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Bonet NF, Cava DG, Vélez M. Quartz crystal microbalance and atomic force microscopy to characterize mimetic systems based on supported lipids bilayer. Front Mol Biosci 2022; 9:935376. [PMID: 35992275 PMCID: PMC9382308 DOI: 10.3389/fmolb.2022.935376] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/05/2022] [Indexed: 11/23/2022] Open
Abstract
Quartz Crystal Microbalance (QCM) with dissipation and Atomic Force Microscopy (AFM) are two characterization techniques that allow describing processes taking place at solid-liquid interfaces. Both are label-free and, when used in combination, provide kinetic, thermodynamic and structural information at the nanometer scale of events taking place at surfaces. Here we describe the basic operation principles of both techniques, addressing a non-specialized audience, and provide some examples of their use for describing biological events taking place at supported lipid bilayers (SLBs). The aim is to illustrate current strengths and limitations of the techniques and to show their potential as biophysical characterization techniques.
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Guidelli R, Becucci L. Functional activity of peptide ion channels in tethered bilayer lipid membranes: Review. ELECTROCHEMICAL SCIENCE ADVANCES 2021. [DOI: 10.1002/elsa.202100180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Rolando Guidelli
- Department of Chemistry University of Florence Sesto Fiorentino Firenze Italy
| | - Lucia Becucci
- Ministero dell'Istruzione Scuola Media “Guglielmo Marconi” San Giovanni Valdarno Arezzo Italy
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3
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Membrane interactions in drug delivery: Model cell membranes and orthogonal techniques. Adv Colloid Interface Sci 2020; 281:102177. [PMID: 32417568 DOI: 10.1016/j.cis.2020.102177] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 03/05/2020] [Accepted: 05/07/2020] [Indexed: 01/22/2023]
Abstract
To generate the desired effect in the human body, the active pharmaceutical ingredient usually needs to interact with a receptor located on the cell membrane or inside the cell. Thus, understanding membrane interactions is of great importance when it comes to the development and testing of new drug molecules or new drug delivery systems. Nowadays, there is a tremendous selection of both model cell membranes and of techniques that can be used to characterize interactions between selected model cell membranes and a drug molecule, an excipient, or a drug delivery system. Having such a wide selection of model cell membranes and techniques available makes it sometimes challenging to select the optimal combination for a specific study. Furthermore, it is difficult to compare results obtained using different model cell membranes and techniques, and not all in vitro studies translate as well to an estimation of the in vivo biological activity or understanding of mode of action. This review provides an overview of the available lipid bilayer-based model cell membranes and of the most widely employed techniques for studying membrane interactions. Finally, the need for employing complimentary characterization techniques in order to acquire more reliable and in-depth information is highlighted.
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Sabirovas T, Valiūnienė A, Gabriunaite I, Valincius G. Mixed hybrid bilayer lipid membranes on mechanically polished titanium surface. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183232. [PMID: 32119863 DOI: 10.1016/j.bbamem.2020.183232] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 02/07/2020] [Accepted: 02/20/2020] [Indexed: 02/04/2023]
Abstract
Mixed self-assembled monolayers of octadecyltrichlorosilane (OTS) and methyltrichlorosilane (MTS) were deposited via simple silanization procedure on a mechanically polished titanium surface. The monolayers act as molecular anchors for mixed hybrid bilayer lipid membranes (mhBLM) which were accomplished via vesicle fusion. A variation of the MTS concentration in silanization solutions significantly affects properties of mhBLMs composed of a 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and cholesterol (Chol). The bilayers become less insulating following an increase of the MTS content. On the other hand, an increase of the MTS concentration provides flexibility of the mhBLM membranes necessary for the functional reconstitution of membrane proteins. The optimal molar ratio of MTS in silanization solution is 40% providing anchors for intact mhBLMs as confirmed by their specific capacitance of 0.86 μF cm-2. We found that the bilayers containing 40% (mol) of cholesterol bind cholesterol dependent pneumolysin (PLY). However, we did not observe functional reconstitution of PLY. While α-hemolysin almost fully disrupts mhBLMs assembled from 100% diphytanoyl. An important advantage of the titanium/OTS/MTS molecular anchor systems is their ability of repetitive regeneration of phospholipid bilayers without losing functional properties as demonstrated in the current study. This creates a possibility for the multiple-use phospholipid membrane biosensors which have a potential of decreasing the cost of such electrochemical/electroanalytical devices.
