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Mimura H, Osaki T, Takamori S, Nakao K, Takeuchi S. Lipid Bilayer Reformation Using the Wiping Blade for Improved Ion Channel Analysis. Anal Chem 2023; 95:17354-17361. [PMID: 37968939 DOI: 10.1021/acs.analchem.3c03707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
The measurement of ion permeation activity across planar lipid bilayers is a useful technique for the functional analysis and drug evaluation of ion channels at the single-molecule level. To enhance the data throughput, parallelization of lipid bilayers is desirable. However, existing parallelized approaches face challenges in simultaneously and efficiently measuring ion channel activities under various conditions on one chip. In this study, we propose an approach to overcome these limitations by developing a device capable of repeated measurements of ion channels incorporated into individually arrayed lipid bilayers. Our device forms an array of a lipid bilayer at a micropore on a separator by merging two lipid monolayers assembled on the surface of aqueous droplets. We introduce a vertically moving, blade-shaped module─referred to as a "wiping blade"─which enables controlled disruption and reformation of the bilayer at the micropore. By optimizing the surface properties and clearance of the wiping blade, we successfully achieved repeated bilayer formation. The arrayed lipid bilayer device with the integrated wiping blade module demonstrates a 5-fold improvement in data throughput during ion channel activity measurements. Finally, we validate the practical utility of our device by evaluating the effects of an ion channel inhibitor. The developed device opens new avenues for high-throughput analysis and screening of ion channels, leading to significant advancements in drug discovery and functional studies of membrane proteins. It offers a powerful tool for researchers in the field and holds promise for accelerating drug development by targeting ion channels.
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Affiliation(s)
- Hisatoshi Mimura
- Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan
| | - Toshihisa Osaki
- Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan
- MAQsys Inc., 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan
| | - Sho Takamori
- Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan
| | - Kenji Nakao
- MAQsys Inc., 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan
| | - Shoji Takeuchi
- Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan
- Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
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2
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Ensslen T, Behrends JC. A chip-based array for high-resolution fluorescence characterization of free-standing horizontal lipid membranes under voltage clamp. LAB ON A CHIP 2022; 22:2902-2910. [PMID: 35839072 DOI: 10.1039/d2lc00357k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Optical techniques, such as fluorescence microscopy, are of great value in characterizing the structural dynamics of membranes and membrane proteins. A particular challenge is to combine high-resolution optical measurements with high-resolution voltage clamp electrical recordings providing direct information on e.g. single ion channel gating and/or membrane capacitance. Here, we report on a novel chip-based array device which facilitates optical access with water or oil-immersion objectives of high numerical aperture to horizontal free-standing lipid membranes while controlling membrane voltage and recording currents using individual micropatterned Ag/AgCl-electrodes. Wide-field and confocal imaging, as well as time-resolved single photon counting on free-standing membranes spanning sub-nanoliter cavities are demonstrated while electrical signals, including single channel activity, are simultaneously acquired. This optically addressable microelectrode cavity array will allow combined electrical-optical studies of membranes and membrane proteins to be performed as a routine experiment.
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Affiliation(s)
- Tobias Ensslen
- Laboratory for Membrane Physiology and Technology, Department of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany.
| | - Jan C Behrends
- Laboratory for Membrane Physiology and Technology, Department of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany.
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3
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Zhou P, He H, Ma H, Wang S, Hu S. A Review of Optical Imaging Technologies for Microfluidics. MICROMACHINES 2022; 13:mi13020274. [PMID: 35208397 PMCID: PMC8877635 DOI: 10.3390/mi13020274] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/07/2022] [Accepted: 01/11/2022] [Indexed: 12/15/2022]
Abstract
Microfluidics can precisely control and manipulate micro-scale fluids, and are also known as lab-on-a-chip or micro total analysis systems. Microfluidics have huge application potential in biology, chemistry, and medicine, among other fields. Coupled with a suitable detection system, the detection and analysis of small-volume and low-concentration samples can be completed. This paper reviews an optical imaging system combined with microfluidics, including bright-field microscopy, chemiluminescence imaging, spectrum-based microscopy imaging, and fluorescence-based microscopy imaging. At the end of the article, we summarize the advantages and disadvantages of each imaging technology.
