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Recent progress of vibrational spectroscopic study on the interfacial structure of biomimetic membranes. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2021. [DOI: 10.1016/j.cjac.2021.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Schneider S, Rudolph M, Bause V, Terfort A. Electrochemical removal of biofilms from titanium dental implant surfaces. Bioelectrochemistry 2018; 121:84-94. [PMID: 29413867 DOI: 10.1016/j.bioelechem.2018.01.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 01/15/2018] [Accepted: 01/15/2018] [Indexed: 10/18/2022]
Abstract
The infection of dental implants may cause severe inflammation of tissue and even bone degradation if not treated. For titanium implants, a new, minimally invasive approach is the electrochemical removal of the biofilms including the disinfection of the metal surface. In this project, several parameters, such as electrode potentials and electrolyte compositions, were varied to understand the underlying mechanisms. Optimal electrolytes contained iodide as well as lactic acid. Electrochemical experiments, such as cyclic voltammetry or measurements of open circuit potentials, were performed in different cell set-ups to distinguish between different possible reactions. At the applied potentials of E < -1.4 V, the hydrogen evolution reaction dominated at the implant surface, effectively lifting off the bacterial films. In addition, several disinfecting species are formed at the anode, such as triiodide and hydrogen peroxide. Ex situ tests with model biofilms of E. coli clearly demonstrated the effectiveness of the respective anolytes in killing the bacteria, as determined by the LIVE/DEAD™ assay. Using optimized electrolysis parameters of 30 s at 7.0 V and 300 mA, a 14-day old wildtype biofilm could be completely removed from dental implants in vitro.
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Affiliation(s)
- Sebastian Schneider
- Institute of Inorganic and Analytical Chemistry, Goethe-University, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
| | - Michael Rudolph
- Institute of Inorganic and Analytical Chemistry, Goethe-University, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
| | - Vanessa Bause
- Institute of Inorganic and Analytical Chemistry, Goethe-University, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
| | - Andreas Terfort
- Institute of Inorganic and Analytical Chemistry, Goethe-University, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany.
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Brand I, Habecker F, Ahlers M, Klüner T. Structure of collagen adsorbed on a model implant surface resolved by polarization modulation infrared reflection-absorption spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 138:216-224. [PMID: 25498816 DOI: 10.1016/j.saa.2014.11.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/11/2014] [Accepted: 11/20/2014] [Indexed: 06/04/2023]
Abstract
The polarization modulation infrared reflection-absorption spectra of collagen adsorbed on a titania surface and quantum chemical calculations are used to describe components of the amide I mode to the protein structure at a sub-molecular level. In this study, imino acid rich and poor fragments, representing the entire collagen molecule, are taken into account. The amide I mode of the collagen triple helix is composed of three absorption bands which involve: (i) (∼1690cm(-1)) the CO stretching modes at unhydrated groups, (ii) (1655-1673cm(-1)) the CO stretching at carbonyl groups at imino acids and glycine forming intramolecular hydrogen bonds with H atoms at both NH2 and, unusual for proteins, CH2 groups at glycine at a neighbouring chain and (iii) (∼1640cm(-1)) the CO stretching at carbonyl groups forming hydrogen bonds between two, often charged, amino acids as well as hydrogen bonds to water along the entire helix. The IR spectrum of films prepared from diluted solutions (c<50μgml(-1)) corresponds to solution spectra indicating that native collagen molecules interact with water adsorbed on the titania surface. In films prepared from solutions (c⩾50μgml(-1)) collagen multilayers are formed. The amide I mode is blue-shifted by 18cm(-1), indicating that intramolecular hydrogen bonds at imino acid rich fragments are weakened. Simultaneous red-shift of the amide A mode implies that the strength of hydrogen bonds at the imino acid poor fragments increases. Theoretically predicted distortion of the collagen structure upon adsorption on the titania surface is experimentally confirmed.
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Affiliation(s)
- Izabella Brand
- Carl von Ossietzky University of Oldenburg, School of Mathematics and Science, Department of Chemistry, CIS - Center of Interface Science, D-26111 Oldenburg, Germany.
