the dynamics and organization of semiflexible actin filaments in confined regions upon the addition of cross-linkers. We characterize how the emergent behavior is influenced by the system shape, the number and type of cross-linking proteins, and the length of filaments. Structures include isolated clusters of filaments, highly connected filament bundles, and networks of interconnected bundles and loops. Elongation of one dimension of the system promotes the formation of long bundles that align with the elongated axis. Dynamics are governed by rapid cross-linking into aggregates, followed by a slower change in their shape and connectivity. Cross-linking decreases the average bending energy of short or sparsely connected filaments by suppressing shape fluctuations. However, it increases the average bending energy in highly connected networks because filament bundles become deformed, and small numbers of filaments exhibit long-lived, highly unfavorable configurations. Indiscriminate cross-linking promotes the formation of high-energy configurations due to the increased likelihood of unfavorable, difficult-to-relax configurations at early times. Taken together, this work demonstrates physical mechanisms by which cross-linker binding and physical confinement impact the emergent behavior of actin networks, which is relevant both in cells and in synthetic environments.
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Affiliation(s)
- Oghosa H Akenuwa
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee
| | - Steven M Abel
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee.
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2
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Milchev A, Egorov SA, Midya J, Binder K, Nikoubashman A. Blends of Semiflexible Polymers: Interplay of Nematic Order and Phase Separation. Polymers (Basel) 2021; 13:2270. [PMID: 34301028 PMCID: PMC8309418 DOI: 10.3390/polym13142270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 11/23/2022] Open
Abstract
Mixtures of semiflexible polymers with a mismatch in either their persistence lengths or their contour lengths are studied by Density Functional Theory and Molecular Dynamics simulation. Considering lyotropic solutions under good solvent conditions, the mole fraction and pressure is systematically varied for several cases of bending stiffness κ (the normalized persistence length) and chain length N. For binary mixtures with different chain length (i.e., NA=16, NB=32 or 64) but the same stiffness, isotropic-nematic phase coexistence is studied. For mixtures with the same chain length (N=32) and large stiffness disparity (κB/κA=4.9 to 8), both isotropic-nematic and nematic-nematic unmixing occur. It is found that the phase diagrams may exhibit a triple point or a nematic-nematic critical point, and that coexisting phases differ appreciably in their monomer densities. The properties of the two types of chains (nematic order parameters, chain radii, etc.) in the various phases are studied in detail, and predictions on the (anisotropic) critical behavior near the critical point of nematic-nematic unmixing are made.
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Affiliation(s)
- Andrey Milchev
- Institute for Physical Chemistry, Bulgarian Academia of Sciences, 1113 Sofia, Bulgaria;
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany; (S.A.E.); (J.M.); (K.B.)
| | - Sergei A. Egorov
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany; (S.A.E.); (J.M.); (K.B.)
- Department of Chemistry, University of Virginia, Charlottesville, VA 22901, USA
| | - Jiarul Midya
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany; (S.A.E.); (J.M.); (K.B.)
- Theoretical Soft Matter and Biophysics, Institute for Advanced Simulation and Institute of Complex Systems, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Kurt Binder
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany; (S.A.E.); (J.M.); (K.B.)
| | - Arash Nikoubashman
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany; (S.A.E.); (J.M.); (K.B.)
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Milchev A, Binder K. How does stiffness of polymer chains affect their adsorption transition? J Chem Phys 2020; 152:064901. [DOI: 10.1063/1.5139940] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- A. Milchev
- Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - K. Binder
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudinger Weg 9, D-55099 Mainz, Germany
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Adeli Koudehi M, Rutkowski DM, Vavylonis D. Organization of associating or crosslinked actin filaments in confinement. Cytoskeleton (Hoboken) 2019; 76:532-548. [PMID: 31525281 DOI: 10.1002/cm.21565] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 09/09/2019] [Accepted: 09/12/2019] [Indexed: 12/13/2022]
Abstract
A key factor of actin cytoskeleton organization in cells is the interplay between the dynamical properties of actin filaments and cell geometry, which restricts, confines and directs their orientation. Crosslinking interactions among actin filaments, together with geometrical cues and regulatory proteins can give rise to contractile rings in dividing cells and actin rings in neurons. Motivated by recent in vitro experiments, in this work we performed computer simulations to study basic aspects of the interplay between confinement and attractive interactions between actin filaments. We used a spring-bead model and Brownian dynamics to simulate semiflexible actin filaments that polymerize in a confining sphere with a rate proportional to the monomer concentration. We model crosslinking, or attraction through the depletion interaction, implicitly as an attractive short-range potential between filament beads. In confining geometries smaller than the persistence length of actin filaments, we show rings can form by curving of filaments of length comparable to, or longer than the confinement diameter. Rings form for optimal ranges of attractive interactions that exist in between open bundles, irregular loops, aggregated, and unbundled morphologies. The probability of ring formation is promoted by attraction to the confining sphere boundary and decreases for large radii and initial monomer concentrations, in agreement with prior experimental data. The model reproduces ring formation along the flat plane of oblate ellipsoids.
