1
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Müller W, Sroka W, Schweins R, Nöcker B, Poon JF, Huber K. Impact of Additive Hydrophilicity on Mixed Dye-Nonionic Surfactant Micelles: Micelle Morphology and Dye Localization. Langmuir 2024; 40:8872-8885. [PMID: 38640353 DOI: 10.1021/acs.langmuir.4c00012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/21/2024]
Abstract
The nonionic surfactant pentaethylene glycol-monododecylether C12E5 forms micelles in aqueous solutions with a lower critical solution temperature. This characteristic solution behavior of C12E5 is independent of the pH. Such micelles are used to solubilize a large variety of active guest molecules like for instance dyestuffs. An example is an acidic azo dye termed Blue used as a hair colorant. Depending on the pH, Blue gradually changes its hydrophilicity from the protonated BlueH at pH = 2 to the bivalent anion Blue2- at pH = 13 while keeping the shape and size of Blue essentially unchanged. These features of C12E5 and Blue offer the unique chance to investigate the sole impact of a tunable hydrophilicity of a guest molecule on the solution behavior of mixed micelles of the guest and C12E5. Accordingly, the present work establishes a phase diagram of Blue-C12E5 micelles and analyzes their morphology including the spatial distribution of Blue in the micelles as a function of the hydrophilicity of Blue. Small angle neutron scattering reveals the size and shape of the micelles, and detailed contrast matching of the C12E5 supported by 1H NMR with NOESY provided insight into the localization of Blue within the micelles as its hydrophilicity changes.
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Affiliation(s)
- Wenke Müller
- Science Division/Large Scale Structures Group Institut Laue-Langevin 71 Avenue des Martyrs, Grenoble 38000, France
| | - Weronika Sroka
- Science Division/Large Scale Structures Group Institut Laue-Langevin 71 Avenue des Martyrs, Grenoble 38000, France
| | - Ralf Schweins
- Science Division/Large Scale Structures Group Institut Laue-Langevin 71 Avenue des Martyrs, Grenoble 38000, France
| | - Bernd Nöcker
- Basic Research & Technology Development KAO Germany GmbH Pfungstädter Straße 98-100, Darmstadt 64297, Germany
| | - Jia-Fei Poon
- European Spallation Source Box 176, Lund SE-221 00, Sweden
- Food Technology, Engineering and Nutrition Lund University Box 117, Lund SE-221 00, Sweden
| | - Klaus Huber
- Fakultät für Naturwissenschaften/Physical Chemistry Universität Paderborn Warburger Straße 100, Paderborn 33098, Germany
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2
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Liao M, Gong H, Liu H, Shen K, Ge T, King S, Schweins R, McBain AJ, Hu X, Lu JR. Combination of a pH-responsive peptide amphiphile and a conventional antibiotic in treating Gram-negative bacteria. J Colloid Interface Sci 2024; 659:397-412. [PMID: 38183806 DOI: 10.1016/j.jcis.2023.12.146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 09/03/2023] [Revised: 12/16/2023] [Accepted: 12/24/2023] [Indexed: 01/08/2024]
Abstract
BACKGROUND Clinical treatments ofgastric infections using antibiotics suffer from the undesired killing of commensal bacteria and emergence of antibiotic resistance. It is desirable to develop pH-responsive antimicrobial peptides (AMPs) that kill pathogenic bacteria such as H. pyloriand resistant E. coli under acidic environment with minimal impact to commensal bacteria whilst not causing antibiotic resistance. EXPERIMENTS Using a combined approach of cell assays, molecular dynamics (MD) simulations and membrane models facilitating biophysical and biochemical measurements including small angle neutron scattering (SANS), we have characterized the pH-responsive physiochemical properties and antimicrobial performance of two amphiphilic AMPs, GIIKDIIKDIIKDI-NH2 and GIIKKIIDDIIKKI-NH2 (denoted as 3D and 2D, respectively), that were designed by selective substitutions of cationic residues of Lys (K) in the extensively studied AMP G(IIKK)3I-NH2 with anionic residue Asp (D). FINDINGS Whilst 2D kept non-ordered coils across the entire pH range studied, 3D displayed a range of secondary structures when pH was shifted from basic to acidic, with distinct self-assembly into nanofibers in aqueous environment. Further experimental and modeling studies revealed that the AMPs interacted differently with the inner and outer membranes of Gram-negative bacteria in a pH-responsive manner and that the structural features characterized by membrane leakage and intramembrane nanoaggregates revealed from fluorescence spectroscopy and SANS were well linked to antimicrobial actions. Different antimicrobial efficacies of 2D and 3D were underlined by the interplay between their ability to bind to the outer membrane lipid LPS (lipopolysaccharide), outer membrane permeability change and inner membrane depolarization and leakage. Furthermore, AMP's binding with the inner membrane under acidic condition caused both the dissipation of membrane potential (Δψ) and the continuous dissipation of transmembrane ΔpH, with Δψ and ΔpH being the key components of the proton motive force. Combinations of antibiotic (Minocycline) with the pH-responsive AMP generated the synergistic effects against Gram-negative bacteria only under acidic condition. These features are crucial to target applications to gastric infections, anti-acne and wound healing.
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Affiliation(s)
- Mingrui Liao
- Biological Physics Laboratory, Department of Physics and Astronomy, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Haoning Gong
- Biological Physics Laboratory, Department of Physics and Astronomy, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Huayang Liu
- Biological Physics Laboratory, Department of Physics and Astronomy, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Kangcheng Shen
- Biological Physics Laboratory, Department of Physics and Astronomy, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Tianhao Ge
- Biological Physics Laboratory, Department of Physics and Astronomy, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Stephen King
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | | | - Andrew J McBain
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Xuzhi Hu
- Biological Physics Laboratory, Department of Physics and Astronomy, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Jian R Lu
- Biological Physics Laboratory, Department of Physics and Astronomy, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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3
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Jimenez JAM, Egan J, Randle RI, Rezig AO, Orimolade BO, Ginesi RE, Schweins R, Riehle MO, Draper ER. Tuning conductivity while maintaining mechanical properties in perylene bisimide hydrogels at physiological pH. Chem Commun (Camb) 2024; 60:3027-3030. [PMID: 38385307 DOI: 10.1039/d3cc04557a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
By using different salts as a method to achieve gelation of two different amino-acid-functionalised perylene bisimides, we were able to tune reduction potentials while maintaining the mechanical and optical properties of the system all at pH 7.4.
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Affiliation(s)
- Juan Antonio Mena Jimenez
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, UK.
- Department of Chemical Engineering, Faculty of Sciences, University of Granada, 18071, Spain
| | - Jacquelyn Egan
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, UK.
| | - Rebecca I Randle
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, UK.
| | - Amina Omelbanine Rezig
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, UK.
- School of Molecular Biosciences, University of Glasgow, Glasgow, UK
| | | | - Rebecca E Ginesi
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, UK.
| | - Ralf Schweins
- Institut Laue-Langevin, Large Scale Structures Group, 71 Avenue des Martyrs, CS 20156, F-38042, Grenoble, Cedex 9, France
| | - Mathis O Riehle
- School of Molecular Biosciences, University of Glasgow, Glasgow, UK
| | - Emily R Draper
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, UK.
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4
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Zika A, Agarwal M, Zika W, Guldi DM, Schweins R, Gröhn F. Photoacid-macroion assemblies: how photo-excitation switches the size of nano-objects. Nanoscale 2024; 16:923-940. [PMID: 38108137 DOI: 10.1039/d3nr04570f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Electrostatic self-assembly of photoacids with oppositely charged macroions yields supramolecular nano-objects in aqueous solutions, whose size is controlled through light irradiation. Nano-assemblies are formed due to electrostatic attractions and mutual hydrogen bonding of the photoacids. Irradiation with UV light leads to the deprotonation of the photoacid and, consequently, a change in particle size. Overall, the hydrodynamic radii of the well-defined photoacid-macroion nano-objects lie between 130 and 370 nm. For a set of photoacids, we determine the acidity constants in the ground and excited state, discuss the sizes of photoacid-macroion nano-objects (by dynamic and static light scattering), their composition and the particle shapes (by small-angle neutron scattering), and relate their charge characteristics to size, structure and shape. We investigate the association thermodynamics and relate nanoscale structures to thermodynamics and, in turn, thermodynamics to molecular features, particularly the ionization energy of the photoacid hydroxyl group proton. Structure-directing effects completely differ from those for previously investigated systems, with hydrogen bonding and entropic effects playing a major role herein. This combined approach allows developing a comprehensive understanding of assembly formation and photo-response, anchored in molecular parameters (pKa, ionization energy, substituent group location), charge characteristics, and the association enthalpy and entropy. This fundamental understanding again paves the way for tailoring application solutions with novel photoresponsive materials.
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Affiliation(s)
- Alexander Zika
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, and Bavarian Polymer Institute Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany.
| | - Mohit Agarwal
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, and Bavarian Polymer Institute Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany.
- DS LSS Institut Laue - Langevin, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble CEDEX 9, France
| | - Wiebke Zika
- Department of Chemistry and Pharmacy, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany
| | - Ralf Schweins
- DS LSS Institut Laue - Langevin, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble CEDEX 9, France
| | - Franziska Gröhn
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, and Bavarian Polymer Institute Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany.
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5
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Agarwal M, Zika A, Schweins R, Gröhn F. Controlling the Morphology in Electrostatic Self-Assembly via Light. Polymers (Basel) 2023; 16:50. [PMID: 38201714 PMCID: PMC10780651 DOI: 10.3390/polym16010050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
Electrostatic self-assembly of macroions is an emerging area with great potential in the development of nanoscale functional objects, where photo-irradiation responsiveness can either elevate or suppress the self-assembly. The ability to control the size and shape of macroion assemblies would greatly facilitate the fabrication of desired nano-objects that can be harnessed in various applications such as catalysis, drug delivery, bio-sensors, and actuators. Here, we demonstrate that a polyelectrolyte with a size of 5 nm and multivalent counterions with a size of 1 nm can produce well-defined nanostructures ranging in size from 10-1000 nm in an aqueous environment by utilizing the concept of electrostatic self-assembly and other intermolecular non-covalent interactions including dipole-dipole interactions. The pH- and photoresponsiveness of polyelectrolytes and azo dyes provide diverse parameters to tune the nanostructures. Our findings demonstrate a facile approach to fabricating and manipulating self-assembled nanoparticles using light and neutron scattering techniques.
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Affiliation(s)
- Mohit Agarwal
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France;
| | - Alexander Zika
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France;
| | - Franziska Gröhn
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany
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6
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Manasi I, Schweins R, Ma K, Edler KJ. Nanostructure in Amphiphile-Based Deep Eutectic Solvents. Langmuir 2023; 39:16776-16784. [PMID: 37965899 PMCID: PMC10688184 DOI: 10.1021/acs.langmuir.3c02105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 11/16/2023]
Abstract
Deep eutectic solvents (DESs) are an emerging class of modern, often "green" solvents with unique properties. Recently, a deep eutectic system based on amphiphilic surfactant N-alkyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (C12 & C14 sulfobetaine) and (1S)-(+)-10-camphor-sulfonic acid in the molar ratio 1:1.5 has been reported. Nanostructuring can be expected in this DES due to the nature of the components. In this work, we have investigated the native nanostructure in the DES comprising C12-C18 alkyl chain sulfobetaines with camphor sulfonic acid and how it interacts with polar and nonpolar species, water and dodecane, respectively, using small angle neutron scattering. By using contrast variation to highlight the relative position of the solvent components and additives, we can resolve the structure of the solvent and how it changes upon interaction with water and dodecane. Scattering from the neat DES shows structures corresponding to the self-assembly of sulfobetaines; the size of the structure increases as the alkyl chain length of the sulfobetaines increases. Water and dodecane interact, respectively, with the hydrophilic and hydrophobic moieties in the DES structure, primarily the sulfobetaine, thereby swelling and solvating the entire structure. The extent of the shift of the peak position, and the swelling, depend on concentration of the additive. The solution phase organization and the interaction of polar and nonpolar species as observed here, have the potential to affect the ordering of inorganic or polymeric materials grown in such solvents, paving new avenues for templating applications.