| | - Florian Habecker
- Carl von Ossietzky University of Oldenburg, School of Mathematics and Science, Department of Chemistry, CIS - Center of Interface Science, D-26111 Oldenburg, Germany
| | - Michael Ahlers
- Carl von Ossietzky University of Oldenburg, School of Mathematics and Science, Department of Chemistry, CIS - Center of Interface Science, D-26111 Oldenburg, Germany
| | - Thorsten Klüner
- Carl von Ossietzky University of Oldenburg, School of Mathematics and Science, Department of Chemistry, CIS - Center of Interface Science, D-26111 Oldenburg, Germany
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Madrid E, Horswell SL. Effect of Electric Field on Structure and Dynamics of Bilayers Formed From Anionic Phospholipids. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.01.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Uchida T, Osawa M, Lipkowski J. SEIRAS studies of water structure at the gold electrode surface in the presence of supported lipid bilayer. J Electroanal Chem (Lausanne) 2014. [DOI: 10.1016/j.jelechem.2013.10.015] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Li Z, Tang Y, Zhang L, Wu J. Label-free study of the function of ion channel protein on a microfluidic optical sensor integrated with artificial cell membrane. LAB ON A CHIP 2014; 14:333-41. [PMID: 24232219 DOI: 10.1039/c3lc50937k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A label-free optical sensor was constructed by integrating pH sensing material and supported phospholipid bilayers (SPBs) in a microfluidic chip. The pH sensing material was composed of a double layer structure consisting of chitosan hydrogel and electrochemically etched porous silicon. The pH change in the microchip could induce a reversible swelling of the chitosan hydrogel layer and consequently caused a shift in effective optical thickness (EOT) of the double layer, which could be observed by Fourier transformed reflectometric interference spectroscopy (FT-RIS). After phospholipid bilayers (PLBs) were self-assembled on the sensing layer, the EOT almost remained constant during the cycling of pH from 7.4 to 6.2, indicating the blockage of H(+) translocation by the PLBs. For studying the behavior of ion channel protein, gramicidin A, a typical ion channel protein, was inserted in the SPBs for mimicking the ion transportation function of cell membrane. Due to the H(+) transportation capability of gramicidin A, the optical response to pH change could partially recover. In the presence of Ca(2+), the pore of the ion channel protein was blocked, causing a significant decrease in the EOT response upon pH change. The bio-functionalized microfluidic sensor fabricated in this work will provide a reliable platform for studying the function of ion channel protein, which is an important class of drug targets.
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Affiliation(s)
- Zhen Li
- Institute of Microanalytical System, Department of Chemistry, Zhejiang University, Hangzhou, 310058, China.
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Biomimetic Membrane Supported at a Metal Electrode Surface. ADVANCES IN PLANAR LIPID BILAYERS AND LIPOSOMES 2014. [DOI: 10.1016/b978-0-12-418698-9.00001-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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Madrid E, Horswell SL. Effect of headgroup on the physicochemical properties of phospholipid bilayers in electric fields: size matters. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:1695-1708. [PMID: 23331178 DOI: 10.1021/la304455d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The effect of molecular structure on ensemble structure of phospholipid films has been investigated. Bilayers of dimyristoyl phosphatidylethanolamine (DMPE) were prepared on Au(111) electrodes using Langmuir-Blodgett and Langmuir-Schaeffer deposition. Capacitance and charge density measurements were used to investigate the adsorption behavior and barrier properties of the lipid bilayers. In situ polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was employed to investigate the organization of the molecules within the bilayer. DMPE bilayers exhibit lower capacitance than bilayers formed from the related lipid, dimyristoyl phosphatidylcholine (DMPC). The infrared data show that these results can be explained by structural differences between the bilayers formed from each molecule. DMPE organizes into bilayers with hydrocarbon chains tilted at a smaller angle to the surface normal, which results in a thicker film. The hydrocarbon chains contain few conformational defects. Spectra in the carbonyl and phosphate stretching mode regions indicate low solvent content of DMPE films. Both of these effects combine to produce films with lower capacitance and enhanced barrier properties. The results are explained in terms of the differences in structure between the constituent molecules.
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Affiliation(s)
- Elena Madrid
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Application of Infrared Spectroscopy for Structural Analysis of Planar Lipid Bilayers Under Electrochemical Control. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/b978-0-12-411515-6.00002-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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Laredo T, Dutcher JR, Lipkowski J. Electric field driven changes of a gramicidin containing lipid bilayer supported on a Au(111) surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:10072-10087. [PMID: 21707110 DOI: 10.1021/la201625c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Langmuir-Blodgett and Langmuir-Schaeffer methods were employed to deposit a mixed bilayer consisting of 90% of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 10% of gramicidin (GD), a short 15 residue ion channel forming peptide, onto a Au(111) electrode surface. This architecture allowed us to investigate the effect of the electrostatic potential applied to the electrode on the orientation and conformation of DMPC molecules in the bilayer containing the ion channel. The charge density data were determined from chronocoulometry experiments. The electric field and the potential across the membrane were determined through the use of charge density curves. The magnitudes of potentials across the gold-supported biomimetic membrane were comparable to the transmembrane potential acting on a natural membrane. The information regarding the orientation and conformation of DMPC and GD molecules in the bilayer was obtained from photon polarization modulation infrared reflection absorption spectroscopy (PMIRRAS) measurements. The results show that the bilayer is adsorbed, in direct contact with the metal surface, when the potential across the interface is more positive than -0.4 V and is lifted from the gold surface when the potential across the interface is more negative than -0.4 V. This change in the state of the bilayer has a significant impact on the orientation and conformation of the phospholipid and gramicidin molecules. The potential induced changes in the membrane containing peptide were compared to the changes in the structure of the pure DMPC bilayer determined in earlier studies.