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Nakatani N, Sakuta H, Hayashi M, Tanaka S, Takiguchi K, Tsumoto K, Yoshikawa K. Specific Spatial Localization of Actin and DNA in a Water/Water Microdroplet: Self-Emergence of a Cell-Like Structure. Chembiochem 2018; 19:1370-1374. [PMID: 29676062 PMCID: PMC6055874 DOI: 10.1002/cbic.201800066] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Indexed: 01/04/2023]
Abstract
The effect of binary hydrophilic polymers on a pair of representative bio-macromolecules in a living cell has been examined. The results showed that these bio-macromolecules exhibited specific localization in cell-sized droplets that were spontaneously formed through water/water microphase segregation under crowding conditions with coexisting polymers. In these experiments, a simple binary polymer system with poly(ethylene glycol) (PEG) and dextran (DEX) was used. Under the conditions of microphase segregation, DNA was entrapped within cell-sized droplets rich in DEX. Similarly, F-actin, linearly polymerized actin, was entrapped specifically within microdroplets rich in DEX, whereas G-actin, a monomeric actin, was distributed evenly inside and outside these droplets. This study has been extended to a system with both F-actin and DNA, and it was found that DNA molecules were localized separately from aligned F-actin proteins to create microdomains inside microdroplets, reflecting the self-emergence of a cellular morphology similar to a stage of cell division.
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Affiliation(s)
- Naoki Nakatani
- Graduate School of Life and Medical SciencesDoshisha UniversityTataramiyakodani 1–3KyotanabeKyoto610-0394Japan
| | - Hiroki Sakuta
- Graduate School of Life and Medical SciencesDoshisha UniversityTataramiyakodani 1–3KyotanabeKyoto610-0394Japan
| | - Masahito Hayashi
- Graduate School of ScienceNagoya UniversityFuro-choChikusa-kuNagoya, Aichi464-8602Japan
- Laboratory for Molecular BiophysicsRIKENCenter for Brain ScienceHirosawa 2–1WakoSaitama351-0198Japan
| | - Shunsuke Tanaka
- Graduate School of ScienceNagoya UniversityFuro-choChikusa-kuNagoya, Aichi464-8602Japan
| | - Kingo Takiguchi
- Graduate School of ScienceNagoya UniversityFuro-choChikusa-kuNagoya, Aichi464-8602Japan
| | - Kanta Tsumoto
- Division of Chemistry for MaterialsGraduate School of EngineeringMie UniversityKurimamachiya-cho 1577TsuMie514-8507Japan
| | - Kenichi Yoshikawa
- Graduate School of Life and Medical SciencesDoshisha UniversityTataramiyakodani 1–3KyotanabeKyoto610-0394Japan
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Milchev A, Egorov SA, Nikoubashman A, Binder K. Conformations and orientational ordering of semiflexible polymers in spherical confinement. J Chem Phys 2017; 146:194907. [PMID: 28527445 PMCID: PMC5438305 DOI: 10.1063/1.4983131] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 04/25/2017] [Indexed: 12/28/2022] Open
Abstract
Semiflexible polymers in lyotropic solution confined inside spherical nanoscopic "containers" with repulsive walls are studied by molecular dynamics simulations and density functional theory, as a first step to model confinement effects on stiff polymers inside of miniemulsions, vesicles, and cells. It is shown that the depletion effects caused by the monomer-wall repulsion depend distinctly on the radius R of the sphere. Further, nontrivial orientational effects occur when R, the persistence length ℓp, and the contour length L of the polymers are of similar magnitude. At intermediate densities, a "shell" of wall-attached chains is forming, such that the monomers belonging to those chains are in a layer at about the distance of one monomer from the container wall. At the same time, the density of the centers of mass of these chains is peaked somewhat further inside, but still near the wall. However, the arrangement of chains is such that the total monomer density is almost uniform in the sphere, apart from a small layering peak at the wall. It is shown that excluded volume effects among the monomers are crucial to account for this behavior, although they are negligible for comparable isolated single semiflexible chains of the same length.