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Affiliation(s)
- Pan Zhou
- School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528225, China;
- Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, Foshan University, Foshan 528225, China;
| | - Haipeng He
- Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, Foshan University, Foshan 528225, China;
| | - Hanbin Ma
- CAS Key Laboratory of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China;
- Guangdong ACXEL Micro & Nano Tech Co., Ltd., Foshan 528000, China
| | - Shurong Wang
- Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, Foshan University, Foshan 528225, China;
- Correspondence: (S.W.); (S.H.)
| | - Siyi Hu
- CAS Key Laboratory of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China;
- Correspondence: (S.W.); (S.H.)
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4
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Lee HR, Lee Y, Oh SS, Choi SQ. Ultra-Stable Freestanding Lipid Membrane Array: Direct Visualization of Dynamic Membrane Remodeling with Cholesterol Transport and Enzymatic Reactions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2002541. [PMID: 32924281 DOI: 10.1002/smll.202002541] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/09/2020] [Indexed: 06/11/2023]
Abstract
Cell membranes actively change their local compositions, serving essential biological processes such as cellular signaling and endocytosis. Although membrane dynamics is vital in the cellular functions, the complexity of natural membranes has made its fundamental understanding and systematic assessment difficult. Here, a powerful artificial membrane system is developed for real-time visualization of the spatiotemporal dynamics of membrane remodeling. Through well-defined air/oil/water interfaces on grid holes, tens of planar lipid bilayer membranes are easily created, and their reproducibility, controllability, and generality are highlighted. The freestanding membranes are large but also highly stable, facilitating direct long-term monitoring of dynamic membrane reconstitution caused by external stimuli. As an example to demonstrate the superiority of this membrane system, the effect of cholesterol trafficking, which significantly affects biophysical properties of cell membranes, is investigated at different membrane compositions. Cholesterol transport into and out of the membranes at different rates causes anomalous lipid arrangements through cholesterol-mediated phase transitions and decomposition, which have never been witnessed before. Furthermore, enzyme-induced membrane dynamics is successfully shown in this platform; sphingomyelinases locally generate asymmetry between two membrane leaflets. This technique is broadly applicable for exploring the membrane heterogeneity under various membrane-based reactions, providing valuable insight into the membrane dynamics.
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Affiliation(s)
- Hyun-Ro Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Yohan Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Seung Soo Oh
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Siyoung Q Choi
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
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5
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Misawa N, Osaki T, Takeuchi S. Membrane protein-based biosensors. J R Soc Interface 2019; 15:rsif.2017.0952. [PMID: 29669891 DOI: 10.1098/rsif.2017.0952] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/19/2018] [Indexed: 01/09/2023] Open
Abstract
This review highlights recent development of biosensors that use the functions of membrane proteins. Membrane proteins are essential components of biological membranes and have a central role in detection of various environmental stimuli such as olfaction and gustation. A number of studies have attempted for development of biosensors using the sensing property of these membrane proteins. Their specificity to target molecules is particularly attractive as it is significantly superior to that of traditional human-made sensors. In this review, we classified the membrane protein-based biosensors into two platforms: the lipid bilayer-based platform and the cell-based platform. On lipid bilayer platforms, the membrane proteins are embedded in a lipid bilayer that bridges between the protein and a sensor device. On cell-based platforms, the membrane proteins are expressed in a cultured cell, which is then integrated in a sensor device. For both platforms we introduce the fundamental information and the recent progress in the development of the biosensors, and remark on the outlook for practical biosensing applications.
