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Rebholz H, Pfaffeneder-Mantai F, Knoll W, Hassel AW, Frank W, Kleber C. Olfactory dysfunction in SARS-CoV-2 infection: Focus on odorant specificity and chronic persistence. Am J Otolaryngol 2021; 42:103014. [PMID: 33873048 PMCID: PMC8041855 DOI: 10.1016/j.amjoto.2021.103014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 03/28/2021] [Indexed: 01/11/2023]
Abstract
Background Smell dysfunction has been recognized as an early symptom of SARS-CoV-2 infection, often occurring before the onset of core symptoms of the respiratory tract, fever or muscle pain. In most cases, olfactory dysfunction is accompanied by reduced sense of taste, is partial (microsmia) and seems to normalize after several weeks, however, especially in cases of virus-induced complete smell loss (anosmia), there are indications of persisting deficits even 2 months after recovery from the acute disease, pointing towards the possibility of chronic or even permanent smell reduction for a significant part of the patient population. To date, we have no knowledge on the specificity of anosmia towards specific odorants or chemicals and about the longer-term timeline of its persistence or reversal. Methods In this longitudinal study, 70 participants from a community in Lower Austria that had been tested positive for either IgG or IgM SARS-CoV-2 titers in June 2020 and a healthy control cohort (N = 348) underwent smell testing with a 12-item Cross-Cultural Smell Identification Test (CC-SIT), based upon items from the University of Pennsylvania Smell Identification Test (UPSIT). The test was performed in October 2020, i.e. 4 months after initial diagnosis via antibody testing. Results were analyzed using statistical tests for contingency for each smell individually in order to detect whether reacquisition of smell is dependent on specific odorant types. Results For all odorants tested, except the odor “smoke”, even 4 months or more after acute SARS-CoV-2 infection, participants with a positive antibody titer had a reduced sense of smell when compared to the control group. On average, while the control cohort detected a set of 12 different smells with 88.0% accuracy, the antibody-positive group detected 80.0% of tested odorants. A reduction of accuracy of detection by 9.1% in the antibody-positive cohort was detected. Recovery of the ability to smell was particularly delayed for three odorants: strawberry (encoded by the aldehyde ethylmethylphenylglycidate), lemon (encoded by citronellal, a monoterpenoid aldehyde), and soap (alkali metal salts of the fatty acids plus odorous additives) exhibit a sensitivity of detection of an infection with SARS-CoV-2 of 31.0%, 41.0% and 40.0%, respectively. Conclusion Four months or more after acute infection, smell performance of SARS-CoV-2 positive patients with mild or no symptoms is not fully recovered, whereby the ability to detect certain odors (strawberry, lemon and soap) is particularly affected, suggesting the possibility that these sensitivity to these smells may not only be lagging behind but may be more permanently affected.
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Affiliation(s)
- H Rebholz
- Center of Neurodegeneration, Faculty of Medicine/Dental Medicine, Danube Private University, Krems, Austria; Institut de Psychiatrie et Neurosciences de Paris (IPNP), UMR S1266, INSERM, Université de Paris, Paris, France; GHU Psychiatrie et Neurosciences, Paris, France
| | - F Pfaffeneder-Mantai
- Department of Physics and Chemistry of Materials, Faculty of Medicine/Dental Medicine, Danube Private University, Krems, Austria.
| | - W Knoll
- Department of Physics and Chemistry of Materials, Faculty of Medicine/Dental Medicine, Danube Private University, Krems, Austria; AIT Austrian Institute of Technology GmbH, Biosensor Technologies, 3430 Tulln, Austria
| | - A W Hassel
- Department of Physics and Chemistry of Materials, Faculty of Medicine/Dental Medicine, Danube Private University, Krems, Austria; Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Linz, Austria
| | - W Frank
- Center of Health Systems Research, Faculty of Medicine/Dental Medicine, Danube Private University, Krems, Austria
| | - C Kleber
- Department of Physics and Chemistry of Materials, Faculty of Medicine/Dental Medicine, Danube Private University, Krems, Austria; Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Linz, Austria
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Sergelen K, Liedberg B, Knoll W, Dostálek J. A surface plasmon field-enhanced fluorescence reversible split aptamer biosensor. Analyst 2018; 142:2995-3001. [PMID: 28744534 DOI: 10.1039/c7an00970d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Surface plasmon field-enhanced fluorescence is reported for the readout of a heterogeneous assay that utilizes low affinity split aptamer ligands. Weak affinity ligands that reversibly interact with target analytes hold potential for facile implementation in continuous monitoring biosensor systems. This functionality is not possible without the regeneration of more commonly used assays relying on high affinity ligands and end-point measurement. In fluorescence-based sensors, the use of low affinity ligands allows avoiding this step but it imposes a challenge associated with the weak optical response to the specific capture of the target analyte which is also often masked by a strong background. The coupling of fluorophore labels with a confined field of surface plasmons is reported for strong amplification of the fluorescence signal emitted from the sensor surface and its efficient discrimination from the background. This optical scheme is demonstrated for time-resolved analysis of chosen model analytes - adenoside and adenosine triphosphate - with a split aptamer that exhibits an equilibrium affinity binding constant between 0.73 and 1.35 mM. The developed biosensor enables rapid and specific discrimination of target analyte concentration changes from low μM to mM in buffer as well as in 10% serum.