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Affiliation(s)
- Tomas Sabirovas
- Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko 24, Vilnius LT-03225, Lithuania
| | - Aušra Valiūnienė
- Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko 24, Vilnius LT-03225, Lithuania
| | - Inga Gabriunaite
- Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko 24, Vilnius LT-03225, Lithuania
| | - Gintaras Valincius
- Vilnius University, Institute of Biochemistry, Life Sciences Center, Sauletekio ave. 7, Vilnius LT-10257, Lithuania.
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Lee HH, Gavutis M, Ruželė Ž, Valiokas R, Liedberg B. Mixed Self-Assembled Monolayers with Terminal Deuterated Anchors: Characterization and Probing of Model Lipid Membrane Formation. J Phys Chem B 2018; 122:8201-8210. [DOI: 10.1021/acs.jpcb.8b05097] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hung-Hsun Lee
- Division of Molecular Physics, Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
| | - Martynas Gavutis
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanorių 231, LT-02300 Vilnius, Lithuania
| | - Živilė Ruželė
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanorių 231, LT-02300 Vilnius, Lithuania
| | - Ramu̅nas Valiokas
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanorių 231, LT-02300 Vilnius, Lithuania
| | - Bo Liedberg
- Division of Molecular Physics, Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
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John T, Voo ZX, Kubeil C, Abel B, Graham B, Spiccia L, Martin LL. Effects of guanidino modified aminoglycosides on mammalian membranes studied using a quartz crystal microbalance. MEDCHEMCOMM 2017; 8:1112-1120. [PMID: 30108822 PMCID: PMC6072410 DOI: 10.1039/c7md00054e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/24/2017] [Indexed: 01/21/2023]
Abstract
The increase in bacterial and viral resistance to current therapeutics has led to intensive research for new antibacterial and antiviral agents. Among these, aminoglycosides and their guanidino derivatives are potent candidates targeting specific RNA sequences. It is necessary that these substances can pass across mammalian membranes in order to reach their intracellular targets. This study investigated the effects of the aminoglycosides kanamycin A and neomycin B and their guanidino derivatives on mammalian mimetic membranes using a quartz crystal microbalance with dissipation monitoring (QCM-D). Lipid bilayers as membrane models were deposited onto gold coated quartz crystals and aminoglycosides added afterwards. Notably, the guanidino derivatives exhibited an initial stiffening of the membrane layer indicating a quick insertion of the planar guanidino groups into the membrane. The guanidino derivatives also reached their maximum binding to the membrane at lower concentrations than the native compounds. Therefore, these modified aminoglycosides are promising agents for the development of new antimicrobial treatments.
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Affiliation(s)
- Torsten John
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
- Leibniz Institute of Surface Modification, and Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry , Leipzig University , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Zhi Xiang Voo
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
| | - Clemens Kubeil
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
| | - Bernd Abel
- Leibniz Institute of Surface Modification, and Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry , Leipzig University , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Bim Graham
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , 381 Royal Parade , Parkville , VIC 3052 , Australia
| | - Leone Spiccia
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
| | - Lisandra L Martin
- School of Chemistry , Monash University , Wellington Rd , Clayton , VIC 3800 , Australia .