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Affiliation(s)
- Iva Manasi
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AX, U.K.
| | - Ralf Schweins
- Institut
Laue-Langevin, CS 20156, Grenoble Cedex 9 38042, France
| | - Kun Ma
- ISIS
Neutron and Muon Source, STFC, Rutherford
Appleton Laboratory, Didcot OX11 0QX, U.K.
| | - Karen J. Edler
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AX, U.K.
- Department
of Chemistry, Centre for Analysis and Synthesis (CAS), Lund University, Lund 221 00, Sweden
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7
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Zika A, Agarwal M, Schweins R, Gröhn F. Double-Wavelength-Switchable Molecular Self-Assembly of a Photoacid and Spirooxazine in an Aqueous Solution. J Phys Chem Lett 2023; 14:9563-9568. [PMID: 37861686 DOI: 10.1021/acs.jpclett.3c02392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Quadruple-switchable nanoscale assemblies are built by combining two types of water-soluble molecular photoswitches through dipole-dipole interaction. Uniting the wavelength-specific proton dissociation of a photoacid and ring-opening of an anionic spirooxazine results in an assembly that can be addressed by irradiation with two different wavelengths: pH and darkness.
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Affiliation(s)
- Alexander Zika
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, Bavarian Polymer Institute, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, D-91058 Erlangen, Germany
| | - Mohit Agarwal
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, Bavarian Polymer Institute, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, D-91058 Erlangen, Germany
- DS/LSS Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble CEDEX 9, France
| | - Ralf Schweins
- DS/LSS Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble CEDEX 9, France
| | - Franziska Gröhn
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, Bavarian Polymer Institute, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, D-91058 Erlangen, Germany
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8
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Krauss SW, Eckardt M, Will J, Spiecker E, Siegel R, Dulle M, Schweins R, Pauw B, Senker J, Zobel M. The H-D-isotope effect of heavy water affecting ligand-mediated nanoparticle formation in SANS and NMR experiments. Nanoscale 2023; 15:16413-16424. [PMID: 37791518 DOI: 10.1039/d3nr02419a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
An isotopic effect of normal (H2O) vs. heavy water (D2O) is well known to fundamentally affect the structure and chemical properties of proteins, for instance. Here, we correlate the results from small angle X-ray and neutron scattering (SAXS, SANS) with high-resolution scanning transmission electron microscopy to track the evolution of CdS nanoparticle size and crystallinity from aqueous solution in the presence of the organic ligand ethylenediaminetetraacetate (EDTA) at room temperature in both H2O and D2O. We provide evidence via SANS experiments that exchanging H2O with D2O impacts nanoparticle formation by changing the equilibria and dynamics of EDTA clusters in solution as investigated by nuclear magnetic resonance analysis. The colloidal stability of the CdS nanoparticles, covered by a layer of [Cd(EDTA)]2- complexes, is significantly reduced in D2O despite the strong stabilizing effect of EDTA in suspensions of normal water. Hence, conclusions about nanoparticle formation mechanisms from D2O solutions reveal limited transferability to reactions in normal water due to isotopic effects, which thus need to be discussed for contrast match experiments.
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Affiliation(s)
- Sebastian W Krauss
- Department of Chemistry, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
| | - Mirco Eckardt
- Department of Chemistry, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
| | - Johannes Will
- Institute of Micro- and Nanostructure Research & Center for Nanoanalysis and Electron Microscopy (CENEM), Friedrich-Alexander-Universität Erlangen-Nürnberg, IZNF, Cauerstraße 3, 91058 Erlangen, Germany
| | - Erdmann Spiecker
- Institute of Micro- and Nanostructure Research & Center for Nanoanalysis and Electron Microscopy (CENEM), Friedrich-Alexander-Universität Erlangen-Nürnberg, IZNF, Cauerstraße 3, 91058 Erlangen, Germany
| | - Renée Siegel
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
| | - Martin Dulle
- JCNS-1/IBI-8: Neutron Scattering and Biological Matter, Forschungszentrum Jülich Gmbh, Wilhelm-Johnen-Straße, 52428 Jülich, Germany
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, Grenoble 38000, France
| | - Brian Pauw
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany
| | - Jürgen Senker
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
| | - Mirijam Zobel
- Institute of Crystallography, RWTH Aachen University, Jägerstr. 17-19, 52066 Aachen, Germany.
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9
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Müller W, Schweins R, Nöcker B, Egold H, Hannappel Y, Huber K. SANS contrast matching for the unambiguous localization of anionic dye in cationic surfactant micelles. Nanoscale Adv 2023; 5:5367-5384. [PMID: 37767037 PMCID: PMC10521298 DOI: 10.1039/d3na00556a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023]
Abstract
Contrast variation in small-angle neutron scattering (SANS) was successfully applied to localize the anionic azo dye Blue in co-assemblies with the cationic surfactant dodecyltrimethylammoniumbromide (DTAB). For this purpose, the scattering contrast between DTAB and the aqueous solvent was eliminated by SANS contrast matching, leaving only the scattering signal from Blue to be detected. Results obtained by contrast matching were confirmed by NOESY NMR-spectroscopy, showing that Blue interacts with the positively charged DTAB head groups and with up to the 4th neighbouring methylene group of the DTAB C12-alkyl chain. Its localization in the outer layer of the Blue-DTAB co-assembly explains the uniaxial growth of spheroidal DTAB micelles to wormlike micelles with increasing [Blue] : [DTAB] ratio from 0 : 1 to 1 : 3. This is in line with the concept of the packing parameter for amphiphilic substances.
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Affiliation(s)
- Wenke Müller
- Institut Laue-Langevin, DS/LSS 71 Avenue des Martyrs 38000 Grenoble France
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS 71 Avenue des Martyrs 38000 Grenoble France
| | - Bernd Nöcker
- KAO Germany GmbH Pfungstädter Straße 98-100 64297 Darmstadt Germany
| | - Hans Egold
- Universität Paderborn Warburger Straße 100 33098 Paderborn Germany
| | - Yvonne Hannappel
- Universität Bielefeld Universitätsstrasse 25 33615 Bielefeld Germany
| | - Klaus Huber
- Universität Paderborn Warburger Straße 100 33098 Paderborn Germany
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10
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Petermann M, Dianteill L, Zeidi A, Vaha Ouloassekpa R, Budisavljevic P, Le Men C, Montanier C, Roblin P, Cabane B, Schweins R, Dumon C, Bouchoux A. Arabinoxylan in Water through SANS: Single-Chain Conformation, Chain Overlap, and Clustering. Biomacromolecules 2023; 24:3619-3628. [PMID: 37526635 DOI: 10.1021/acs.biomac.3c00374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 08/02/2023]
Abstract
Using small-angle neutron scattering (SANS), we examine the structure and conformational behavior of wheat arabinoxylan (AX) prepared at various concentrations in a sodium phosphate aqueous buffer. As for another major hemicellulose, xyloglucan, we observe a small number of large clusters surrounded by AX chains that behave exactly as a polymer in good solvent with a Flory exponent ν = 0.588. The fit of the data at high q-values to a standard worm-like chain model gives the persistence length lp = 45 Å and cross section of the chains 2Rc = 11-12 Å. In addition, using a dedicated modeling approach, we extract from the SANS data at the intermediate q-range the correlation length ξ of the solutions in the semidilute regime. The decay of ξ with concentration follows a scaling law that further confirms the self-avoiding statistical behavior of the AX chains. This first comprehensive study about the properties of water-soluble AX at different length scales may help in the development of products and processes involving AX as a substitute for fossil carbon molecules.
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Affiliation(s)
- Maike Petermann
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
| | - Lucie Dianteill
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
| | - Amal Zeidi
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
| | | | | | - Claude Le Men
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
| | - Cédric Montanier
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
| | - Pierre Roblin
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, 31062 Toulouse, France
| | | | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, CS-20156, 38042 Grenoble, France
| | - Claire Dumon
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
| | - Antoine Bouchoux
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
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11
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Coulter SM, Pentlavalli S, Vora LK, An Y, Cross ER, Peng K, McAulay K, Schweins R, Donnelly RF, McCarthy HO, Laverty G. Enzyme-Triggered l-α/d-Peptide Hydrogels as a Long-Acting Injectable Platform for Systemic Delivery of HIV/AIDS Drugs. Adv Healthc Mater 2023; 12:e2203198. [PMID: 36880399 DOI: 10.1002/adhm.202203198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/24/2023] [Indexed: 03/08/2023]
Abstract
Eradicating HIV/AIDS by 2030 is a central goal of the World Health Organization. Patient adherence to complicated dosage regimens remains a key barrier. There is a need for convenient long-acting formulations that deliver drugs over sustained periods. This paper presents an alternative platform, an injectable in situ forming hydrogel implant to deliver a model antiretroviral drug (zidovudine [AZT]) over 28 days. The formulation is a self-assembling ultrashort d or l-α peptide hydrogelator, namely phosphorylated (naphthalene-2-ly)-acetyl-diphenylalanine-lysine-tyrosine-OH (NapFFKY[p]-OH), covalently conjugated to zidovudine via an ester linkage. Rheological analysis demonstrates phosphatase enzyme instructed self-assembly, with hydrogels forming within minutes. Small angle neutron scattering data suggest hydrogels form narrow radius (≈2 nm), large length fibers closely fitting the flexible cylinder elliptical model. d-Peptides are particularly promising for long-acting delivery, displaying protease resistance for 28 days. Drug release, via hydrolysis of the ester linkage, progress under physiological conditions (37 °C, pH 7.4, H2 O). Subcutaneous administration of Napffk(AZT)Y[p]G-OH in Sprague Dawley rats demonstrate zidovudine blood plasma concentrations within the half maximal inhibitory concentration (IC50 ) range (30-130 ng mL-1 ) for 35 days. This work is a proof-of-concept for the development of a long-acting combined injectable in situ forming peptide hydrogel implant. These products are imperative given their potential impact on society.