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Affiliation(s)
- K Sergelen
- BioSensor Technologies, AIT-Austrian Institute of Technology, Muthgasse 11, 1190 Vienna, Austria.
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Affiliation(s)
- A. Vagias
- Max Planck Institute
for Polymer Research, Ackermannweg
10, 55128 Mainz, Germany
| | - K. Sergelen
- Biosensor
Technologies, AIT-Austrian Institute of Technology GmbH, Muthgasse
11, Wien 1190, Austria
- International
Graduate School on Bionanotechnology, University of Natural Resources
and Life Sciences, Nanyang Technological University, Singapore 639798
| | - K. Koynov
- Max Planck Institute
for Polymer Research, Ackermannweg
10, 55128 Mainz, Germany
| | - P. Košovan
- Department
of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - J. Dostalek
- Biosensor
Technologies, AIT-Austrian Institute of Technology GmbH, Muthgasse
11, Wien 1190, Austria
| | - U. Jonas
- Macromolecular
Chemistry, Department Chemistry - Biology, University of Siegen, 57076 Siegen, Germany
| | - W. Knoll
- Biosensor
Technologies, AIT-Austrian Institute of Technology GmbH, Muthgasse
11, Wien 1190, Austria
| | - G. Fytas
- Max Planck Institute
for Polymer Research, Ackermannweg
10, 55128 Mainz, Germany
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Knoll W, Peters J, Kursula P, Gerelli Y, Natali F. Influence of myelin proteins on the structure and dynamics of a model membrane with emphasis on the low temperature regime. J Chem Phys 2015; 141:205101. [PMID: 25429962 DOI: 10.1063/1.4901738] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Myelin is an insulating, multi-lamellar membrane structure wrapped around selected nerve axons. Increasing the speed of nerve impulses, it is crucial for the proper functioning of the vertebrate nervous system. Human neurodegenerative diseases, such as multiple sclerosis, are linked to damage to the myelin sheath through demyelination. Myelin exhibits a well defined subset of myelin-specific proteins, whose influence on membrane dynamics, i.e., myelin flexibility and stability, has not yet been explored in detail. In a first paper [W. Knoll, J. Peters, P. Kursula, Y. Gerelli, J. Ollivier, B. Demé, M. Telling, E. Kemner, and F. Natali, Soft Matter 10, 519 (2014)] we were able to spotlight, through neutron scattering experiments, the role of peripheral nervous system myelin proteins on membrane stability at room temperature. In particular, the myelin basic protein and peripheral myelin protein 2 were found to synergistically influence the membrane structure while keeping almost unchanged the membrane mobility. Further insight is provided by this work, in which we particularly address the investigation of the membrane flexibility in the low temperature regime. We evidence a different behavior suggesting that the proton dynamics is reduced by the addition of the myelin basic protein accompanied by negligible membrane structural changes. Moreover, we address the importance of correct sample preparation and characterization for the success of the experiment and for the reliability of the obtained results.
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Affiliation(s)
- W Knoll
- University Joseph Fourier, UFR PhiTEM, Grenoble, France
| | - J Peters
- University Joseph Fourier, UFR PhiTEM, Grenoble, France
| | | | - Y Gerelli
- Institut Laue-Langevin, Grenoble, France
| | - F Natali
- Institut Laue-Langevin, Grenoble, France
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Miller CE, Meyer WH, Knoll W, Wegner G. Surface plasmon resonance as a technique to study adsorption to aluminum oxide surfaces. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/bbpc.19920960705] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Brunsen A, Ritz U, Mateescu A, Höfer I, Frank P, Menges B, Hofmann A, Rommens PM, Knoll W, Jonas U. Photocrosslinkable dextran hydrogel films as substrates for osteoblast and endothelial cell growth. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm34006b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Johannsmann D, Embs F, Willson CG, Wegner G, Knoll W. Visco-elastic properties of thin films probed with a quartz crystal resonator. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19910460133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Helm CA, Schmitt FJ, Israelachvili JN, Knoll W. Ligand-receptor interactions directly measured with the surface forces apparatus. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19910460114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sawodny M, Schmidt A, Urban C, Ringsdorf H, Knoll W. Optical data storage in Langmuir-Blodgett-Kuhn multilayer assemblies of azo-dye side chain LC-polymers. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19910460128] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Schmitt FJ, Weisenhorn AL, Hansma PK, Knoll W. Interfacial recognition reactions as seen by fluorescence-, surface plasmon-and atomic force microscopies. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19910460117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Lee S, Dutcher JR, Hillebrands B, Stegeman GI, Knoll W, Duda G, Wegner G, Nizzoli F. Structural Dependence of the Elastic Constants of Polymeric Langmuir-Blodgett Films Studied Using Brillouin Scattering. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-188-355] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTWe have used Brillouin scattering to study the dependence of the elastic constants of uniaxial polymeric Langmuir-Blodgett thin films on the thickness of the polymeric molecule monolayers. With increasing monolayer thickness, an overall decrease in the elastic constants and an increase in the refractive index n33 was observed.
