Magnetic multilamellar liposomes produced by in situ synthesis of iron oxide nanoparticles: "magnetonions".

We report the formation of magnetic onion-type multilamellar vesicles. Iron oxide nanoparticles (np's) were synthesized inside lipidic multilamellar vesicles by coprecipitation of vesicle-encapsulated Fe(2+) and Fe(3+) ions induced by HO(-) diffusion through vesicle lamellae. The iron ion encapsulation efficiency of onions was measured by potentiometry and UV-vis absorbance spectroscopy.