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Affiliation(s)
- Sophie M Coulter
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
| | - Sreekanth Pentlavalli
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
| | - Lalitkumar K Vora
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
| | - Yuming An
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
| | - Emily R Cross
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
| | - Ke Peng
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
| | - Kate McAulay
- School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, Scotland, G12 8QQ, UK
- School of Computing, Engineering and Built Environment, Glasgow Caledonian University, Glasgow, Scotland, G4 0BA, UK
| | - Ralf Schweins
- Large Scale Structures Group, Institut Laue - Langevin, 71 Avenue des Martyrs, CS 20156, Grenoble Cedex 9, 38042, France
| | - Ryan F Donnelly
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
| | - Helen O McCarthy
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
| | - Garry Laverty
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, Co. Antrim, Northern Ireland, BT9 7BL, UK
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12
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Müller W, Schweins R, Nöcker B, Kohlbrecher J, Smales GJ, Huber K. Comparative study of the co-assembly behaviour of 3-chloro-4-hydroxy-phenylazo dyes with DTAB. Soft Matter 2023. [PMID: 37310375 DOI: 10.1039/d3sm00501a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The co-assembly of three one-fold negatively charged 3-chloro-4-hydroxy-phenylazo dyes (Yellow, Blue and Red) with the cationic surfactant dodecyltrimethylammoniumbromide (DTAB) was studied to probe dye-DTAB binding stoichiometry and assembly morphology. For each dye, phase separation was observed above a given dye : DTAB ratio with the ratio depending on the dye. While Yellow and DTAB showed liquid/liquid phase separation above Yellow : DTAB = 1 : 1.67, crystalline dye-DTAB complexes were observed for Blue-DTAB and Red-DTAB above Blue : DTAB = 1 : 2.56 and Red : DTAB = 1 : 2.94 respecively. In homogeneous solution, UV/vis spectroscopic investigations suggest stochiometries of Yellow : DTAB = 1 : 2, Blue : DTAB = 1 : 3 and Red : DTAB = 1 : 4. It was concluded, that Yellow exhibits the highest dye : DTAB binding stoichiometry in both, dye-surfactant complexes in the 2-phase region and in solution, whereas the lowest dye : DTAB binding stoichiometry was observed for Red-DTAB in both cases. The observed stoichiometries are inversely correlated to the impact dye addition has on the morphology of DTAB micelles. Generally, addition of dye to DTAB micelles leads to a reduction in spontaneous curvature of these micelles and to the formation of triaxial ellipsoidal or cylindrical micelles from oblate ellipsoidal DTAB micelles. At a DTAB concentration of 30 mM and a dye concentration of 5 mM, this effect was most pronounced for Red and least pronounced for Yellow, whilst Blue showed an intermediate effect.
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Affiliation(s)
- Wenke Müller
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, 38000 Grenoble, France.
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, 38000 Grenoble, France.
| | - Bernd Nöcker
- KAO Germany GmbH, Pfungstädter Straße 98-100, 64297 Darmstadt, Germany
| | - Joachim Kohlbrecher
- Paul Scherrer Institut, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
| | - Glen J Smales
- Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, 12205 Berlin, Germany
| | - Klaus Huber
- Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
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13
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Müller W, Schweins R, Nöcker B, Egold H, Huber K. Comparative study of the self-assembly behaviour of 3-chloro-4-hydroxy-phenylazo dyes. Soft Matter 2023. [PMID: 37310076 DOI: 10.1039/d3sm00500c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The complexity of intermolecular interactions and the difficulty to predict assembly behaviour solely based on chemical constitution was demonstrated by studying the self-assembly of three one-fold negatively charged 3-chloro-4-hydroxy-phenylazo dyes (Yellow, Blue and Red). Dye self-assembly was investigated using UV/vis- and NMR-spectroscopy, light- and small-angle neutron scattering. Significant differences between the three dyes were observed. While Yellow does not self-assemble, Red assembles into higher-order aggregates and Blue forms well-defined H-aggregate dimers with a dimerization constant of KD = (728 ± 8) L mol-1. Differences between dyes were suggested to emerge from variations in the propensity to form π-π-interactions due to electrostatic repulsion, sterical constraints and hydrogen-bonding interactions.
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Affiliation(s)
- Wenke Müller
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, 38000 Grenoble, France.
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, 38000 Grenoble, France.
| | - Bernd Nöcker
- KAO Germany GmbH, Pfungstädter Straße 98-100, 64297 Darmstadt, Germany
| | - Hans Egold
- Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Klaus Huber
- Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
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14
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Guan Q, McAulay K, Xu T, Rogers SE, Edwards-Gayle C, Schweins R, Cui H, Seddon AM, Adams DJ. Self-Sorting in Diastereomeric Mixtures of Functionalized Dipeptides. Biomacromolecules 2023. [PMID: 37257089 DOI: 10.1021/acs.biomac.3c00246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Self-sorting in functionalized dipeptide systems can be driven by the chirality of a single amino acid, both at a high pH in the micellar state and at a low pH in the gel state. The structures formed are affected to some degree by the relative concentrations of each component showing the complexity of such an approach. The structures underpinning the gel network are predefined by the micellar structures at a high pH. Here, we describe the systems prepared from two dipeptide-based gelators that differ only by the chirality of one of the amino acids. We provide firm evidence for self-sorting in the micellar and gel phases using small-angle neutron scattering and cryo-transmission electron microscopy (cryo-TEM), showing that complete self-sorting occurs across a range of relative concentrations.
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Affiliation(s)
- Qingwen Guan
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Kate McAulay
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Tian Xu
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Sarah E Rogers
- ISIS Pulsed Neutron Source, Rutherford Appleton Laboratory, Didcot, OX11 0QX, U.K
| | | | - Ralf Schweins
- Large Scale Structures Group, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, F-38042 Grenoble,CEDEX 9, France
| | - Honggang Cui
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Annela M Seddon
- School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K
| | - Dave J Adams
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K
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15
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Petrunin AV, Schmidt MM, Schweins R, Houston JE, Scotti A. Self-Healing of Charged Microgels in Neutral and Charged Environments. Langmuir 2023. [PMID: 37220302 DOI: 10.1021/acs.langmuir.2c03054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The softness of microgels depends on many aspects, such as particle characteristic lengths, sample concentration, chemical composition of the sample, and elastic moduli of the particle. Here, the response to crowding of ionic microgels is studied. Charged and uncharged ionic microgels are studied in concentrated suspensions of both neutral and ionic microgels with the same swollen size. The combination of small-angle X-ray and neutron scattering with contrast variation allows us to probe both the particle-to-particle arrangement and the response of individual ionic microgels to crowding. When the ionic microgels are uncharged, initial isotropic deswelling followed by faceting is observed. Therefore, the ionizable groups in the polymeric network do not affect the response of the ionic microgel to crowding, which is similar to what has been reported for neutral microgels. In contrast, the kind of microgels composing the matrix plays a key role once the ionic microgels are charged. If the matrix is composed of neutral microgels, a pronounced faceting and negligible deswelling is observed. When only charged ionic microgels are present in the suspension, isotropic deswelling without faceting is dominant.
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Affiliation(s)
- Alexander V Petrunin
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
| | - Maximilian M Schmidt
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
| | - Ralf Schweins
- Institut Laue-Langevin ILL, DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - Judith E Houston
- European Spallation Source ERIC, Box 176, SE-221 00 Lund, Sweden
| | - Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
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16
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Hasan MR, Niebuur BJ, Siebrecht M, Kuttich B, Schweins R, Widmer-Cooper A, Kraus T. The Colloidal Stability of Apolar Nanoparticles in Solvent Mixtures. ACS Nano 2023; 17:9302-9312. [PMID: 37163685 DOI: 10.1021/acsnano.3c00812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Solvent engineering is a powerful and versatile method to tune colloidal stability. Here, we link the molecular structure of apolar ligand shells on gold nanoparticles with their colloidal stability in solvent mixtures. The agglomeration temperature of the particles was measured with small-angle X-ray scattering. It depended on solvent composition and changed linearly for hexane-hexadecane mixtures, but nonlinearly for cyclohexane-hexadecane and hexanol-hexadecane mixtures. Molecular dynamics (MD) simulations indicate that agglomeration is dominated by temperature-dependent ligand order in the alkane mixtures and that the temperature at which the ligand shell orders depends on the solvent composition near the ligands, which can differ substantially from the bulk composition. Small-angle neutron scattering confirmed that, at intermediate solvent compositions above the agglomeration temperature, the fraction of cyclohexane near the ligands was larger than in the bulk. The enrichment of cyclohexane near the ligands stabilized their disordered state, which, consequently, led to the experimentally observed nonlinear trend of the agglomeration temperature. In contrast, hexanol was depleted from the ligand shell at all temperatures. This again stabilized the disordered state. Furthermore, we found that agglomeration at high hexanol fractions was driven by a solvophobic effect that exceeded the influence of ligand order. The results show that strong nonlinearities in the colloidal stability of nanoparticle dispersions in solvent mixtures are directly linked to the molecular details of ligand-solvent and solvent-solvent interactions, which can be used to precisely tune stability.
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Affiliation(s)
- Mohammad Rashedul Hasan
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Bart-Jan Niebuur
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Martin Siebrecht
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Björn Kuttich
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Ralf Schweins
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble, France
| | - Asaph Widmer-Cooper
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
- The University of Sydney Nano Institute, University of Sydney, 66123 Sydney, New South Wales, Australia
| | - Tobias Kraus
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
- Colloid and Interface Chemistry, Saarland University, Campus D2 2, 66123 Saarbrücken, Germany
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17
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Zika A, Agarwal M, Schweins R, Gröhn F. Joining Two Switches in One Nano-Object: Photoacidity and Photoisomerization in Electrostatic Self-Assembly. Chemistry 2023; 29:e202203373. [PMID: 36336659 DOI: 10.1002/chem.202203373] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
Multi-switchable supramolecular nano-objects that respond to irradiation of different wavelengths with changes in size and shape have been built from two different water-soluble molecular switches, joined by attachment to the same polyelectrolyte. Accordingly, two wavelength-specific reactions, namely the excited-state proton dissociation of a photoacid and the cis-trans isomerization of an azo dye, are combined in one supramolecular nano-object that is stable in aqueous solution. The concept has potential in the fields of sensors, molecular motors, and transport.
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Affiliation(s)
- Alexander Zika
- Department of Chemistry and Pharmacy &, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058, Erlangen, Germany
| | - Mohit Agarwal
- Department of Chemistry and Pharmacy &, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058, Erlangen, Germany.,DS / LSS, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20 156, 38042, Grenoble Cedex 9, France
| | - Ralf Schweins
- DS / LSS, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20 156, 38042, Grenoble Cedex 9, France
| | - Franziska Gröhn
- Department of Chemistry and Pharmacy &, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058, Erlangen, Germany
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18
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Randle RI, Ginesi RE, Matsarskaia O, Schweins R, Draper ER. Process Dependent Complexity in Multicomponent Gels. Macromol Rapid Commun 2023; 44:e2200709. [PMID: 36177680 DOI: 10.1002/marc.202200709] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/20/2022] [Indexed: 11/06/2022]
Abstract
Mixing low molecular weight gelators (LMWGs) can be used to combine favorable properties of the individual components within a multifunctional gel. Such multicomponent systems are complex enough in themselves but the method of combining components is not commonly considered something to influence self-assembly. Herein, two multicomponent systems comprising of a naphthalene-based dipeptide hydrogelator and one of two modified naphthalene diimides (NDIs), one of which forms gels, and the other does not, are investigated. These systems are probed, examining the structures formed and their gel properties (when preparing a solution from either a mixed powder of both components or by mixing pre-formed solutions of each component) using rheology, small angle neutron scattering (SANS), and absorbance spectroscopy. It is found that by altering the method of preparation, it is can either induce self-sorting or co-assembly within the fibers formed that underpin the gel network.
