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Greco G, Agafonova A, Cosentino A, Cardullo N, Muccilli V, Puglia C, Anfuso CD, Sarpietro MG, Lupo G. Solid Lipid Nanoparticles Encapsulating a Benzoxanthene Derivative in a Model of the Human Blood-Brain Barrier: Modulation of Angiogenic Parameters and Inflammation in Vascular Endothelial Growth Factor-Stimulated Angiogenesis. Molecules 2024; 29:3103. [PMID: 38999055 PMCID: PMC11243179 DOI: 10.3390/molecules29133103] [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: 05/07/2024] [Revised: 06/12/2024] [Accepted: 06/24/2024] [Indexed: 07/14/2024] Open
Abstract
Lignans, a class of secondary metabolites found in plants, along with their derivatives, exhibit diverse pharmacological activities, including antioxidant, antimicrobial, anti-inflammatory, and antiangiogenic ones. Angiogenesis, the formation of new blood vessels from pre-existing ones, is a crucial process for cancer growth and development. Several studies have elucidated the synergistic relationship between angiogenesis and inflammation in various inflammatory diseases, highlighting a correlation between inflammation and vascular endothelial growth factor (VEGF)-induced angiogenesis. Thus, the identification of novel molecules capable of modulating VEGF effects presents promising prospects for developing therapies aimed at stabilizing, reversing, or even arresting disease progression. Lignans often suffer from low aqueous solubility and, for their use, encapsulation in a delivery system is needed. In this research, a bioinspired benzoxantene has been encapsulated in solid lipid nanoparticles that have been characterized for their pharmacotechnical properties and their thermotropic behavior. The effects of these encapsulated nanoparticles on angiogenic parameters and inflammation in VEGF-induced angiogenesis were evaluated using human brain microvascular endothelial cells (HBMECs) as a human blood-brain barrier model.
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Affiliation(s)
- Giuliana Greco
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
| | - Aleksandra Agafonova
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
| | - Alessia Cosentino
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
| | - Nunzio Cardullo
- Department of Chemical Sciences, University of Catania, 95125 Catania, Italy
| | - Vera Muccilli
- Department of Chemical Sciences, University of Catania, 95125 Catania, Italy
| | - Carmelo Puglia
- Department of Drug and Health Sciences, University of Catania, 95125 Catania, Italy
- NANOMED-Research Center on Nanomedicine and Pharmaceutical Nanotechnology, University of Catania, 95125 Catania, Italy
| | - Carmelina Daniela Anfuso
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
| | - Maria Grazia Sarpietro
- Department of Drug and Health Sciences, University of Catania, 95125 Catania, Italy
- NANOMED-Research Center on Nanomedicine and Pharmaceutical Nanotechnology, University of Catania, 95125 Catania, Italy
| | - Gabriella Lupo
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
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Mechanisms of membrane protein crystallization in 'bicelles'. Sci Rep 2022; 12:11109. [PMID: 35773455 PMCID: PMC9246360 DOI: 10.1038/s41598-022-13945-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/31/2022] [Indexed: 12/14/2022] Open
Abstract
Despite remarkable progress, mainly due to the development of LCP and ‘bicelle’ crystallization, lack of structural information remains a bottleneck in membrane protein (MP) research. A major reason is the absence of complete understanding of the mechanism of crystallization. Here we present small-angle scattering studies of the evolution of the “bicelle” crystallization matrix in the course of MP crystal growth. Initially, the matrix corresponds to liquid-like bicelle state. However, after adding the precipitant, the crystallization matrix transforms to jelly-like state. The data suggest that this final phase is composed of interconnected ribbon-like bilayers, where crystals grow. A small amount of multilamellar phase appears, and its volume increases concomitantly with the volume of growing crystals. We suggest that the lamellar phase surrounds the crystals and is critical for crystal growth, which is also common for LCP crystallization. The study discloses mechanisms of “bicelle” MP crystallization and will support rational design of crystallization.
