Water-soluble gadolinium fullerenes Gd@C82-TEGs as a potential magnetic resonance imaging contrast agent

The water-soluble gadolinium fullerenes Gd@C82-TEGs nanoparticles as a novel magnetic resonance imaging (MRI) contrast agent were fabricated by the metal fullerenes Gd@C82 assembled with tetraethylene glycol (TEG). The loading Gd amount in Gd@C82-TEGs nanoparticles was 8.0 wt%. The average particle size of water-soluble Gd@C82-TEGs nanoparticles was 97 nm and the nanoparticles were uniformly spherical shape and had good dispersibility and no aggregation. The 97 nm spherical shape of Gd@C82-TEG nanoparticles ensured high relaxivity. The proton relaxivity (r1) and transverse relaxivity (r2) were high up to 37.1 mM-1·s-1 and 64.9 mM-1·s-1, which greater than that of commercial Magnevist under the same conditions. The Gd@C82-TEGs nanoparticles exhibited pronounced T1-weighted MRI in vitro. The MRI signal-enhancing efficiency of Gd@C82-TEGs nanoparticles was superior to that of gadolinium diethylenetriamine pentaacetate Gd-DTPA (Magnevist). The Gd@C82-TEGs nanoparticles had no significant effect on cell metabolism and structure, and the survival rate of cells was more than 80%, which indicated that the as-prepared Gd@C82-TEGs nanoparticles were no cytotoxicity.