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Miyazako H, Hoshino T. Rapid pattern formation in model cell membranes when using an electron beam. Colloids Surf B Biointerfaces 2022. [DOI: 10.1016/j.colsurfb.2022.112967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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2
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Peng Z, Shimba K, Miyamoto Y, Yagi T. A Study of the Effects of Plasma Surface Treatment on Lipid Bilayers Self-Spreading on a Polydimethylsiloxane Substrate under Different Treatment Times. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:10732-10740. [PMID: 34464138 DOI: 10.1021/acs.langmuir.1c01319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Plasma-treated poly(dimethylsiloxane) (PDMS)-supported lipid bilayers are used as functional tools for studying cell membrane properties and as platforms for biotechnology applications. Self-spreading is a versatile method for forming lipid bilayers. However, few studies have focused on the effect of plasma treatment on self-spreading lipid bilayer formation. In this paper, we performed lipid bilayer self-spreading on a PDMS surface with different treatment times. Surface characterization of PDMS treated with different treatment times is evaluated by AFM and SEM, and the effects of plasma treatment of the PDMS surface on lipid bilayer self-spreading behavior is investigated by confocal microscopy. The front-edge velocity of lipid bilayers increases with the plasma treatment time. By theoretical analyses with the extended-DLVO modeling, we find that the most likely cause of the velocity change is the hydration repulsion energy between the PDMS surface and lipid bilayers. Moreover, the growth behavior of membrane lobes on the underlying self-spreading lipid bilayer was affected by topography changes in the PDMS surface resulting from plasma treatment. Our findings suggest that the growth of self-spreading lipid bilayers can be controlled by changing the plasma treatment time.
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Affiliation(s)
- Zugui Peng
- School of Engineering, Tokyo Institute of Technology, 403, Ishikawadai Bldg. 3, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 Japan
| | - Kenta Shimba
- School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yoshitaka Miyamoto
- School of Engineering, Tokyo Institute of Technology, 403, Ishikawadai Bldg. 3, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 Japan
- Department of Reproductive Biology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan
| | - Tohru Yagi
- School of Engineering, Tokyo Institute of Technology, 403, Ishikawadai Bldg. 3, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 Japan
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3
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Seimei A, Saeki D, Matsuyama H. Effect of polyelectrolyte structure on formation of supported lipid bilayers on polyelectrolyte multilayers prepared using the layer-by-layer method. J Colloid Interface Sci 2020; 569:211-218. [DOI: 10.1016/j.jcis.2020.02.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/20/2020] [Accepted: 02/19/2020] [Indexed: 11/17/2022]
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4
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Ionic strength for tailoring the synthesis of monomodal stealth cationic liposomes in microfluidic devices. Colloids Surf B Biointerfaces 2019; 179:233-241. [DOI: 10.1016/j.colsurfb.2019.03.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 03/23/2019] [Accepted: 03/25/2019] [Indexed: 01/06/2023]
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5
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Kakimoto Y, Tachihara Y, Okamoto Y, Miyazawa K, Fukuma T, Tero R. Morphology and Physical Properties of Hydrophilic-Polymer-Modified Lipids in Supported Lipid Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:7201-7209. [PMID: 29788718 DOI: 10.1021/acs.langmuir.8b00870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Lipid molecules such as glycolipids that are modified with hydrophilic biopolymers participate in the biochemical reactions occurring on cell membranes. Their functions and efficiency are determined by the formation of microdomains and their physical properties. We investigated the morphology and properties of domains induced by the hydrophilic-polymer-modified lipid applying a polyethylene glycol (PEG)-modified lipid as a model modified lipid. We formed supported lipid bilayers (SLBs) using a 0-10 mol % range of PEG-modified lipid concentration ( CPEG). We studied their morphology and fluidity by fluorescence microscopy, the fluorescence recovery after photobleaching method, and atomic force microscopy (AFM). Fluorescence images showed that domains rich in the PEG-modified lipid appeared and SLB fluidity decreased when CPEG ≥ 5%. AFM topographies showed that clusters of the PEG-modified lipid appeared prior to domain formation and the PEG-lipid-rich domains were observed as depressions. Frequency-modulation AFM revealed a force-dependent appearance of the PEG-lipid-rich domain.
