title: Magnetic multilamellar liposomes produced by in situ synthesis of iron oxide nanoparticles: "magnetonions".
abstract: 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. Its high value (75 +/- 5% for both Fe(2+) and Fe(3+)) ensures an intravesicular synthesis, as confirmed by cryo-transmission electron microscopy (TEM) imaging. The as-grown nanoparticles are characterized by X-ray diffraction analysis and TEM, and magnetic onions are imaged by cryo-TEM. The np size, controlled by temperature and time, ranges from 3 to 6 nm and is shown to be a key parameter for onion stability.
authors.affiliation: Centre de Recherche Paul Pascal, CNRS-Universite Bordeaux, Pessac, France. shigeo-ssk@chem.kyushu-univ.jp
authors.forename: Chrystel
authors.initials: C
authors.lastname: Faure
authors.forename: Marie-Edith
authors.initials: ME
authors.lastname: Meyre
authors.forename: Sylvain
authors.initials: S
authors.lastname: Trépout
authors.forename: Olivier
authors.initials: O
authors.lastname: Lambert
authors.forename: Eric
authors.initials: E
authors.lastname: Lebraud
mesh_terms: D004058:Diffusion; D005290:Ferric Compounds / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D010316:Particle Size; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D005290:Ferric Compounds; D008081:Liposomes; D009930:Organic Chemicals; C000499:ferric oxide; D007501:Iron