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van Os MT, Menges B, Förch R, Knoll W, Timmons RB, Vancso GJ. Thin Film Plasma Deposition of Allylamine; Effects of Solvent Treatment. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-544-45] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractAmine-functionalized thin films were prepared by plasma induced deposition of allylamine. Radio frequency (rf) plasma polymerization was carried out under both continuous wave (CW) and pulsed plasma conditions to control the film chemistry, all other process variables being held constant. Using plasma polymerized films for subsequent grafting reactions or for direct biomedical applications usually involves exposure of the films to a solvent environment. It was the major focus of this work to investigate both the chemical and physical effects of solvents on plasma polymerized allylamine films. Film properties were determined using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Waveguide Mode Spectroscopy (WaMS) and Surface Plasmon Spectroscopy (SPS). WaMS provided an ideal opportunity to study the complex swelling and drying behaviour of these films by allowing a simultaneous study of the changes in film thickness and refractive index. Although the amine groups of the monomer were increasingly retained in the films as the RF duty cycle was lowered, a larger amount of oxygen was also found to be incorporated upon exposure to air. Extraction in ethanol led to a decrease in film thickness, especially for the films produced at low duty cycles, but appeared to have little effect on the film composition, as measured by XPS and FTIR.
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Schach D, Nowak C, Gennis R, Ferguson-Miller S, Knoll W, Walz D, Naumann R. Modeling direct electron transfer to a multi-redox center protein: Cytochrome c oxidase. J Electroanal Chem (Lausanne) 2010. [DOI: 10.1016/j.jelechem.2010.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
We demonstrate that surface-plasmon microscopy allows one to monitor the specific binding of streptavidin to biotinylated lipid molecules selectively enriched in one of the two coexisting phase domains of a phospholipid monolayer transferred in its phase transition region from the water-air interface to a solid support.
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Affiliation(s)
- F J Schmitt
- Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-6500 Mainz, Germany
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Affiliation(s)
- J Spinke
- Max-Planck-Institut für Polymerforschung, W-6500 Mainz, Germany
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Fischer A, Heithier H, Knoll W, Möhwald H. Pressure induced reorientation and aggregation of pheophytin in monomolecular layers. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19810850305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Sekkat Z, Knoll W. Stationary state and dynamics of birefringence and nonlinear optical properties induced by electric field poling in polymeric films. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19940981004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Schiller SM, Kambhampati D, Stengel G, Dolderer J, Nielsen PE, Förch R, Knoll W. “Plastic Trash goes Biohybrid”-Rapid and Selective Functionalization of Inert Plastic Surfaces with Biomolecules. MACROMOL CHEM PHYS 2009. [DOI: 10.1002/macp.200900518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Schiller S, Reisinger-Friebis A, Götz H, Hawker C, Frank C, Naumann R, Knoll W. Biomimetische Lipo-Glycopolymer-Membranen: photochemische Oberflächenanbindung supramolekularer Architekturen mit definierter Orientierung. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200901544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Nowak C, Luening C, Knoll W, Naumann RLC. A two-layer gold surface with improved surface enhancement for spectro-electrochemistry using surface-enhanced infrared absorption spectroscopy. Appl Spectrosc 2009; 63:1068-1074. [PMID: 19796491 DOI: 10.1366/000370209789379330] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A two-layer gold surface is developed for use with surface-enhanced infrared absorption spectroscopy (SEIRAS) consisting of a conducting underlayer onto which Au nanoparticles (AuNPs) are grown by self-catalyzed electroless deposition. AuNPs are grown on protruding substructures of the 25 nm thin underlayer. The enhancement factor of the two-layer gold surface is controlled by the growth conditions. Cytochrome c adsorbed to a self-assembled monolayer of mercaptoethanol is used as a reference system. Under optimum conditions the absorbance of the amide I band is increased by a factor of 5 versus the classical SEIRAS surface. Reversible reduction/oxidation of cytochrome c on the two-layer gold surface is shown to take place by cyclic voltammetry.
