Synthesis and Application of Magnetic Iron Oxide Nanoparticles as High Efficiency Magnetic Resonance Imaging Contrast Agent

Iron oxide nanoparticles were synthesized by thermal decomposition of iron (III) acetylacetonate (Fe(acac)3) in poly(ethylene glycol) (PEG), which was used as the solvent, reducing agent and modifying agent. X-ray powder diffraction (XRD) analysis indicates that the nanoparticles have magnetite crystal structure. The results of transmission electron microscope (TEM) show that the shapes of iron oxide nanoparticles coated with PEG are equiaxial with uniform morphology. Particles and Zeta potential analyses show that the surface of iron oxide nanoparticles is negatively charged, and their hydrodynamics size dispersed in deionized water is 20 nm. Iron oxide nanoparticles show superparamagnetic behavior at room temperature and high r2/r1 ratio. MTT studies show that PEG-SPIONs have low cytotoxicity. In vivo magnetic resonance imaging reveals their excellent contrast effects of the PEG-SPIONs. This work demonstrates that iron oxide nanoparticles coated with PEG can be excellent T2 MRI contrast agents.