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Affiliation(s)
- Andrey Milchev
- Institute for Physical Chemistry, Bulgarian Academia of Sciences, 1113 Sofia, Bulgaria
| | - Sergei A Egorov
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Arash Nikoubashman
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Kurt Binder
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany
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Membrane Charge Directs the Outcome of F-BAR Domain Lipid Binding and Autoregulation. Cell Rep 2015; 13:2597-2609. [PMID: 26686642 DOI: 10.1016/j.celrep.2015.11.044] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 10/20/2015] [Accepted: 11/12/2015] [Indexed: 12/23/2022] Open
Abstract
F-BAR domain proteins regulate and sense membrane curvature by interacting with negatively charged phospholipids and assembling into higher-order scaffolds. However, regulatory mechanisms controlling these interactions are poorly understood. Here, we show that Drosophila Nervous Wreck (Nwk) is autoregulated by a C-terminal SH3 domain module that interacts directly with its F-BAR domain. Surprisingly, this autoregulation does not mediate a simple "on-off" switch for membrane remodeling. Instead, the isolated Nwk F-BAR domain efficiently assembles into higher-order structures and deforms membranes only within a limited range of negative membrane charge, and autoregulation elevates this range. Thus, autoregulation could either reduce membrane binding or promote higher-order assembly, depending on local cellular membrane composition. Our findings uncover an unexpected mechanism by which lipid composition directs membrane remodeling.
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Ito H, Nishigami Y, Sonobe S, Ichikawa M. Wrinkling of a spherical lipid interface induced by actomyosin cortex. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:062711. [PMID: 26764731 DOI: 10.1103/physreve.92.062711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Indexed: 06/05/2023]
Abstract
Actomyosin actively generates contractile forces that provide the plasma membrane with the deformation stresses essential to carry out biological processes. Although the contractile property of purified actomyosin has been extensively studied, to understand the physical contribution of the actomyosin contractile force on a deformable membrane is still a challenging problem and of great interest in the field of biophysics. Here, we reconstitute a model system with a cell-sized deformable interface that exhibits anomalous curvature-dependent wrinkling caused by the actomyosin cortex underneath the spherical closed interface. Through a shape analysis of the wrinkling deformation, we find that the dominant contributor to the wrinkled shape changes from bending elasticity to stretching elasticity of the reconstituted cortex upon increasing the droplet curvature radius of the order of the cell size, i.e., tens of micrometers. The observed curvature dependence is explained by the theoretical description of the cortex elasticity and contractility. Our present results provide a fundamental insight into the deformation of a curved membrane induced by the actomyosin cortex.