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Affiliation(s)
- Yasuhiro Kakimoto
- Department of Environmental and Life Sciences , Toyohashi University of Technology , Toyohashi , Aichi 441-8580 , Japan
| | - Yoshihiro Tachihara
- Department of Environmental and Life Sciences , Toyohashi University of Technology , Toyohashi , Aichi 441-8580 , Japan
| | - Yoshiaki Okamoto
- Department of Environmental and Life Sciences , Toyohashi University of Technology , Toyohashi , Aichi 441-8580 , Japan
| | - Keisuke Miyazawa
- Division of Electrical Engineering and Computer Science , Kanazawa University , Kakuma-machi, Kanazawa 920-1192 , Japan
| | - Takeshi Fukuma
- Division of Electrical Engineering and Computer Science , Kanazawa University , Kakuma-machi, Kanazawa 920-1192 , Japan
- Nano Life Science Institute (WPI-NanoLSI) , Kakuma-machi, Kanazawa 920-1192 , Japan
| | - Ryugo Tero
- Department of Environmental and Life Sciences , Toyohashi University of Technology , Toyohashi , Aichi 441-8580 , Japan
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Ito K, Ogawa Y, Yokota K, Matsumura S, Minamisawa T, Suga K, Shiba K, Kimura Y, Hirano-Iwata A, Takamura Y, Ogino T. Host Cell Prediction of Exosomes Using Morphological Features on Solid Surfaces Analyzed by Machine Learning. J Phys Chem B 2018; 122:6224-6235. [PMID: 29771528 DOI: 10.1021/acs.jpcb.8b01646] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Exosomes are extracellular nanovesicles released from any cells and found in any body fluid. Because exosomes exhibit information of their host cells (secreting cells), their analysis is expected to be a powerful tool for early diagnosis of cancers. To predict the host cells, we extracted multidimensional feature data about size, shape, and deformation of exosomes immobilized on solid surfaces by atomic force microscopy (AFM). The key idea is combination of support vector machine (SVM) learning for individual exosome particles and their interpretation by principal component analysis (PCA). We observed exosomes derived from three different cancer cells on SiO2/Si, 3-aminopropyltriethoxysilane-modified-SiO2/Si, and TiO2 substrates by AFM. Then, 14-dimensional feature vectors were extracted from AFM particle data, and classifiers were trained in 14-dimensional space. The prediction accuracy for host cells of test AFM particles was examined by the cross-validation test. As a result, we obtained prediction of exosome host cells with the best accuracy of 85.2% for two-class SVM learning and 82.6% for three-class one. By PCA of the particle classifiers, we concluded that the main factors for prediction accuracy and its strong dependence on substrates are incremental decrease in the PCA-defined aspect ratio of the particles with their volume.
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Affiliation(s)
- Kazuki Ito
- Yokohama National University , 79-5, Tokiwadai , Hodogaya-ku, Yokohama 240-8501 , Japan
| | - Yuta Ogawa
- Yokohama National University , 79-5, Tokiwadai , Hodogaya-ku, Yokohama 240-8501 , Japan
| | - Keiji Yokota
- Yokohama National University , 79-5, Tokiwadai , Hodogaya-ku, Yokohama 240-8501 , Japan
| | - Sachiko Matsumura
- Japanese Foundation for Cancer Research , 3-8-31 Ariake , Koto-ku, Tokyo 135-8550 , Japan
| | - Tamiko Minamisawa
- Japanese Foundation for Cancer Research , 3-8-31 Ariake , Koto-ku, Tokyo 135-8550 , Japan
| | - Kanako Suga
- Japanese Foundation for Cancer Research , 3-8-31 Ariake , Koto-ku, Tokyo 135-8550 , Japan
| | - Kiyotaka Shiba
- Japanese Foundation for Cancer Research , 3-8-31 Ariake , Koto-ku, Tokyo 135-8550 , Japan
| | - Yasuo Kimura
- Tokyo University of Technology , 1404-1, Katakura-Cho , Hachioji 192-0914 , Japan
| | - Ayumi Hirano-Iwata
- Tohoku University , 2-1-1, Katahira , Aoba-ku, Sendai , Miyagi 980-8577 , Japan
| | - Yuzuru Takamura
- Japan Advanced Institute of Science and Technology , 1-1, Asahi-Dai , Nomi , Ishikawa 923-1292 , Japan
| | - Toshio Ogino
- Yokohama National University , 79-5, Tokiwadai , Hodogaya-ku, Yokohama 240-8501 , Japan.,Japan Advanced Institute of Science and Technology , 1-1, Asahi-Dai , Nomi , Ishikawa 923-1292 , Japan
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7