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Alahmadi I, Hoy D, Tahmasbi Rad A, Patil S, Alahmadi A, Kinnun J, Scott HL, Katsaras J, Nieh MP. Changes Experienced by Low-Concentration Lipid Bicelles as a Function of Temperature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:4332-4340. [PMID: 35357197 DOI: 10.1021/acs.langmuir.2c00078] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Differential scanning calorimetry (DSC) of dipalmitoyl phosphatidylcholine (DPPC), dihexanoyl phosphatidylcholine, and dipalmitoyl phosphatidylglycerol bicelles reveals two endothermic peaks. Based on analysis of small angle neutron scattering and small angle X-ray scattering data, the two DSC peaks are associated with the melting of DPPC and a change in bicellar morphology─namely, either bicelle-to-spherical vesicle or oblate-to-spherical vesicle. The reversibility of the two structural transformations was examined by DSC and found to be consistent with the corresponding small angle scattering data. However, the peak that is not associated with the melting of DPPC does not correspond to any structural transformation for bicelles containing distearoyl phosphatidylethanolamine conjugated with polyethylene glycol. Based on complementary experimental data, we conclude that membrane flexibility, lipid miscibility, and differential solubility between the long- and short-chain lipids in water are important parameters controlling the reversibility of morphologies experienced by the bicelles.
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Affiliation(s)
- Ibtihal Alahmadi
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Donyeil Hoy
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Armin Tahmasbi Rad
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Sanyukta Patil
- Department of Chemical & Biomolecular Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Anas Alahmadi
- Department of Electrical Engineering, Technical and Vocational Training Corporation, Riyadh 11472, Saudi Arabia
| | - Jacob Kinnun
- Large Scale Structures Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Haden L Scott
- Large Scale Structures Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - John Katsaras
- Labs and Soft Matter Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Mu-Ping Nieh
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
- Department of Chemical & Biomolecular Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
- Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
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Taguchi S, Kang BS, Suga K, Okamoto Y, Jung HS, Umakoshi H. A novel method of vesicle preparation by simple dilution of bicelle solution. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107725] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Systematic Characterization of DMPC/DHPC Self-Assemblies and Their Phase Behaviors in Aqueous Solution. COLLOIDS AND INTERFACES 2018. [DOI: 10.3390/colloids2040073] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Self-assemblies composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) form several kinds of structures, such as vesicle, micelle, and bicelle. Their morphological properties have been studied widely, but their interfacial membrane properties have not been adequately investigated. Herein, we report a systematic characterization of DMPC/DHPC assemblies at 20 °C. To investigate the phase behavior, optical density OD500, size (by dynamic light scattering), membrane fluidity 1/PDPH (using 1,6-diphenyl-1,3,5-hexatriene), and membrane polarity GP340 (using 6-dodecanoyl-N,N-dimethyl-2-naphthylamine) were measured as a function of molar ratio of DHPC (XDHPC). Based on structural properties (OD500 and size), large and small assemblies were categorized into Region (i) (XDHPC < 0.4) and Region (ii) (XDHPC ≥ 0.4), respectively. The DMPC/DHPC assemblies with 0.33 ≤ XDHPC ≤ 0.67 (Region (ii-1)) showed gel-phase-like interfacial membrane properties, whereas DHPC-rich assemblies (XDHPC ≥ 0.77) showed disordered membrane properties (Region (ii-2)). Considering the structural and interfacial membrane properties, the DMPC/DHPC assemblies in Regions (i), (ii-1), and (ii-2) can be determined to be vesicle, bicelle, and micelle, respectively.
