Preparation, microstructure and function for injectable liposome-hydrogels A Physicochemical and engineering aspects

A novel injectable liposome-hydrogels was prepared by combined methods of thin-film evaporation and supercritical carbon dioxide technique (TE-scCO2) for drug delivery of tissue regeneration. The liposome-hydrogels with thermosensitive is colloidal sol at room temperature, but it is gel at body temperature. Therefore, the thermosensitive liposome-hydrogels can get into the target area by injecting process at room temperature, and it will convert to gel at body temperature. In curcumin liposome-hydrogels (Cur-Lps-H), curcumin (Cur) as model drug was loaded in liposomes and the liposome was embedded in three-dimensional porous chitosan/β-glycerophosphate hydrogel. The microstructure of Cur-Lps-H was studied by using pyrene and 1,6-diphenyl-1,3,5-hexatriene (DPH) as fluorescent probes, and it was found that Cur was entrapped in bilayer of liposomes and its saturated concentration in bilayer of liposomes was about 0.012 (mass ratio of Cur to lecithin). The Cur-Lps-H prepared by TE-scCO2 method had higher entrapment efficiency and better stability in comparasion with that prepared by thin film hydration (FH). Moreover, the Cur-Lps-H possessed obviously sustained-release effect (extend to 12 days) in vitro, which was longer than other drug delivery system. Therefore injectable liposome-hydrogels is a potential drug delivery system.