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Peng PY, Chiang PC, Chao L. Controllable occurrence of free-standing lipid membranes on nanograting structured supports. ACS APPLIED MATERIALS & INTERFACES 2014; 6:12261-12269. [PMID: 24988277 DOI: 10.1021/am501861a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Supported lipid bilayers (SLBs) have been widely used to study protein-lipid membrane interactions because their planar geometry is suitable for many surface analysis tools. However, the friction coupling between the support and the membrane can influence the properties of biomolecules in the membrane. Many studies have attempted to span SLBs over nanostructured supports to create free-standing regions in SLBs for biosensor applications. However, membranes following the support surface contour are more frequently observed than are free-standing membranes on structured supports, indicating that the parameter range suitable for formation of free-standing SLBs might be narrow and more information is necessary to understand the required conditions. The objective of this study was to estimate the system energies of free-standing and contour-following membrane states and determine which state is the most energetically favorable under various conditions. For a lipid membrane preferring to stay close to the support, an energy reward occurs when they are in close proximity; however, increasing the contact area on a structured surface can result in an energy penalty because of the bending of the lipid bilayer. Whether the energy reward or the energy penalty dominates could determine the membrane state. We used the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and the Helfrich bending theory to relate the energy sizes to experimentally controllable parameters. We experimentally examined whether the membrane state followed the model prediction when we used various buffer ionic strengths, various lipid types, and nanograting supports with three different geometries. Because it is difficult to observe the experimental membrane state directly at the nanoscale, we developed a method to use the fluorescence recovery shape change after photobleaching to distinguish experimental membrane states at the micrometer scale. Our experimental results closely matched the theoretical predictions, suggesting that the developed model can be used to predict suitable conditions for formation of free-standing bilayers on nanostructured solid supports.
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Affiliation(s)
- Po-Yu Peng
- Department of Chemical Engineering, National Taiwan University , Taipei 106, Taiwan
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MOTEGI T, TAKIMOTO B, NABIKA H, MURAKOSHI K. Molecule Manipulation at Electrified Interfaces using Metal Nanogates. ELECTROCHEMISTRY 2014. [DOI: 10.5796/electrochemistry.82.712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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9
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Motegi T, Nabika H, Murakoshi K. Single-molecule observations for determining the orientation and diffusivity of dye molecules in lipid bilayers. Phys Chem Chem Phys 2013; 15:12895-902. [PMID: 23812281 DOI: 10.1039/c3cp51585k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular orientation and diffusion of dye molecules in artificial lipid bilayers were observed using total internal reflection fluorescence microscopy. An artificial lipid bilayer composed of a ternary lipid mixture of 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), and cholesterol was used. The molecular orientation, which was obtained through defocused imaging, clarified the microscopic features, including cholesterol-induced changes in the local packing structure. Diffusion analysis gave insights into the macroscopic aspects of phase distribution in the heterogeneous bilayer system. Combining these two independent investigations, we revealed the effect of cholesterol addition on microscopic local packing and macroscopic phase structures. Our observations showed a transition from a DLPC-network-like structure to a DPPC-network-like structure upon the addition of cholesterol, which was not evident from previous domain shape observations. The present single-molecule observations yielded the actual phase structure that controls the motion of molecules in the membrane. The results imply that the orientation and diffusivity of molecules offer useful information regarding the phase distribution, which may be hindered by the apparent phase structure in a heterogeneous lipid bilayer that contains cholesterol.
