SYNTHESIS OF GADOLINIUM OXIDE BASED NANOCOMPOSITES AS EFFECTIVE MAGNETIC RESONANCE IMAGING T1 CONTRAST AGENTS

Abstract

Magnetic resonance imaging (MRI) has been widely used to diagnose various diseases. As a positive MRI contrast agent, gadolinium oxide (Gd2O3) is the most promising one due to its paramagnetism and good biocompatibility. However, post-modification on hydrophobic Gd2O3 nanoparticles (NPs) often yield water soluble nanocomposites with some problems: particles aggregation which reduces the number of effective surface Gd ions; and thick coating on NPs which increases the distance between Gd ion and water proton. Such drawbacks influence total longitudinal. Thus, it is significant to develop better designed nanostructures and better controlled post-modification process. This thesis aimed at improving current paramagnetic Gd2O3 NPs based contrast agent utilized in MRI and other application field. We employed new surfactant, controlled the NPs spatial distribution in modification process precisely, and designed new nanostructure for high-performance positive contrast agents. MR test showed all Gd2O3 based contrast agents discussed in this thesis exhibited effective T1 enhancement.