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Affiliation(s)
- Nobuo Misawa
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu, Kawasaki 213-0012, Japan
| | - Toshihisa Osaki
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu, Kawasaki 213-0012, Japan.,Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
| | - Shoji Takeuchi
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu, Kawasaki 213-0012, Japan .,Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
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6
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Heo P, Ramakrishnan S, Coleman J, Rothman JE, Fleury JB, Pincet F. Highly Reproducible Physiological Asymmetric Membrane with Freely Diffusing Embedded Proteins in a 3D-Printed Microfluidic Setup. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1900725. [PMID: 30977975 DOI: 10.1002/smll.201900725] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/28/2019] [Indexed: 06/09/2023]
Abstract
Experimental setups to produce and to monitor model membranes have been successfully used for decades and brought invaluable insights into many areas of biology. However, they all have limitations that prevent the full in vitro mimicking and monitoring of most biological processes. Here, a suspended physiological bilayer-forming chip is designed from 3D-printing techniques. This chip can be simultaneously integrated to a confocal microscope and a path-clamp amplifier. It is composed of poly(dimethylsiloxane) and consists of a ≈100 µm hole, where the horizontal planar bilayer is formed, connecting two open crossed-channels, which allows for altering of each lipid monolayer separately. The bilayer, formed by the zipping of two lipid leaflets, is free-standing, horizontal, stable, fluid, solvent-free, and flat with the 14 types of physiologically relevant lipids, and the bilayer formation process is highly reproducible. Because of the two channels, asymmetric bilayers can be formed by making the two lipid leaflets of different composition. Furthermore, proteins, such as transmembrane, peripheral, and pore-forming proteins, can be added to the bilayer in controlled orientation and keep their native mobility and activity. These features allow in vitro recapitulation of membrane process close to physiological conditions.
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Affiliation(s)
- Paul Heo
- Laboratoire de Physique de l'Ecole Normale Supérieure, PSL Research University, CNRS, Sorbonne Université, Université Sorbonne Paris Cité, Paris, 75005, France
| | - Sathish Ramakrishnan
- Laboratoire de Physique de l'Ecole Normale Supérieure, PSL Research University, CNRS, Sorbonne Université, Université Sorbonne Paris Cité, Paris, 75005, France
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, 06510, USA
| | - Jeff Coleman
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, 06510, USA
| | - James E Rothman
- Ecole Normale Supérieure, PSL University, Paris, 75005, France
| | - Jean-Baptiste Fleury
- Department of Experimental Physics and Center for Biophysics, Saarland University, Saarbruecken, D-66123, Germany
| | - Frederic Pincet
- Laboratoire de Physique de l'Ecole Normale Supérieure, PSL Research University, CNRS, Sorbonne Université, Université Sorbonne Paris Cité, Paris, 75005, France
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7
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Shoji K, Kawano R. Microfluidic Formation of Double-Stacked Planar Bilayer Lipid Membranes by Controlling the Water-Oil Interface. MICROMACHINES 2018; 9:mi9050253. [PMID: 30424186 PMCID: PMC6187563 DOI: 10.3390/mi9050253] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/18/2018] [Accepted: 05/18/2018] [Indexed: 11/24/2022]
Abstract
This study reports double-stacked planar bilayer lipid membranes (pBLMs) formed using a droplet contact method (DCM) for microfluidic formation with five-layered microchannels that have four micro guide pillars. pBLMs are valuable for analyzing membrane proteins and modeling cell membranes. Furthermore, multiple-pBLM systems have broadened the field of application such as electronic components, light-sensors, and batteries because of electrical characteristics of pBLMs and membrane proteins. Although multiple-stacked pBLMs have potential, the formation of multiple-pBLMs on a micrometer scale still faces challenges. In this study, we applied a DCM strategy to pBLM formation using microfluidic techniques and attempted to form double-stacked pBLMs in micro-meter scale. First, microchannels with micro pillars were designed via hydrodynamic simulations to form a five-layered flow with aqueous and lipid/oil solutions. Then, pBLMs were successfully formed by controlling the pumping pressure of the solutions and allowing contact between the two lipid monolayers. Finally, pore-forming proteins were reconstituted in the pBLMs, and ion current signals of nanopores were obtained as confirmed by electrical measurements, indicating that double-stacked pBLMs were successfully formed. The strategy for the double-stacked pBLM formation can be applied to highly integrated nanopore-based systems.
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Affiliation(s)
- Kan Shoji
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo 184-8588, Japan.
| | - Ryuji Kawano
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo 184-8588, Japan.