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Miranda C, Booth VK, Morrow MR. Effects of Amphipathic Polypeptides on Membrane Organization Inferred from Studies Using Bicellar Lipid Mixtures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11759-11771. [PMID: 30196696 DOI: 10.1021/acs.langmuir.8b02257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
SP-B63-78, a lung surfactant protein fragment, and magainin 2, an antimicrobial peptide, are amphipathic peptides with the same overall charge but different biological functions. Deuterium nuclear magnetic resonance has been used to compare the interactions of these peptides with dispersions of 1,2-dimyristoyl- sn-glycero-3-phophocholine (DMPC)/1,2-dihexanoyl- sn-glycero-3-phophocholine (DHPC) (4:1) and DMPC/1,2-dimyristoyl- sn-glycero-3-phopho-(1'-rac-glycerol) (DMPG)/DHPC (3:1:1), two mixtures of long-chain and short-chain lipids that display bicellar behavior. This study exploited the sensitivity of a bicellar system structural organization to factors that modify partitioning of their lipid components between different environments. In small bicelle particles formed at low temperatures, short-chain components preferentially occupy curved rim environments around bilayer disks of the long-chain components. Changes in chain order and lipid mixing, on heating, can drive transitions to more extended assemblies including a magnetically orientable phase at intermediate temperature. In this work, neither peptide had a substantial effect on the behavior of the zwitterionic DMPC/DHPC mixture. For bicellar mixtures containing the anionic lipid DMPG, the peptide SP-B63-78 lowered the temperature at which magnetically orientable particles coalesced into more extended lamellar structures. SP-B63-78 did not promote partitioning of the zwitterionic and anionic long-chain lipid components into different environments. Magainin 2, on the other hand, was found to promote separation of the anionic lipid, DMPG, and the zwitterionic lipid, DMPC, into different environments for temperatures above 34 °C. The contrast between the effects of these two peptides on the lipid mixtures studied appears to be consistent with their functional roles in biological systems.
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Affiliation(s)
- Chris Miranda
- Department of Physics and Physical Oceanography , Memorial University of Newfoundland , St. John's , Newfoundland and Labrador , Canada A1B 3X7
| | - Valerie K Booth
- Department of Biochemistry , Memorial University of Newfoundland , St. John's , Newfoundland and Labrador , Canada A1B 3X9
| | - Michael R Morrow
- Department of Physics and Physical Oceanography , Memorial University of Newfoundland , St. John's , Newfoundland and Labrador , Canada A1B 3X7
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Yin Q, Shi X, Ding H, Dai X, Wan G, Qiao Y. Interactions of borneol with DPPC phospholipid membranes: a molecular dynamics simulation study. Int J Mol Sci 2014; 15:20365-81. [PMID: 25383679 PMCID: PMC4264172 DOI: 10.3390/ijms151120365] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/17/2014] [Accepted: 10/22/2014] [Indexed: 01/11/2023] Open
Abstract
Borneol, known as a “guide” drug in traditional Chinese medicine, is widely used as a natural penetration enhancer in modern clinical applications. Despite a large number of experimental studies on borneol’s penetration enhancing effect, the molecular basis of its action on bio-membranes is still unclear. We carried out a series of coarse-grained molecular dynamics simulations with the borneol concentration ranging from 3.31% to 54.59% (v/v, lipid-free basis) to study the interactions of borneol with aDPPC(1,2-dipalmitoylsn-glycero-3-phosphatidylcholine) bilayer membrane, and the temperature effects were also considered. At concentrations below 21.89%, borneol’s presence only caused DPPC bilayer thinning and an increase in fluidity; A rise in temperature could promote the diffusing progress of borneol. When the concentration was 21.89% or above, inverted micelle-like structures were formed within the bilayer interior, which led to increased bilayer thickness, and an optimum temperature was found for the interaction of borneol with the DPPC bilayer membrane. These findings revealed that the choice of optimal concentration and temperature is critical for a given application in which borneol is used as a penetration enhancer. Our results not only clarify some molecular basis for borneol’s penetration enhancing effects, but also provide some guidance for the development and applications of new preparations containing borneol.
