Synthesis of Sub-100-nm Liposomes via Hydration in a Packed Bed of Colloidal Particles

Drug delivery using liposomal carriers for targeting the afflicted areas of the host has attracted significant interest in the scientific community. While traditional liposome preparation techniques result in polydisperse suspension, postprocessing steps such as extrusion or filtering is required to obtain monodisperse liposomes in the sub-100-nm size range. Here, we describe a novel technique to synthesize monodisperse liposomes in the sub-100-nm size range using a packed bed of colloidal particles which could also be used to simultaneously encapsulate a drug. The methodology involves drying lipids dispersed in an organic solvent in a capillary packed with colloidal particles, which upon hydration with an aqueous buffer containing a drug leads to liposome formation with simultaneous encapsulation of the drug. Our experiments show that the size of the liposome is independent of the particle size or the pore size. The robustness of the process and the extremely tight control on the liposome size range make...