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8
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Schulze Greiving VC, de Boer HL, Bomer JG, van den Berg A, Le Gac S. Integrated microfluidic biosensing platform for simultaneous confocal microscopy and electrophysiological measurements on bilayer lipid membranes and ion channels. Electrophoresis 2017; 39:496-503. [PMID: 29193178 DOI: 10.1002/elps.201700346] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/04/2017] [Accepted: 11/05/2017] [Indexed: 01/19/2023]
Abstract
Combining high-resolution imaging and electrophysiological recordings is key for various types of experimentation on lipid bilayers and ion channels. Here, we propose an integrated biosensing platform consisting of a microfluidic cartridge and a dedicated chip-holder to conduct such dual measurements on suspended lipid bilayers, in a user-friendly manner. To illustrate the potential of the integrated platform, we characterize lipid bilayers in terms of thickness and fluidity while simultaneously monitoring single ion channel currents. For that purpose, POPC lipid bilayers are supplemented with a fluorescently-tagged phospholipid (NBD-PE, 1% mol) for Fluorescence Recovery After Photobleaching (FRAP) measurements and a model ion channel (gramicidin, 1 nM). These combined measurements reveal that NBD-PE has no effect on the lipid bilayer thickness while gramicidin induces thinning of the membrane. Furthermore, the presence of gramicidin does not alter the lipid bilayer fluidity. Surprisingly, in lipid bilayers supplemented with both probes, a reduction in gramicidin open probability and lifetime is observed compared to lipid bilayers with gramicidin only, suggesting an influence of NBD-PE on the gramicidin ion function. Altogether, our proposed microfluidic biosensing platform in combination with the herein presented multi-parametric measurement scheme paves the way to explore the interdependent relationship between lipid bilayer properties and ion channel function.
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Affiliation(s)
- Verena C Schulze Greiving
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Hans L de Boer
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Johan G Bomer
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Albert van den Berg
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Séverine Le Gac
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
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9
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Affiliation(s)
- Toshihisa Osaki
- Artificial Cell
Membrane
Systems Group, Kanagawa Academy of Science and Technology, 3-2-1
Sakado, Takatsu, 213-0012 Kawasaki, Japan
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, 153-8505 Tokyo, Japan
| | - Shoji Takeuchi
- Artificial Cell
Membrane
Systems Group, Kanagawa Academy of Science and Technology, 3-2-1
Sakado, Takatsu, 213-0012 Kawasaki, Japan
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, 153-8505 Tokyo, Japan
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10
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Tomoike F, Tonooka T, Osaki T, Takeuchi S. Repetitive formation of optically-observable planar lipid bilayers by rotating chambers on a microaperture. LAB ON A CHIP 2016; 16:2423-2426. [PMID: 27256329 DOI: 10.1039/c6lc00363j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Optical observation of a planar lipid bilayer is an effective method of lipid bilayer characterization. However, previous methods for optically observable lipid bilayer formation are unsuitable for repetitive formation of lipid bilayers. In this paper, we propose a system that facilitates repetitive formation of horizontal lipid bilayers via mechanical rotation of the rotating part. We show that multiple bilayers can be observed within a short period, and that the electrical and optical characteristics of a bilayer can be analyzed simultaneously.
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Affiliation(s)
- Fumiaki Tomoike
- Center for International Research on Integrative Biomedical Systems (CIBiS), Institute of Industrial Science (IIS), The University of Tokyo, 4-6-1 Komaba Meguro-ku, Tokyo 153-8505, Japan.
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11
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Bright LK, Baker CA, Bränström R, Saavedra SS, Aspinwall CA. Methacrylate Polymer Scaffolding Enhances the Stability of Suspended Lipid Bilayers for Ion Channel Recordings and Biosensor Development. ACS Biomater Sci Eng 2016; 1:955-963. [PMID: 26925461 PMCID: PMC4764998 DOI: 10.1021/acsbiomaterials.5b00205] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Black lipid membranes (BLMs) provide a synthetic environment that facilitates measurement of ion channel activity in diverse analytical platforms. The limited electrical, mechanical and temporal stabilities of BLMs pose a significant challenge to development of highly stable measurement platforms. Here, ethylene glycol dimethacrylate (EGDMA) and butyl methacrylate (BMA) were partitioned into BLMs and photopolymerized to create a cross-linked polymer scaffold in the bilayer lamella that dramatically improved BLM stability. The commercially available methacrylate monomers provide a simple, low cost, and broadly accessible approach for preparing highly stabilized BLMs useful for ion channel analytical platforms. When prepared on silane-modified glass microapertures, the resulting polymer scaffold-stabilized (PSS)-BLMs exhibited significantly improved lifetimes of 23 ± 9 to 40 ± 14 h and > 10-fold increase in mechanical stability, with breakdown potentials > 2000 mV attainable, depending on surface modification and polymer cross-link density. Additionally, the polymer scaffold exerted minimal perturbations to membrane electrical integrity as indicated by mean conductance measurements. When gramicidin A and α-hemolysin were reconstituted into PSS-BLMs, the ion channels retained function comparable to conventional BLMs. This approach is a key advance in the formation of stabilized BLMs and should be amenable to a wide range of receptor and ion channel functionalized platforms.
