Biocompatible superparamagnetic iron oxide nanoparticles used for contrast agents: a structural and magnetic study

Biocompatible superparamagnetic iron oxide nanoparticles used for contrast agents: a structural and magnetic study
30 November 2004
L.F. Gamarra, G.E.S. Brito, W.M. Pontuschka, E. Amaro, A.H.C. Parma and G.F. Goya
Science Direct
Abstract
The magnetic properties of different biocompatible magnetic iron oxide nanoparticles (MION) are presented. Dextran-coated, magnetite (Fe3O4) MIONs were studied as supplied and after lyophilization, to disentangle the effects of particle interactions. All samples showed superparamagnetic behavior at room temperature, with blocking transitions at TB40?56 K (at 100 Oe), depending on the particle interactions. The dynamics of the thermally activated blocking process reveals that the effect of dipolar interactions is to increase the energy barriers of the individual particles.
Keywords: Magnetic nanoparticles; Contrast media; Magnetic anisotropy