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Sahu S, Talele P, Patra B, Verma RS, Mishra AK. A Multiparametric Fluorescence Probe to Understand the Physicochemical Properties of Small Unilamellar Lipid Vesicles in Poly(ethylene glycol)-Water Medium. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4842-4852. [PMID: 32283935 DOI: 10.1021/acs.langmuir.9b03902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
FDAPT (2-formyl-5-(4'-N,N-dimethylaminophenyl)thiophene) efficiently senses the minimum alteration of lipid bilayer microenvironment with all six different fluorescence parameters namely emission wavelength, fluorescence intensity, steady-state anisotropy, and their corresponding time-dependent parameters (Sahu et al., J. Phys. Chem. B 2018, 122, 7308-7318). In the present work, the effect of poly(ethylene glycol) on the small unilamellar vesicle is demonstrated with the emission behavior of the FDAPT probe. A medium and a high molecular weight PEG were chosen to perturb the lipid vesicles. The alteration of the bilayer polarity, water content inside bilayer, lipid packing density in the perturbed vesicles reflect significant changes in different fluorescence parameters of FDAPT probe. The effect of PEG on the unilamellar vesicle was rationalized with the alteration of the emission behavior, fluorescence lifetime, steady-state anisotropy and anisotropy decay of the probe. The simple and convenient fluorescence measurements provide new insights into the effect of PEG on the packing density, water volume, micro polarity, and microviscosity of the small unilamellar vesicle. The physiological understanding was extended to rationalize the cryoprotecting behavior of PEG.
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Affiliation(s)
- Saugata Sahu
- Department of Chemistry, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, Chennai-600036, Tamil Nadu India
| | - Paurnima Talele
- Department of Chemistry, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, Chennai-600036, Tamil Nadu India
| | - Bamadeb Patra
- Department of Biotechnology, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, Chennai-600036, Tamil Nadu India
| | - Rama Shanker Verma
- Department of Biotechnology, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, Chennai-600036, Tamil Nadu India
| | - Ashok Kumar Mishra
- Department of Chemistry, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, Chennai-600036, Tamil Nadu India
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Sagisaka M, Fujita Y, Nakanishi Y, Takahashi H, Tsuyoshi N, James C, Yoshizawa A, Mohamed A, Guittard F, Eastoe J. Periodic Formation/Breakdown of Lamellar Aggregates with Anionic Cyanobiphenyl Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:13040-13047. [PMID: 26542352 DOI: 10.1021/acs.langmuir.5b03564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This study reports unusual behavior of aqueous-phase lamellar aggregates with a new class of hybrid surfactant, CB-B2ES, having mesogenic units {6-[4-(4-cyanophenyl)phenyloxy]hexyl} and temperature-sensitive oxyethylated (butoxyethoxyethyl) tails. These tails are poorly miscible and likely to microsegregate if the surfactant molecules assemble. Lamellar aggregates appear at CB-B2ES concentrations higher than 5 wt % and were found to undergo repeat formation/breakdown periodically at 30 °C, with an average domain lifetime of ∼10 s. To investigate effects of the temperature-sensitive oxyethylene units on the hydrophilic/lipophilic balance (HLB) of the CB-B2ES bilayers, a fluorescence probe 1-pyrene-carboxaldehide was solubilized in the mixtures to sense the micro-environmental polarities. Fluorimetric measurements suggested that the polarity of CB-B2ES bilayers is very similar to that of the non-ethoxylated CB-B2ES analogue at high temperatures (≥65 °C). However, for CB-B2ES, polarity increased with a decreasing temperature, in contrast with the small decrease in polarity observed for analogous non-ethoxylated bilayers. This is consistent with increased hydration of the oxyethylene units in CB-B2ES bilayers at low temperatures. The periodic formation/breakdown and cooling-induced hydrophilicity of the CB-B2ES lamellar aggregates did not appear in the non-hybrid and/or non-ethoxylated surfactant systems. Therefore, the combination of two unsymmetrical tails, one containing oxyethylene units and the other containing cyanobiphenyl terminal tips, must play an important role promoting this unusual behavior.
