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Xu Z, Seddon JM, Beales PA, Rappolt M, Tyler AII. Breaking Isolation to Form New Networks: pH-Triggered Changes in Connectivity inside Lipid Nanoparticles. J Am Chem Soc 2021; 143:16556-16565. [PMID: 34591464 DOI: 10.1021/jacs.1c06244] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
There is a growing demand to develop smart nanomaterials that are structure-responsive as they have the potential to offer enhanced dose, temporal and spatial control of compounds and chemical processes. The naturally occurring pH gradients found throughout the body make pH an attractive stimulus for guiding the response of a nanocarrier to specific locations or (sub)cellular compartments in the body. Here we have engineered highly sensitive lyotropic liquid crystalline nanoparticles that reversibly respond to changes in pH by altering the connectivity within their structure at physiological temperatures. At pH 7.4, the nanoparticles have an internal structure consisting of discontinuous inverse micellar "aqueous pockets" based on space group Fd3m. When the pH is ≤6, the nanoparticles change from a compartmentalized to an accessible porous internal structure based on a 2D inverse hexagonal phase (plane group p6mm). We validate the internal symmetry of the nanoparticles using small-angle X-ray scattering and cryogenic transmission electron microscopy. The high-resolution electron microscopy images obtained have allowed us for the first time to directly visualize the internal structure of the Fd3m nanoparticles and resolve the two different-sized inverse micelles that make up the structural motif within the Fd3m unit cell, which upon structural analysis reveal excellent agreement with theoretical geometrical models.
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Affiliation(s)
- Zexi Xu
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom.,School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - John M Seddon
- Department of Chemistry, Imperial College London, London W12 0BZ, United Kingdom
| | - Paul A Beales
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Michael Rappolt
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Arwen I I Tyler
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom
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2
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Holme M, Rashid MH, Thomas MR, Barriga HMG, Herpoldt K, Heenan RK, Dreiss CA, Bañuelos JL, Xie HN, Yarovsky I, Stevens MM. Fate of Liposomes in the Presence of Phospholipase C and D: From Atomic to Supramolecular Lipid Arrangement. ACS CENTRAL SCIENCE 2018; 4:1023-1030. [PMID: 30159399 PMCID: PMC6107861 DOI: 10.1021/acscentsci.8b00286] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Indexed: 05/04/2023]
Abstract
Understanding the origins of lipid membrane bilayer rearrangement in response to external stimuli is an essential component of cell biology and the bottom-up design of liposomes for biomedical applications. The enzymes phospholipase C and D (PLC and PLD) both cleave the phosphorus-oxygen bonds of phosphate esters in phosphatidylcholine (PC) lipids. The atomic position of this hydrolysis reaction has huge implications for the stability of PC-containing self-assembled structures, such as the cell wall and lipid-based vesicle drug delivery vectors. While PLC converts PC to diacylglycerol (DAG), the interaction of PC with PLD produces phosphatidic acid (PA). Here we present a combination of small-angle scattering data and all-atom molecular dynamics simulations, providing insights into the effects of atomic-scale reorganization on the supramolecular assembly of PC membrane bilayers upon enzyme-mediated incorporation of DAG or PA. We observed that PC liposomes completely disintegrate in the presence of PLC, as conversion of PC to DAG progresses. At lower concentrations, DAG molecules within fluid PC bilayers form hydrogen bonds with backbone carbonyl oxygens in neighboring PC molecules and burrow into the hydrophobic region. This leads initially to membrane thinning followed by a swelling of the lamellar phase with increased DAG. At higher DAG concentrations, localized membrane tension causes a change in lipid phase from lamellar to the hexagonal and micellar cubic phases. Molecular dynamics simulations show that this destabilization is also caused in part by the decreased ability of DAG-containing PC membranes to coordinate sodium ions. Conversely, PLD-treated PC liposomes remain stable up to extremely high conversions to PA. Here, the negatively charged PA headgroup attracts significant amounts of sodium ions from the bulk solution to the membrane surface, leading to a swelling of the coordinated water layer. These findings are a vital step toward a fundamental understanding of the degradation behavior of PC lipid membranes in the presence of these clinically relevant enzymes, and toward the rational design of diagnostic and drug delivery technologies for phospholipase-dysregulation-based diseases.