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Affiliation(s)
- C Nowak
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Schiller S, Reisinger-Friebis A, Götz H, Hawker C, Frank C, Naumann R, Knoll W. Biomimetic Lipoglycopolymer Membranes: Photochemical Surface Attachment of Supramolecular Architectures with Defined Orientation. Angew Chem Int Ed Engl 2009; 48:6896-9. [DOI: 10.1002/anie.200901544] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Knoll W. Wintersport im Hochgebirge. Dtsch Med Wochenschr 2009. [DOI: 10.1055/s-0028-1124858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Sato A, Knoll W, Pennec Y, Djafari-Rouhani B, Fytas G, Steinhart M. Anisotropic propagation and confinement of high frequency phonons in nanocomposites. J Chem Phys 2009; 130:111102. [DOI: 10.1063/1.3096972] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Knoll W, Naumann R, Friedrich M, Robertson JWF, Lösche M, Heinrich F, McGillivray DJ, Schuster B, Gufler PC, Pum D, Sleytr UB. Solid supported lipid membranes: new concepts for the biomimetic functionalization of solid surfaces. Biointerphases 2008; 3:FA125. [PMID: 20408662 PMCID: PMC2876326 DOI: 10.1116/1.2913612] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Surface-layer (S-layer) supported lipid membranes on solid substrates are interfacial architectures mimicking the supramolecular principle of cell envelopes which have been optimized for billions of years of evolution in most extreme habitats. The authors implement this biological construction principle in a variety of layered supramolecular architectures consisting of a stabilizing protein monolayer and a functional phospholipid bilayer for the design and development of new types of solid-supported biomimetic membranes with a considerably extended stability and lifetime-compared to existing platforms-as required for novel types of bioanalytical sensors. First, Langmuir monolayers of lipids at the water/air interface are used as test beds for the characterization of different types of molecules which all interact with the lipid layers in various ways and, hence, are relevant for the control of the structure, stability, and function of supported membranes. As an example, the interaction of S-layer proteins from the bulk phase with a monolayer of a phospholipid synthetically conjugated with a secondary cell wall polymer (SCWP) was studied as a function of the packing density of the lipids in the monolayer. Furthermore, SCWPs were used as a new molecular construction element. The exploitation of a specific lectin-type bond between the N-terminal part of selected S-layer proteins and a variety of glycans allowed for the buildup of supramolecular assemblies and thus functional membranes with a further increased stability. Next, S-layer proteins were self-assembled and characterized by the surface-sensitive techniques, surface plasmon resonance spectroscopy and quartz crystal microbalance with dissipation monitoring. The substrates were either planar gold or silicon dioxide sensor surfaces. The assembly of S-layer proteins from solution to solid substrates could nicely be followed in-situ and in real time. As a next step toward S-layer supported bilayer membranes, the authors characterized various architectures based on lipid molecules that were modified by a flexible spacer separating the amphiphiles from the anchor group that allows for a covalent coupling of the lipid to a solid support, e.g., using thiols for Au substrates. Impedance spectroscopy confirmed the excellent charge barrier properties of these constructs with a high electrical resistance. Structural details of various types of these tethered bimolecular lipid membranes were studied by using neutron reflectometry. Finally, first attempts are reported to develop a code based on a SPICE network analysis program which is suitable for the quantitative analysis of the transient and steady-state currents passing through these membranes upon the application of a potential gradient.
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Affiliation(s)
- W Knoll
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55021 Mainz, Germany.
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Vasilev K, Zhu T, Glasser G, Knoll W, Kreiter M. Preparation of gold nanoparticles in an aqueous medium using 2-mercaptosuccinic acid as both reduction and capping agent. J Nanosci Nanotechnol 2008; 8:2062-2068. [PMID: 18572615 DOI: 10.1166/jnn.2008.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Monolayer protected gold nanoparticles with diameters above 10 nm were prepared by a simple, one step reaction in water. 2-mercaptosuccinic acid (MSA) was used both as reduction agent for hydrogen tetrachloroaurate (HAuCl4) and as stabilizing agent for the gold nanoparticles. Size distribution and surface chemistry were investigated by UV-Vis spectroscopy, scanning electron microscopy and Fourier Transform Infrared Spectroscopy. Particle size can be controlled by adjusting the molar portions of the reactants. The resulting particles are efficiently stabilized against aggregation when MSA is used in a concentration of 40% and above. Below a minimum MSA concentration a long-term particle growth is observed.
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Affiliation(s)
- K Vasilev
- Max-Planck-Lnstitute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Förch R, Chifen A, Bousquet A, Khor H, Jungblut M, Chu LQ, Zhang Z, Osey-Mensah I, Sinner EK, Knoll W. Recent and Expected Roles of Plasma-Polymerized Films for Biomedical Applications. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/cvde.200604035] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Francesch L, Borros S, Knoll W, Förch R. Surface reactivity of pulsed-plasma polymerized pentafluorophenyl methacrylate (PFM) toward amines and proteins in solution. Langmuir 2007; 23:3927-31. [PMID: 17338554 DOI: 10.1021/la062422d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Pulsed-plasma polymerization has been used to deposit ultrathin layers of pentafluorophenyl methacrylate by using low duty cycles and low power input. The monomer structure can be retained such that the chemical reactivity of the active ester group could be studied using the reaction with a simple amine. The film properties in aqueous phosphate buffer have been investigated using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and real time surface plasmon resonance spectroscopy. The films react readily with diaminohexane and immunoglobulin (IgG), yet the reactivity shows a dependence on the extent of hydrolysis of the ester group.