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Affiliation(s)
- Qianqian Yin
- School of Traditional Chinese Medicine, Capital Medical University, No. 10 of Xitoutiao Outside Youanmen, Fengtai District, Beijing 100069, China.
| | - Xinyuan Shi
- Key Laboratory of TCM-Information Engineer, Beijing University of Chinese Medicine, No. 6 of Zhonghuan South Road, Wangjing, Chaoyang District, Beijing 100102, China.
| | - Haiou Ding
- Civil Aviation General Hospital, No. 1 of Chaowai Takai A, Beijing 100123, China.
| | - Xingxing Dai
- Key Laboratory of TCM-Information Engineer, Beijing University of Chinese Medicine, No. 6 of Zhonghuan South Road, Wangjing, Chaoyang District, Beijing 100102, China.
| | - Guang Wan
- School of Traditional Chinese Medicine, Capital Medical University, No. 10 of Xitoutiao Outside Youanmen, Fengtai District, Beijing 100069, China.
| | - Yanjiang Qiao
- Key Laboratory of TCM-Information Engineer, Beijing University of Chinese Medicine, No. 6 of Zhonghuan South Road, Wangjing, Chaoyang District, Beijing 100102, China.
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Vácha R, Frenkel D. Stability of bicelles: a simulation study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4229-4235. [PMID: 24670113 DOI: 10.1021/la4048159] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Aqueous mixtures of long-tailed lipids (e.g., dimyristoylphosphatidylcholine - DMPC) and detergents can sometimes form membrane disks called bicelles. Bicelles have found applications as an embedding medium for membrane proteins in the context of NMR studies and protein crystallization. However, the parameters that determine the thermodynamic stability of bicelles are not well understood. Here we report a coarse-grained simulation study of the relationship between lipid-aggregate morphology and the composition and temperature of the surfactant mixture. In agreement with experiments, we find that bicellar mixtures are destabilized at higher temperatures and detergents are present at membrane edges as well as in flat membranes with a strong preference for the edges. In addition, our results suggest that the free-energy difference between bicelles and the perforated lamellar phase is typically very small for molecules without intrinsic curvature and charge. Cone shaped surfactant molecules tend to favor the formation of bicelles; however, none of the systems that we have studied provide unambiguous evidence for the existence of thermodynamically stable bicelles in mixtures of uncharged lipids with long and short tails. We speculate that small changes in the properties of the system (charge, dopants) may make bicelles thermodynamically stable.
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Affiliation(s)
- Robert Vácha
- National Centre for Biomolecular Research, Faculty of Science and CEITEC - Central European Institute of Technology, Masaryk University , Kamenice 5, 625 00 Brno-Bohunice, Czech Republic
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MacEachern L, Sylvester A, Flynn A, Rahmani A, Morrow MR. Dependence of bicellar system phase behavior and dynamics on anionic lipid concentration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:3688-3699. [PMID: 23441840 DOI: 10.1021/la305136q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Bicellar dispersions of chain perdeuterated 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC-d54) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) were prepared with the molar fraction of DHPC held fixed at 20% and varying amounts of DMPC replaced by the anionic lipid 1,2-dimyristoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DMPG). (2)H NMR spectra were examined to assess the effect of added DMPG on mixture phase behavior and morphology. Quadrupole echo decay and quadrupole-Carr-Purcell-Mieboom-Gill echo train measurements provided information about slow motions contributing to echo decay in the high temperature phases. The spectra and quadrupole echo decay properties of DMPC-d54/DHPC (4:1) and DMPC-d54/DMPG/DHPC (3:1:1) were qualitatively similar. With increasing DMPG concentration, the transition between the magnetically orientable phase and the higher temperature phase became increasingly distinct, and the spectral shape and echo decay characteristics of the high temperature bicellar phase became increasingly similar to those of DMPC-d54 in the liquid crystalline phase. The observation that DMPG changes spectra in the orientable phase incrementally while increasing the distinction between the orientable and high temperature bicellar phases provides new insights into how DMPG influences bicellar mixture morphology.
