The Delivery of Lipidic Compounds to Model Membrane Interfaces by Non-lamellar Liquid Crystalline Nano-particles

Abstract

There is an increasing demand for methods to study processes at the lipid-aqueous solution interface, due to the importance of lipids and lipid self-assembly structures as regulators both for biological activity and for drug delivery vehicles. The biological membrane is one of the most important interfaces that the drug delivery vehicles encounter. The potential use of non-lamellar lipid structures delivery systems in pharmaceutical, food and cosmetic applications has invoked a number of studies of the assembly and interactions of cubic phases of these materials. One such system is a colloidal dispersion of the cubic liquid crystalline phase of glycerol monooleate. We will discuss some aspects of what happens when these liquid crystalline lipid nanoparticle encounters a lipid bilayer, consisting dioleoylphosphaticylcholine, either as supported bilayer or as a vesicle. Null ellipsometry and QCM-D provides kinetic information about the adsorption and triggerable release of the nanoparticles. Using contrast matching of the supported lipid bilayer, neutron reflectivity makes it possible to assess the exchange of material from one ordered lipid phase to another. Synchrotron Small Angle X-Ray Diffraction allowed us to in detail study the phase transition when non-lamellar glycerol monooleate based nanoparticle interact with phospholipid vesicles. Together the four techniques provide insight into the interaction mechanism and shows that the release of the particles are likely to be caused by phase transition of the lipid self-assembled structures.