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Affiliation(s)
- L Francesch
- Institut Químic de Sarrià-Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
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Affiliation(s)
- N. Ara-kato
- a Frontier Research Program, RIKEN , Wako, Saitama , 351-01 , Japan
| | - M. Kara
- a Frontier Research Program, RIKEN , Wako, Saitama , 351-01 , Japan
| | - H. Sasabe
- a Frontier Research Program, RIKEN , Wako, Saitama , 351-01 , Japan
| | - W. Knoll
- a Frontier Research Program, RIKEN , Wako, Saitama , 351-01 , Japan
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Eisenberg S, Jal JF, Dupuy J, Chieux P, Knoll W. Neutron diffraction determination of the partial structure factors of molten CuCl. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/01418618208239914] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tsuboi K, Kajikawa K, Hamada N, Fujita K, Hara M, Sasabe H, Knoll W, Seki K, Ouchi Y. Reflection Spectroscopy of Merocyanine Self-assembled Monolayer on a Gold Substrate. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259808030222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- K. Tsuboi
- a Department of Chemistry , Graduate School of Science, Nagoya University , Furo-cho Chikusa-ku, Nagoya , 464-8602 , Japan
| | - K. Kajikawa
- a Department of Chemistry , Graduate School of Science, Nagoya University , Furo-cho Chikusa-ku, Nagoya , 464-8602 , Japan
| | - N. Hamada
- a Department of Chemistry , Graduate School of Science, Nagoya University , Furo-cho Chikusa-ku, Nagoya , 464-8602 , Japan
| | - K. Fujita
- b Frontier Research Program, The Institute of Physical and Chemical Research (RIKEN) , Hirosawa 2-1, Wako, Saitama , 351-0198 , Japan
| | - M. Hara
- b Frontier Research Program, The Institute of Physical and Chemical Research (RIKEN) , Hirosawa 2-1, Wako, Saitama , 351-0198 , Japan
| | - H. Sasabe
- b Frontier Research Program, The Institute of Physical and Chemical Research (RIKEN) , Hirosawa 2-1, Wako, Saitama , 351-0198 , Japan
| | - W. Knoll
- b Frontier Research Program, The Institute of Physical and Chemical Research (RIKEN) , Hirosawa 2-1, Wako, Saitama , 351-0198 , Japan
| | - K. Seki
- a Department of Chemistry , Graduate School of Science, Nagoya University , Furo-cho Chikusa-ku, Nagoya , 464-8602 , Japan
| | - Y. Ouchi
- a Department of Chemistry , Graduate School of Science, Nagoya University , Furo-cho Chikusa-ku, Nagoya , 464-8602 , Japan
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Affiliation(s)
- E. Aust
- a Frontier Research Program , The Institute of Chemical and Physical Research (RIKEN) , 2-1 Hirosawa, Wako, Saitama , 351-01 , Japan
| | - W. Hickel
- b Hoechst AG, Angewandte Physik , 6230 Frankfurt/Main 80, Germany
| | - H. Knobloch
- a Frontier Research Program , The Institute of Chemical and Physical Research (RIKEN) , 2-1 Hirosawa, Wako, Saitama , 351-01 , Japan
| | - H. Orendi
- a Frontier Research Program , The Institute of Chemical and Physical Research (RIKEN) , 2-1 Hirosawa, Wako, Saitama , 351-01 , Japan
| | - W. Knoll
- a Frontier Research Program , The Institute of Chemical and Physical Research (RIKEN) , 2-1 Hirosawa, Wako, Saitama , 351-01 , Japan
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Fitrilawati F, Renu R, Baskar C, Xu LG, Chan HSO, Valiyaveettil S, Tamada K, Knoll W. Langmuir-Blodgett-Kuhn and self-assembled films of asymmetrically substituted poly(paraphenylene). Langmuir 2005; 21:12146-52. [PMID: 16342986 DOI: 10.1021/la0505667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Asymmetrically substituted poly(paraphenylene) (PhPPP) with hydrophilic and hydrophobic side chains was investigated. The polymer behavior at the air-water interface was studied on the basis of surface pressure-area (pi-A) isotherms and compression/expansion hysteresis measurements. PhPPP can form stable monolayers with an area per repeat unit of A=0.20+/-0.02 nm2 and a collapse pressure in the range of pi=25 mN/m. Then, Langmuir-Blodgett-Kuhn (LBK) films of PhPPP were prepared by horizontally and vertically transferring the Langmuir monolayers onto hydrophilic solid substrates at pi=12 mN/m. Cross-section analysis of the AFM tapping-mode topography images of a single transferred monolayer reveals a thickness of d0=0.9+/-0.1 nm. Taking into account the obtained monolayer thickness, curve-fitting calculations of angular scan data of LB monolayers measured using surface plasmon resonance (SPR) spectroscopy lead to a value for the refractive index of n=1.78+/-0.02 at lambda=632.8 nm. Next, the spontaneous formation of a PhPPP monolayer by adsorption from solution was studied ex situ by atomic force microscopy and UV-vis spectroscopy and in situ by using SPR spectroscopy. Stable self-assembled monolayers of PhPPP can be formed on hydrophilic surfaces with a thickness similar to that of the monolayer obtained using the LB method. The characterization results confirmed the amphiphilic character and the self-assembly properties of PhPPP, as well as the possibility of preparing homogeneous monolayer and multilayer films.