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Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Yayoi Fujita
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Yusuke Nakanishi
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Hisayuki Takahashi
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Narumi Tsuyoshi
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Craig James
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | | | - Frédéric Guittard
- Equipe Surfaces et Interfaces, Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis , Parc Valrose, 06100 Nice, France
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
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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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Montalvo G, Pons R, Zhang G, Díaz M, Valiente M. Structure and phase equilibria of the soybean lecithin/PEG 40 monostearate/water system. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:14369-79. [PMID: 24205925 DOI: 10.1021/la402764w] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PEG stearates are extensively used as emulsifiers in many lipid-based formulations. However, the scheme of the principles of the lipid-surfactant polymer interactions are still poorly understood and need more studies. A new phase diagram of a lecithin/PEG 40 monostearate/water system at 30 °C is reported. First, we have characterized the binary PEG 40 monostearate/water system by the determination of the critical micelle concentration value and the viscous properties. Then, the ternary phase behavior and the influence of phase structure on their macroscopic properties are studied by a combination of different techniques, namely, optical microscopy, small-angle X-ray scattering, differential scanning calorimetry, and rheology. The phase behavior is complex, and some samples evolve even at long times. The single monophasic regions correspond to micellar, swollen lamellar, and lamellar gel phases. The existence of extended areas of phase coexistence (hexagonal, cubic, and lamellar liquid crystalline phases) may be a consequence of the low miscibility of S40P in the lecithin bilayer as well as of the segregation of the phospholipid polydisperse hydrophobic chains. The presence of the PEG 40 monostearate has less effect in the transformation to the cubic phase for lecithin than that found in other systems with simple glycerol-based lipids.
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Affiliation(s)
- G Montalvo
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá , E28871 Alcalá de Henares (Madrid), Spain
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Unique liquid crystal behavior in water of anionic fluorocarbon–hydrocarbon hybrid surfactants containing oxyethylene units. J Colloid Interface Sci 2011; 357:400-6. [DOI: 10.1016/j.jcis.2011.02.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 02/06/2011] [Accepted: 02/08/2011] [Indexed: 11/19/2022]
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Alves M, Peric M. An EPR study of the interfacial properties of phosphatidylcholine vesicles with different lipid chain lengths. Biophys Chem 2006; 122:66-73. [PMID: 16517048 DOI: 10.1016/j.bpc.2006.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 02/09/2006] [Accepted: 02/09/2006] [Indexed: 11/18/2022]
Abstract
The hydrophobic spin probe 2,2,6,6-tetramethyl-piperidin-1-oxyl-4-yl octadecanoate (TEMPO-stearate) is used to study the interfacial properties of a variety of phosphatidylcholine vesicles. Since the spin probe exhibits a fast motional electron paramagnetic resonance (EPR) spectrum above the phase transition, the EPR spectrum of the spin probe is analyzed by nonlinear least-squares spectral fitting. EPR spectral line fitting provides high precision spectral parameters, which can be used to construct a detailed picture of the dynamics of the probe and its environment. The hyperfine coupling spacing is used to estimate the effective water concentration in the polar shell of vesicles, while the rotational correlation times give the information on the motion of the spin probe. The effective water concentration of the polar shell of dimyristoyl-phosphatidylglycerol (DMPG) vesicles is greater on average by about 4.0M than the effective water concentration of the polar shell of dimyristoyl-phosphatidylcholine (DMPC) vesicles. The effective water concentration decreases by about 0.5M for an increase of two carbons in the chain, and increases noticeably with hydrocarbon chain unsaturation, which is in good agreement with literature values. The nitroxide moiety rotates preferentially along the N-O bond, that is, parallel to its hydrocarbon chain.
