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Dahl M, Gommes CJ, Haverkamp R, Wood K, Prévost S, Schröer P, Omasta T, Stank TJ, Hellweg T, Wellert S. Confinement induced change of microemulsion phase structure in controlled pore glass (CPG) monoliths. RSC Adv 2024; 14:28272-28284. [PMID: 39239284 PMCID: PMC11372560 DOI: 10.1039/d4ra04090b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Accepted: 08/26/2024] [Indexed: 09/07/2024] Open
Abstract
We use small-angle neutron scattering (SANS) to investigate the structure and phase behavior of a complex fluid within meso- and macroporous matrices. Specifically, bicontinuous microemulsions of the temperature-dependent ternary system C10E4-water-n-octane are investigated in controlled pore glass (CPG) membranes with nominal pore diameters of 10 nm, 20 nm, 50 nm, and 100 nm. The scattering data were analyzed using the Teubner-Strey model and a multiphase generalization of clipped Gaussian-field models. The analysis indicates changes in the phase structure of the bicontinuous microemulsion in the membranes with the smallest pores. This is attributed to a shift in the ternary phase diagram toward a three-phase structure at lower surfactant concentrations. This effect is likely related to a larger internal surface area in the membranes with smaller pores, which enhances surfactant adsorption onto the pore walls.
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Affiliation(s)
- Margarethe Dahl
- Department of Chemistry, Technische Universität Berlin Straße des 17. Juni 124 10623 Berlin Germany
| | - Cedric J Gommes
- Department of Chemical Engineering, University of Liège B6 A 3 Allée du 6 Août B-4000 Liège Belgium
| | - René Haverkamp
- Department of Physical and Biophysical Chemistry, University of Bielefeld, Universitätsstraße 25 33615 Bielefeld Germany
| | - Kathleen Wood
- Australian Nuclear and Technology Organisation New Illawarra Rd Lucas Heights NSW 2234 Australia
| | - Sylvain Prévost
- Institut Laue-Langevin 71 Avenue des Martyrs F-38042 Grenoble France
| | - Pierre Schröer
- Department of Chemistry, Technische Universität Berlin Straße des 17. Juni 124 10623 Berlin Germany
| | - Tomáš Omasta
- Department of Chemistry, Technische Universität Berlin Straße des 17. Juni 124 10623 Berlin Germany
| | - Tim Julian Stank
- Department of Physical and Biophysical Chemistry, University of Bielefeld, Universitätsstraße 25 33615 Bielefeld Germany
| | - Thomas Hellweg
- Department of Physical and Biophysical Chemistry, University of Bielefeld, Universitätsstraße 25 33615 Bielefeld Germany
| | - Stefan Wellert
- Department of Chemistry, Technische Universität Berlin Straße des 17. Juni 124 10623 Berlin Germany
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Unruh T, Götz K, Vogel C, Fröhlich E, Scheurer A, Porcar L, Steiniger F. Mesoscopic Structure of Lipid Nanoparticle Formulations for mRNA Drug Delivery: Comirnaty and Drug-Free Dispersions. ACS NANO 2024; 18:9746-9764. [PMID: 38514237 DOI: 10.1021/acsnano.4c02610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Lipid nanoparticles (LNPs) produced by antisolvent precipitation (ASP) are used in formulations for mRNA drug delivery. The mesoscopic structure of such complex multicomponent and polydisperse nanoparticulate systems is most relevant for their drug delivery properties, medical efficiency, shelf life, and possible side effects. However, the knowledge on the structural details of such formulations is very limited. Essentially no such information is publicly available for pharmaceutical dispersions approved by numerous medicine agencies for the use in humans and loaded with mRNA encoding a mimic of the spike protein of the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) as, e.g., the Comirnaty formulation (BioNTech/Pfizer). Here, we present a simple preparation method to mimic the Comirnaty drug-free LNPs including a comparison of their structural properties with those of Comirnaty. Strong evidence for the liquid state of the LNPs in both systems is found in contrast to the designation of the LNPs as solid lipid nanoparticles by BioNTech. An exceptionally detailed and reliable structural model for the LNPs i.a. revealing their unexpected narrow size distribution will be presented based on a combined small-angle X-ray scattering and photon correlation spectroscopy (SAXS/PCS) evaluation method. The results from this experimental approach are supported by light microscopy, 1H NMR spectroscopy, Raman spectroscopy, cryogenic electron microscopy (cryoTEM), and simultaneous SAXS/SANS studies. The presented results do not provide direct insights on particle formation or dispersion stability but should contribute significantly to better understanding the LNP drug delivery process, enhancing their medical benefit, and reducing side effects.