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Affiliation(s)
- Hiroaki Ito
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yukinori Nishigami
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Seiji Sonobe
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Harima Science Park City, Hyogo 678-1297, Japan
| | - Masatoshi Ichikawa
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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10
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van Zalinge H, Ramsey LC, Aveyard J, Persson M, Mansson A, Nicolau DV. Surface-Controlled Properties of Myosin Studied by Electric Field Modulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:8354-8361. [PMID: 26161584 DOI: 10.1021/acs.langmuir.5b01549] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The efficiency of dynamic nanodevices using surface-immobilized protein molecular motors, which have been proposed for diagnostics, drug discovery, and biocomputation, critically depends on the ability to precisely control the motion of motor-propelled, individual cytoskeletal filaments transporting cargo to designated locations. The efficiency of these devices also critically depends on the proper function of the propelling motors, which is controlled by their interaction with the surfaces they are immobilized on. Here we use a microfluidic device to study how the motion of the motile elements, i.e., actin filaments propelled by heavy mero-myosin (HMM) motor fragments immobilized on various surfaces, is altered by the application of electrical loads generated by an external electric field with strengths ranging from 0 to 8 kVm(-1). Because the motility is intimately linked to the function of surface-immobilized motors, the study also showed how the adsorption properties of HMM on various surfaces, such as nitrocellulose (NC), trimethylclorosilane (TMCS), poly(methyl methacrylate) (PMMA), poly(tert-butyl methacrylate) (PtBMA), and poly(butyl methacrylate) (PBMA), can be characterized using an external field. It was found that at an electric field of 5 kVm(-1) the force exerted on the filaments is sufficient to overcome the frictionlike resistive force of the inactive motors. It was also found that the effect of assisting electric fields on the relative increase in the sliding velocity was markedly higher for the TMCS-derivatized surface than for all other polymer-based surfaces. An explanation of this behavior, based on the molecular rigidity of the TMCS-on-glass surfaces as opposed to the flexibility of the polymer-based ones, is considered. To this end, the proposed microfluidic device could be used to select appropriate surfaces for future lab-on-a-chip applications as illustrated here for the almost ideal TMCS surface. Furthermore, the proposed methodology can be used to gain fundamental insights into the functioning of protein molecular motors, such as the force exerted by the motors under different operational conditions.
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Affiliation(s)
| | | | | | - Malin Persson
- ‡Department of Chemistry and Biomedical Sciences, Linnaeus University, 39182 Kalmar, Sweden
| | - Alf Mansson
- ‡Department of Chemistry and Biomedical Sciences, Linnaeus University, 39182 Kalmar, Sweden
| | - Dan V Nicolau
- §Department of Bioengineering, McGill University, Montreal, H3A 0C3 Quebec, Canada
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11
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Cell-sized spherical confinement induces the spontaneous formation of contractile actomyosin rings in vitro. Nat Cell Biol 2015; 17:480-9. [DOI: 10.1038/ncb3142] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 02/19/2015] [Indexed: 12/13/2022]
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12
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Yanagisawa M, Sakaue T, Yoshikawa K. Characteristic Behavior of Crowding Macromolecules Confined in Cell-Sized Droplets. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 307:175-204. [DOI: 10.1016/b978-0-12-800046-5.00007-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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13
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Glagoleva AA, Vasilevskaya VV, Yoshikawa K, Khokhlov AR. Self-assembly of an amphiphilic macromolecule under spherical confinement: An efficient route to generate hollow nanospheres. J Chem Phys 2013; 139:244901. [PMID: 24387390 DOI: 10.1063/1.4839795] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A A Glagoleva
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova St. 28, 119991 Moscow, Russia
| | - V V Vasilevskaya
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova St. 28, 119991 Moscow, Russia
| | - K Yoshikawa
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe 610-0394, Japan
| | - A R Khokhlov
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova St. 28, 119991 Moscow, Russia
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Kapus A, Janmey P. Plasma membrane--cortical cytoskeleton interactions: a cell biology approach with biophysical considerations. Compr Physiol 2013; 3:1231-81. [PMID: 23897686 DOI: 10.1002/cphy.c120015] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
From a biophysical standpoint, the interface between the cell membrane and the cytoskeleton is an intriguing site where a "two-dimensional fluid" interacts with an exceedingly complex three-dimensional protein meshwork. The membrane is a key regulator of the cytoskeleton, which not only provides docking sites for cytoskeletal elements through transmembrane proteins, lipid binding-based, and electrostatic interactions, but also serves as the source of the signaling events and molecules that control cytoskeletal organization and remolding. Conversely, the cytoskeleton is a key determinant of the biophysical and biochemical properties of the membrane, including its shape, tension, movement, composition, as well as the mobility, partitioning, and recycling of its constituents. From a cell biological standpoint, the membrane-cytoskeleton interplay underlies--as a central executor and/or regulator--a multitude of complex processes including chemical and mechanical signal transduction, motility/migration, endo-/exo-/phagocytosis, and other forms of membrane traffic, cell-cell, and cell-matrix adhesion. The aim of this article is to provide an overview of the tight structural and functional coupling between the membrane and the cytoskeleton. As biophysical approaches, both theoretical and experimental, proved to be instrumental for our understanding of the membrane/cytoskeleton interplay, this review will "oscillate" between the cell biological phenomena and the corresponding biophysical principles and considerations. After describing the types of connections between the membrane and the cytoskeleton, we will focus on a few key physical parameters and processes (force generation, curvature, tension, and surface charge) and will discuss how these contribute to a variety of fundamental cell biological functions.