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7
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Zhu J, Wang W, Kong L, Ma C, Li Y, Liu B, Tan L. Real-time monitoring of oxidative injury of vascular endothelial cells and protective effect of quercetin using quartz crystal microbalance. Anal Bioanal Chem 2016; 408:8415-8425. [DOI: 10.1007/s00216-016-9959-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 09/10/2016] [Accepted: 09/19/2016] [Indexed: 10/20/2022]
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8
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Grossutti M, Seenath R, Noël JA, Lipkowski J. Infrared and fluorescence spectroscopic studies of a phospholipid bilayer supported by a soft cationic hydrogel scaffold. J Colloid Interface Sci 2016; 473:162-71. [PMID: 27064742 DOI: 10.1016/j.jcis.2016.03.055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/24/2016] [Accepted: 03/24/2016] [Indexed: 10/22/2022]
Abstract
Polarized attenuated total reflection (ATR-IR) spectroscopy and fluorescence microscopy techniques were used to characterize a 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) membrane supported on porous, cationic hydrogel beads. Fluorescence microscopy images showed that the DPhPC coated the external surface of the hydrogel scaffold. In addition, a fluorescence assay of the emission intensity of the Tb(3+)/dipicolinic acid complex demonstrated that the DPhPC coating acted as a barrier to Tb(3+) efflux from the scaffolded vesicle and successfully sealed the porous hydrogel bead. Fluorescence quenching and ATR-IR spectroscopic measurements revealed that the lipid coating has a bilayer structure. The phytanoyl chains were found to exhibit significant trans-gauche isomerization, characteristic of the fluid liquid phase. However, no lipid lateral mobility was observed by fluorescence recovery after photobleaching (FRAP) measurements. The phosphocholine headgroup was found to be well hydrated and oriented such that the cationic choline group tucked in behind the anionic phosphate group, consistent with an electrostatic attraction between the cationic scaffold and zwitterionic lipid. The absence of lipid lateral mobility may be due to the strength of this attraction.
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Affiliation(s)
- Michael Grossutti
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Ryan Seenath
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - John A Noël
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Jacek Lipkowski
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
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Wlodek M, Szuwarzynski M, Kolasinska-Sojka M. Effect of Supporting Polyelectrolyte Multilayers and Deposition Conditions on the Formation of 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine/1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine Lipid Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:10484-10492. [PMID: 26334376 DOI: 10.1021/acs.langmuir.5b02560] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The formation of complete supported lipid bilayers by vesicle adsorption and rupture was studied in relation to deposition conditions of vesicles and underlying cushion formed from various polyelectrolytes. Lipid vesicles were formed from zwitterionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and negatively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) in phosphate buffer of various pH with or without NaCl addition. Polyelectrolyte multilayer films (PEM) were constructed by sequential adsorption of alternately charged polyelectrolytes from their solutions-layer-by-layer deposition (LBL). The mechanism of the formation of supported lipid bilayer on polyelectrolyte films was studied by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). QCM-D allowed following the adsorption kinetics while AFM measurements verified the morphology of lipid vesicles and isolated bilayer patches on the PEM cushions providing local topological images in terms of lateral organization. Additionally, polyelectrolyte cushions were characterized with ellipsometry to find thickness and swelling properties, and their roughness was determined using AFM. It has been demonstrated that the pH value and an addition of NaCl in the buffer solution as well as the type of the polyelectrolyte cushion influence the kinetics of bilayer formation and the quality of formed bilayer patches.