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Affiliation(s)
- Toshinori Motegi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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10
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Harb FF, Tinland B. Effect of ionic strength on dynamics of supported phosphatidylcholine lipid bilayer revealed by FRAPP and Langmuir-Blodgett transfer ratios. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:5540-5546. [PMID: 23581462 DOI: 10.1021/la304962n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
To determine how lipid bilayer/support interactions are affected by ionic strength, we carried out lipid diffusion coefficient measurements by fluorescence recovery after patterned photobleaching (FRAPP) and transfer ratio measurements using a Langmuir balance on supported bilayers of phosphatidylcholine lipids. The main effect of increasing ionic strength is shown to be enhanced diffusion of the lipids due to a decrease in the electrostatic interaction between the bilayer and the support. We experimentally confirm that the two main parameters governing bilayer behavior are electrostatic interaction and bilayer/support distance. Both these parameters can therefore be used to vary the potential that acts on the bilayer. Additionally, our findings show that FRAPP is an extremely sensitive tool to study interaction effects: here, variations in diffusion coefficient as well as the presence or absence of leaflet decoupling.
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11
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Substrate Effects on the Formation Process, Structure and Physicochemical Properties of Supported Lipid Bilayers. MATERIALS 2012. [PMCID: PMC5449048 DOI: 10.3390/ma5122658] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Supported lipid bilayers are artificial lipid bilayer membranes existing at the interface between solid substrates and aqueous solution. Surface structures and properties of the solid substrates affect the formation process, fluidity, two-dimensional structure and chemical activity of supported lipid bilayers, through the 1–2 nm thick water layer between the substrate and bilayer membrane. Even on SiO2/Si and mica surfaces, which are flat and biologically inert, and most widely used as the substrates for the supported lipid bilayers, cause differences in the structure and properties of the supported membranes. In this review, I summarize several examples of the effects of substrate structures and properties on an atomic and nanometer scales on the solid-supported lipid bilayers, including our recent reports.
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12
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Nabika H, Murakoshi K. Electric-field-assisted Control of Lipid Bilayer Stacking Structure. CHEM LETT 2012. [DOI: 10.1246/cl.2012.1306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hideki Nabika
- Department of Chemistry, Faculty of Science, Hokkaido University
| | - Kei Murakoshi
- Department of Chemistry, Faculty of Science, Hokkaido University
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13
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Motegi T, Nabika H, Murakoshi K. Enhanced Brownian ratchet molecular separation using a self-spreading lipid bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:6656-6661. [PMID: 22500817 DOI: 10.1021/la300410j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A new approach is proposed for two-dimensional molecular separation based on the Brownian ratchet mechanism by use of a self-spreading lipid bilayer as both a molecular transport and separation medium. In addition to conventional diffusivity-dependence on the ratchet separation efficiency, the difference in the intermolecular interactions between the target molecules and the lipid bilayer is also incorporated as a new separation factor in the present self-spreading ratchet system. Spreading at the gap between two ratchet obstacles causes a local change in the lipid density at the gap. This effect produces an additional opportunity for a molecule to be deflected at the ratchet obstacle and thus causes an additional angle shift. This enables the separation of molecules with the same diffusivity but with different intermolecular interaction between the target molecule and surrounding lipid molecules. Here we demonstrate this aspect by using cholera toxin subunit B (CTB)-ganglioside GM1 (GM1) complexes with different configurations. The present results will unlock a new strategy for two-dimensional molecular manipulation with ultrasmall devices.
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Affiliation(s)
- Toshinori Motegi
- Department of Chemistry, Faculty of Science, Hokkaido University , N10W8, Kita, Sapporo 060-0810, Japan
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14
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Nabika H, Oowada M, Murakoshi K. Control of dynamics and molecular distribution in a self-spreading lipid bilayer using surface-modified metal nanoarchitectures. Phys Chem Chem Phys 2011; 13:5561-4. [PMID: 21336415 DOI: 10.1039/c0cp01790f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular distribution and spreading dynamics of self-spreading lipid bilayers can be tuned by surface-modified metallic nanoarchitectures. Interactions between lipids and molecules in the surface modification alter the self-spreading behavior at the gate regions between adjacent nanoarchitectures, leading to molecular filtering/concentrating effects and modification of the dynamics. The hydrophilic surface can tune the spreading velocity without changing the molecular distribution in the spreading bilayer, whereas the hydrophobic surface provides a molecular concentrating function to the nanogates. This indicates that a combination of unmodified/hydrophobic/hydrophilic nanoarchitectures has a wide range of potential applications since it can be used to independently control the self-spreading dynamics and the molecular distribution.