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Affiliation(s)
- Margaret
N. Holme
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - M. Harunur Rashid
- School
of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Michael R. Thomas
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Hanna M. G. Barriga
- Department
of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Karla−Luise Herpoldt
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Richard K. Heenan
- STFC ISIS
Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
| | - Cécile A. Dreiss
- School
of Cancer and Pharmaceutical Sciences, King’s
College London, London SE1 9NH, United Kingdom
| | - José Leobardo Bañuelos
- STFC ISIS
Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
- Department
of Physics, The University of Texas at El
Paso, El Paso, Texas 79968, United States
| | - Hai-nan Xie
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Irene Yarovsky
- School
of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
- E-mail:
| | - Molly M. Stevens
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department of Bioengineering and Institute of Biomedical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
- E-mail:
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3
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Kulkarni CV, Yaghmur A, Steinhart M, Kriechbaum M, Rappolt M. Effects of High Pressure on Internally Self-Assembled Lipid Nanoparticles: A Synchrotron Small-Angle X-ray Scattering (SAXS) Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11907-11917. [PMID: 27782407 DOI: 10.1021/acs.langmuir.6b03300] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present the first report on the effects of hydrostatic pressure on colloidally stabilized lipid nanoparticles enveloping inverse nonlamellar self-assemblies in their interiors. These internal self-assemblies were systematically tuned into bicontinuous cubic (Pn3m and Im3m), micellar cubic (Fd3m), hexagonal (H2), and inverse micellar (L2) phases by regulating the lipid/oil ratio as the hydrostatic pressure was varied from atmospheric pressure to 1200 bar and back to atmospheric pressure. The effects of pressure on these lipid nanoparticles were compared with those on their equilibrium bulk, nondispersed counterparts, namely, inverse nonlamellar liquid-crystalline phases and micellar solutions under excess-water conditions, using the synchrotron small-angle X-ray scattering (SAXS) technique. In the applied pressure range, induced phase transitions were observed solely in fully hydrated bulk samples, whereas the internal self-assemblies of the corresponding lipid nanoparticles displayed only pressure-modulated single phases. Interestingly, both the lattice parameters and the linear pressure expansion coefficients were larger for the self-assemblies enveloped inside the lipid nanoparticles as compared to the bulk states. This behavior can, in part, be attributed to enhanced lipid layer undulations in the lipid particles in addition to induced swelling effects in the presence of the triblock copolymer F127. The bicontinuous cubic phases both in the bulk state and inside lipid cubosome nanoparticles swell on compression, even as both keep swelling further upon decompression at relatively high pressures before shrinking again at ambient pressures. The pressure dependence of the phases is also modulated by the concentration of the solubilized oil (tetradecane). These studies demonstrate the tolerance of lipid nanoparticles [cubosomes, hexosomes, micellar cubosomes, and emulsified microemulsions (EMEs)] for high pressures, confirming their robustness for various technological applications.
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Affiliation(s)
- Chandrashekhar V Kulkarni
- Biological and Soft Systems, Cavendish Laboratory, University of Cambridge , JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
- Centre for Materials Science, School of Physical Sciences and Computing, University of Central Lancashire , Preston PR1 2HE, United Kingdom
| | - Anan Yaghmur
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen , DK-2100 Copenhagen, Denmark
| | - Milos Steinhart
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , 162 06 Prague, Czech Republic
| | - Manfred Kriechbaum
- Institute of Inorganic Chemistry, Graz University of Technology , A-8010 Graz, Austria
| | - Michael Rappolt
- Institute of Inorganic Chemistry, Graz University of Technology , A-8010 Graz, Austria
- School of Food Science & Nutrition, University of Leeds , Leeds LS2 9JT, U.K
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4
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McCarthy NLC, Ces O, Law RV, Seddon JM, Brooks NJ. Separation of liquid domains in model membranes induced with high hydrostatic pressure. Chem Commun (Camb) 2016; 51:8675-8. [PMID: 25907808 DOI: 10.1039/c5cc02134k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have imaged the formation of membrane microdomains immediately after their induction using a novel technology platform coupling high hydrostatic pressure to fluorescence microscopy. After formation, the ordered domains are small and highly dynamic. This will enhance links between model lipid assemblies and dynamic processes in cellular membranes.