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Affiliation(s)
- Thamara Laredo
- Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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Ramin MA, Le Bourdon G, Daugey N, Bennetau B, Vellutini L, Buffeteau T. PM-IRRAS investigation of self-assembled monolayers grafted onto SiO2/Au substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:6076-6084. [PMID: 21486004 DOI: 10.1021/la2006293] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was used to characterize self-assembled monolayers (SAMs). Novel ester-terminated organosilicon coupling agents possessing a trialkoxysilyl headgroup and a urea group in the linear alkyl chains (4) were synthesized and grafted onto SiO(2)/Au substrates (SiO(2) film of 200 Å thickness deposited on gold mirror). This composite substrate allowed the anchoring of SAMs and preserved the high reflectivity for infrared radiation. PM-IRRAS spectra with very high signal-to-noise ratios have been obtained in the mid-infrared spectral range allowing monitoring of the grafted SAMs. Quantitative analysis of the measured signal is described to compare PM-IRRAS and conventional IRRAS spectra. This quantitative analysis has been validated since the band intensities in the corrected PM-IRRAS and conventional IRRAS spectra are identical. Orientation information on the different functional groups has been obtained comparing the corrected PM-IRRAS spectrum with the one calculated using isotropic optical constants of ester-terminated organosilicon coupling agents 4. The carbonyls of the urea groups are preferentially parallel to the substrate surface favoring intermolecular hydrogen bonding and consequently a close packing of the molecules attached to the surface. By contrast, the alkyl chains present gauche defects and are poorly oriented.
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Affiliation(s)
- Michaël A Ramin
- Institut des Sciences Moléculaires (UMR 5255-CNRS), Université Bordeaux 1, 351 Cours de la Libération, 33405 Talence, France
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Abstract
This article describes efforts to build a model biological membrane at a surface of a gold electrode. In this architecture, the membrane may be exposed to static electric fields on the order of 10(7) to 10(8) V m(-1). These fields are comparable in magnitude to the static electric field acting on a natural biological membrane. The field may be conveniently used to manipulate organic molecules within the membrane. By turning a knob on the control instrument one can deposit or lift the membrane from the gold surface. Electrochemical techniques can be used to control the physical state of the film while the infrared reflection absorption spectroscopy (IRRAS), surface imaging by STM and AFM and neutron scattering techniques can be employed to study conformational changes of organic molecules and their ordering within the membrane. This is shown on examples of membranes built of a simple zwitterionic phospholipid such as 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) and a mixed membrane composed of DMPC and cholesterol. The results illustrate the tremendous effect of cholesterol on the membrane structure. Two methods of membrane deposition at the electrode surface, namely by unilamellar vesicles fusion and using the Langmuir-Blodgett technique, are compared. Applications of these model systems to study interactions of small antibiotic peptides with lipids are discussed.
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Affiliation(s)
- Jacek Lipkowski
- Department of Chemistry, University of Guelph, Guelph, Ontario, CanadaN1G 2W1.
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Orendorff CJ, Alam TM, Sasaki DY, Bunker BC, Voigt JA. Phospholipid-gold nanorod composites. ACS NANO 2009; 3:971-983. [PMID: 19317440 DOI: 10.1021/nn900037k] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Phospholipids comprise an enormous range of chemical structures that provide much of the functionality associated with cellular membranes. We have developed a simple method for incorporating phospholipids onto the surfaces of anisotropic gold nanorods as a stepping-stone for creating responsive and multifunctional nanocomposites. In this report, we demonstrate how phospholipids can be used to control the self-assembly of gold nanorods into agglomerate architectures ranging from open "end-to-end" networks to densely packed "side-to-side" arrays. The results indicate that lipid-gold nanorod assembly is governed by the tuning of electrostatic interactions within the phospholipid layers as well as by how the phospholipid layers organize themselves around anisotropic nanorod surfaces.
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