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Affiliation(s)
- F Fitrilawati
- Departments of Chemistry and of Materials Science, National University of Singapore, 10 Science Drive 4, Singapore 117543
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Vogt AK, Brewer GJ, Decker T, Böcker-Meffert S, Jacobsen V, Kreiter M, Knoll W, Offenhäusser A. Independence of synaptic specificity from neuritic guidance. Neuroscience 2005; 134:783-90. [PMID: 16009499 DOI: 10.1016/j.neuroscience.2005.04.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Revised: 04/13/2005] [Accepted: 04/16/2005] [Indexed: 10/25/2022]
Abstract
Neuronal circuits are interconnected with a high degree of specificity. While axonal guidance has been demonstrated to be crucial for the choice of the correct target region, its role in specificity at the level of individual cells remains unclear. Specificity of synapse formation may either result from precise guidance of axonal outgrowth onto the target or depend on a molecular "match" between pre- and postsynapse. To distinguish between these possibilities, an in vitro system was used in which neuritic outgrowth of rat cortical neurons is accurately guided along the narrow pathways of a surface micropattern. The micropattern consisted of a blend of extracellular matrix molecules applied to a cell repellent background of polystyrene by microcontact printing. The system reproduces guidance by attractant and repellent surface cues while no other signals that may influence synapse formation, like gradients of trophic factors or accumulations of signaling molecules, are provided. While the number of contact points between neighboring cells was strongly reduced on patterned substrates due to the geometrical restrictions, frequency of synapse formation was not different from homogeneous cultures. Thus it was unaffected by stringent guidance onto the target cell or by the number of cell-cell contacts. Moreover, a statistically significant enrichment of reciprocal contacts between mixed pairs of excitatory and inhibitory neurons over probabilistic predictions was found, which has similarly been shown by others in dissociated neuronal cultures. Our results indicate that precise axonal guidance is insufficient for target-specific synapse formation and suggest that instead recognition between individual cells is required.
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Affiliation(s)
- A K Vogt
- Max-Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
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Lauer L, Vogt AK, Kauff C, Nelles G, Yasuda A, Knoll W, Offenhäusser A. Analysis of electrotonic coupling in patterned neuronal networks. ACTA ACUST UNITED AC 2004; 151:122-7. [PMID: 16475854 DOI: 10.1049/ip-nbt:20040776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Microcontact printing of laminin is known as an efficient approach for guiding neuronal cell migration and neurite outgrowth on artificial surfaces. In the present study, ultrathin (approximately 250 microm) brain stem slices of Sprague-Dawley rats (E15-E18) were cultured on laminin-patterned substrates, such that neuronal cells migrating out of the slices formed grid-shaped neuronal networks along the geometry defined by the pattern. The interconnections between neighbouring pairs of neurons within these artificial networks were assessed electrophysiologically by double patch-clamp recordings and optically by microinjection of fluorescent dyes. Both functional and electrotonic synapses were detected. Based on the recorded data and simulations in PSpice, an electrical model for electrotonically coupled cells was derived. In this model the neuritic pathway is described as a cylindric cable, and gap junctions are represented by an ohmic resistor. Applying this model in the data analysis, the average inner radius of neurites could be determined to be approximately 0.1 microm. In addition, evidence was found for a correlation between the path-width of the applied pattern and the diameter of neurites growing along these paths.