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Affiliation(s)
- Nicola L C McCarthy
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
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Godoy CA, Valiente M, Pons R, Montalvo G. Effect of fatty acids on self-assembly of soybean lecithin systems. Colloids Surf B Biointerfaces 2015; 131:21-8. [PMID: 25938851 DOI: 10.1016/j.colsurfb.2015.03.065] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 03/23/2015] [Accepted: 03/31/2015] [Indexed: 11/25/2022]
Abstract
With the increasing interest in natural formulations for drug administration and functional foods, it is desirable a good knowledge of the phase behavior of lecithin/fatty acid formulations. Phase structure and properties of ternary lecithin/fatty acids/water systems are studied at 37°C, making emphasis in regions with relatively low water and fatty acid content. The effect of fatty acid saturation degree on the phase microstructure is studied by comparing a fully saturated (palmitic acid, C16:0), monounsaturated (oleic acid, C18:1), and diunsaturated (linoleic acid, C18:2) fatty acids. Phase determinations are based on a combination of polarized light microscopy and small-angle X-ray scattering measurements. Interestingly, unsaturated (oleic acid and linoleic acid) fatty acid destabilizes the lamellar bilayer. Slight differences are observed between the phase diagrams produced by the unsaturated ones: small lamellar, medium cubic and large hexagonal regions. A narrow isotropic fluid region also appears on the lecithin-fatty acid axis, up to 8wt% water. In contrast, a marked difference in phase microsctructure was observed between unsaturated and saturated systems in which the cubic and isotropic fluid phases are not formed. These differences are, probably, a consequence of the high Krafft point of the C16 saturated chains that imply rather rigid chains. However, unsaturated fatty acids result in more flexible tails. The frequent presence of, at least, one unsaturated chain in phospholipids makes it very likely a better mixing situation than in the case of more rigid chains. This swelling potential favors the formation of reverse hexagonal, cubic, and micellar phases. Both unsaturated fatty acid systems evolve by aging, with a reduction of the extension of reverse hexagonal phase and migration of the cubic phase to lower fatty acid and water contents. The kinetic stability of the systems seems to be controlled by the unsaturation of fatty acids.
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Affiliation(s)
- C A Godoy
- Departamento de Ingeniería de los procesos Agroalimentarios y Biotecnológicos (GIPAB), Universidad del Valle, A.A. 25360 Cali, Colombia
| | - M Valiente
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Faculty of Pharmacy, University of Alcalá, Ctra. Madrid-Barcelona Km 33.6, E-28871 Alcalá de Henares, Madrid, Spain
| | - R Pons
- Department de Tecnologia Química i de Tensioactius, Institut de Química Avançada de Catalunya, IQAC-CSIC, E-08034 Barcelona, Spain
| | - G Montalvo
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Faculty of Pharmacy, University of Alcalá, Ctra. Madrid-Barcelona Km 33.6, E-28871 Alcalá de Henares, Madrid, Spain; University Institute of Research in Police Sciences (IUICP), University of Alcalá, Ctra. Madrid-Barcelona Km 33.6, E-28871 Alcalá de Henares, Madrid, Spain.
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6
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Chong K, Tan OLL, Almsherqi ZA, Lin Q, Kohlwein SD, Deng Y. Isolation of mitochondria with cubic membrane morphology reveals specific ionic requirements for the preservation of membrane structure. PROTOPLASMA 2015; 252:689-696. [PMID: 25226828 DOI: 10.1007/s00709-014-0698-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 09/01/2014] [Indexed: 06/03/2023]
Abstract
Biological membranes with cubic symmetry are a hallmark of virus-infected or diseased cells. The mechanisms of formation and specific cellular functions of cubic membranes, however, are unclear. The best-documented cubic membrane formation occurs in the free-living giant amoeba Chaos carolinense. In that system, mitochondrial inner membranes undergo a reversible structural change from tubular to cubic membrane organization upon starvation of the organism. As a prerequisite to further analyze the structural and functional features of cubic membranes, we adapted protocols for the isolation of mitochondria from starved amoeba and have identified buffer conditions that preserve cubic membrane morphology in vitro. The requirement for high concentration of ion-chelating agents in the isolation media supports the importance of a balanced ion milieu in establishing and maintaining cubic membranes in vivo.
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Affiliation(s)
- Ketpin Chong
- Cubic Membrane Laboratory, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
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7
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Brooks NJ. Pressure effects on lipids and bio-membrane assemblies. IUCRJ 2014; 1:470-7. [PMID: 25485127 PMCID: PMC4224465 DOI: 10.1107/s2052252514019551] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 08/28/2014] [Indexed: 05/06/2023]
Abstract
Membranes are amongst the most important biological structures; they maintain the fundamental integrity of cells, compartmentalize regions within them and play an active role in a wide range of cellular processes. Pressure can play a key role in probing the structure and dynamics of membrane assemblies, and is also critical to the biology and adaptation of deep-sea organisms. This article presents an overview of the effect of pressure on the mesostructure of lipid membranes, bilayer organization and lipid-protein assemblies. It also summarizes recent developments in high-pressure structural instrumentation suitable for experiments on membranes.