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Affiliation(s)
- Hideki Nabika
- Department of Chemistry, Graduate School of Science, Hokkaido University, Kita, Sapporo, Japan
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15
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Takimoto B, Nabika H, Murakoshi K. Force applied to a single molecule at a single nanogate molecule filter. NANOSCALE 2010; 2:2591-2595. [PMID: 20957277 DOI: 10.1039/c0nr00455c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have investigated the origin of molecule filtering system based on a chemical potential barrier produced by thermodynamically driven molecular flow in a nanoscopic space at nanogates. Single molecule tracking experiments prove that the highly localized potential barrier allows for selective manipulation of the target molecule. We propose the presence of a force, a few fN per molecule, to decelerate the molecule's movement at the nanogate, which is comparable to or larger than the force applied by conventional electrophoretic operation. The present force can be tuned by changing the nanogate width at the nanometre level. These findings allow us to propose an accurate design of novel devices for molecular manipulation on an ultra small scale using a very small number of molecules without any external biases.
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Affiliation(s)
- Baku Takimoto
- Department of Chemistry, Faculty of Science, Hokkaido University, N10W8, Kita, Sapporo, 060-0810, Japan.
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Oleson TA, Sahai N. Interaction energies between oxide surfaces and multiple phosphatidylcholine bilayers from extended-DLVO theory. J Colloid Interface Sci 2010; 352:316-26. [DOI: 10.1016/j.jcis.2010.08.056] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 08/18/2010] [Accepted: 08/20/2010] [Indexed: 11/27/2022]
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17
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Oleson TA, Sahai N, Pedersen JA. Electrostatic effects on deposition of multiple phospholipid bilayers at oxide surfaces. J Colloid Interface Sci 2010; 352:327-36. [DOI: 10.1016/j.jcis.2010.08.057] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 08/18/2010] [Accepted: 08/20/2010] [Indexed: 11/27/2022]
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18
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Isono T, Ikeda T, Ogino T. Evolution of supported planar lipid bilayers on step-controlled sapphire surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:9607-9611. [PMID: 20345104 DOI: 10.1021/la100179q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Self-organized step/terrace structures on a sapphire surface were used to investigate interface properties between a solid surface and a supported planar lipid bilayer (SPB). We prepared random-stepped, single-stepped and multistepped sapphire surfaces. Some multistepped surfaces covered with crossing steps exhibit phase-separation into hydrophilic and hydrophobic domains. We studied evolution of self-spreading lipid bilayers that are subject to the atomic structures and chemical states on the surfaces. The growth direction of SPBs in the self-spreading method is regulated by the atomic steps. While the SPBs were apparently uniform after a 1 h self-spreading, a density gradient of the lipid molecules was observed even after 24 h spreading. We found that various patterns of the SPBs that depend on the density of the lipid molecules are self-assembled on the phase-separated surfaces. Although the SPB is supported on the sapphire surface via an about 1 nm water layer, the self-spreading direction and the morphology of the SPBs are affected by the atomic steps, whose height is much smaller than that of the water layer.
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Affiliation(s)
- Toshinari Isono
- Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan.
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MacKinnon N, Guérin G, Liu B, Gradinaru CC, Rubinstein JL, Macdonald PM. Triggered instability of liposomes bound to hydrophobically modified core-shell PNIPAM hydrogel beads. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:1081-1089. [PMID: 19754070 DOI: 10.1021/la902423v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The ability to trigger a destabilization of the membrane integrity of liposomes bound to environmentally sensitive hydrophobically modified core-shell hydrogel beads is demonstrated. Hydrogel beads with a core composed of poly(N-isopropylacrylamide) lightly cross-linked with bisacrylamide (BA) (pNIPAM) and a shell composed of NIPAM highly cross-linked with BA and containing varying amounts of acrylic acid (AA) [p(NIPAM-co-AA)] undergo a volume phase transition (VPT) at approximately 32 degrees C, as determined from (1)H magic angle spinning (MAS) NMR, regardless of the AA content of the shell. When the shell was hydrophobically modified with either decylamine or tetradecylamine, binding of extruded large unilamellar vesicles (eLUVs) composed of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) was quantitative, as determined via fluorescence spectroscopy. Fluorescence microscopy showed that such bound eLUVs did not fuse. Hydrogel-bound eLUV membrane permeability was assessed using (31)P MAS NMR in the presence of the chemical shift agent praseodymium and demonstrated that only at lower degrees of hydrophobic modification of the core-shell hydrogels was eLUV membrane barrier integrity maintained when T < VPT. At a low degree of hydrophobic modification, cycling the temperature above the VPT even for short periods caused the eLUV membranes to become leaky. Hence, eLUV membrane permeability was coupled to the hydrogel VPT, a situation that would be useful in applications requiring triggered release of liposomal contents.