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Affiliation(s)
- Marilene Alves
- Department of Physics and Astronomy and The Center for Supramolecular Studies, California State University at Northridge, Northridge, CA 91330-8268, USA
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Abstract
One approach to the understanding of fusion in cells and model membranes involves stalk formation and expansion of the hemifusion diaphragm. We predict theoretically the initiation of hemifusion by stalk expansion and the dynamics of mesoscopic hemifusion diaphragm expansion in the light of recent experiments and theory that suggested that hemifusion is driven by intramembrane tension far from the fusion zone. Our predictions include a square-root scaling of the hemifusion zone size on time as well as an estimate of the minimal tension for initiation of hemifusion. Whereas a minimal amount of pressure is evidently needed for stalk formation, it is not necessarily required for stalk expansion. The energy required for tension-induced fusion is much smaller than that required for pressure-driven fusion.
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Affiliation(s)
- Guy Hed
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel.
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Safran SA, Kuhl TL, Israelachvili JN. Polymer-induced membrane contraction, phase separation, and fusion via Marangoni flow. Biophys J 2001; 81:659-66. [PMID: 11463614 PMCID: PMC1301542 DOI: 10.1016/s0006-3495(01)75730-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Experiments have shown that the depletion of polymer in the region between two apposed (contacting or nearly contacting) bilayer membranes leads to fusion. In this paper we show theoretically that the addition of nonadsorbing polymer in solution can promote lateral contraction and phase separation of the lipids in the outer monolayers of the membranes exposed to the polymer solution, i.e., outside the contact zone. This initial phase coexistence of higher- and lower-density lipid domains in the outer monolayer results in surface tension gradients in the outer monolayer. Initially, the inner layer lipids are not exposed to the polymer solution and remain in their original "unstressed" state. The differential stresses on the bilayers give rise to a Marangoni flow of lipid from the outer monolayers in the "contact zone" (where there is little polymer and hence a uniform phase) to the outer monolayers in the "reservoir" (where initially the surface tension gradients are large due to the polymer-induced phase separation). As a result, the low-density domains of the outer monolayers in the contact zone expose their hydrophobic chains, and those of the inner monolayers, to the solvent and to each other across the narrow water gap, allowing fusion to occur via a hydrophobic interaction. More generally, this type of mechanism suggests that fusion and other intermembrane interactions may be triggered by Marangoni flows induced by surface tension gradients that provide "action at a distance" far from the fusion or interaction zone.
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Affiliation(s)
- S A Safran
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel. sam,
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Heimburg T. A model for the lipid pretransition: coupling of ripple formation with the chain-melting transition. Biophys J 2000; 78:1154-65. [PMID: 10692305 PMCID: PMC1300718 DOI: 10.1016/s0006-3495(00)76673-2] [Citation(s) in RCA: 203] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Below the thermotropic chain-melting transition, lipid membrane c(P) traces display a transition of low enthalpy called the lipid pretransition. It is linked to the formation of periodic membrane ripples. In the literature, these two transitions are usually regarded as independent events. Here, we present a model that is based on the assumption that both pretransition and main transition are caused by the same physical effect, namely chain melting. The splitting of the melting process into two peaks is found to be a consequence of the coupling of structural changes and chain-melting events. On the basis of this concept, we performed Monte Carlo simulations using two coupled monolayer lattices. In this calculation, ripples are considered to be one-dimensional defects of fluid lipid molecules. Because lipids change their area by approximately 24% upon melting, line defects are the only ones that are topologically possible in a triangular lattice. The formation of a fluid line defect on one monolayer leads to a local bending of the membrane. Geometric constraints result in the formation of periodic patterns of gel and fluid domains. This model, for the first time, is able to predict heat capacity profiles, which are comparable to the experimental c(P) traces that we obtained using calorimetry. The basic assumptions are in agreement with a large number of experimental observations.
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Affiliation(s)
- T Heimburg
- Max-Planck Institut für biophysikalische Chemie, 37070 Göttingen, Germany.
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