Small-Angle Neutron Scattering investigation of cholesterol-doped DMPC liposomes interacting with β-cyclodextrin

Abstract

The Small Angle Neutron Scattering technique (SANS) has been applied to investigate the interaction between a cyclodextrin (CD) and liposomes. From the modelling of the experimental neutron scattering cross sections, the detailed structure of dimyristoylphosphatidylcholine (DMPC) liposomes is assessed upon addition of increasing amounts of randomly methylated β-CD (RAMEB). This study has been performed at two temperatures bracketing the phase transition of the DMPC bilayers. The fraction of DMPC molecules incorporated into the vesicles is inferred. The dose-dependent phospholipidic extraction by RAMEB is quantified as well as the concomitant evolution of the liposome radius and of the thickness of the hydrophobic and hydrophilic parts of the membrane. The possible formation of CD-DMPC inclusion complexes is also assessed. The data suggest the dose-dependent coverage by RAMEB of the outer liposome interface. Our analysis highlights the important role of temperature on the mechanism of action of RAMEB. These results are discussed in the framework of the Area-Difference-Elasticity model.

Advances in Hybrid Polymer-Based Materials for Sustained Drug Release

“…Liposomes are composed of lipid bilayers, in which amphiphilic phospholipids carry a hydrophilic group (head) and two hydrophobic acyl chains (tail) [69]. In these lipid vesicles, formed by the hydrophobic effect to maximize the interaction between the acyl chains, protecting them from the contact with the aqueous medium, the hydrophobic tails turn towards the inside of the lamella and the polar heads are exposed outward, in contact with water [69].…”

“…In these lipid vesicles, formed by the hydrophobic effect to maximize the interaction between the acyl chains, protecting them from the contact with the aqueous medium, the hydrophobic tails turn towards the inside of the lamella and the polar heads are exposed outward, in contact with water [69]. Due to the presence of an aqueous compartment and lipid bilayers, liposomes can incorporate hydrophilic and hydrophobic molecules, which is quite interesting for a drug carrier [70].…”