Preparation and Characterization of A Novel MRI/CT Dual-function Contrast Agent

• 1、Biomedical Engineering School, Shanghai Jiaotong University, Shanghai 200030

Abstract： In this paper, we prepare a novel MRI/ CT dual-functional contrast agent. Methods Hydrophobic size- controllable gold and Fe3O4 nanoparticles were prepared by high-temperature organometallic route. Then the particles were assembled by an amphiphilic polymer (mPEG-PLA) into hydrophilic nanoclusters. The clusters' morphology, composition, size, and stability were examined by scanning electron microscope (TEM), X ray spectrometer (EDS) and dynamic light scattering (DLS), respectively. The encapsuled efficiency (EE), loading capacity (LC) and MRI/CT properties corresponding to different compositions of Au/ Fe3O4 nanoparticles were also studied. Results As-synthesized Au and Fe3O4 nanoparticles were spherical in shape with the mean size of 7.25 nm and 9 nm , respectively. The molecular weight of PLA was 6246. The EE and LC of Au nanoparticles, Fe3O4 nanoparticles and the composite nanoclusters were diverse. The r2 increased with the increase of Fe3O4 component in the composite clustes , which led to more prominent contrast in MRI. In contrast, the CT contrast increased with increase of Au component. Conclusion In summary, we have synthesized Au/ Fe3O4 composite nanoclusters for MRI/CT dual-functional imaging. The novel contrast agent was stable in physiological condition and promising for clinical use in future.

Keywords： biomaterial CT MRI gold nanoparticles Fe3O4 nanoparticles