Internalization of silica nanoparticles into fluid liposomes: formation of interesting hybrid colloids.

The formation of hybrid materials consisting of membrane-coated silica nanoparticles (SiNPs) concentrated within small unilamellar vesicles (SUVs) of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) is described. They are formed by a simple self-assembly process resulting from invagination of the SiNPs into the SUVs and subsequent vesicle fusion, thereby retaining an almost constant size. This process was followed under conditions where it proceeds slowly and could be analyzed in structural detail. The finally formed well-defined SiNP-filled vesicles are long-time stable hybrid colloids and their structure is conveniently controlled by the initial mixing ratio of SiNPs and vesicles.