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Affiliation(s)
- Rebecca I Randle
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Rebecca E Ginesi
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Olga Matsarskaia
- Institut Laue-Langevin, Large Scale Structures Group, 71 Avenue des Martyrs, CS 20156, Grenoble CEDEX 9, F-38042, France
| | - Ralf Schweins
- Institut Laue-Langevin, Large Scale Structures Group, 71 Avenue des Martyrs, CS 20156, Grenoble CEDEX 9, F-38042, France
| | - Emily R Draper
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
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19
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Palinske M, Muza UL, Moreno S, Appelhans D, Boye S, Schweins R, Lederer A. Potential of Small‐Angle Neutron Scattering for Evaluating Protein Locus within a Polymersome. MACROMOL CHEM PHYS 2023. [DOI: 10.1002/macp.202300014] [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: 02/22/2023]
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20
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Bosak A, Dubois M, Korobkina E, Lychagin E, Muzychka A, Nekhaev G, Nesvizhevsky V, Nezvanov A, Saerbeck T, Schweins R, Strelkov A, Turlybekuly K, Zhernenkov K. Effect of Nanodiamond Sizes on the Efficiency of the Quasi-Specular Reflection of Cold Neutrons. Materials (Basel) 2023; 16:703. [PMID: 36676440 PMCID: PMC9866128 DOI: 10.3390/ma16020703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/04/2023] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Nanomaterials can intensively scatter and/or reflect radiation. Such processes and materials are of theoretical and practical interest. Here, we study the quasi-specular reflections (QSRs) of cold neutrons (CNs) and the reflections of very cold neutrons (VCNs) from nanodiamond (ND) powders. The fluorination of ND increased its efficiency by removing/replacing hydrogen, which is otherwise the dominant cause of neutron loss due to incoherent scattering. The probability of the diffuse reflection of VCNs increased for certain neutron wavelengths by using appropriate ND sizes. Based on model concepts of the interaction of CNs with ND, and in reference to our previous work, we assume that the angular distribution of quasi-specularly reflected CNs is narrower, and that the probability of QSRs of longer wavelength neutrons increases if we increase the characteristic sizes of NDs compared to standard detonation nanodiamonds (DNDs). However, the probability of QSRs of CNs with wavelengths below the cutoff of ~4.12 Å decreases due to diffraction scattering on the ND crystal lattice. We experimentally compared the QSRs of CNs from ~4.3 nm and ~15.0 nm ND. Our qualitative conclusions and numerical estimates can help optimize the parameters of ND for specific practical applications based on the QSRs of CNs.
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Affiliation(s)
- Alexei Bosak
- European Synchrotron Radiation Facility, 71 Av. des Martyrs, F-38043 Grenoble, France
| | - Marc Dubois
- Clermont Auvergne INP, Université Clermont Auvergne, CNRS UMR6296, 24 Av. Blaise Pascal, F-63178 Aubière, France
| | - Ekaterina Korobkina
- Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Egor Lychagin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, Ru-141980 Dubna, Russia
| | - Alexei Muzychka
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, Ru-141980 Dubna, Russia
| | - Grigory Nekhaev
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, Ru-141980 Dubna, Russia
| | - Valery Nesvizhevsky
- Institut Max von Laue—Paul Langevin, 71 Av. des Martyrs, F-38042 Grenoble, France
| | - Alexander Nezvanov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, Ru-141980 Dubna, Russia
| | - Thomas Saerbeck
- Institut Max von Laue—Paul Langevin, 71 Av. des Martyrs, F-38042 Grenoble, France
| | - Ralf Schweins
- Institut Max von Laue—Paul Langevin, 71 Av. des Martyrs, F-38042 Grenoble, France
| | - Alexander Strelkov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, Ru-141980 Dubna, Russia
| | - Kylyshbek Turlybekuly
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, Ru-141980 Dubna, Russia
- Faculty of Physics and Technology, L.N. Gumilyov Eurasian National University, Satpayev Str. 2, Astana 010000, Kazakhstan
- The Institute of Nuclear Physics, Ministry of Energy of the Republic of Kazakhstan, Ibragimova Str. 1, Almaty 0500032, Kazakhstan
| | - Kirill Zhernenkov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, Ru-141980 Dubna, Russia
- JCNS at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungzentrum Jülich GmbH, 1 Lichtenbergstrasse, D-85748 Garching, Germany
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21
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Palinske M, Muza UL, Moreno S, Appelhans D, Boye S, Schweins R, Lederer A. Potential of Small‐Angle Neutron Scattering for Evaluating Protein Locus within a Polymersome. MACROMOL CHEM PHYS 2023. [DOI: 10.1002/macp.202370002] [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: 01/11/2023]
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22
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Galvan Josa VM, Farhi E, Schweins R, Jackson A, Mondelli C. OPUS: an easy way to push the limits of SANS instruments towards USANS. J Appl Crystallogr 2022. [DOI: 10.1107/s1600576722008834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Chemistry and physics have made major advances in recent years, yielding much more complex systems with high hierarchical order across multiple length scales. Accordingly, characterization tools are required that can elucidate the structure of such new materials over all length scales. Simultaneous small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) measurements are a unique tool to study such complexity and can be applied to very different fields of science. The OPUS (Option USANS) project is the study of a USANS option for SANS instruments, designed to be very versatile and easy to implement. The main idea is to provide the opportunity to study at the same time, and under the same experimental conditions, complex systems such as polymers, bio-systems, complex fibres and self-assembling systems. More specifically, this work presents the design of an option that could be applied to the suite of SANS instruments at the European Spallation Source (ESS) which will allow exploration of a Q range with a minimum Q down to one order of magnitude lower than the value attainable with the standard SANS instrument at the ESS. The proposed setup, based on the SAMBA (small-angle multi-beam analysis) approach, is very easy and fast to implement on a conventional SANS instrument and constitutes a multi-beam approach involving two multi-slits and a set of lenses near the sample position. This contribution describes all the focusing elements necessary to attain the proposed configuration and a detailed study using McStas simulations to optimize all the parameters involved for two SANS instruments: the future LoKI at the ESS and the present D11 at the Institut Laue–Langevin, the latter used as a benchmark for the model. Simulations performed without taking into account gravity effects show that the multi-beam approach allows extending the Q ranges to 9 × 10−5–7 × 10−4 Å−1 and 5 × 10−5–3 × 10−4 Å−1 for LoKI and D11, respectively.
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23
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Nickel AC, Denton AR, Houston JE, Schweins R, Plivelic TS, Richtering W, Scotti A. Beyond simple self-healing: How anisotropic nanogels adapt their shape to their environment. J Chem Phys 2022; 157:194901. [DOI: 10.1063/5.0119527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The response of soft colloids to crowding depends sensitively on the particles’ compressibility. Nanogel suspensions provide model systems that are often studied to better understand the properties of soft materials and complex fluids from the formation of colloidal crystals to the flow of viruses, blood, or platelet cells in the body. Large spherical nanogels, when embedded in a matrix of smaller nanogels, have the unique ability to spontaneously deswell to match their size to that of the nanogel composing the matrix. In contrast to hard colloids, this self-healing mechanism allows for crystal formation without giving rise to point defects or dislocations. Here, we show that anisotropic ellipsoidal nanogels adapt both their size and their shape depending on the nature of the particles composing the matrix in which they are embedded. Using small-angle neutron scattering with contrast variation, we show that ellipsoidal nanogels become spherical when embedded in a matrix of spherical nanogels. In contrast, the anisotropy of the ellipsoid is enhanced when they are embedded in a matrix of anisotropic nanogels. Our experimental data are supported by Monte Carlo simulations that reproduce the trend of decreasing aspect ratio of ellipsoidal nanogels with increasing crowding by a matrix of spherical nanogels.
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Affiliation(s)
- Anne C. Nickel
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - Alan R. Denton
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050, USA
| | | | - Ralf Schweins
- Institut Laue-Langevin ILL DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - Tomàs S. Plivelic
- MAX IV Laboratory, Lund University, P.O. Box 118, 22100 Lund, Sweden
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
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24
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Palinske M, Muza UL, Moreno S, Appelhans D, Boye S, Schweins R, Lederer A. The Potential of Small‐Angle Neutron Scattering for Evaluating Protein Locus within a Polymersome. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Max Palinske
- Leibniz‐Institut für Polymerforschung Dresden e.V. Hohe Str. 6 1069 Dresden Germany
- Technische Universität Dresden School of Science 01062 Dresden Germany
| | - Upenyu L. Muza
- Leibniz‐Institut für Polymerforschung Dresden e.V. Hohe Str. 6 1069 Dresden Germany
| | - Silvia Moreno
- Leibniz‐Institut für Polymerforschung Dresden e.V. Hohe Str. 6 1069 Dresden Germany
| | - Dietmar Appelhans
- Leibniz‐Institut für Polymerforschung Dresden e.V. Hohe Str. 6 1069 Dresden Germany
| | - Susanne Boye
- Leibniz‐Institut für Polymerforschung Dresden e.V. Hohe Str. 6 1069 Dresden Germany
| | - Ralf Schweins
- Institut Laue‐Langevin DS / LSS, CS 20 156, 71 Avenue des Martyrs Grenoble 38042 France
| | - Albena Lederer
- Leibniz‐Institut für Polymerforschung Dresden e.V. Hohe Str. 6 1069 Dresden Germany
- Department of Chemistry and Polymer Science Stellenbosch University Private Bag X1 Matieland 7602 South Africa
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25
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Bharatiya B, Wlodek M, Harniman R, Schweins R, Mantell J, Wang G, Warszynski P, Briscoe WH. Solution and interfacial self-assembly of Bacillus subtilis bacterial lipoteichoic acid (LTA): nanoclustering, and effects of Ca 2+ and temperature. Nanoscale 2022; 14:12265-12274. [PMID: 35861484 DOI: 10.1039/d2nr00595f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Lipoteichoic acid (LTA) is a major structural and functional molecule in the Gram-positive bacteria membrane. Knowledge of LTA adsorption at interfaces and its solution self-assembly is crucial to understanding its role in bacterial adhesion and colonisation, infections and inflammations. Here, we report the self-assembly behaviour of LTA extracted from Bacillus subtilis, a Gram-positive bacterium, in an aqueous solution using cryogenic transmission electron microscopy (Cryo-TEM) and small-angle neutron scattering (SANS) and its adsorption behaviour at the solid-liquid interface using atomic force microscopy (AFM) imaging and quartz crystal microbalance with dissipation monitoring (QCM-D). The Cryo-TEM results indicated the formation of spherical LTA micelles that decreased in size on addition of calcium chloride (CaCl2), attributed to charge neutralisation and possible formation of stable Ca2+-bridges between the phosphate groups on neighbouring LTA chains. Analysis of the SANS data from the polydisperse LTA aggregates in solution using the two Lorentzian model revealed the existence of two correlation lengths, which could respectively account for the presence of LTA micelle clusters and the local structure arising from LTA intra-molecular interactions. In the presence of CaCl2, the decrease in the correlation lengths of the clusters indicated possible disruption of H-bonding by Ca2+, leading to poorer water-LTA interactions. At higher temperatures, the correlation length corresponding to the clusters increased, indicating a temperature assisted growth caused by the fluidization of micellar core and dehydration of the polar LTA chains. AFM imaging showed that adsorption of LTA aggregates at the SiO2-water interface was significantly prompted by the addition of CaCl2, also confirmed by QCM-D measurements. These unprecedented nanoscopic structural details on the morphology of LTA aggregates in solution and at the solid-liquid interface add to our fundamental understanding of its self-assembly behaviour hitherto underexplored.
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Affiliation(s)
- Bhavesh Bharatiya
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Magdalena Wlodek
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland
| | - Robert Harniman
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, Grenoble 38000, France
| | - Judith Mantell
- Wolfson Bioimaging Facility, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Gang Wang
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Piotr Warszynski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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26
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Randle R, Fuentes-Caparrós AM, Cavalcanti LP, Schweins R, Adams DJ, Draper ER. Investigating Aggregation Using In Situ Electrochemistry and Small-Angle Neutron Scattering. J Phys Chem C Nanomater Interfaces 2022; 126:13427-13432. [PMID: 35983316 PMCID: PMC9376955 DOI: 10.1021/acs.jpcc.2c03210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Using small-angle neutron scattering to investigate the aggregation of self-assembling molecules is well established. Some of these molecules are electrochemically useful, for example, in electrochromic devices. Electrochemistry can also be used in some cases to induce aggregation. Here, we describe an approach whereby electrochemistry can be directly carried out on a sample in the neutron beam, allowing us to monitor changes directly in situ. We exemplify with two examples but highlight that there are many other potential opportunities.
