Solubilization of multilamellar liposomes of egg yolk lecithin by the bile salt sodiumtaurodeoxycholate and the effect of cholesterol — a rapid-ultrafiltration study

Müller, Karl; Schuster, Annemarie

doi:10.1016/0009-3084(90)90155-k

Cited by 12 publications

(4 citation statements)

References 34 publications

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“…First, mixed micelles have in general larger diameter than single direct micelles. Second, the complex process involved in the mixed micelle formation between surfactant molecules able to form micelles and PC molecules which normally form bilayers, in accordance with the findings reported by a number of authors (Schurtenberger et al, 1985(Schurtenberger et al, , 1986Matsuzaki et al, 1989;Malloy & Binford, 1990;Mü ller & Schuster, 1990;Nagata et al, 1990;Spink et al, 1991;Lee et al, 1992;de la Maza & Parra, 1994a, 1994b. The specific association of the double-tailed structure of PC with the single one corresponding to the SC in mixed micelles as well as the different molecular structure of these two compounds could explain the specific characteristics of these aggregates.…”

Section: Mm)supporting

confidence: 87%

“…Given that the aggregation states of bile salt-phospholipid mixtures are fairly variable and concentration dependent their physicochemical properties have been studied under a variety of methods and dilutions (Schurtenberger et al, 1985(Schurtenberger et al, , 1986Spink et al, 1991;Laggner & Kriechbaum, 1991;Lee et al, 1992). Thus, PC liposomes have been used extensively as simplified membrane models in the study of these interactions (Matsuzaki et al, 1989;Malloy & Binford, 1990;Mü ller & Schuster, 1990;Nagata et al, 1990). From the structural viewpoint, some mechanistic hypotheses have been put forward to account for these interactions, where dispersed hexagonal phases coexist with aqueous bile salt monomers and either micellar or unilamellar phases appear as crucial intermediates in the solubilization and reconstitution of liposomes (Schurtenberger et al, 1985(Schurtenberger et al, , 1986.…”

Section: Introductionmentioning

confidence: 99%

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Intermediate aggregates resulting in the interaction of bile salt with liposomes studied by transmission electron microscopy and light scattering techniques

Maza

Manich

Parra

1997

Journal of Microscopy

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SummaryThe interaction of sodium cholate (SC) with phosphatidylcholine liposomes was studied by means of transmission electron microscopy (TEM), changes in the mean particle size (quasielastic light scattering, QELS) and in the static light scattering (SLS) of the system during liposome solubilization. A good correlation was found between the TEM diameter of particles and the mean hydrodynamic diameter (HD) determined by QELS. The intermediate aggregates resulting in this interaction were dependent on the SC concentration in the system. Thus, an initial vesicle growth occurred when the SC concentration in the system was 13 . 79 mol%. Additional SC amounts (41 . 17 mol% SC) led to the formation of the largest vesicles (HD 410 nm). Increasing SC amounts led to a slight fall in the vesicle diameter and in the SLS of the system. Thus, for 47 . 08 mol% SC, TEM images still showed the presence of vesicles albeit with traces of smaller structures and signs of vesicle fusion. When SC concentration exceeded 48 mol% an abrupt decrease in SLS occurred, the size curve starting to show a bimodal distribution. Thus, for 50 mol% SC a sharp distribution curve appeared at 52 nm indicating the formation of small particles and TEM images showed clear signs of vesicle disintegration with formation of tubular structures. The subsequent self organization of these tubular structures (54 mol% SC) led to the formation of open multilayered structures in coexistence with small particles. A gradual increase in the number of these small particles (mixed micelles) led to the complete solubilization of liposomes.

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Section: Mm)supporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Intermediate aggregates resulting in the interaction of bile salt with liposomes studied by transmission electron microscopy and light scattering techniques

Maza

Manich

Parra

1997

Journal of Microscopy

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“…The fact that only 70-95% of calcein was released during 3 h-instead of 100%-could be explained by the variable lamellarity of the different vesicles. It is known, that multilamellar vesicles are solubilized by a fast initial process of micelle formation followed by a slow step involving a successive "peeling-off" of the lamellar layers of the vesicles [79]. This "incomplete" release of calcein from vesicles incubated in media containing bile salts has been reported previously [76,80].…”

Section: Stability Of Bolasomes In Different Digestive Mediamentioning

confidence: 66%

Bolalipid-Doped Liposomes: Can Bolalipids Increase the Integrity of Liposomes Exposed to Gastrointestinal Fluids?