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Affiliation(s)
- Leonard K. Bright
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721
| | - Christopher A. Baker
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721
| | - Robert Bränström
- Endocrine and Sarcoma Surgery Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | - S. Scott Saavedra
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721
- BIO5 Institute, University of Arizona, Tucson, AZ 85721
| | - Craig A. Aspinwall
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721
- BIO5 Institute, University of Arizona, Tucson, AZ 85721
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721
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12
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Teng W, Ban C, Hahn JH. Formation of lipid bilayer membrane in a poly(dimethylsiloxane) microchip integrated with a stacked polycarbonate membrane support and an on-site nanoinjector. BIOMICROFLUIDICS 2015; 9:024120. [PMID: 26015832 PMCID: PMC4409621 DOI: 10.1063/1.4919066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/14/2015] [Indexed: 06/04/2023]
Abstract
This paper describes a new and facile approach for the formation of pore-spanning bilayer lipid membranes (BLMs) within a poly(dimethylsiloxane) (PDMS) microfluidic device. Commercially, readily available polycarbonate (PC) membranes are employed for the support of BLMs. PC sheets with 5 μm, 2 μm, and 0.4 μm pore diameters, respectively, are thermally bonded into a multilayer-stack, reducing the pore density of 0.4 μm-pore PC by a factor of 200. The BLMs on this support are considerably stable (a mean lifetime: 17 h). This multilayer-stack PC (MSPC) membrane is integrated into the PDMS chip by an epoxy bonding method developed to secure durable bonding under the use of organic solvents. The microchip has a special channel for guiding a micropipette in the proximity of the MSPC support. With this on-site injection technique, tens to hundreds of nanoliters of solutions can be directly dispensed to the support. Incorporating gramicidin ion channels into BLMs on the MSPC support has confirmed the formation of single BLMs, which is based on the observation from current signals of 20 pS conductance that is typical to single channel opening. Based on the bilayer capacitance (1.4 pF), about 15% of through pores across the MSPC membrane are estimated to be covered with BLMs.
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Affiliation(s)
- Wei Teng
- Department of Chemistry, BioNanotechnology Center, Pohang University of Science and Technology , 77 Cheongam-Ro, Nam-Gu, 790-784 Pohang, South Korea
| | - Changill Ban
- Department of Chemistry, BioNanotechnology Center, Pohang University of Science and Technology , 77 Cheongam-Ro, Nam-Gu, 790-784 Pohang, South Korea
| | - Jong Hoon Hahn
- Department of Chemistry, BioNanotechnology Center, Pohang University of Science and Technology , 77 Cheongam-Ro, Nam-Gu, 790-784 Pohang, South Korea
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13
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Czekalska MA, Kaminski TS, Jakiela S, Tanuj Sapra K, Bayley H, Garstecki P. A droplet microfluidic system for sequential generation of lipid bilayers and transmembrane electrical recordings. LAB ON A CHIP 2015; 15:541-8. [PMID: 25412368 DOI: 10.1039/c4lc00985a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper demonstrates a microfluidic system that automates i) formation of a lipid bilayer at the interface between a pair of nanoliter-sized aqueous droplets in oil, ii) exchange of one droplet of the pair to form a new bilayer, and iii) current measurements on single proteins. A new microfluidic architecture is introduced - a set of traps designed to localize the droplets with respect to each other and with respect to the recording electrodes. The system allows for automated execution of experimental protocols by active control of the flow on chip with the use of simple external valves. Formation of stable artificial lipid bilayers, incorporation of α-hemolysin into the bilayers and electrical measurements of ionic transport through the protein pore are demonstrated.