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Affiliation(s)
- Magdalena Wlodek
- Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences , 30-239 Cracow, Poland
| | | | - Marta Kolasinska-Sojka
- Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences , 30-239 Cracow, Poland
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Valincius G, Mickevicius M. Tethered Phospholipid Bilayer Membranes. ADVANCES IN PLANAR LIPID BILAYERS AND LIPOSOMES 2015. [DOI: 10.1016/bs.adplan.2015.01.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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11
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Lipid bilayers supported on bare and modified gold – Formation, characterization and relevance of lipid rafts. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2013.07.117] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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12
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Onaizi SA, Nasser MS, Twaiq F. Lysozyme binding to tethered bilayer lipid membranes prepared by rapid solvent exchange and vesicle fusion methods. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 43:191-8. [DOI: 10.1007/s00249-014-0955-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 03/07/2014] [Accepted: 03/13/2014] [Indexed: 11/30/2022]
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13
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Zagnoni M. Miniaturised technologies for the development of artificial lipid bilayer systems. LAB ON A CHIP 2012; 12:1026-1039. [PMID: 22301684 DOI: 10.1039/c2lc20991h] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Artificially reproducing cellular environments is a key aim of synthetic biology, which has the potential to greatly enhance our understanding of cellular mechanisms. Microfluidic and lab-on-a-chip (LOC) techniques, which enable the controlled handling of sub-microlitre volumes of fluids in an automated and high-throughput manner, can play a major role in achieving this by offering alternative and powerful methodologies in an on-chip format. Such techniques have been successfully employed over the last twenty years to provide innovative solutions for chemical analysis and cell-, molecular- and synthetic- biology. In the context of the latter, the formation of artificial cell membranes (or artificial lipid bilayers) that incorporate membrane proteins within miniaturised LOC architectures offers huge potential for the development of highly sensitive molecular sensors and drug screening applications. The aim of this review is to give a comprehensive and critical overview of the field of microsystems for creating and exploiting artificial lipid bilayers. Advantages and limitations of three of the most popular approaches, namely suspended, supported and droplet-based lipid bilayers, are discussed. Examples are reported that show how artificial cell membrane microsystems, by combining together biological procedures and engineering techniques, can provide novel methodologies for basic biological and biophysical research and for the development of biotechnology tools.
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Affiliation(s)
- Michele Zagnoni
- Centre for Microsystems and Photonics, University of Strathclyde, Glasgow, UK.
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14
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Zhang X, Tanner P, Graff A, Palivan CG, Meier W. Mimicking the cell membrane with block copolymer membranes. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/pola.26000] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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15
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Yang LM, Wray R, Parker J, Wilson D, Duran RS, Blount P. Three routes to modulate the pore size of the MscL channel/nanovalve. ACS NANO 2012; 6:1134-1141. [PMID: 22206349 PMCID: PMC3289768 DOI: 10.1021/nn203703j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
MscL is a bacterial mechanosensitive channel that protects cells from lysis upon acute decrease in external osmotic environment. It is one of the best characterized mechanosensors known, thus serving as a paradigm of how such molecules sense and respond to stimuli. In addition, the fact that it can be genetically modified, expressed, isolated, and manipulated has led to its proposed use as a triggered nanovalve for various functions including sensors within microelectronic array chips, as well as vesicular-based targeted drug release. X-ray crystallography reveals a homopentameric complex with each subunit containing two transmembrane α-helices (TM1 and TM2) and a single carboxyl terminal α-helix arranging within the complex to form a 5-fold cytoplasmic bundle (CB), whose function and stability remain unclear. In this study, we show three routes that throttle the open channel conductance. When the linker between the TM2 and CB domain is shortened by deletions or constrained by either cross-linking or heavy metal coordination, the conductance of the channel is reduced; in the later two cases, even reversibly. While they have implications for the stability of the CB, these data also provide routes for engineering MscL sensors that are more versatile for potential nanotech devices.