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Affiliation(s)
- András Kapus
- Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael's Hospital and Department of Surgery, University of Toronto, Ontario, Canada.
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15
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Giustini M, Giuliani AM, Gennaro G. Natural or synthetic nucleic acids encapsulated in a closed cavity of amphiphiles. RSC Adv 2013. [DOI: 10.1039/c3ra23208e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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Yamamoto A, Ichikawa M. Direct measurement of single soft lipid nanotubes: nanoscale information extracted in a noninvasive manner. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:061905. [PMID: 23367974 DOI: 10.1103/physreve.86.061905] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 09/07/2012] [Indexed: 06/01/2023]
Abstract
We investigated the dynamics of single soft nanotubes of phospholipids to extract nanoscale information such as the size of the tube, which were several tens to hundreds of nanometers thick. The dynamic properties of the tubes obtained from direct observation by fluorescent microscopy, such as their persistence length, enable us to access the nanoscale characteristics through a simple elastic model of the membrane. The present methodology should be applicable to the nanosized membrane structure in living cells.
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Affiliation(s)
- Akihisa Yamamoto
- Department of Physics, Kyoto University, Sakyo, Kyoto 606-8502, Japan
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Hamada T, Yoshikawa K. Cell-Sized Liposomes and Droplets: Real-World Modeling of Living Cells. MATERIALS 2012. [PMCID: PMC5449011 DOI: 10.3390/ma5112292] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent developments in studies concerning cell-sized vesicles, such as liposomes with a lipid bilayer and water-in-oil droplets covered by a lipid monolayer, aim to realize the real-world modeling of living cells. Compartmentalization with a membrane boundary is essential for the organization of living systems. Due to the relatively large surface/volume ratio in microconfinement, the membrane interface influences phenomena related to biological functions. In this article, we mainly focus on the following subjects: (i) conformational transition of biopolymers in a confined space; (ii) molecular association on the membrane surface; and (iii) remote control of cell-sized membrane morphology.
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Affiliation(s)
- Tsutomu Hamada
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi, Ishikawa 923-1292, Japan
- Authors to whom correspondence should be addressed; E-Mails: (T.H.); (K.Y.); Tel./Fax: +81-761-51-1670 (T.H.); +81-774-65-6243 (K.Y.)
| | - Kenichi Yoshikawa
- Faculty of Life and Medical Sciences, Doshisha University, 1-3, Tatara Miyakodani, Kyotanabe, Kyoto 610-0394, Japan
- Authors to whom correspondence should be addressed; E-Mails: (T.H.); (K.Y.); Tel./Fax: +81-761-51-1670 (T.H.); +81-774-65-6243 (K.Y.)
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Ito H, Yanagisawa M, Ichikawa M, Yoshikawa K. Emergence of a thread-like pattern with charged phospholipids on an oil/water interface. J Chem Phys 2012; 136:204903. [DOI: 10.1063/1.4722079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Cell-Sized confinement in microspheres accelerates the reaction of gene expression. Sci Rep 2012; 2:283. [PMID: 22359735 PMCID: PMC3283880 DOI: 10.1038/srep00283] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 02/02/2012] [Indexed: 11/08/2022] Open
Abstract
Cell-sized water-in-oil droplet covered by a lipid layer was used to understand how lipid membranes affect biochemical systems in living cells. Here, we report a remarkable acceleration of gene expression in a cell-sized water-in-oil droplet entrapping a cell-free translation system to synthesize GFP (green fluorescent protein). The production rate of GFP (V(GFP)) in each droplet remained almost constant at least for on the order of a day, which implies 0(th)-order reaction kinetics. Interestingly, V(GFP) was inversely proportional to radius of droplets (R) when R is under 50 μm, and V(GFP) in droplets with R ∼ 10 μm was more than 10 times higher than that in the bulk. The acceleration rates of GFP production in cell-sized droplets strongly depended on the lipid types. These results demonstrate that the membrane surface has the significant effect to facilitate protein production, especially when the scale of confinement is on the order of cell-size.