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Affiliation(s)
- L Lauer
- Max Planck Institute for Polymer Research, Mainz, Germany
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Ji W, Elim HI, He J, Fitrilawati F, Baskar C, Valiyaveettil S, Knoll W. Photophysical and Nonlinear-Optical Properties of a New Polymer: Hydroxylated Pyridyl Para-phenylene. J Phys Chem B 2003. [DOI: 10.1021/jp0347116] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Naumann R, Walz D, Schiller S, Knoll W. Kinetics of valinomycin-mediated K+ ion transport through tethered bilayer lipid membranes. J Electroanal Chem (Lausanne) 2003. [DOI: 10.1016/s0022-0728(03)00013-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Bund A, Baba A, Berg S, Johannsmann D, Lübben J, Wang Z, Knoll W. Combining Surface Plasmon Resonance and Quartz Crystal Microbalance for the in Situ Investigation of the Electropolymerization and Doping/Dedoping of Poly(pyrrole). J Phys Chem B 2003. [DOI: 10.1021/jp034043o] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. Bund
- Institute of Physical Chemistry and Electrochemistry, Dresden University of Technology, Mommsenstrasse 13, D-01062 Dresden, Germany, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany, Institute of Physical Chemistry, Arnold-Sommerfeld-Strasse 4, 38678 Clausthal-Zellerfeld, Germany
| | - A. Baba
- Institute of Physical Chemistry and Electrochemistry, Dresden University of Technology, Mommsenstrasse 13, D-01062 Dresden, Germany, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany, Institute of Physical Chemistry, Arnold-Sommerfeld-Strasse 4, 38678 Clausthal-Zellerfeld, Germany
| | - S. Berg
- Institute of Physical Chemistry and Electrochemistry, Dresden University of Technology, Mommsenstrasse 13, D-01062 Dresden, Germany, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany, Institute of Physical Chemistry, Arnold-Sommerfeld-Strasse 4, 38678 Clausthal-Zellerfeld, Germany
| | - D. Johannsmann
- Institute of Physical Chemistry and Electrochemistry, Dresden University of Technology, Mommsenstrasse 13, D-01062 Dresden, Germany, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany, Institute of Physical Chemistry, Arnold-Sommerfeld-Strasse 4, 38678 Clausthal-Zellerfeld, Germany
| | - J. Lübben
- Institute of Physical Chemistry and Electrochemistry, Dresden University of Technology, Mommsenstrasse 13, D-01062 Dresden, Germany, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany, Institute of Physical Chemistry, Arnold-Sommerfeld-Strasse 4, 38678 Clausthal-Zellerfeld, Germany
| | - Z. Wang
- Institute of Physical Chemistry and Electrochemistry, Dresden University of Technology, Mommsenstrasse 13, D-01062 Dresden, Germany, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany, Institute of Physical Chemistry, Arnold-Sommerfeld-Strasse 4, 38678 Clausthal-Zellerfeld, Germany
| | - W. Knoll
- Institute of Physical Chemistry and Electrochemistry, Dresden University of Technology, Mommsenstrasse 13, D-01062 Dresden, Germany, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany, Institute of Physical Chemistry, Arnold-Sommerfeld-Strasse 4, 38678 Clausthal-Zellerfeld, Germany
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Abstract
Polymer-tethered phospholipid bilayers, which are based on a phospholipid-lipopolymer mixture, represent a very promising approach to stabilize complex biomimicking composite membranes. Furthermore, they are interesting model systems to study problems of hindered diffusion in two-dimensional liquids. Here, we present fluorescence recovery after photobleaching experiments (FRAP) on mixed phospholipid-lipopolymer monolayers of DMPC and DSPE-EO(45) at the air-water interface. In contrast to recent polymer-tethered bilayer experiments where the hydrophobic lipopolymer anchors behaved as immobile obstacles within the fluid phospholipid matrix,(1) this paper investigates the influence of mobile lipopolymer obstacles on the lateral diffusion of phospholipids. We found that the lateral diffusion of phospholipids with D = 7.1 +/- 0.5 microm(2)/s is independent of the lipopolymer obstacle concentration if adjacent polymer chains do not interact with each other. However, the diffusion coefficient of nontethered phospholipids gradually decreases from D = 7.1 +/- 0.5 microm(2)/s to D = 3.4 +/- 0.1 microm(2)/s in the case of increasing polymer-polymer interactions based on frictional coupling. This can be understood by a slowing down of the obstacle mobility. While phospholipids still show a significant lateral diffusion as long as the polymer moieties interact with each other only via frictional coupling, they become rather immobile (D = 0.9 +/- 0.1 microm(2)/s) if lipopolymers form a two-dimensional physical network.
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Affiliation(s)
- C A Naumann
- Department of Chemical Engineering, Stanford University, 381 North-South Mall, Stanford, California 94305-5025, USA.
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Baumgart T, Kreiter M, Lauer H, Naumann R, Jung G, Jonczyk A, Offenhäusser A, Knoll W. Fusion of small unilamellar vesicles onto laterally mixed self-assembled monolayers of thiolipopeptides. J Colloid Interface Sci 2003; 258:298-309. [PMID: 12618100 DOI: 10.1016/s0021-9797(02)00098-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Monolayers of the thiolipopeptide NH(2)-Cys-Ala-Ser-Ala-Ala-Ser-Ser-Ala-Pro-Ser-Ser-(Myr)Lys(Myr)-OH (III) were formed on gold surfaces by self-assembly, mixed with a lateral spacer of the same peptide composition, NH(2)-Cys-Ala-Ser-Ala-Ala-Ser-Ser-Ala-Pro-Ser-Ser-Lys-OH (I). Different mixing ratios were employed ranging from 0.1 to 1, corresponding to 10-100% thiolipopeptide. These self-assembled monolayers (SAMs) were then exposed to a suspension of liposomes with the aim of forming lipid bilayers as a function of the mixing ratio. A clear optimum with respect to homogeneity and electrical properties of the membranes was obtained in the middle region (0.5) of mixing ratio, as revealed by surface plasmon resonance spectroscopy, impedance spectroscopy, and fluorescence microscopy. The combination of these methods was shown to be a powerful tool, although a true lipid bilayer was not obtained. Instead, vesicle adsorption was shown to be the predominant process, and FRAP (fluorescence recovery after photobleaching) measurements showed that the films were not fluid on the micrometer length scale.