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Affiliation(s)
- Li-Min Yang
- Department of Physiology, University of Texas Medical Center at Dallas, Dallas, Texas, USA
| | - Robin Wray
- Department of Physiology, University of Texas Medical Center at Dallas, Dallas, Texas, USA
| | - Juandell Parker
- Department of Physiology, University of Texas Medical Center at Dallas, Dallas, Texas, USA
| | - Danyell Wilson
- Department of Chemistry, University of Florida, current address Moffitt Cancer Center, Tampa, FL
| | - Randolph S. Duran
- Department of Chemistry, Louisiana State University, Baton Rouge, LA
| | - Paul Blount
- Department of Physiology, University of Texas Medical Center at Dallas, Dallas, Texas, USA
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Basit H, Van der Heyden A, Gondran C, Nysten B, Dumy P, Labbé P. Tethered bilayer lipid membranes on mixed self-assembled monolayers of a novel anchoring thiol: impact of the anchoring thiol density on bilayer formation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:14317-14328. [PMID: 21962085 DOI: 10.1021/la202847r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Tethered bilayer lipid membranes (tBLMs) are designed on mixed self-assembled monolayers (SAMs) of a novel synthetic anchoring thiol, 2,3-di-o-palmitoylglycerol-1-tetraethylene glycol mercaptopropanoic acid ester (TEG-DP), and a new short dilution thiol molecule, tetraethylene glycol mercaptopropanoic acid ester (TEG). tBLM formation was accomplished by self-directed fusion of small unilamellar vesicles of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine. The influence of the dilution of the anchoring thiol molecule in the SAM on the vesicle fusion process and on the properties of the resulting tBLMs is studied. It is observed by quartz crystal microbalance that vesicle fusion is a one-step process for a pure TEG-DP SAM as well as for mixed SAMs containing a high concentration of the anchoring thiol. However, upon dilution of the anchoring thiol to moderate concentrations, this process is decelerated and possibly follows a pathway different from that observed on a pure TEG-DP SAM. Electrochemical impedance spectroscopy is used to qualitatively correlate the composition of the SAM to the electrical properties of the tBLM. In this paper we also delineate the necessity of a critical concentration of this anchoring TEG-DP thiol as a requisite for inducing the fusion of vesicles to form a tBLM.
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Affiliation(s)
- Hajra Basit
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France.
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Becker B, Cooper MA. A survey of the 2006-2009 quartz crystal microbalance biosensor literature. J Mol Recognit 2011; 24:754-87. [DOI: 10.1002/jmr.1117] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Vesicle and bilayer formation of diphytanoylphosphatidylcholine (DPhPC) and diphytanoylphosphatidylethanolamine (DPhPE) mixtures and their bilayers’ electrical stability. Colloids Surf B Biointerfaces 2011; 82:550-61. [DOI: 10.1016/j.colsurfb.2010.10.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 09/28/2010] [Accepted: 10/11/2010] [Indexed: 11/23/2022]
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19
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Kwak KJ, Valincius G, Liao WC, Hu X, Wen X, Lee A, Yu B, Vanderah DJ, Lu W, Lee LJ. Formation and finite element analysis of tethered bilayer lipid structures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:18199-18208. [PMID: 20977245 DOI: 10.1021/la1021802] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Rapid solvent exchange of an ethanolic solution of diphytanoyl phosphatidylcholine (DPhyPC) in the presence of a mixed self-assembled monolayer (SAM) [thiolipid/β-mercaptoethanol (βME) (3/7 mol/mol) on Au] shows a transition from densely packed tethered bilayer lipid membranes [(dp)tBLMs], to loosely packed tethered bilayer lipid membranes [(lp)tBLMs], and tethered bilayer liposome nanoparticles (tBLNs) with decreasing DPhyPC concentration. The tethered lipidic constructs in the aqueous medium were analyzed by atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). Finite element analysis (FEA) was applied to interpret spectral EIS features without referring to equivalent circuit modeling. Using structural data obtained earlier from neutron reflectometry and dielectric constants of lipid bilayers, we reproduced experimentally observed features of the electrochemical impedance (EI) spectra of complex surface constructs involving small pinhole defects, large membrane-free patches, and bound liposomes. We demonstrated by FEA that highly insulating (dp)tBLMs with low-defect density exhibit EI spectra in the shape of a perfect semicircle with or without low-frequency upward "tails" in the Cole-Cole representation. Such EI spectra were observed at DPhyPC concentrations of >5 × 10(-3) mol L(-1). While AFM was not able to visualize very small lateral defects in such films, EI spectra unambiguously signaled their presence by increased low frequency "tails". Using FEA we demonstrate that films with large diameter visible defects (>25 nm by AFM) produce EI spectral features consisting of two semicircles of comparable size. Such films were typically obtained at DPhyPC concentrations of <5 × 10(-3) mol L(-1). At DPhyPC concentrations of <1.0 × 10(-3) mol L(-1) the planar bilayer structures were replaced by ellipsoidal liposomes with diameters ranging from 50 to 500 nm as observed in AFM images. Despite the distinct surface morphology change, the EI curves exhibited two semicircle spectral features typical for the large size defects in planar tBLMs. FEA revealed that, to account for these EI features for bound liposome systems (50-500 nm diameter), one needs to assume much lower tBLM conductivities of the submembrane space, which separates the electrode surface and the phospholipid bilayer. Alternatively, FEA indicates that such features may also be observed on composite surfaces containing both bound liposomes and patches of planar bilayers. Triple semicircular features, observed in some of the experimental EI curves, were attributed to an increased complexity of the real tBLMs. The modeling demonstrated that such features are typical for heterogeneous tBLM surfaces containing large patches of different defectiveness levels. By integrating AFM, EIS, and FEA data, our work provides diagnostic criteria allowing the precise characterization of the properties and the morphology of surface supported bilayer systems.
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Affiliation(s)
- Kwang Joo Kwak
- NSF Nanoscale Science and Engineering, Center for Affordable Nanoengineering of Polymeric Biomedical Devices, Ohio State University, Columbus, Ohio 43210, United States
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Zhan W, Jiang K, Smith MD, Bostic HE, Best MD, Auad ML, Ruppel JV, Kim C, Zhang XP. Photocurrent generation from porphyrin/fullerene complexes assembled in a tethered lipid bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:15671-15679. [PMID: 20831144 DOI: 10.1021/la102884u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A modular photocurrent generation system, based on amphiphilic porphyrin and fullerene species assembled in a tethered lipid bilayer matrix, is reported here. The key findings are (1) the amount of photoactive species can be quantitatively controlled in each leaflet of the bilayer and (2) the sequential formation of the bilayer allows a directional organization of these agents on electrodes. Photocurrent generation from seven differently configured photoactive bilayers is studied, which reveals several critical factors in achieving efficient photoinduced electron transfer across lipid membranes. Detailed fluorescence characterization is performed on porphyrin samples either in liposomes or surface-tethered bilayers; and the observed fluorescence quenching is correlated with photocurrents generated from the electrode-immobilized lipid films. The potential usefulness of this lipid-based approach is discussed in connection to several existing molecular photovoltaic systems.
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Affiliation(s)
- Wei Zhan
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA.
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21
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DU BY, FAN X, CAO Z, GUO XL. Applications and Outlooks of Quartz Crystal Microbalance in Studies of Polymer Thin Films. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2010. [DOI: 10.3724/sp.j.1096.2010.00752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Formation of tethered bilayer lipid membranes probed by various surface sensitive techniques. Biointerphases 2010; 4:19-26. [PMID: 20408719 DOI: 10.1116/1.3122019] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Tethered bilayer lipid membranes are promising biomimetic architectures. Their formation has been investigated using four different surface sensitive techniques, including optical, acoustic, and electrical methods. The lipid bilayers are built in a two-step procedure; the proximal layer is formed by self-assembly and is then completed to a bilayer by fusion with small vesicles. The different technical approaches revealed specific aspects of the layer formation processes, namely, first a fast adsorption process followed by a longer rearrangement period. Similar phenomena have been observed for the vesicle fusion process. The results allow for a more controlled assembly protocol for the preparation of highly insulating lipid membranes.
