Wormlike reverse micelles in lecithin/bile salt/water mixtures in oil

Cautela, Jacopo; Giustini, Mauro; Pavel, Nicolae Viorel; Palazzo, Gerardo; Galantini, Luciano

doi:10.1016/j.colsurfa.2017.04.052

Cited by 20 publications

(18 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…TheS AXS curve shown in Figure 1A has the profile typical of elongated scattering particles, for which an average cross-sectionalg yration radius (R c )o f( 6.0 AE 0.1) was estimated by the Guinierp lot in the form suitable for rod-like particles ( Figure 1A,i nset). The overall SAXS curve can also be fitted by using the form factor of infinitely long cylinders (i.e.,a ssumingr ods characterised by ap ersistencel ength much larger than that of the experimental resolution of 150 ) [25] to obtain ab est fit parameter of ac rosssection radius of (9.7 AE 0.1) ( Figure 1A). Therefore, SAXS analysis reveals the presence of elongated, 1D, rigid structures that account fort he dramatic growth in solution viscosity.I na ddition, fluorescencer ecovery after photobleaching (FRAP) measurements do not showany appreciable recovery of the fluorescence signal within at ime intervalo f1 0safter bleaching (Figure S1 in the SupportingI nformation).…”

Section: Resultsmentioning

confidence: 99%

A Stereochemically Driven Supramolecular Polymerisation

Tasca

D’Abramo

Galantini

et al. 2018

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

Anthracyclines self-assemble in water into dimers. In the presence of sufficiently high salt (NaCl) concentrations, solutions of the antibiotic doxorubicin, but not those of the closely related molecules daunomycin and epirubicin, turn into gels barely compatible with the presence of small oligomers. The use of spectroscopic, scattering, imaging and computational techniques, allowed light to be shed on the self-assembly process that triggered doxorubicin gelification. A complex picture emerged, with doxorubicin molecules assembled into long, highly chiral, supramolecular aggregates made of hundreds of units, showing redshifted fluorescence spectra, very short fluorescence lifetimes and small-angle X-ray scattering profiles compatible with long cylinders. The involvement of specific chemical groups and the need for a specific stereochemistry of the monomers in the formation of a hydrogen-bond network to stabilise the supramolecular aggregates was supported by molecular dynamics calculations. A salt-induced, temperature-dependent, cooperative nucleation-elongation supramolecular polymerisation of the doxorubicin molecules is deduced.

show abstract

Section: Resultsmentioning

confidence: 99%

A Stereochemically Driven Supramolecular Polymerisation

Tasca

D’Abramo

Galantini

et al. 2018

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…Similarly, the viscosity build-up caused by an entanglement of worm-like mixed micelles in lipid-bile salt mixtures has been reported earlier. 8,29,76…”

Section: Emulsification Of Lipid Self-assemblies Into Discrete Particlesmentioning

confidence: 99%

Bile Salts Caught in the Act: From Emulsification to Nanostructural Reorganization of Lipid Self-Assemblies

et al. 2018

View full text Add to dashboard Cite

Bile salts (BS) are important for digestion and absorption of fats and fat-soluble vitamins in the small intestine. In this work, we scrutinized, with small angle X-ray scattering (SAXS), the crucial functions of bile salts beyond their capacity for interfacial stabilization of submicron sized lipid particles. By studying a wide compositional range of BS-lipid dispersions using two widely applied lipids for drug-delivery systems (one a monoglyceride being stabilizer-sensitive and the other an aliphatic alcohol being relatively stabilizer-insensitive), we identified the necessary BS to lipid ratios for guaranteeing full emulsification. A novel ad hoc developed global small angle-X-ray scattering analysis method revealed that the addition of BS hardly changes the bilayer thicknesses in bicontinuous phases, while a significant membrane thinning is observed in the coexisting fluid lamellar phase. Furthermore, we show that BS strongly decreases the average critical packing parameter. At increasing BS concentration, the order of phases formed are (i) the bicontinuous diamond cubic (Pn3m), (ii) the bicontinuous primitive cubic (Im3m) followed by (iii) the fluid lamellar phase (L α). These distinctive findings on BS driven 'emulsification' and 'membrane curvature reduction' provide new molecular scale insights for the understanding of the interfacial action of bile salts on lipid-assemblies.

show abstract

“…This moiety is bounded to glycerol and two fatty acyl groups (to provide lipophilicity), such as palmitic, stearic, oleic, and linoleic acids. PtdCho molecules can self-assemble when present above the critical micelle concentration (CMC), forming either spherical or ellipsoidal reverse micelles when dispersed in oily phase or bilayers (lamellar phase) (Cautela et al, 2017;Shchipunov, 2001;Walde et al, 1990). Above the CMC of lecithin, a viscoelastic structure can be formed by establishment of a transient network of entangled micelles (Dreiss, 2007;Schurtenberger et al, 1989).…”

Section: Introductionmentioning

confidence: 99%

Self‐Organizing Structures of Phosphatidylcholine in Nonaqueous Solvents: Tailoring Gel‐like Systems

Okuro

Malfatti-Gasperini

Fasolin

et al. 2020

J Surfact & Detergents

View full text Add to dashboard Cite

In this paper, we investigated the role played by solvent type and additives (water [W] and citric acid [CA]) on the self-assembly of phosphatidylcholine (PtdCho) into gels. Soybean lecithin (L) served as the PtdCho source used in this study. Lecithin was combined with different oils: hexadecane (HEX), sunflower oil, and medium-chain triacylglycerol to explore its ability to form organogels. Among the solvents, only HEX was able to form a translucent self-sustainable gel with lecithin. It was found that the lower water solubility and viscosity of HEX favored gel formation. Small-angle X-ray scattering revealed different structures arisen from lecithin organization depending on the organic medium type. In addition, the gel properties of the L-HEX binary system were also tailored through inclusion of the "primers" W or CA. Oscillatory rheological behavior of organogels was effectively described by a single relaxation-time Maxwell model, with good fitting at low and intermediate frequencies and with deviations at higher frequencies, indicating the presence of reverse wormlike micelles. Organogels were thermoreversible and, upon CA addition, a substantial increase in zero-shear viscosity was observed. Incorporation of W led to a similar microstructure to that obtained only with L, whereas CA promoted a different ordering of PtdCho assemblies. Formation and properties of PtdCho-based organogels were dictated by using different oil types or by changing the polarity of the medium with the incorporation of primers. A better understanding of phospholipid-based nonlamellar mesophases in organic solvent offers the prospect of adapting the gel properties to the desired application and functionality.

show abstract

Wormlike reverse micelles in lecithin/bile salt/water mixtures in oil

Cited by 20 publications

References 74 publications

A Stereochemically Driven Supramolecular Polymerisation

A Stereochemically Driven Supramolecular Polymerisation

Bile Salts Caught in the Act: From Emulsification to Nanostructural Reorganization of Lipid Self-Assemblies

Self‐Organizing Structures of Phosphatidylcholine in Nonaqueous Solvents: Tailoring Gel‐like Systems

Contact Info

Product

Resources

About