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Affiliation(s)
| | | | - Leide P. Cavalcanti
- ISIS
Neutron and Muon Source User Office, Science and Technology Facilities
Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, U.K.
| | - Ralf Schweins
- Large
Scale Structures Group, Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9, France
| | - Dave J. Adams
- School
of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K.
| | - Emily R. Draper
- School
of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K.
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27
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Houston JE, Fruhner L, de la Cotte A, Rojo González J, Petrunin AV, Gasser U, Schweins R, Allgaier J, Richtering W, Fernandez-Nieves A, Scotti A. Resolving the different bulk moduli within individual soft nanogels using small-angle neutron scattering. Sci Adv 2022; 8:eabn6129. [PMID: 35776796 PMCID: PMC10883365 DOI: 10.1126/sciadv.abn6129] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The bulk modulus, K, quantifies the elastic response of an object to an isotropic compression. For soft compressible colloids, knowing K is essential to accurately predict the suspension response to crowding. Most colloids have complex architectures characterized by different softness, which additionally depends on compression. Here, we determine the different values of K for the various morphological parts of individual nanogels and probe the changes of K with compression. Our method uses a partially deuterated polymer, which exerts the required isotropic stress, and small-angle neutron scattering with contrast matching to determine the form factor of the particles without any scattering contribution from the polymer. We show a clear difference in softness, compressibility, and evolution of K between the shell of the nanogel and the rest of the particle, depending on the amount of cross-linker used in their synthesis.
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Affiliation(s)
| | - Lisa Fruhner
- Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science (JCNS-1) and Institute for Biological Information Processing (IBI-8), 52425 Jülich, Germany
| | - Alexis de la Cotte
- Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain
| | - Javier Rojo González
- Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain
| | | | - Urs Gasser
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Ralf Schweins
- Institut Laue-Langevin ILL DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - Jürgen Allgaier
- Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science (JCNS-1) and Institute for Biological Information Processing (IBI-8), 52425 Jülich, Germany
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
- JARA-SOFT, 52056 Aachen, Germany
| | - Alberto Fernandez-Nieves
- Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain
- ICREA-Institucio Catalana de Recerca i Estudis Avancats, 08010 Barcelona, Spain
| | - Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
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Prause A, Hechenbichler M, von Lospichl B, Feoktystov A, Schweins R, Mahmoudi N, Laschewsky A, Gradzielski M. Aggregation Behavior of Nonsymmetrically End-Capped Thermoresponsive Block Copolymers in Aqueous Solutions: Between Polymer Coils and Micellar States. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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)
- Albert Prause
- FG Physical Chemistry/Molecular Material Science, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Michelle Hechenbichler
- Department of Chemistry, Universität Potsdam, Karl-Liebknecht-Straße 24−25, 14476 Potsdam, Germany
| | - Benjamin von Lospichl
- FG Physical Chemistry/Molecular Material Science, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Artem Feoktystov
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, 85748 Garching, Germany
| | - Ralf Schweins
- Institut Laue−Langevin, DS/LSS, 71 Avenue des Martyrs, CS 20 156, F-38042 Grenoble Cedex 9, France
| | - Najet Mahmoudi
- ISIS Facility, STFC, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, U.K
| | - André Laschewsky
- Department of Chemistry, Universität Potsdam, Karl-Liebknecht-Straße 24−25, 14476 Potsdam, Germany
- Fraunhofer Institute of Applied Polymer Research IAP, Geiselbergstraße 69, 14476 Potsdam, Germany
| | - Michael Gradzielski
- FG Physical Chemistry/Molecular Material Science, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
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29
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Meyer G, Schweins R, Youngs T, Dufrêche JF, Billard I, Plazanet M. How Temperature Rise Can Induce Phase Separation in Aqueous Biphasic Solutions. J Phys Chem Lett 2022; 13:2731-2736. [PMID: 35312328 DOI: 10.1021/acs.jpclett.2c00146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ionic-liquid-based acidic aqueous biphasic solutions (AcABSs) recently offered a breakthrough in the field of metal recycling. The particular mixture of tributyltetradecylphosphonium chloride ([P4,4,4,14]Cl), acid, and water presents the unusual characteristic of a lower solution critical temperature (LCST), leading to phase separation upon a temperature rise of typically a few tens of degrees. We address here the microscopic mechanisms driving the phase separation. Using small-angle neutron scattering, we characterized the spherical micelle formation in a binary ionic liquid/water solution and the micelle aggregation upon the addition of acid due to the screening of electrostatic repulsion. The increase in both the acid concentration and the temperature eventually leads to micelle flocculation and phase separation. This last step is achieved through chloride ion adsorption at the surface of the micelle. This exothermic adsorption compensates for the entropic cost, leading to a counterintuitive behavior, and may be generalized to a number of molecular systems with an LCST.
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Affiliation(s)
- Gautier Meyer
- Université Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
| | | | - Tristan Youngs
- ISIS Pulsed Neutron and Muon Source STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, United Kingdom
| | - Jean-François Dufrêche
- Institut de Chimie Séparative de Marcoule. UMR 5257 CEA/CNRS/ENSCM/Université Montpellier, Site de Marcoule, Bâtiment 426 BP 17171, 30207 Bagnols-sur-Cèze Cedex, France
| | - Isabelle Billard
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, Grenoble INP, LEPMI, 1130 rue de la Piscine, 38402 Saint Martin d'Héres, France
| | - Marie Plazanet
- Université Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
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30
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Hu X, Gong H, Liu H, Wang X, Wang W, Liao M, Li Z, Ma K, Li P, Rogers S, Schweins R, Liu X, Padia F, Bell G, Lu JR. Contrasting impacts of mixed nonionic surfactant micelles on plant growth in the delivery of fungicide and herbicide. J Colloid Interface Sci 2022; 618:78-87. [PMID: 35334364 DOI: 10.1016/j.jcis.2022.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/13/2022] [Accepted: 03/01/2022] [Indexed: 10/18/2022]
Abstract
HYPOTHESIS Nonionic alkyl ethoxylate surfactants are widely used in agrochemicals to facilitate the permeation of systemic herbicides and fungicides across the plant waxy film. Industrial grade surfactants are often highly mixed and how the mixing affects their interactions with pesticides and wax films remains largely unexplored. A better understanding could enable design of mixed nonionic surfactants for herbicides and fungicides to maximize their efficiency and reduce wastage whilst controlling their impact on plant wax films. EXPERIMENT In this study, nonionic surfactants with general structure n-oxyethylene glycol monododecyl ether (C12En) were used to form surfactant mixtures with the same average ethoxylate numbers but different hydrophilic-lipophilic balance (HLB) values. Their mixed micellar systems were then used to solubilize a herbicide diuron (DN) and a fungicide cyprodinil (CP), followed by plant wax solubilization upon contact with wax films. These processes were monitored by 1H NMR and SANS. FINDING Pesticide solubilization made surfactant micelles effectively more hydrophobic but subsequent wax dissolution caused pesticide release and the restoration of the micellar amphiphilicity. Nonionic surfactants with lower HLBs form larger nanoaggregates, show enhanced wettability, and have better ability to solubilize and permeate pesticides across the wax film, but may cause significant damage to plant growth. These observations help explain why herbicides applied on weeds would benefit from surfactants with lower HLB values while fungicides require surfactants with HLBs to balance between delivery efficiency and potential phytotoxicity risks.
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Affiliation(s)
- Xuzhi Hu
- Biological Physics Group, Department of Physics and Astronomy, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Haoning Gong
- Biological Physics Group, Department of Physics and Astronomy, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Huayang Liu
- Biological Physics Group, Department of Physics and Astronomy, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Xi Wang
- Department of Materials, School of Natural Sciences, the University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Weimiao Wang
- Department of Materials, School of Natural Sciences, the University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Mingrui Liao
- Biological Physics Group, Department of Physics and Astronomy, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Zongyi Li
- Biological Physics Group, Department of Physics and Astronomy, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Kun Ma
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - Peixun Li
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - Sarah Rogers
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - Ralf Schweins
- Large Scale Structures Group, Institut Laue-Langevin, CS 20 156, 38042 Grenoble CEDEX 9, France
| | - Xuqing Liu
- Department of Materials, School of Natural Sciences, the University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Faheem Padia
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Gordon Bell
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Jian R Lu
- Biological Physics Group, Department of Physics and Astronomy, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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31
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Zhang J, Gong H, Liao M, Li Z, Schweins R, Penny J, Lu JR. How do terminal modifications of short designed IIKK peptide amphiphiles affect their antifungal activity and biocompatibility? J Colloid Interface Sci 2022; 608:193-206. [PMID: 34626966 DOI: 10.1016/j.jcis.2021.09.170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/31/2021] [Accepted: 09/26/2021] [Indexed: 12/15/2022]
Abstract
HYPOTHESIS The widespread and prolonged use of antifungal antibiotics has led to the rapid emergence of multidrug resistant Candida species that compromise current treatments. Natural and synthetic antimicrobial peptides (AMPs) offer potential alternatives but require further development to overcome some of their current drawbacks. AMPs kill pathogenic fungi by permeabilising their membranes but it remains unclear how AMPs can be designed to maximise their antifungal potency whilst minimising their toxicity to host cells. EXPERIMENTS We have designed a group of short (IIKK)3 AMPs via selective terminal modifications ending up with different amphiphilicities. Their antifungal performance was assessed by minimum inhibition concentration (MICs) and dynamic killing to 4 Candida strains and Cryptococcus neoformans, and the minimum biofilm-eradicating concentrations to kill 95% of the C. albicans biofilms (BEC95). Different antifungal actions were interpreted on the basis of structural disruptions of the AMPs to small unilamellar vesicles from fluorescence leakage, Zeta potential, small angle neutron scattering (SANS) and molecular dynamics simulations (MD). FINDING AMPs possess high antifungal activities against the Candida species and Cryptococcus neoformans; some of them displayed faster dynamic killing than antibiotics like amphotericin B. G(IIKK)3I-NH2 and (IIKK)3II-NH2 were particularly potent against not only planktonic microbes but also fungal biofilms with low cytotoxicity to host cells. It was found that their high selectivity and fast action were well correlated to their fast membrane lysis, evident from data measured from Zeta potential measurements, SANS and MD, and also consistent with the previously observed antibacterial and anticancer performance. These studies demonstrate the important role of colloid and interface science in further developing short, potent and biocompatible AMPs towards clinical treatments via structure design and optimization.
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Affiliation(s)
- Jing Zhang
- Biological Physics Laboratory, School of Physics and Astronomy, Faculty of Science and Engineering, Oxford Road, The University of Manchester, Manchester M13 9PL, UK
| | - Haoning Gong
- Biological Physics Laboratory, School of Physics and Astronomy, Faculty of Science and Engineering, Oxford Road, The University of Manchester, Manchester M13 9PL, UK
| | - Mingrui Liao
- Biological Physics Laboratory, School of Physics and Astronomy, Faculty of Science and Engineering, Oxford Road, The University of Manchester, Manchester M13 9PL, UK
| | - Zongyi Li
- Biological Physics Laboratory, School of Physics and Astronomy, Faculty of Science and Engineering, Oxford Road, The University of Manchester, Manchester M13 9PL, UK
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, CS-20156, 38042 Grenoble, France
| | - Jeffrey Penny
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, Oxford Road, The University of Manchester, Manchester M13 9PL, UK
| | - Jian R Lu
- Biological Physics Laboratory, School of Physics and Astronomy, Faculty of Science and Engineering, Oxford Road, The University of Manchester, Manchester M13 9PL, UK.