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20
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Streichfuss M, Erbs F, Uhrig K, Kurre R, Clemen AEM, Böhm CHJ, Haraszti T, Spatz JP. Measuring forces between two single actin filaments during bundle formation. NANO LETTERS 2011; 11:3676-3680. [PMID: 21838252 DOI: 10.1021/nl201630y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Bundles of filamentous actin are dominant cytoskeletal structures, which play a crucial role in various cellular processes. As yet quantifying the fundamental interaction between two individual actin filaments forming the smallest possible bundle has not been realized. Applying holographic optical tweezers integrated with a microfluidic platform, we were able to measure the forces between two actin filaments during bundle formation. Quantitative analysis yields forces up to 0.2 pN depending on the concentration of bundling agents.
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Affiliation(s)
- Martin Streichfuss
- Max Planck Institute for Intelligent Systems, Department of New Materials and Biosystems, 70569 Stuttgart, Germany
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21
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Negishi M, Ichikawa M, Nakajima M, Kojima M, Fukuda T, Yoshikawa K. Phase behavior of crowded like-charged mixed polyelectrolytes in a cell-sized sphere. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:061921. [PMID: 21797417 DOI: 10.1103/physreve.83.061921] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Indexed: 05/23/2023]
Abstract
We studied the phase behavior of a mixture of two semiflexible negatively charged polyelectrolytes, giant DNA and alginate, under crowded condition in a cell-sized sphere (5-40 μm in diameter), where the persistence length of giant DNA is 50 nm and that of alginate is 5 nm. Through microscopic observation, we found that the polymer mixture exhibits a unique phase behavior, which depends on the size of the sphere, whereas the mixture remains homogeneous and isotropic in bulk solution. When the sphere is small, DNA is completely depleted on the surface. When the sphere is medium sized, a portion of the DNA is depleted on the surface, and the remainder stays within the sphere. By introducing a curvature-dependent term for the interaction between DNA and the surface into the Flory-Huggins model, we interpret the observed characteristics of the phase behavior in terms of the relative importance of the surface-to-volume effect.
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Affiliation(s)
- Makiko Negishi
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto, Japan
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Hadorn M, Eggenberger Hotz P. Encapsulated Multi-vesicle Assemblies of Programmable Architecture: Towards Personalized Healthcare. BIOMEDICAL ENGINEERING SYSTEMS AND TECHNOLOGIES 2011. [DOI: 10.1007/978-3-642-18472-7_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Nakajima M, Matsuno Y, Kojima M, Takiguchi Y, Takiguchi K, Nogawa K, Homma M, Fukuda T. Quantitative Evaluation of Injected Molecules into Phospholipid-Coated Microdroplets for In situ Biological Reactions. JOURNAL OF ROBOTICS AND MECHATRONICS 2010. [DOI: 10.20965/jrm.2010.p0651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This paper presents a quantitative evaluation of the amount of biological molecules injected into phospholipid-coated microdroplets. Research on developing an artificial cell model using lipid membrane vesicles has been pursued to determine the function between biomembranes and biological molecules. The method is needed to introduce biological molecules into the biomembrane model and observe their reactions. Conventionally, molecules are introduced into vesicles by hydrating dried lipid films or freeze-dried lipid blocks with a solution already including biological molecules. It is difficult, however, to observe reaction in real time and step-by-step for different types of biological molecules, because the reaction has already started by the time vesicles are formed. Our proposal uses micro/nanopipettes based on micromanipulation. It is demonstrated that the injection of different types of biological molecules into a phospholipid-coated microdroplet. Biological molecules, such as F-actin, heavy meromyosin (HMM), and adenosine triphosphate (ATP), were introduced into a phospholipidcoated microdroplet in sequence, and these reactions were observed inside the microdroplet. The amount of molecules introduced into the microdroplet was evaluated quantitatively from the intensity of fluorescent labels through our microchannel calibration method.
