title: Fine tuning of the relaxometry of γ-Fe2O3@SiO2 nanoparticles by tweaking the silica coating thickness.
abstract: We report the fine-tuning of the relaxometry of gamma-Fe2O3@SiO2 core-shell nanoparticles by adjusting the thickness of the coated silica layer. It is clear that the coating thickness of Fe2O3@SiO2 nanoparticles has a significant impact on the r(1) (at low B0 fields), r(2), and r(2)* relaxivities of their aqueous suspensions. These studies clearly indicate that the silica layer is heterogeneous and has regions that are porous to water and others-that are not. It is also shown, that the viability and the mitochondrial dehydrogenase expression of the microglial cells do not appear to be sensitive to the vesicular load with these core-shell nanoparticles. The adequate silica-shell thickness can therefore be tuned to allow for both a sufficiently high response as contrast agent, and-adequate grafting of targeted biomolecules.
authors.affiliation: CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr. A. Schweitzer, Pessac F-33608, France.
authors.forename: Sonia L C
authors.initials: SL
authors.lastname: Pinho
authors.forename: Giovannia A
authors.initials: GA
authors.lastname: Pereira
authors.forename: Pierre
authors.initials: P
authors.lastname: Voisin
authors.forename: Jinane
authors.initials: J
authors.lastname: Kassem
authors.forename: Véronique
authors.initials: V
authors.lastname: Bouchaud
authors.forename: Laetitia
authors.initials: L
authors.lastname: Etienne
authors.forename: Joop A
authors.initials: JA
authors.lastname: Peters
authors.forename: Luis
authors.initials: L
authors.lastname: Carlos
authors.forename: Stéphane
authors.initials: S
authors.lastname: Mornet
authors.forename: Carlos F G C
authors.initials: CF
authors.lastname: Geraldes
authors.forename: João
authors.initials: J
authors.lastname: Rocha
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Delville
mesh_terms: D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D005290:Ferric Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D017628:Microglia / Q000166:cytology / Q000187:drug effects; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; D014867:Water; C000499:ferric oxide; D012822:Silicon Dioxide