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Affiliation(s)
- Neil MacKinnon
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
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Nabika H, Iijima N, Takimoto B, Ueno K, Misawa H, Murakoshi K. Segregation of molecules in lipid bilayer spreading through metal nanogates. Anal Chem 2009; 81:699-704. [PMID: 19093749 DOI: 10.1021/ac802130e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new methodology for nanoscopic molecular filtering was developed using a substrate with a periodic array of metallic nanogates with various widths between 75 and 500 nm. A self-spreading lipid bilayer was employed as the molecular transport and filtering medium. Dye-labeled molecules doped in the self-spreading lipid bilayer were filtered after the spreading less than a few tens of micrometers on the nanogate array. Quantitative analysis of the spreading dynamics suggests that the filtering effect originates from the formation of the chemical potential barrier at the nanogate region, which is believed to be due to structural change such as compression imposed on the spreading lipid bilayer at the gate. A highly localized chemical potential barrier affects the ability of the doped dye-labeled molecules to penetrate the gate. The use of the self-spreading lipid bilayer allows molecular transportation without the use of any external field such as an electric field as is used in electrophoresis. The present system could be applied micro- and nanoscopic device technologies as it provides a completely nonbiased filtering methodology.
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Affiliation(s)
- Hideki Nabika
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, 060-0810, Japan
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Single Molecule Tracking of Cholera-Toxin Subunit B on GM1-ganlioside Containing Lipid Bilayer. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2009. [DOI: 10.1380/ejssnt.2009.74] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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22
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Tero R, Ujihara T, Urisu T. Lipid bilayer membrane with atomic step structure: supported bilayer on a step-and-terrace TiO2(100) surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11567-11576. [PMID: 18785710 DOI: 10.1021/la801080f] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The formation of a supported planar lipid bilayer (SPLB) and its morphology on step-and-terrace rutile TiO 2(100) surfaces were investigated by fluorescence microscopy and atomic force microscopy. The TiO 2(100) surfaces consisting of atomic steps and flat terraces were formed on a rutile TiO 2 single-crystal wafer by a wet treatment and annealing under a flow of oxygen. An intact vesicular layer formed on the TiO 2(100) surface when the surface was incubated in a sonicated vesicle suspension under the condition that a full-coverage SPLB forms on SiO 2, as reported in previous studies. However, a full-coverage, continuous, fluid SPLB was obtained on the step-and-terrace TiO 2(100) depending on the lipid concentration, incubation time, and vesicle size. The SPLB on the TiO 2(100) also has step-and-terrace morphology following the substrate structure precisely even though the SPLB is in the fluid phase and an approximately 1-nm-thick water layer exists between the SPLB and the substrate. This membrane distortion on the atomic scale affects the phase-separation structure of a binary bilayer of micrometer order. The interaction energy calculated including DLVO and non-DLVO factors shows that a lipid membrane on the TiO 2(100) gains 20 times more energy than on SiO 2. This specifically strong attraction on TiO 2 makes the fluid SPLB precisely follow the substrate structure of angstrom order.
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Affiliation(s)
- Ryugo Tero
- Division of Biomolecular Sensing, Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan.
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Nabika H, Takimoto B, Iijima N, Murakoshi K. Observation of self-spreading lipid bilayer on hydrophilic surface with a periodic array of metallic nano-gate. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2008.01.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Nabika H, Takimoto B, Murakoshi K. Molecular separation in the lipid bilayer medium: electrophoretic and self-spreading approaches. Anal Bioanal Chem 2008; 391:2497-506. [DOI: 10.1007/s00216-008-2140-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 04/01/2008] [Accepted: 04/15/2008] [Indexed: 11/29/2022]
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Nabika H, Fukasawa A, Murakoshi K. Tuning the dynamics and molecular distribution of the self-spreading lipid bilayer. Phys Chem Chem Phys 2008; 10:2243-8. [DOI: 10.1039/b715983h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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