Müller

Gruhle

Meister³

et al. 2019

Pharmaceutics

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The use of archaeal lipids and their artificial analogues, also known as bolalipids, represents a promising approach for the stabilization of classical lipid vesicles for oral application. In a previous study, we investigated the mixing behavior of three single-chain alkyl-branched bolalipids PC-C32(1,32Cn)-PC (n = 3, 6, 9) with either saturated or unsaturated phosphatidyl-cholines. We proved, that the bolalipids PC-C32(1,32C6)-PC and PC-C32(1,32C9)-PC show miscibility with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). In the present work, we extended our vesicle system to natural lipid mixtures using phosphatidylcholine from soy beans, and we investigated the effect of incorporated bolalipids on the integrity of these mixed liposomes (bolasomes) in different gastrointestinal fluids using a dithionite assay and a calcein release assay in combination with particle size measurements. Finally, we also studied the retention of calcein within the bolasomes during freeze-drying. As a main result, we could show that in particular PC-C32(1,32C6)-PC is able to increase the stability of bolasomes in simulated gastric fluid—a prerequisite for the further use of liposomes as oral drug delivery vehicles.

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“…A number of studies have investigated the interactions of bile salts with simplified membrane models as liposomes (7)(8)(9)(10)(11). From the structural viewpoint, some mechanistic hypotheses have been offered to account for these interactions where a dispersed hexagonal phase in coexistence with aqueous bile salt monomers and either micellar or unilamellar phases appears as crucial intermediate both in the closure and solubilization processes (6,12,13).…”

mentioning

confidence: 99%

Assembly properties of the aggregates resulting in the solubilization of phosphatidylcholine bilayers by sodium cholate

Maza

Parra

1998

J Surfact & Detergents

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The interaction of sodium cholate with phosphatidylcholine liposomes was investigated. Permeability alterations were detected as a change in 5(6)-carboxyfluorescein (CF) released from the interior of vesicles and bilayer solubilization as a decrease in the static light-scattered by liposomes. Free surfactant concentration at subsolubilizing and solubilizing levels showed, respectively, values that were lower than and similar to the surfactant critical micelle concentration, and indicated that permeability alterations and solubilization were determined, respectively, by the action of surfactant monomer and by the formation of mixed micelles. A direct relationship was established in the initial steps [effective surfactant/lipid molar ratio (Re) lower than 0.07] between the growth of vesicles, the leakage of entrapped CF (fluidity of vesicles), and Re. These changes could be correlated with the increasing presence of surfactant molecules in the outer monolayer of vesicles and its saturation. The subsequent increase in Re led to a lower growth of vesicles in coexistence with a similar increase in the CF release. This behavior could be related to a increased rate of flipflop of the sodium cholate molecules, making the inner monolayer also available for the interaction with added surfactant. A direct dependence was also established in the initial solubilization steps (Re values up to 0.6) between the surfactant-phosphatidylcholine aggregate size, the static light-scattering of the system, and Re. In the Re interval 0.36-0.84 mixed vesicles and mixed micelles coexisted. JSD 1, 41-47 (1998). KEY WORDS:Carboxyfluorescein release, permeability alterations and bilayer solubilization, phosphatidylcholine liposomes, phosphatidylcholine/sodium cholate mixed micelles, phosphatidylcholine/sodium cholate mixed vesicles, sodium cholate, static light-scattering measurements, surfactant-PC aggregate size, surfactant/phospholipid molar ratios. FIG. 3. Gibbs triangle for SC/PC/water system (99% of water in weight) with PC concentration ranging from 0.5 to 5.0 mM. See Figures 1 and 2 for abbreviations.46

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Solubilization of multilamellar liposomes of egg yolk lecithin by the bile salt sodiumtaurodeoxycholate and the effect of cholesterol — a rapid-ultrafiltration study

Cited by 12 publications

References 34 publications

Intermediate aggregates resulting in the interaction of bile salt with liposomes studied by transmission electron microscopy and light scattering techniques

Intermediate aggregates resulting in the interaction of bile salt with liposomes studied by transmission electron microscopy and light scattering techniques

Bolalipid-Doped Liposomes: Can Bolalipids Increase the Integrity of Liposomes Exposed to Gastrointestinal Fluids?

Assembly properties of the aggregates resulting in the solubilization of phosphatidylcholine bilayers by sodium cholate

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