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Affiliation(s)
- Tobias Unruh
- Institute for Crystallography and Structural Physics, Physics Department, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 3, 91058 Erlangen, Germany
- Interdisciplinary Center for Nanostructured Films (IZNF) and Center for Nanoanalysis and Electron Microscopy (CENEM), Cauerstraße 3, 91058 Erlangen, Germany
| | - Klaus Götz
- Institute for Crystallography and Structural Physics, Physics Department, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 3, 91058 Erlangen, Germany
- Interdisciplinary Center for Nanostructured Films (IZNF) and Center for Nanoanalysis and Electron Microscopy (CENEM), Cauerstraße 3, 91058 Erlangen, Germany
| | - Carola Vogel
- Institute for Crystallography and Structural Physics, Physics Department, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 3, 91058 Erlangen, Germany
- Interdisciplinary Center for Nanostructured Films (IZNF) and Center for Nanoanalysis and Electron Microscopy (CENEM), Cauerstraße 3, 91058 Erlangen, Germany
| | - Erik Fröhlich
- Institute for Crystallography and Structural Physics, Physics Department, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 3, 91058 Erlangen, Germany
| | - Andreas Scheurer
- Lehrstuhl für Anorganische und Allgemeine Chemie, Department Chemie und Pharmazie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Lionel Porcar
- Large Scale Structures Group, Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Frank Steiniger
- Electron Microscopy Center, Jena University Hospital, Friedrich Schiller University Jena, 07743 Jena, Germany
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Wang Z, Teixeira SCM, Strother C, Bowen A, Casadevall A, Cordero RJB. Neutron Scattering Analysis of Cryptococcus neoformans Polysaccharide Reveals Solution Rigidity and Repeating Fractal-like Structural Patterns. Biomacromolecules 2024; 25:690-699. [PMID: 38157431 PMCID: PMC10922810 DOI: 10.1021/acs.biomac.3c00911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Cryptococcus neoformans is a fungal pathogen that can cause life-threatening brain infections in immunocompromised individuals. Unlike other fungal pathogens, it possesses a protective polysaccharide capsule that is crucial for its virulence. During infections, Cryptococcus cells release copious amounts of extracellular polysaccharides (exo-PS) that interfere with host immune responses. Both exo-PS and capsular-PS play pivotal roles in Cryptococcus infections and serve as essential targets for disease diagnosis and vaccine development strategies. However, understanding their structure is complicated by their polydispersity, complexity, sensitivity to sample isolation and processing, and scarcity of methods capable of isolating and analyzing them while preserving their native structure. In this study, we employ small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) for the first time to investigate both fungal cell suspensions and extracellular polysaccharides in solution. Our data suggests that exo-PS in solution exhibits collapsed chain-like behavior and demonstrates mass fractal properties that indicate a relatively condensed pore structure in aqueous environments. This observation is also supported by scanning electron microscopy (SEM). The local structure of the polysaccharide is characterized as a rigid rod, with a length scale corresponding to 3-4 repeating units. This research not only unveils insights into exo-PS and capsular-PS structures but also demonstrates the potential of USANS for studying changes in cell dimensions and the promise of contrast variation in future neutron scattering studies.
