Facile functionalization of lipid bilayer vesicles by titania: the use of cerasome-forming lipids for surface and core modification.

Two kinds of functionalization of a lipid bilayer vesicle by titania were achieved by utilizing a cerasome-forming lipid, which is the starting material to prepare a cerasome, a morphologically stable lipid bilayer vesicle having an atomic layer of siloxane networks on its surface. One system is the preparation of the titania-coated cerasomes by immobilizing nanaometer-sizes of titania onto the surface siloxane network of cerasomes. The other is the creation of an asymmetric lipid bilayer structure on the surface of the colloidal titania particles. The characteristics of these surface- and core-functionalized vesicles were investigated, and it was found that these conjugates showed photocatalytic activity as evaluated by photolysis experiments of the cationic dye methylene blue.