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Affiliation(s)
- Magdalena A Czekalska
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
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14
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del Rio Martinez JM, Zaitseva E, Petersen S, Baaken G, Behrends JC. Automated formation of lipid membrane microarrays for ionic single-molecule sensing with protein nanopores. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:119-125. [PMID: 25115837 DOI: 10.1002/smll.201402016] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Indexed: 06/03/2023]
Abstract
Efficient use of membrane protein nanopores in ionic single-molecule sensing requires technology for the reliable formation of suspended molecular membranes densely arrayed in formats that allow high-resolution electrical recording. Here, automated formation of bimolecular lipid layers is shown using a simple process where a poly(tetrafluoroethylene)-coated magnetic bar is remotely actuated to perform a turning motion, thereby spreading phospholipid in organic solvent on a nonpolar surface containing a <1 mm(2) 4 × 4 array of apertures with embedded microelectrodes (microelectrode cavity array). Parallel and high-resolution single-molecule detection by single nanopores is demonstrated on the resulting bilayer arrays, which are shown to form by a classical but very rapid self-assembly process. The technique provides a robust and scalable solution for the problem of reliable, automated formation of multiple independent lipid bilayers in a dense microarray format, while preserving the favorable electrical properties of the microelectrode cavity array.
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Affiliation(s)
- Juan M del Rio Martinez
- Laboratory for Membrane Physiology and -Technology, Department of Physiology, University of Freiburg, Hermann-Herder-Str. 7, 79104, Freiburg, Germany
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15
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Saha SC, Powl AM, Wallace BA, de Planque MRR, Morgan H. Screening ion-channel ligand interactions with passive pumping in a microfluidic bilayer lipid membrane chip. BIOMICROFLUIDICS 2015; 9:014103. [PMID: 25610515 PMCID: PMC4288537 DOI: 10.1063/1.4905313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Accepted: 12/19/2014] [Indexed: 05/16/2023]
Abstract
We describe a scalable artificial bilayer lipid membrane platform for rapid electrophysiological screening of ion channels and transporters. A passive pumping method is used to flow microliter volumes of ligand solution across a suspended bilayer within a microfluidic chip. Bilayers are stable at flow rates up to ∼0.5 μl/min. Phospholipid bilayers are formed across a photolithographically defined aperture made in a dry film resist within the microfluidic chip. Bilayers are stable for many days and the low shunt capacitance of the thin film support gives low-noise high-quality single ion channel recording. Dose-dependent transient blocking of α-hemolysin with β-cyclodextrin (β-CD) and polyethylene glycol is demonstrated and dose-dependent blocking studies of the KcsA potassium channel with tetraethylammonium show the potential for determining IC50 values. The assays are fast (30 min for a complete IC50 curve) and simple and require very small amounts of compounds (100 μg in 15 μl). The technology can be scaled so that multiple bilayers can be addressed, providing a screening platform for ion channels, transporters, and nanopores.
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Affiliation(s)
- Shimul C Saha
- Electronics and Computer Science and Institute for Life Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom
| | - Andrew M Powl
- Institute of Structural and Molecular Biology, Birkbeck College, University of London , London WC1E 7HX, United Kingdom
| | - B A Wallace
- Institute of Structural and Molecular Biology, Birkbeck College, University of London , London WC1E 7HX, United Kingdom
| | - Maurits R R de Planque
- Electronics and Computer Science and Institute for Life Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom
| | - Hywel Morgan
- Electronics and Computer Science and Institute for Life Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom
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16
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Basit H, Gaul V, Maher S, Forster RJ, Keyes TE. Aqueous-filled polymer microcavity arrays: versatile & stable lipid bilayer platforms offering high lateral mobility to incorporated membrane proteins. Analyst 2015; 140:3012-8. [DOI: 10.1039/c4an02317j] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A robust new supported cell membrane model is described comprising lipid bilayers supported on aqueous filled spherical cap pores in PDMS, both lipid and reconstituted membrane proteins diffuse unhindered by the underlying support.
