Synthesis and Characterization of Iron Oxide Nanoparticles Encapsulated in Lipid Membranes

Over the last years, great interest has developed in the potential use of magnetic loaded particles in medicine and particularly for drug delivery purposes or probes for magnetic resonance imaging. Iron oxide nanocrystals with a diameter of ca. 5 nm were synthesized and characterized with X-ray diffraction, dynamic light scattering, zeta-potential and transmission electron microscopy. Magnetoliposomes, consisted of egg-phosphatidylcholine, were prepared by incorporating these crystals into their structure. The incorporation of the iron oxide nanoparticles into liposomes altered their physicochemical properties. A decrease of the surface charge of the nanocrystals was noticed upon their encapsulation into liposomes providing evidence of their successful incorporation into the liposomal bilayers. Moreover, visualization studies confirmed that the ferrofluid is mainly located in the aqueous compartment of liposomes. These preliminary results demonstrate a simple method to prepare magnetoliposomes containing iron oxide nanocrystals.