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Affiliation(s)
- Nicholas J. Brooks
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
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8
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Gillams RJ, Nylander T, Plivelic TS, Dymond MK, Attard GS. Formation of inverse topology lyotropic phases in dioleoylphosphatidylcholine/oleic acid and dioleoylphosphatidylethanolamine/oleic acid binary mixtures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3337-3344. [PMID: 24605989 DOI: 10.1021/la404275u] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The addition of saturated fatty acids (FA) to phosphatidylcholine lipids (PC) that have saturated acyl chains has been shown to promote the formation of lyotropic liquid-crystalline phases with negative mean curvature. PC/FA mixtures may exhibit inverse bicontinuous cubic phases (Im3m, Pn3m) or inverse topology hexagonal phases (HII), depending on the length of the acyl chains/fatty acid. Here we report a detailed study of the phase behavior of binary mixtures of dioleoylphosphatidylcholine (DOPC)/oleic acid (OA) and dioleoylphosphatidylethanolamine (DOPE)/oleic acid at limiting hydration, constructed using small-angle X-ray diffraction (SAXD) data. The phase diagrams of both systems show a succession of phases with increasing negative mean curvature with increasing OA content. At high OA concentrations, we have observed the occurrence of an inverse micellar Fd3m phase in both systems. Hitherto, this phase had not been reported for phosphatidylethanolamine/fatty acid mixtures, and as such it highlights an additional route through which fatty acids may increase the propensity of bilayer lipid membranes to curve. We also propose a method that uses the temperature dependence of the lattice parameters of the HII phases to estimate the spontaneous radii of curvature (R0) of the binary mixtures and of the component lipids. Using this method, we calculated the R0 values of the complexes comprising one phospholipid molecule and two fatty acid molecules, which have been postulated to drive the formation of inverse phases in PL/FA mixtures. These are -1.8 nm (±0.4 nm) for DOPC(OA)2 and -1.1 nm (±0.1 nm) for DOPE(OA)2. R0 values estimated in this way allow the quantification of the contribution that different lipid species make to membrane curvature elastic properties and hence of their effect on the function of membrane-bound proteins.
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Affiliation(s)
- Richard J Gillams
- Faculty of Natural & Environmental Sciences, University of Southampton , Southampton SO17 1BJ, U.K
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9
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Yaghmur A, Rappolt M. The Micellar Cubic Fd3m Phase. ADVANCES IN PLANAR LIPID BILAYERS AND LIPOSOMES 2013. [DOI: 10.1016/b978-0-12-411515-6.00005-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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10
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Schröder-Turk GE, de Campo L, Evans ME, Saba M, Kapfer SC, Varslot T, Grosse-Brauckmann K, Ramsden S, Hyde ST. Polycontinuous geometries for inverse lipid phases with more than two aqueous network domains. Faraday Discuss 2013; 161:215-47; discussion 273-303. [DOI: 10.1039/c2fd20112g] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Angelov B, Angelova A, Papahadjopoulos-Sternberg B, Hoffmann SV, Nicolas V, Lesieur S. Protein-Containing PEGylated Cubosomic Particles: Freeze-Fracture Electron Microscopy and Synchrotron Radiation Circular Dichroism Study. J Phys Chem B 2012; 116:7676-86. [DOI: 10.1021/jp303863q] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Borislav Angelov
- Institute of Macromolecular
Chemistry, Academy of Sciences of the Czech Republic, Heyrovského nam. 1888/2, Praha 6, Czech Republic
| | - Angelina Angelova
- CNRS UMR8612 Physico-chimie-Pharmacotechnie-Biopharmacie,
Univ Paris Sud 11, LabEx LERMIT, 92296
Châtenay-Malabry, France
| | | | - Søren V. Hoffmann
- Institute for Storage Ring Facilities
(ISA), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Valérie Nicolas
- Imaging platform, IFR141, Institut
Paris-Sud d’Innovation Thérapeutique (IPSIT), Univ Paris Sud 11, 92290 Châtenay-Malabry, France
| | - Sylviane Lesieur
- CNRS UMR8612 Physico-chimie-Pharmacotechnie-Biopharmacie,
Univ Paris Sud 11, LabEx LERMIT, 92296
Châtenay-Malabry, France
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Tenchov B, Koynova R. Cubic phases in membrane lipids. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2012; 41:841-50. [DOI: 10.1007/s00249-012-0819-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Accepted: 04/21/2012] [Indexed: 11/29/2022]
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