Characterization and potential applications of nanostructured aqueous dispersions

The present article highlights recent advances and current status in the characterization and the utilization of nanostructured aqueous dispersions in which the submicron-sized dispersed particles envelope a distinctive well-defined self-assembled interior. The scope of this review covers dispersions of both inverted-type liquid-crystalline particles (cubosomes, hexosomes, micellar cubosomes, and sponge phases), and microemulsion droplets (emulsified microemulsions, EMEs). Recent investigations that have attempted to shed light on the characterization and the control of confined nanostructures of aqueous dispersions are surveyed, as these nanoobjects are attractive for various pharmaceutical and food applications. The focus has been placed on three main subjects: (1) our findings on the formation of EMEs and the modulation of the internal nanostructure, exploring how variations in temperature, oil content, and lipid composition significantly affect the confined nanostructures; (2) recent developments in the field of electron microscopy: using the tilt-angle cryo-TEM method or cryo-field emission scanning electron microscopy (cryo-FESEM) for observing the three dimensional (3D) morphology of non-lamellar liquid-crystalline nanostructured particles (cubosome and hexosome particles); and (3) recent studies on the utilization of nanostructured dispersions as drug nanocarriers.