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32
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Liu H, Fa K, Hu X, Li Z, Ma K, Liao M, Zhang L, Schweins R, Maestro A, Li P, Webster JRP, Petkov J, Thomas RK, Lu JR. How do chain lengths of acyl-l-carnitines affect their surface adsorption and solution aggregation? J Colloid Interface Sci 2021; 609:491-502. [PMID: 34863541 DOI: 10.1016/j.jcis.2021.11.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS l-carnitines in our body systems can be readily converted into acyl-l-carnitines which have a prominent place in cellular energy generation by supporting the transport of long-chain fatty acids into mitochondria. As biocompatible surfactants, acyl-l-carnitines have potential to be useful in technical, personal care and healthcare applications. However, the lack of understanding of the effects of their molecular structures on their physical properties has constrained their potential use. EXPERIMENTS This work reports the study of the influence of the acyl chain lengths of acyl-l-carnitines (CnLC) on solubility, surface adsorption and aggregation. Critical micellar concentrations (CMCs) of CnLC were determined by surface tension measurements. Neutron reflection (NR) was used to further examine the structure and composition of the adsorbed CnLC layer. The structural changes of the micellar aggregates under different concentrations of CnLC, pH and ionic strength were determined by dynamic light scattering (DLS) and small angle neutron scattering (SANS). FINDINGS C12LC is fully soluble over a wide temperature and concentration range. There is however a strong decline of solubility with increasing acyl chain length. The adsorption and aggregation behavior of C14LC was therefore studied at 30 °C and C16LC at 45 °C. The solubility boundaries displayed distinct hysteresis with respect to heating and cooling. The CMCs of C12LC, C14LC and C16LC at pH 7 were 1.1 ± 0.1, 0.10 ± 0.02 and 0.010 ± 0.005 mM, respectively, with the limiting values of the area per molecule at the CMC being 45.4 ± 2, 47.5 ± 2 and 48.8 ± 2 Å2 and the thicknesses of the adsorbed CnLC layers at the air/water interface increasing from 21.5 ± 2 to 22.6 ± 2 to 24.2 ± 2 Å, respectively. All three surfactants formed core-shell spherical micelles with comparable dimensional parameters apart from an increase in core radius with acyl chain length. This study outlines the effects of acyl chain length on the physicochemical properties of CnLCs under different environmental conditions, serving as a useful basis for developing their potential applications.
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Affiliation(s)
- Huayang Liu
- Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Ke Fa
- Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Xuzhi Hu
- Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Zongyi Li
- Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Kun Ma
- ISIS Neutron Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - Mingrui Liao
- Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Lin Zhang
- Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Ralf Schweins
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9, France
| | - Armando Maestro
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9, France
| | - Peixun Li
- ISIS Neutron Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - John R P Webster
- ISIS Neutron Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - Jordan Petkov
- Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK; Arxada, Hexagon Tower, Delaunays Road, Blackley, Manchester M9 8ZS, UK.
| | - Robert K Thomas
- Physical and Theoretical Chemistry, University of Oxford, South Parks, Oxford OX1 3QZ, UK
| | - Jian Ren Lu
- Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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33
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Affiliation(s)
- Carlos G. Lopez
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, Aachen 52056, Germany
| | - Ferenc Horkay
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 13 South Drive, Bethesda, Maryland 20892, United States
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, CS 20156, Grenoble Cedex 9 38042, France
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, Aachen 52056, Germany
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34
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Aleksenskii A, Bleuel M, Bosak A, Chumakova A, Dideikin A, Dubois M, Korobkina E, Lychagin E, Muzychka A, Nekhaev G, Nesvizhevsky V, Nezvanov A, Schweins R, Shvidchenko A, Strelkov A, Turlybekuly K, Vul’ A, Zhernenkov K. Effect of Particle Sizes on the Efficiency of Fluorinated Nanodiamond Neutron Reflectors. Nanomaterials (Basel) 2021; 11:nano11113067. [PMID: 34835831 PMCID: PMC8620422 DOI: 10.3390/nano11113067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/04/2021] [Accepted: 11/11/2021] [Indexed: 11/25/2022]
Abstract
Over a decade ago, it was confirmed that detonation nanodiamond (DND) powders reflect very cold neutrons (VCNs) diffusively at any incidence angle and that they reflect cold neutrons quasi-specularly at small incidence angles. In the present publication, we report the results of a study on the effect of particle sizes on the overall efficiency of neutron reflectors made of DNDs. To perform this study, we separated, by centrifugation, the fraction of finer DND nanoparticles (which are referred to as S-DNDs here) from a broad initial size distribution and experimentally and theoretically compared the performance of such a neutron reflector with that from deagglomerated fluorinated DNDs (DF-DNDs). Typical commercially available DNDs with the size of ~4.3 nm are close to the optimum for VCNs with a typical velocity of ~50 m/s, while smaller and larger DNDs are more efficient for faster and slower VCN velocities, respectively. Simulations show that, for a realistic reflector geometry, the replacement of DF-DNDs (a reflector with the best achieved performance) by S-DNDs (with smaller size DNDs) increases the neutron albedo in the velocity range above ~60 m/s. This increase in the albedo results in an increase in the density of faster VCNs in such a reflector cavity of up to ~25% as well as an increase in the upper boundary of the velocities of efficient VCN reflection.
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Affiliation(s)
- Aleksander Aleksenskii
- Laboratory of Physics for Cluster Structures, Ioffe Institute, Polytechnicheskaya Str. 26, 194021 St. Petersburg, Russia; (A.A.); (A.D.); (A.S.); (A.V.)
| | - Marcus Bleuel
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, MD 20899, USA;
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - Alexei Bosak
- European Synchrotron Radiation Facility, 71 av. des Martyrs, F-38042 Grenoble, France; (A.B.); (A.C.)
| | - Alexandra Chumakova
- European Synchrotron Radiation Facility, 71 av. des Martyrs, F-38042 Grenoble, France; (A.B.); (A.C.)
| | - Artur Dideikin
- Laboratory of Physics for Cluster Structures, Ioffe Institute, Polytechnicheskaya Str. 26, 194021 St. Petersburg, Russia; (A.A.); (A.D.); (A.S.); (A.V.)
| | - Marc Dubois
- Institut de Chimie de Clermont-Ferrand (ICCF UME 6296), Université Clermont Auvergne, CNRS, 24 av. Blaise Pascal, F-63178 Aubière, France;
| | - Ekaterina Korobkina
- Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695, USA;
| | - Egor Lychagin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, 141980 Dubna, Russia; (E.L.); (A.M.); (G.N.); (A.N.); (A.S.); (K.T.); (K.Z.)
- Faculty of Physics, Lomonosov Moscow State University, GSP-1, Leninskie Gory, 119991 Moscow, Russia
- Department of Nuclear Physics, Dubna State University, Universitetskaya 19, 141982 Dubna, Russia
| | - Alexei Muzychka
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, 141980 Dubna, Russia; (E.L.); (A.M.); (G.N.); (A.N.); (A.S.); (K.T.); (K.Z.)
| | - Grigory Nekhaev
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, 141980 Dubna, Russia; (E.L.); (A.M.); (G.N.); (A.N.); (A.S.); (K.T.); (K.Z.)
| | - Valery Nesvizhevsky
- Institut Max von Laue–Paul Langevin, 71 av. des Martyrs, F-38042 Grenoble, France;
- Correspondence:
| | - Alexander Nezvanov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, 141980 Dubna, Russia; (E.L.); (A.M.); (G.N.); (A.N.); (A.S.); (K.T.); (K.Z.)
| | - Ralf Schweins
- Institut Max von Laue–Paul Langevin, 71 av. des Martyrs, F-38042 Grenoble, France;
| | - Alexander Shvidchenko
- Laboratory of Physics for Cluster Structures, Ioffe Institute, Polytechnicheskaya Str. 26, 194021 St. Petersburg, Russia; (A.A.); (A.D.); (A.S.); (A.V.)
| | - Alexander Strelkov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, 141980 Dubna, Russia; (E.L.); (A.M.); (G.N.); (A.N.); (A.S.); (K.T.); (K.Z.)
| | - Kylyshbek Turlybekuly
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, 141980 Dubna, Russia; (E.L.); (A.M.); (G.N.); (A.N.); (A.S.); (K.T.); (K.Z.)
- Faculty of Physics and Technology, L.N. Gumilyov Eurasian National University, Satpayev Str. 2, Nur-Sultan 010000, Kazakhstan
- The Institute of Nuclear Physics, Ministry of Energy of the Republic of Kazakhstan, Ibragimova Str. 1, Almaty 050032, Kazakhstan
| | - Alexander Vul’
- Laboratory of Physics for Cluster Structures, Ioffe Institute, Polytechnicheskaya Str. 26, 194021 St. Petersburg, Russia; (A.A.); (A.D.); (A.S.); (A.V.)
| | - Kirill Zhernenkov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot Curie, 141980 Dubna, Russia; (E.L.); (A.M.); (G.N.); (A.N.); (A.S.); (K.T.); (K.Z.)
- JCNS at Heinz Maier-Leibnitz Zentrum (MLZ), Forshungzentrum Julich GmbH, 1 Lichtenbergstrasse, G-85748 Garching, Germany
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Fernandez Bordín SP, Andrada HE, Carreras AC, Castellano G, Schweins R, Cuello GJ, Mondelli C, Galván Josa VM. Water channel structure of alternative perfluorosulfonic acid membranes for fuel cells. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119559] [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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Marshall LJ, Matsarskaia O, Schweins R, Adams DJ. Enhancement of the mechanical properties of lysine-containing peptide-based supramolecular hydrogels by chemical cross-linking. Soft Matter 2021; 17:8459-8464. [PMID: 34494056 DOI: 10.1039/d1sm01136g] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Exposure of lysine-containing peptide-based gelators to the cross-linking agent glutaraldehyde allows tuning of gel mechanical properties. The effect of cross-linking depends on the position of the lysine residue in the peptide chain, the concentration of gelator and the conditions under which cross-linking takes place. Through control of these factors, cross-linking leads to increased gel strength.
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Affiliation(s)
- Libby J Marshall
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Olga Matsarskaia
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - Ralf Schweins
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - Dave J Adams
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
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37
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Genix AC, Bocharova V, Carroll B, Dieudonné-George P, Sztucki M, Schweins R, Sokolov AP, Oberdisse J. Direct Structural Evidence for Interfacial Gradients in Asymmetric Polymer Nanocomposite Blends. ACS Appl Mater Interfaces 2021; 13:36262-36274. [PMID: 34291639 DOI: 10.1021/acsami.1c06971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Understanding the complex structure of polymer blends filled with nanoparticles (NPs) is key to design their macroscopic properties. Here, the spatial distribution of hydrogenated (H) and deuterated (D) polymer chains asymmetric in mass is studied by small-angle neutron scattering. Depending on the chain mass, a qualitatively new large-scale organization of poly(vinyl acetate) chains beyond the random-phase approximation is evidenced in nanocomposites with attractive polymer-silica interactions. The silica is found to systematically induce bulk segregation. Only with long H-chains, a strong scattering signature is observed in the q range of the NP size: it is the sign of interfacial isotopic enrichment, that is, of contrasted polymer shells close to the NP surface. A quantitative model describing both the bulk segregation and the interfacial gradient (over ca. 10-20 nm depending on the NP size) is developed, showing that both are of comparable strength. In all cases, NP surfaces trap the polymer blend in a non-equilibrium state, with preferential adsorption around NPs only if the chain length and isotopic preference toward the surface combine their entropic and enthalpic driving forces. This structural evidence for interfacial polymer gradients will open the road for quantitative understanding of the dynamics of many-chain nanocomposite systems.
