Relaxometric and magnetic characterization of ultrasmall iron oxide nanoparticles with high magnetization. Evaluation as potential T1 magnetic resonance imaging contrast agents for molecular imaging.
Here we report on the synthesis of ultrasmall gamma-Fe2O3 nanoparticles (5 nm) presenting a very narrow particle size distribution and an exceptionally high saturation magnetization. The synthesis has been carried out by decomposition of an iron organometallic precursor in an organic medium. The particles were subsequently stabilized in an aqueous solution at physiological pH, and the colloidal dispersions have been thoroughly characterized by complementary techniques. Particular attention has been given to the assessment of the mean particle size by transmission electron microscopy, X-ray diffraction, dynamic light scattering, magnetic, and relaxometric measurements. The good agreement found between the different techniques points to a very narrow particle size distribution. Regarding the magnetic properties, the particles are superparamagnetic at room temperature and present an unusually high saturation magnetization value. In addition, we describe the potential of these particles as specific positive contrast agents for magnetic resonance molecular imaging.
Taboada
Elena
E
Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas (ICMAB-CSIC), Esfera de la UAB, 08193 Bellaterra, Catalunya, Spain.
Rodríguez
Elisenda
E
Roig
Anna
A
Oró
Judit
J
Roch
Alain
A
Muller
Robert N
RN
D002626:Chemistry, Pharmaceutical / Q000379:methods; D003287:Contrast Media / Q000494:pharmacology*; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008027:Light; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D010087:Oxides / Q000737:chemistry; D012542:Scattering, Radiation; D013696:Temperature; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
D003287:Contrast Media; D005290:Ferric Compounds; D010087:Oxides; D014867:Water; C000499:ferric oxide