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Affiliation(s)
- T Baumgart
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
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Hernandez-Lopez J, Bauer R, Chang WS, Glasser G, Grebel-Koehler D, Klapper M, Kreiter M, Leclaire J, Majoral JP, Mittler S, Müllen K, Vasilev K, Weil T, Wu J, Zhu T, Knoll W. Functional polymers as nanoscopic building blocks. Materials Science and Engineering: C 2003. [DOI: 10.1016/s0928-4931(02)00256-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Solid-supported lipid membranes are important for their roles in fundamental biophysical research as well as in applications such as biosensors. In our study, lipopolymers containing alkyl side chains were synthesized and a mixture of the lipopolymer and free lipids was preorganized at the air-water interface and then transferred to a solid substrate using the Langmuir-Blodgett technique. A photochemical reaction between a substrate-functionalized benzophenone and C-H bonds on the lipopolymer was used to attach the lipopolymers to the substrate. The final assembly of the membrane was completed by vesicle fusion. Langmuir film experiments at the air-water interface indicate tighter molecular packing for the lipopolymers with 28 mol % alkyl side chains than for the ones with 22 mol %. Atomic force microscopy images point to phase separation of lipopolymers on the substrates due to their dewetting from hydrophobic surfaces. However, a mixture of lipopolymers and free lipids formed a smooth film on the same substrate. After the addition of the second lipid layer on the lipopolymer/free lipid layer, the fluorescence images of the polymer-supported bilayer suggested that the distal lipid layer is homogeneous on the micrometer scale. The relaxation of the fluorescent probe lipids was analyzed after application of an electric field to determine their diffusion coefficient; the distal lipid layer was mobile with an average diffusion coefficient of approximately 0.1 microm(2)/s. Moreover, the immobile fraction of the lipids in the distal layer was estimated to be around 15%.
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Affiliation(s)
- W W Shen
- Department of Chemical Engineering, Stanford University, 381 North-South Mall, Stanford, California 94305-5025, USA
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Abstract
Dissociated neuronal cultures on substrates patterned with extracellular matrix (ECM) proteins have yielded much information in the past. However, although the culture of brain slices has many advantages over dissociated neuronal cultures, its feasibility on patterned substrates has not been demonstrated to date. In the present study, neuronal outgrowth from brain stem slices onto homogeneous control substrates, and onto laminin structures of grid- and line-shape was achieved. Cultures were evaluated by means of phase contrast microscopy, antibody staining, and patch-clamp measurements. Only patterns with line sizes of more than 4 microm yielded satisfactory neuronal outgrowth. The size of the nodes in the pattern influenced the nodal compliance of the spreading cells and the amount of unstructured overgrowth. Best grid patterns were 4 microm lines and 10 microm nodes, best line patterns were 4 microm lines and 20 microm nodes. On patterned substrates, average sodium and potassium currents were reduced by approximately 50% compared to controls, whereas area-normalized ion-currents were in the same order of magnitude. This indicates that as a consequence of the pattern-enforced geometrical confinement, neurons tend to have a smaller surface. In addition, neurons on patterned substrates were rapidly covered with glial overgrowth. This was shown by antibody staining.
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Affiliation(s)
- L Lauer
- Max Planck Institute for Polymer Research, Mainz, Germany
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Abstract
In this work, we report the influence of the electrostatic interaction between lipid bilayer membranes and their solid polyelectrolyte multilayer support on the properties of the membrane. All involved sample preparation steps were carried out as convenient adsorption procedures from aqueous solutions. The lipid fluidity within the membrane as well as the surface coverage of the support could be tailored via the electrostatic interaction strength between the lipid bilayer and the supporting polyelectrolyte cushion.
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Affiliation(s)
- R Kügler
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
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Mathauer K, Schmidt A, Knoll W, Wegner G. Synthesis and Langmuir-Blodgett Multilayer-Forming Properties of Photo-Cross-Linkable Polyglutamate Derivatives. Macromolecules 2002. [DOI: 10.1021/ma00108a058] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schmidt A, Lehmann S, Georgelin M, Katana G, Mathauer K, Kremer F, Schmidt-Rohr K, Boeffel C, Wegner G, Knoll W. Molecular Dynamics of "Hairy Rod" Molecules in the Solid State: Poly(.gamma.-methyl L-glutamate)-co-(.gamma.-n-octadecyl L-glutamate) in Solution-Cast Films. Macromolecules 2002. [DOI: 10.1021/ma00120a012] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Quint P, Knoll W, Hara M, Sasabe H, Duran RS. Scanning Tunneling Microscopy Studies of Langmuir-Blodgett-Deposited Alkyl-Substituted Polyaniline and Its Corresponding Monomer. Macromolecules 2002. [DOI: 10.1021/ma00115a041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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