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Affiliation(s)
- Anne-Caroline Genix
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, F-34095 Montpellier, France
| | - Vera Bocharova
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Bobby Carroll
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | | | - Michael Sztucki
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble Cedex 9, France
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9, France
| | - Alexei P Sokolov
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Julian Oberdisse
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, F-34095 Montpellier, France
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38
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Giuri D, Marshall LJ, Dietrich B, McDowall D, Thomson L, Newton JY, Wilson C, Schweins R, Adams DJ. Exploiting and controlling gel-to-crystal transitions in multicomponent supramolecular gels. Chem Sci 2021; 12:9720-9725. [PMID: 34349943 PMCID: PMC8293982 DOI: 10.1039/d1sc02347k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/11/2021] [Indexed: 12/31/2022] Open
Abstract
Multicomponent supramolecular gels provide opportunities to form materials that are not accessible when using the single components alone. Different scenarios are possible when mixing multiple components, from complete co-assembly (mixing of the components within the self-assembled structures formed) to complete self-sorting such that each structure contains only one of the components. Most examples of multicomponent gels that currently exist form stable gels. Here, we show that this can be used to control the mechanical properties of the gels, but what is probably most exciting is that we show that we can use a magnetic field to control the shape of the crystals. The gelling component aligns in a magnetic field and so results in anisotropic crystals being formed.
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Affiliation(s)
- Demetra Giuri
- Dipartimento di Chimica Giacomo Ciamician, Alma Mater Studiorum, Università di Bologna Via Selmi, 2 40126 Bologna Italy
| | | | - Bart Dietrich
- School of Chemistry, University of Glasgow Glasgow G12 8QQ UK
| | - Daniel McDowall
- School of Chemistry, University of Glasgow Glasgow G12 8QQ UK
| | - Lisa Thomson
- School of Chemistry, University of Glasgow Glasgow G12 8QQ UK
| | - Jenny Y Newton
- School of Chemistry, University of Glasgow Glasgow G12 8QQ UK
| | - Claire Wilson
- School of Chemistry, University of Glasgow Glasgow G12 8QQ UK
| | - Ralf Schweins
- Large Scale Structures Group, Institut Laue-Langevin 71 Avenue des Martyrs, CS 20156 F-38042 Grenoble CEDEX 9 France
| | - Dave J Adams
- School of Chemistry, University of Glasgow Glasgow G12 8QQ UK
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39
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Turkin A, Holzapfel M, Agarwal M, Fischermeier D, Mitric R, Schweins R, Gröhn F, Lambert C. Solvent Induced Helix Folding of Defined Indolenine Squaraine Oligomers. Chemistry 2021; 27:8380-8389. [PMID: 33871113 PMCID: PMC8251825 DOI: 10.1002/chem.202101063] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Indexed: 01/01/2023]
Abstract
A protecting group strategy was employed to synthesise a series of indolenine squaraine dye oligomers up to the nonamer. The longer oligomers show a distinct solvent dependence of the absorption spectra, that is, either a strong blue shift or a strong red shift of the lowest energy bands in the near infrared spectral region. This behaviour is explained by exciton coupling theory as being due to H- or J-type coupling of transition moments. The H-type coupling is a consequence of a helix folding in solvents with a small Hansen dispersity index. DOSY NMR, small angle neutron scattering (SANS), quantum chemical and force field calculations agree upon a helix structure with an unusually large pitch and open voids that are filled with solvent molecules, thereby forming a kind of clathrate. The thermodynamic parameters of the folding process were determined by temperature dependent optical absorption spectra.
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Affiliation(s)
- Arthur Turkin
- Institut für Organische ChemieUniversität WürzburgAm Hubland97074WürzburgGermany
| | - Marco Holzapfel
- Institut für Organische ChemieUniversität WürzburgAm Hubland97074WürzburgGermany
| | - Mohit Agarwal
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM) and Bavarian Polymer Institute (BPI)University of Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
- Institut Max von Laue - Paul Langevin (ILL), DS / LSS71, Avenue des Martyrs - CS 2015638042Grenoble Cedex 9France
| | - David Fischermeier
- Institut für Physikalische und Theoretische ChemieUniversität WürzburgAm Hubland97074WürzburgGermany
| | - Roland Mitric
- Institut für Physikalische und Theoretische ChemieUniversität WürzburgAm Hubland97074WürzburgGermany
- Center for Nanosystems ChemistryUniversität WürzburgAm Hubland97074WürzburgGermany
| | - Ralf Schweins
- Institut Max von Laue - Paul Langevin (ILL), DS / LSS71, Avenue des Martyrs - CS 2015638042Grenoble Cedex 9France
| | - Franziska Gröhn
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM) and Bavarian Polymer Institute (BPI)University of Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Christoph Lambert
- Institut für Organische ChemieUniversität WürzburgAm Hubland97074WürzburgGermany
- Center for Nanosystems ChemistryUniversität WürzburgAm Hubland97074WürzburgGermany
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Hanio S, Schlauersbach J, Lenz B, Spiegel F, Böckmann RA, Schweins R, Nischang I, Schubert US, Endres S, Pöppler AC, Brandl FP, Smit TM, Kolter K, Meinel L. Drug-Induced Dynamics of Bile Colloids. Langmuir 2021; 37:2543-2551. [PMID: 33587852 DOI: 10.1021/acs.langmuir.0c02282] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Bile colloids containing taurocholate and lecithin are essential for the solubilization of hydrophobic molecules including poorly water-soluble drugs such as Perphenazine. We detail the impact of Perphenazine concentrations on taurocholate/lecithin colloids using analytical ultracentrifugation, dynamic light scattering, small-angle neutron scattering, nuclear magnetic resonance spectroscopy, coarse-grained molecular dynamics simulations, and isothermal titration calorimetry. Perphenazine impacted colloidal molecular arrangement, structure, and binding thermodynamics in a concentration-dependent manner. At low concentration, Perphenazine was integrated into stable and large taurocholate/lecithin colloids and close to lecithin. Integration of Perphenazine into these colloids was exothermic. At higher Perphenazine concentration, the taurocholate/lecithin colloids had an approximately 5-fold reduction in apparent hydrodynamic size, heat release was less exothermic upon drug integration into the colloids, and Perphenazine interacted with both lecithin and taurocholate. In addition, Perphenazine induced a morphological transition from vesicles to wormlike micelles as indicated by neutron scattering. Despite these surprising colloidal dynamics, these natural colloids successfully ensured stable relative amounts of free Perphenazine throughout the entire drug concentration range tested here. Future studies are required to further detail these findings both on a molecular structural basis and in terms of in vivo relevance.
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Affiliation(s)
- Simon Hanio
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany
| | - Jonas Schlauersbach
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany
| | - Bettina Lenz
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany
| | - Franziska Spiegel
- Computational Biology, Friedrich Alexander-University Erlangen-Nürnberg, Staudtstrasse 5, 91057 Erlangen, Germany
| | - Rainer A Böckmann
- Computational Biology, Friedrich Alexander-University Erlangen-Nürnberg, Staudtstrasse 5, 91057 Erlangen, Germany
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, CS 20 156, 38042 Grenoble, CEDEX 9, France
| | - Ivo Nischang
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Ulrich S Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Sebastian Endres
- Institute of Organic Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg Germany
| | - Ann-Christin Pöppler
- Institute of Organic Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg Germany
| | | | - Theo M Smit
- BASF SE, R&D Pharma Ingredients, 67063 Ludwigshafen, Germany
| | - Karl Kolter
- BASF SE, R&D Pharma Ingredients, 67063 Ludwigshafen, Germany
| | - Lorenz Meinel
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany
- Helmholtz Institute for RNA-based Infection Research (HIRI), Josef-Schneider-Strasse 2, 97080 Wuerzburg, Germany
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Hayward DW, Magro G, Hörmann A, Prévost S, Schweins R, Richardson RM, Gradzielski M. A temperature-controlled electric field sample environment for small-angle neutron scattering experiments. Rev Sci Instrum 2021; 92:033903. [PMID: 33820030 DOI: 10.1063/5.0040675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
A new sample environment is introduced for the study of soft matter samples in electric fields using small-angle neutron scattering instruments. The sample environment is temperature controlled and features external electrodes, allowing standard quartz cuvettes to be used and conducting samples or samples containing ions to be investigated without the risk of electrochemical reactions occurring at the electrodes. For standard 12.5 mm quartz cuvettes, the maximum applied field is 8 kV/cm, and the applied field may be static or alternating (up to 10 kHz for 8 kV/cm and up to 60 kHz for 4 kV/cm). The electric fields within the sample are calculated and simulated under a number of different conditions, and the capabilities of the setup are demonstrated using a variety of liquid crystalline samples. Measurements were performed as a function of temperature and time spent in the electric field. Finally, the advantages, drawbacks, and potential optimization of the sample environment are discussed with reference to applications in the fields of complex soft matter, biology, and electrorheology.
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Affiliation(s)
- Dominic W Hayward
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straβe des 17. Juni 124, D-10623 Berlin, Germany
| | - Germinal Magro
- School of Physics, University of Bristol, Tyndall Avenue, BS8 1TL Bristol, United Kingdom
| | - Anja Hörmann
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straβe des 17. Juni 124, D-10623 Berlin, Germany
| | - Sylvain Prévost
- Institut Laue-Langevin, 71 Avenue des Martyrs, F-38042 Grenoble Cedex 9, France
| | - Ralf Schweins
- Institut Laue-Langevin, 71 Avenue des Martyrs, F-38042 Grenoble Cedex 9, France
| | - Robert M Richardson
- School of Physics, University of Bristol, Tyndall Avenue, BS8 1TL Bristol, United Kingdom
| | - Michael Gradzielski
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straβe des 17. Juni 124, D-10623 Berlin, Germany
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Cross ER, Coulter SM, Fuentes-Caparrós AM, McAulay K, Schweins R, Laverty G, Adams DJ. Tuning the antimicrobial activity of low molecular weight hydrogels using dopamine autoxidation. Chem Commun (Camb) 2021; 56:8135-8138. [PMID: 32691773 DOI: 10.1039/d0cc02569k] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We present a method to trigger the formation of dipeptide-based hydrogels by the simple addition of dopamine. Dopamine undergoes oxidation in air, reducing the pH to induce gelation. The production of polydopamine and release of reactive oxygen species such as hydrogen peroxide confers antimicrobial activity. Gel stiffness can be controlled by modulating the initial starting pH of the gelator solution. We can use this method to tune the antimicrobial activity of the gels, with gels that are less stiff demonstrating increased bactericidal efficacy against Gram-positive bacteria.
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Affiliation(s)
- Emily R Cross
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Sophie M Coulter
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, BT9 7BL, Northern Ireland, UK.
| | | | - Kate McAulay
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Ralf Schweins
- Large Scale Structures Group, Institut Laue - Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - Garry Laverty
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, BT9 7BL, Northern Ireland, UK.
| | - Dave J Adams
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
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Scotti A, Denton AR, Brugnoni M, Schweins R, Richtering W. Absence of crystals in the phase behavior of hollow microgels. Phys Rev E 2021; 103:022612. [PMID: 33736081 DOI: 10.1103/physreve.103.022612] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 01/29/2021] [Indexed: 05/20/2023]
Abstract
Solutions of microgels have been widely used as model systems to gain insight into atomic condensed matter and complex fluids. We explore the thermodynamic phase behavior of hollow microgels, which are distinguished from conventional colloids by a central cavity. Small-angle neutron and x-ray scattering are used to probe hollow microgels in crowded environments. These measurements reveal an interplay among deswelling, interpenetration, and faceting and an unusual absence of crystals. Monte Carlo simulations of model systems confirm that, due to the cavity, solutions of hollow microgels more readily form a supercooled liquid than for microgels with a cross-linked core.