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Affiliation(s)
- Hajra Basit
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Vinnie Gaul
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Sean Maher
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Robert J. Forster
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Tia E. Keyes
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
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17
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Bomer JG, Prokofyev AV, van den Berg A, Le Gac S. Wafer-scale fabrication of glass-FEP-glass microfluidic devices for lipid bilayer experiments. LAB ON A CHIP 2014; 14:4461-4464. [PMID: 25284632 DOI: 10.1039/c4lc00921e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report a wafer-scale fabrication process for the production of glass-FEP-glass microdevices using UV-curable adhesive (NOA81) as gluing material, which is applied using a novel "spin & roll" approach. Devices are characterized for the uniformity of the gluing layer, presence of glue in the microchannels, and alignment precision. Experiments on lipid bilayers with electrophysiological recordings using a model pore-forming polypeptide are demonstrated.
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Affiliation(s)
- Johan G Bomer
- BIOS - Lab on a Chip group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
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18
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Baker CA, Aspinwall CA. Emerging trends in precision fabrication of microapertures to support suspended lipid membranes for sensors, sequencing, and beyond. Anal Bioanal Chem 2014; 407:647-52. [PMID: 25120184 DOI: 10.1007/s00216-014-8079-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/24/2014] [Accepted: 07/29/2014] [Indexed: 10/24/2022]
Abstract
Suspended lipid membranes, also called black lipid membranes (BLMs), are an important model system that approximates the lipid bilayer environment of cell membranes. Increasingly, BLMs are utilized in sensing strategies that harness high sensitivity measurements of ion flux across the membrane, typically facilitated by ion channel proteins. BLMs are suspended across microapertures that connect two otherwise isolated fluidic compartments, and the precision fabrication of such microapertures can contribute to the stability and performance of the resulting BLM. Here, we highlight two emerging trends in the precision fabrication of microapertures for BLM formation: microfabrication in silicon-based thin film substrates, and microfabrication in the negative photoresist material SU-8. Four unique fabrication strategies are outlined, and we project the impact that these microfabrication strategies will have for BLM-integrated bioanalytical technologies.
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Affiliation(s)
- Christopher A Baker
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd, Tucson, AZ, 85721, USA
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19
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Tsuji Y, Kawano R, Osaki T, Kamiya K, Miki N, Takeuchi S. Droplet Split-and-Contact Method for High-Throughput Transmembrane Electrical Recording. Anal Chem 2013; 85:10913-9. [DOI: 10.1021/ac402299z] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Yutaro Tsuji
- Artificial
Cell
Membrane System Group, Kanagawa Academy of Science and Technology (KAST), 3-2-1
Sakado, Takatsu-ku, Kawasaki 213-0012, Japan
- Department
of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi,
Kohoku-ku, Yokohama 223-8522, Japan
| | - Ryuji Kawano
- Artificial
Cell
Membrane System Group, Kanagawa Academy of Science and Technology (KAST), 3-2-1
Sakado, Takatsu-ku, Kawasaki 213-0012, Japan
| | - Toshihisa Osaki
- Artificial
Cell
Membrane System Group, Kanagawa Academy of Science and Technology (KAST), 3-2-1
Sakado, Takatsu-ku, Kawasaki 213-0012, Japan
| | - Koki Kamiya
- Artificial
Cell
Membrane System Group, Kanagawa Academy of Science and Technology (KAST), 3-2-1
Sakado, Takatsu-ku, Kawasaki 213-0012, Japan
| | - Norihisa Miki
- Artificial
Cell
Membrane System Group, Kanagawa Academy of Science and Technology (KAST), 3-2-1
Sakado, Takatsu-ku, Kawasaki 213-0012, Japan
- Department
of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi,
Kohoku-ku, Yokohama 223-8522, Japan
| | - Shoji Takeuchi
- Artificial
Cell
Membrane System Group, Kanagawa Academy of Science and Technology (KAST), 3-2-1
Sakado, Takatsu-ku, Kawasaki 213-0012, Japan
- CIRMM-IIS, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
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