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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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Han X, Achalkumar AS, Cheetham MR, Connell SDA, Johnson BRG, Bushby RJ, Evans SD. A Self-assembly Route for Double Bilayer Lipid Membrane Formation. Chemphyschem 2010; 11:569-74. [DOI: 10.1002/cphc.200900798] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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25
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Tang Y, Wang Z, Xiao J, Yang S, Wang YJ, Tong P. Studies of Phospholipid Vesicle Deposition/Transformation on a Polymer Surface by Dissipative Quartz Crystal Microbalance and Atomic Force Microscopy. J Phys Chem B 2009; 113:14925-33. [DOI: 10.1021/jp9068224] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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26
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Leitch J, Kunze J, Goddard JD, Schwan AL, Faragher RJ, Naumann R, Knoll W, Dutcher JR, Lipkowski J. In situ PM-IRRAS studies of an archaea analogue thiolipid assembled on a au(111) electrode surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:10354-10363. [PMID: 19499931 DOI: 10.1021/la900907d] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) has been applied to determine the conformation, orientation, and hydration of a monolayer of 2,3-di-O-phytanyl-sn-glycerol-1-tetraethylene glycol-dl-alpha-lipoic acid ester (DPTL) self-assembled at a gold electrode surface. This Archaea analogue thiolipid has been recently employed to build tethered lipid bilayers. By synthesizing DPT(d16)L, a DPTL molecule with a deuterium substituted tetraethylene glycol spacer, it was possible to differentiate the C-H stretch vibrations of the phytanyl chains from the tetraethylene glycol spacer and acquire the characteristic IR spectra for the chains, spacer, and lipoic acid headgroup separately. Our results show that the structure of the monolayer displays remarkable stability in a broad range of electrode potentials and that the phytanyl chains remain in a liquid crystalline state. The tetraethylene glycol chains are coiled, and the IR spectrum for this region shows that it is in the disordered state. The most significant result of this study is the information that in contrast to expectations the spacer region is poorly hydrated. Our results have implications for the design of a tethered lipid membrane based on this thiolipid.
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Affiliation(s)
- Jay Leitch
- Department of Chemistry, University of Guelph, Guelph, Ontario, N1G2W1 Canada
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27
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Zagnoni M, Sandison M, Morgan H. Microfluidic array platform for simultaneous lipid bilayer membrane formation. Biosens Bioelectron 2009; 24:1235-40. [DOI: 10.1016/j.bios.2008.07.022] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2008] [Revised: 06/29/2008] [Accepted: 07/14/2008] [Indexed: 10/21/2022]
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28
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Goksu EI, Vanegas JM, Blanchette CD, Lin WC, Longo ML. AFM for structure and dynamics of biomembranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:254-66. [DOI: 10.1016/j.bbamem.2008.08.021] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 08/26/2008] [Accepted: 08/31/2008] [Indexed: 12/17/2022]
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29
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Han X, Cheetham MR, Sheikh K, Olmsted PD, Bushby RJ, Evans SD. Manipulation and charge determination of proteins in photopatterned solid supported bilayers. Integr Biol (Camb) 2008; 1:205-11. [PMID: 20023804 DOI: 10.1039/b815601h] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This work demonstrates the use of deep UV micropatterned chlorotrimethylsilane (TMS) monolayers to support lipid membranes on SiO(2) surfaces. After immersing such a patterned surface into a solution containing small unilamellar vesicles of egg PC, supported bilayer lipid membranes were formed on the hydrophilic, photolyzed regions and lipid monolayer over the hydrophobic, non-photolyzed regions. A barrier between the lipid monolayer and bilayer regions served to stop charged lipids migrating between the two. This allows the system to be used to separate charged lipids or proteins by electrophoresis. Either oppositely charged fluorescence labeled lipids [Texas Red DHPE (negative charge) and D291 (positive charge)] or lipids with different charge numbers [Texas Red DHPE (one negative charge) and NBD PS (two negative charges)] can be separated. We have also studied the migration of streptavidin attached to a biotinylated lipid. Negatively charged streptavidin responds to the applied electric field by moving in the direction of electroosmotic flow, i.e. towards the negative electrode. However the direction of streptavidin movement can be controlled by altering the difference in zeta potential between that of the streptavidin (zeta(1)) and the lipid membrane (zeta(2)). If zeta(1) > zeta(2), streptavidin moves to the negative electrode, while if zeta(1) < zeta(2), streptavidin moves to the positive electrode. This balance was manipulated by adding positively charged lipid DOTAP to the membrane. After measuring the average drift velocity of streptavidin as a function of DOTAP concentration, the point where zeta(1) approximately zeta(2) was found. At this point zeta(1) was calculated to be -9.8 mV which is in good agreement with the value of -13 mV from force measurements and corresponds to a charge of -2e per streptavidin, thus demonstrating the applicability of this method for determining protein charge.