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Negishi M, Sakaue T, Takiguchi K, Yoshikawa K. Cooperation between giant DNA molecules and actin filaments in a microsphere. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 81:051921. [PMID: 20866275 DOI: 10.1103/physreve.81.051921] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Indexed: 05/23/2023]
Abstract
We report the appearance of a spatially segregated state in a microsphere as a result of cooperation between actin filaments and giant DNA molecules. When the coexisting actin concentration is high enough, DNA molecules are excluded toward the surface by forming an assembly with actin filaments. With a decrease in the actin concentration, actin filaments tend to dissolve within the sphere whereas DNA molecules remain to be excluded onto the surface. When the actin concentration becomes still lower, DNA molecules dissolve within the sphere by avoiding surface attachment. We interpret these experimental trends by introducing the concept of an "exclusion zone" for actin filaments within a microsphere.
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Affiliation(s)
- Makiko Negishi
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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Ohno M, Hamada T, Takiguchi K, Homma M. Dynamic behavior of giant liposomes at desired osmotic pressures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:11680-11685. [PMID: 19725557 DOI: 10.1021/la900777g] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To apply accurate and uniform osmotic pressures to liposomes, they can be formed using the spontaneous transfer method in solutions with different osmolarities. The majority of liposomes unexpectedly opened large holes (several micrometers in diameter) in response to the osmotic pressure regardless of its strength, that is, the difference between the outside and inside solute (sucrose or KCl) concentrations. However, the lag time for any response, including the opening of a hole, after the formation of the liposome decreased with increasing osmotic pressure.
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Affiliation(s)
- Masae Ohno
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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Aksan A, Hubel A, Bischof JC. Frontiers in biotransport: water transport and hydration. J Biomech Eng 2009; 131:074004. [PMID: 19640136 DOI: 10.1115/1.3173281] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Biotransport, by its nature, is concerned with the motions of molecules in biological systems while water remains as the most important and the most commonly studied molecule across all disciplines. In this review, we focus on biopreservation and thermal therapies from the perspective of water, exploring how its molecular motions, properties, kinetic, and thermodynamic transitions govern biotransport phenomena and enable preservation or controlled destruction of biological systems.
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Affiliation(s)
- Alptekin Aksan
- Center for Biotransport, Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN 55455, USA
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Abstract
Biotransport, by its nature, is concerned with the motions of molecules in biological systems while water remains as the most important and the most commonly studied molecule across all disciplines. In this review, we focus on biopreservation and thermal therapies from the perspective of water, exploring how its molecular motions, properties, kinetic, and thermodynamic transitions govern biotransport phenomena and enable preservation or controlled destruction of biological systems.
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Affiliation(s)
- Alptekin Aksan
- Center for Biotransport, Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN 55455; Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - Allison Hubel
- Center for Biotransport, Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN 55455; Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - John C. Bischof
- Center for Biotransport, Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN 55455; Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455
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Takiguchi K, Yamada A, Negishi M, Honda M, Tanaka-Takiguchi Y, Yoshikawa K. Chapter 3 - Construction of cell-sized liposomes encapsulating actin and actin-cross-linking proteins. Methods Enzymol 2009; 464:31-53. [PMID: 19903549 DOI: 10.1016/s0076-6879(09)64003-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
To shed light on the mechanism underlying the active morphogenesis of living cells in relation to the organization of internal cytoskeletal networks, the development of new methodologies to construct artificial cell models is crucial. Here, we describe the successful construction of cell-sized liposomes entrapping cytoskeletal proteins. We discuss experimental protocols to prepare giant liposomes encapsulating desired amounts of actin and cross-linking proteins including molecular motor proteins, such as fascin, alpha-actinin, filamin, myosin-I isolated from brush border (BBMI), and heavy meromyosin (HMM). Subfragment 1 (S-1) is also studied in comparison to HMM, where S-1 and HMM are single-headed and double-headed derivatives of conventional myosin (myosin-II), respectively. In the absence of cross-linking proteins, actin filaments (F-actin) are distributed homogeneously without any order within the liposomes. In contrast, when actin is encapsulated together with an actin-cross-linking protein, mesh structures emerge that are similar to those in living motile cells. Optical microscopic observations on the active morphological changes of the liposomes are reported.