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Affiliation(s)
- A Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - A R Denton
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 USA
| | - M Brugnoni
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - R Schweins
- Institut Laue-Langevin ILL DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - W Richtering
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
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Abstract
Herein we report on the synthesis and characterisation of a water soluble deep blue naphthalene diimide, (iPrNH)2NDI–V.
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Affiliation(s)
| | - Olga Matsarskaia
- Institut Laue-Langevin
- Large Scale Structures Group
- F-38042 Grenoble CEDEX 9
- France
| | - Ralf Schweins
- Institut Laue-Langevin
- Large Scale Structures Group
- F-38042 Grenoble CEDEX 9
- France
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45
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Larsson J, Sanchez-Fernandez A, Leung AE, Schweins R, Wu B, Nylander T, Ulvenlund S, Wahlgren M. Molecular structure of maltoside surfactants controls micelle formation and rheological behavior. J Colloid Interface Sci 2021; 581:895-904. [DOI: 10.1016/j.jcis.2020.08.116] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 12/11/2022]
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Penttilä PA, Altgen M, Awais M, Österberg M, Rautkari L, Schweins R. Bundling of cellulose microfibrils in native and polyethylene glycol-containing wood cell walls revealed by small-angle neutron scattering. Sci Rep 2020; 10:20844. [PMID: 33257738 PMCID: PMC7705696 DOI: 10.1038/s41598-020-77755-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 11/17/2020] [Indexed: 12/02/2022] Open
Abstract
Wood and other plant-based resources provide abundant, renewable raw materials for a variety of applications. Nevertheless, their utilization would greatly benefit from more efficient and accurate methods to characterize the detailed nanoscale architecture of plant cell walls. Non-invasive techniques such as neutron and X-ray scattering hold a promise for elucidating the hierarchical cell wall structure and any changes in its morphology, but their use is hindered by challenges in interpreting the experimental data. We used small-angle neutron scattering in combination with contrast variation by poly(ethylene glycol) (PEG) to identify the scattering contribution from cellulose microfibril bundles in native wood cell walls. Using this method, mean diameters for the microfibril bundles from 12 to 19 nm were determined, without the necessity of cutting, drying or freezing the cell wall. The packing distance of the individual microfibrils inside the bundles can be obtained from the same data. This finding opens up possibilities for further utilization of small-angle scattering in characterizing the plant cell wall nanostructure and its response to chemical, physical and biological modifications or even in situ treatments. Moreover, our results give new insights into the interaction between PEG and the wood nanostructure, which may be helpful for preservation of archaeological woods.
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Affiliation(s)
- Paavo A Penttilä
- Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076, Aalto, Finland.
- Large-Scale Structures Group, Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, 38042, Grenoble, France.
| | - Michael Altgen
- Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076, Aalto, Finland
| | - Muhammad Awais
- Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076, Aalto, Finland
| | - Monika Österberg
- Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076, Aalto, Finland
| | - Lauri Rautkari
- Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076, Aalto, Finland
| | - Ralf Schweins
- Large-Scale Structures Group, Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, 38042, Grenoble, France
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Scotti A, Houston JE, Brugnoni M, Schmidt MM, Schulte MF, Bochenek S, Schweins R, Feoktystov A, Radulescu A, Richtering W. Phase behavior of ultrasoft spheres show stable bcc lattices. Phys Rev E 2020; 102:052602. [PMID: 33327194 DOI: 10.1103/physreve.102.052602] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/01/2020] [Indexed: 06/12/2023]
Abstract
The phase behavior of supersoft spheres is explored using solutions of ultralow cross-linked poly(N-isopropylacrylamide)-based microgels as a model system. For these microgels, the effects of the electric charges on their surfaces can be neglected and therefore only the role of softness on the phase behavior is investigated. The samples show a liquid-to-crystal transition at higher volume fraction with respect to both hard spheres and stiffer microgels. Furthermore, stable body centered cubic (bcc) crystals are observed in addition to the expected face centered cubic (fcc) crystals. Small-angle x-ray and neutron scattering with contrast variation allow the characterization of both the microgel-to-microgel distance and the architecture of single microgels in crowded solutions. The measurements reveal that the stable bcc crystals depend on the interplay between the collapse and the interpenetration of the external shell of the ultralow cross-linked microgels.
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Affiliation(s)
- A Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - J E Houston
- European Spallation Source ERIC, Box 176, SE-221 00 Lund, Sweden
| | - M Brugnoni
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - M M Schmidt
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - M F Schulte
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - S Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - R Schweins
- Institut Laue-Langevin ILL DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - A Feoktystov
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS at Heinz Maier-Leibnitz Zentrum MLZ, 85748 Garching, Germany
| | - A Radulescu
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS at Heinz Maier-Leibnitz Zentrum MLZ, 85748 Garching, Germany
| | - W Richtering
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
- JARA-SOFT, 52056 Aachen, Germany
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Buchold P, Ram-On M, Talmon Y, Hoffmann I, Schweins R, Gradzielski M. Uncommon Structures of Oppositely Charged Hyaluronan/Surfactant Assemblies under Physiological Conditions. Biomacromolecules 2020; 21:3498-3511. [PMID: 32786536 DOI: 10.1021/acs.biomac.0c00221] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Self-assembled aggregates formed by semidilute polyanion hyaluronan (hyaluronic acid, HA) and an oppositely charged surfactant tetradecyltrimethylammonium bromide (TTAB) in an aqueous phosphate-buffered saline (PBS) solution have been studied via light scattering (LS), small-angle neutron scattering (SANS), and cryogenic transmission electron microscopy (cryo-TEM). The addition of 0-20 mM TTAB to a 27.7 mM (monomer, 1 wt %) HA solution (597 kDa) in PBS buffer leads to soluble complexes until phase separation occurs near charge equilibrium (>20 mM TTAB). While the viscosity remains rather constant, already small amounts of added TTAB lead to the formation of large globular superstructures, which are built in a hierarchical fashion from a locally threadlike structural arrangement of TTA micelles along the stiff HA chains, within the little changed HA network. These globular domains have radii of 60-100 nm and contain 500-700 TTA micelles, which means that they are very "fluffy" and composed of about 99% water. They do not grow in size or number upon further TTAB addition, but, instead, the additional TTA micelles form further threadlike complexes outside of the big globular domains. Such a type of polyelectrolyte-surfactant complexes (PESCs) has not been described before and has to be attributed to the particular properties of HA, which are high stiffness and relatively weak interactions with oppositely charged micelles due to having the charged carboxylic group close to the polysaccharide backbone. These findings demonstrate that the HA network structure in solution basically remains unaffected by complexation with an oppositely charged surfactant, explaining the unchanged rheological behavior and the formation of a unique PESC local "coacervate" structure within the HA hydrogel network.
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Affiliation(s)
- Philipp Buchold
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, D-10623 Berlin, Germany.,Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, CS 20 156, F-38042 Grenoble Cedex 9, France
| | - Maor Ram-On
- Department of Chemical Engineering and The Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Yeshayahu Talmon
- Department of Chemical Engineering and The Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Ingo Hoffmann
- Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, CS 20 156, F-38042 Grenoble Cedex 9, France
| | - Ralf Schweins
- Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, CS 20 156, F-38042 Grenoble Cedex 9, France
| | - Michael Gradzielski
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, D-10623 Berlin, Germany
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Matsarskaia O, Bühl L, Beck C, Grimaldo M, Schweins R, Zhang F, Seydel T, Schreiber F, Roosen-Runge F. Evolution of the structure and dynamics of bovine serum albumin induced by thermal denaturation. Phys Chem Chem Phys 2020; 22:18507-18517. [PMID: 32780038 DOI: 10.1039/d0cp01857k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Protein denaturation in concentrated solutions consists of the unfolding of the native protein structure, and subsequent cross-linking into clusters or gel networks. While the kinetic evolution of structure has been studied for some cases, the underlying microscopic dynamics of proteins has so far been neglected. However, protein dynamics is essential to understand the specific nature of assembly processes, such as diffusion-limited growth, or vitrification of dense liquids. Here, we present a study on thermal denaturation of concentrated solutions of bovine serum albumin (BSA) in D2O with and without NaCl. Using small-angle scattering, we provide information on structure before, during and after denaturation. Using quasi-elastic neutron scattering, we monitor in real-time the microscopic dynamics and dynamical confinement throughout the entire denaturation process covering protein unfolding and cross-linking. After denaturation, the protein dynamics is slowed down in salty solutions compared to those in pure water, while the stability and dynamics of the native solution appears unaffected by salt. The approach presented here opens opportunities to link microscopic dynamics to emerging structural properties, with implications for assembly processes in soft and biological matter.
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Affiliation(s)
- Olga Matsarskaia
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, France.
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Schneider K, Verkoyen P, Krappel M, Gardiner C, Schweins R, Frey H, Sottmann T. Efficiency Boosting of Surfactants with Poly(ethylene oxide)-Poly(alkyl glycidyl ether)s: A New Class of Amphiphilic Polymers. Langmuir 2020; 36:9849-9866. [PMID: 32689803 DOI: 10.1021/acs.langmuir.0c01491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Twenty years ago, it was found that adding small amounts of amphiphilic block copolymers like poly(ethylene propylene)-co-poly(ethylene oxide) (PEP-b-PEO) to microemulsion systems strongly increases the efficiency of medium-chain surfactants to solubilize water and oil. Although being predestined to serve as a milestone in microemulsion research, the effect has only scarcely found its way into applications. In this work, we propose new types of efficiency boosters, namely, poly(ethylene oxide)-poly(alkyl glycidyl ether carbonate)s (PEO-b-PAlkGE) and their "carbonated" poly(ethylene oxide)-poly(carbonate alkyl glycidyl ether) analogs. Their synthesis via anionic ring-opening polymerization (AROP) from commercially available long-chain alkyl glycidyl ethers (AlkGE) and monomethoxypoly(ethylene glycol)s as macroinitiators can be performed at low cost and on a large scale. We demonstrate that these new PEO-b-PAlkGE copolymers with dodecyl and hexadecyl side chains in the nonpolar block strongly increase the efficiency of both pure and technical-grade n-alkyl polyglycol ether surfactants to form microemulsions containing pure n-alkanes or even technical-grade waxes, a result that could be of interest for industrial applications where reduced surfactant needs would have significant economic and ecological implications. For n-decane microemulsions, the boosting effect of PEO-b-PAlkGE and PEP-b-PEO polymers can be scaled on top of each other, when plotting the efficiency semilogarithmically versus the polymeric coverage of the amphiphilic film. Interestingly, a somewhat different scaling behavior was observed for n-octacosane microemulsions at elevated temperatures, suggesting that the polymers show less self-avoidance and rather behave as almost ideal chains. A similar trend was found for the increase of the bending rigidity κ upon polymeric coverage of the amphiphilic film, which was obtained from the analysis of small-angle neutron scattering (SANS) measurements.
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Affiliation(s)
- Kristina Schneider
- Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Patrick Verkoyen
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Maximilian Krappel
- Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Christina Gardiner
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, 71 avenue des Martyrs, CS 20156, 38042 Grenoble CEDEX 9, France
| | - Holger Frey
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Thomas Sottmann
- Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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