Immobilization of nanostructured lipid particles in polysaccharide films.

Lipid-based equilibrium self-assemblies and their hierarchically ordered forms have been known since the last few decades. Related progress in colloids and interface science led the development of oil-in-water type internally self-assembled lipid particles, known as Isasomes, which have aroused great interest in biotechnological applications. These submicrometer-sized lipid particles are internally nanostructured in a form of various liquid-crystalline or microemulsion phases, which facilitate their loading with hydrophilic, hydrophobic, and amphiphilic molecules. Their internal nanostructure can also be finely tuned. Recently, it has been shown that Isasomes can be entrapped in thermoreversible polysaccharide hydrogels. Herein, we report on the immobilization of Isasomes in solid polysaccharide films prepared by drying particle-loaded κ-carrageenan and methyl cellulose-based hydrogels. These rather simple but elegant media facilitate the storage of these functional particles and their subsequent release by simple resolubilization in water and/or thermal transitions. Systematic rehydration studies of such Isasome-loaded films have shown that the Isasomes can be remobilized and/or recovered after resolubilization of loaded films, even after several months.