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Affiliation(s)
- Lauren MacEachern
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador A1B 3X7, Canada
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Rodríguez G, Rubio L, Barba C, López-Iglesias C, de la Maza A, López O, Cócera M. Characterization of new DOPC/DHPC platform for dermal applications. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2012; 42:333-45. [DOI: 10.1007/s00249-012-0878-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 11/20/2012] [Accepted: 11/29/2012] [Indexed: 11/24/2022]
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Flynn A, Ducey M, Yethiraj A, Morrow MR. Dynamic properties of bicellar lipid mixtures observed by rheometry and quadrupole echo decay. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:2782-2790. [PMID: 22196024 DOI: 10.1021/la204111z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In bicellar dispersions of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC), the transition from isotropic reorientation to partial orientational order, on warming, is known to coincide with a sharp increase in viscosity. In this work, cone-and-plate rheometry, (2)H NMR spectroscopy, and quadrupole echo decay observations have been used to obtain new insights into the dynamics of phases observed in bicellar DMPC/DHPC mixtures. Samples with 25% of the DMPC component deuterated were used to correlate rheological measurements with phase behavior observed by (2)H NMR spectroscopy. Mixtures containing only normal DMPC (DMPC/DHPC) or only chain perdeuterated DMPC (DMPC-d(54)/DHPC) were used to refine rheology and quadrupole echo decay measurements respectively. The viscosity peaked at 4-9 Pa·s, just above the isotropic-to-nematic transition, and then dropped as samples were warmed through the nematic-to-lamellar transition. Quadrupole echo decay times above the nematic-to-lamellar transition were significantly longer than typically observed in the liquid crystalline phase of saturated lipid multilamellar vesicles. This may indicate a damping of slow bilayer undulations resulting from the coupling of opposite bilayer surfaces by DHPC-lined pores.
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Affiliation(s)
- Alanna Flynn
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada, A1B 3X7
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Bicellar systems as modifiers of skin lipid structure. Colloids Surf B Biointerfaces 2011; 84:390-4. [DOI: 10.1016/j.colsurfb.2011.01.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 01/18/2011] [Accepted: 01/22/2011] [Indexed: 11/23/2022]
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Uddin MN, Morrow MR. Bicellar mixture phase behavior examined by variable-pressure deuterium NMR and ambient pressure DSC. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:12104-12111. [PMID: 20536154 DOI: 10.1021/la1014362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Variable-pressure deuterium nuclear magnetic resonance ((2)H NMR) has been used to study the pressure-temperature phase diagram of bicellar mixtures containing 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC). Spectra were obtained for DMPC-d(54)/DHPC (3:1), DMPC-d(54)/DHPC (4.4:1), DMPC/DHPC-d(22) (3:1), and DMPC/DHPC-d(22) (4.4:1) in the range 10-68 degrees C at ambient pressure, 66 MPa, 102 MPa, and 135 MPa. Isotropic-to-nematic and nematic-to-lamellar transition temperatures were found to rise with pressure at approximately 0.15 and approximately 0.14 degrees C/MPa, respectively, for DMPC-d(54)/DHPC (3:1) and at at approximately 0.19 and approximately 0.18 degrees C/MPa, respectively, for DMPC-d(54)/DHPC (4.4:1). Pressure had little effect on the range of DMPC-d(54) chain orientational order through the nematic phase temperature range, but the behavior of chain orientational order at the nematic-to-lamellar transition was found to vary slightly with pressure. Comparison of differential scanning calorimetry (DSC) observations with ambient-pressure (2)H NMR observations of DMPC-d(54) in the bicellar mixtures suggests that absorption of heat persists for a few degrees above the onset of axially symmetric DMPC-d(54) reorientation.
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Affiliation(s)
- Md Nasir Uddin
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada A1B 3X7
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