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Affiliation(s)
- Kingo Takiguchi
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
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Takiguchi K, Yamada A, Negishi M, Tanaka-Takiguchi Y, Yoshikawa K. Entrapping desired amounts of actin filaments and molecular motor proteins in giant liposomes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11323-11326. [PMID: 18816022 DOI: 10.1021/la802031n] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We have successfully prepared cell-sized giant liposomes encapsulating desired amounts of actoHMM, a mixture of actin filament (F-actin) and heavy meromyosin (HMM, an actin-related molecular motor), in the presence of 5 mM MgCl 2 and 50 mM KCl. We employed a spontaneous transfer method to prepare those liposomes. In the absence of HMM, F-actin was distributed homogeneously inside the liposomes. In contrast, when F-actin was encapsulated in liposomes together with HMM, network structures were generated. Such network structures are attributable to the cross-linking of F-actin by HMM.
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Affiliation(s)
- Kingo Takiguchi
- Department of Molecular Biology, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
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Negishi M, Seto H, Hase M, Yoshikawa K. How does the mobility of phospholipid molecules at a water/oil interface reflect the viscosity of the surrounding oil? LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:8431-8434. [PMID: 18646878 DOI: 10.1021/la8015172] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The mobility of phospholipid molecules at a water/oil interface on cell-sized phospholipid-coated microdroplets was investigated through the measurement of diffusion constants by fluorescence recovery after photobleaching. It is found that the diffusion constant of phospholipids showed the relation D approximately (eta water + eta oil) -0.85, where D is the diffusion constant, eta water is the viscosity of water, and eta oil is the viscosity of oil. This observation indicates that the viscosity of the surrounding oil is the primary factor that determines the diffusibility of phospholipids at a water/oil interface.
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Affiliation(s)
- Makiko Negishi
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto, Japan
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Hase M, Yamada A, Hamada T, Baigl D, Yoshikawa K. Manipulation of cell-sized phospholipid-coated microdroplets and their use as biochemical microreactors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:348-52. [PMID: 17209573 DOI: 10.1021/la0618521] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Cell-sized water droplets coated by a phospholipid layer mimicking the inner surface of living cells were manipulated by laser tweezers and used as biochemical microreactors. The cell-sized phospholipid-coated microdroplets (CPMDs) consisted of a water droplet in mineral oil with a diameter of 1-100 microm and coated by 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine. We monitored the time development of biochemical reactions in a single CPMD obtained after the controlled fusion of two CPMDs containing a substrate and an enzyme, respectively. We present results on two enzymatic reactions: calcein production in the presence of esterase and green fluorescence protein expression.
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Affiliation(s)
- M Hase
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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Yamada A, Yamanaka T, Hamada T, Hase M, Yoshikawa K, Baigl D. Spontaneous transfer of phospholipid-coated oil-in-oil and water-in-oil micro-droplets through an oil/water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:9824-8. [PMID: 17106968 DOI: 10.1021/la062221+] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We studied the evolution of oil-in-oil (O/O) and water-in-oil (W/O) phospholipid-coated micro-droplets at an oil/water interface. We found that, in both cases, micro-droplets spontaneously transferred from the oil phase to the water phase. O/O micro-droplets transformed into oil-in-water micro-droplets, while W/O micro-droplets led to the formation of liposomes.
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Affiliation(s)
- Ayako Yamada
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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Hase M, Watanabe SN, Yoshikawa K. Rhythmic motion of a droplet under a dc electric field. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 74:046301. [PMID: 17155167 DOI: 10.1103/physreve.74.046301] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Indexed: 05/12/2023]
Abstract
The effect of a stationary electric field on a water droplet with a diameter of several tens micrometers in oil was examined. Such a droplet exhibits repetitive translational motion between the electrodes in a spontaneous manner. The state diagram of this oscillatory motion was deduced; at 0-20 V the droplet is fixed at the surface of the electrode, at 20-70 V the droplet exhibits small-amplitude oscillatory motion between the electrodes, and at 70-100 V the droplet shows large-amplitude periodic motion between the electrodes. The observed rhythmic motion is explained in a semiquantitative manner by using differential equations, which includes the effect of charging the droplet under an electric field. We also found that twin droplets exhibit synchronized rhythmic motion between the electrodes.
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Affiliation(s)
- Masahiko Hase
- Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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Hase M, Yamada A, Hamada T, Yoshikawa K. Transport of a cell-sized phospholipid micro-container across water/oil interface. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.06.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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