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Affiliation(s)
- Xiaojun Han
- School of Physics and Astronomy, University of Leeds, Leeds, UK
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Andrä J, Böhling A, Gronewold TMA, Schlecht U, Perpeet M, Gutsmann T. Surface acoustic wave biosensor as a tool to study the interaction of antimicrobial peptides with phospholipid and lipopolysaccharide model membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:9148-9153. [PMID: 18605705 DOI: 10.1021/la801252t] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Surface acoustic wave biosensors are a powerful tool for the study of biomolecular interactions. The modulation of a surface-confined acoustic wave is utilized here for the analysis of surface binding. Phase and amplitude of the wave correspond roughly to mass loading and viscoelastic properties of the surface, respectively. We established a procedure to reconstitute phospholipid and lipopolysaccharide bilayers on the surface of a modified gold sensor chip to study the mode of action of membrane-active peptides. The procedure included the formation of a self-assembled monolayer of 11-mercaptoundecanol, covalent coupling of carboxymethyl-dextran, and subsequent coating with a poly- l-lysine layer. The lipid coverage of the surface is highly reproducible and homogeneous as demonstrated in atomic force micrographs. Ethanol/triton treatment removed the lipids completely, which provided the basis for continuous sequences of independent experiments. The setup was applied to investigate the binding of human cathelicidin-derived peptide LL32, as an example for antimicrobial peptides, to immobilized phosphatidylserine membranes. The peptide-membrane interaction results in a positive phase shift and an increase in amplitude, indicating a mass increase along with a loss in viscosity. This suggests that the bilayer becomes more rigid upon interaction with LL32.
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Affiliation(s)
- Jörg Andrä
- Research Center Borstel, Division of Biophysics, Parkallee 10, Borstel, Germany
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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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32
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Prolonged stochastic single ion channel recordings in S-layer protein stabilized lipid bilayer membranes. Colloids Surf B Biointerfaces 2008; 65:178-85. [PMID: 18602253 DOI: 10.1016/j.colsurfb.2008.04.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 04/03/2008] [Accepted: 04/04/2008] [Indexed: 11/20/2022]
Abstract
S-layer proteins are commonly found in bacteria and archaea as two-dimensional monomolecular crystalline arrays as the outermost cell membrane component. These proteins have the unique property that following disruption by chemical agents, monomers of the protein can re-assemble to their original lattice structure. This unique property makes S-layers interesting for utilization in bio-nanotechnological applications. Here, we show that the addition of S-layer proteins to bilayer lipid membranes increases the lifetime and the stability of the bilayer. M2delta ion channels were functionally incorporated into these S-layer stabilized membranes and we were able to record their activity for up to 20 h. Transmission electron microscopy (TEM) was used to visualize the 2D crystalline pattern of the S-layer and the M2delta ion channel characteristics in bilayer lipid membrane's were compared in the presence and absence of S-layers.
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