Preparation of water-dispersible and biocompatible iron oxide nanoparticles for MRI agent

Abstract

Highly monodisperse superparamagnetic iron oxide nanoparticles (SPIONs, 7.5 nm gamma - Fe2O3) were synthesized by thermal decomposition of iron pentacarbonyl and consecutive aeration in organic medium. By treating with a small amount of iron pentacarbonyl, Fe-rich surface has been formed on SPION. Water-dispersible SPIONs (SPION-MPA) were prepared by Fe-S covalent conjugation between Fe-rich SPION and mercaptopropionic acid (MPA) and then, transformed to SPION - MPA - dextran composite by physical adsorption of biocompatible polymer dextran. The hydrodynamic diameter of SPION - MPA - dextran was in the range of 225 similar to 237 urn in water. MR contrast and spin-spin relaxation intensity of our SPION - MPA - dextran were similar to those of the commercial products, Ferridex and Resovist.