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Affiliation(s)
- Ziwei Wang
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, 21205, USA
| | - Susana C. M. Teixeira
- NIST Center of Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899, USA
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, 19716, USA
| | - Camilla Strother
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, 21205, USA
| | - Anthony Bowen
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, 21205, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, 21205, USA
| | - Radamés JB Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, 21205, USA
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Heiden-Hecht T, Wu B, Schwärzer K, Förster S, Kohlbrecher J, Holderer O, Frielinghaus H. New insights into protein stabilized emulsions captured via neutron and X-ray scattering: An approach with β-lactoglobulin at triacylglyceride-oil/water interfaces. J Colloid Interface Sci 2024; 655:319-326. [PMID: 37948805 DOI: 10.1016/j.jcis.2023.10.155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 10/25/2023] [Accepted: 10/29/2023] [Indexed: 11/12/2023]
Abstract
HYPOTHESIS To analyze protein stabilized emulsions, SAXS and SANS are emerging techniques capturing oil droplet radius, interfacial coverage and structure. Protein shape, thus protein structure change during interfacial adsorption with partial protein unfolding is detected via SAXS analysis at and below the monolayer concentration for proteins, known as critical interfacial concentration (CIC). SANS determines the same phenomena below and above the CIC, via contrast variation and coarse-grained modelling. EXPERIMENTS β-lactoglobulin concentration dependent SAXS experiments were performed focusing on molecular length scales to characterize protein shape in water, and interfacial structure in emulsions. Complementary SANS experiments with contrast variation via deuterated triacylglyceride-oil provided insight into oil droplet radius, interfacial coverage and structure via data analysis with scattering models and low-resolution shape reconstruction with the DENFERT model. FINDINGS SAXS and SANS experiments allowed to determine the interfacial structure below and above the CIC, as well as oil droplet radius and interfacial coverage. These findings were identified via Q-4 Porod scattering at low-Q, protein scattering at high Q, and a Q-2 scattering of the interface. Since SANS with accurate contrast variation highlights the interface in comparison to other techniques like FTIR, the presented results show a high impact to understand interfaces in emulsions.
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Affiliation(s)
- Theresia Heiden-Hecht
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany.
| | - Baohu Wu
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
| | - Kuno Schwärzer
- Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Stephan Förster
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany; Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | | | - Olaf Holderer
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
| | - Henrich Frielinghaus
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
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Kohlbrecher J, Breßler I. Updates in SASfit for fitting analytical expressions and numerical models to small-angle scattering patterns. J Appl Crystallogr 2022; 55:1677-1688. [PMID: 36570652 PMCID: PMC9721323 DOI: 10.1107/s1600576722009037] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 09/09/2022] [Indexed: 11/22/2022] Open
Abstract
Small-angle scattering is an increasingly common method for characterizing particle ensembles in a wide variety of sample types and for diverse areas of application. SASfit has been one of the most comprehensive and flexible curve-fitting programs for decades, with many specialized tools for various fields. Here, a selection of enhancements and additions to the SASfit program are presented that may be of great benefit to interested and advanced users alike: (a) further development of the technical basis of the program, such as new numerical algorithms currently in use, a continuous integration practice for automated building and packaging of the software, and upgrades on the plug-in system for easier adoption by third-party developers; (b) a selection of new form factors for anisotropic scattering patterns and updates to existing form factors to account for multiple scattering effects; (c) a new type of a very flexible distribution called metalog [Keelin (2016). Decis. Anal. 13, 243-277], and regularization techniques such as the expectation-maximization method [Dempster et al. (1977). J. R. Stat. Soc. Ser. B (Methodological), 39, 1-22; Richardson (1972) J. Opt. Soc. Am. 62, 55; Lucy (1974). Astron. J. 79, 745; Lucy (1994). Astron. Astrophys. 289, 983-994], which is compared with fits of analytical size distributions via the non-linear least-squares method; and (d) new structure factors, especially for ordered nano- and meso-scaled material systems, as well as the Ornstein-Zernike solver for numerical determination of particle interactions and the resulting structure factor when no analytical solution is available, with the aim of incorporating its effects into the small-angle scattering intensity model used for fitting with SASfit.
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Affiliation(s)
- Joachim Kohlbrecher
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Ingo Breßler
- BAM Federal Institute for Materials Research and Testing, 12205 Berlin, Germany
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Pietras Z, Wood K, Whitten AE, Jeffries CM. Technical considerations for small-angle neutron scattering from biological macromolecules in solution: Cross sections, contrasts, instrument setup and measurement. Methods Enzymol 2022; 677:157-189. [DOI: 10.1016/bs.mie.2022.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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