Colloids containing gadolinium-capped gold nanoparticles as high relaxivity dual-modality contrast agents for CT and MRI.

A type of novel macromolecular colloid was prepared from gadolinium-based poly(l-succinimide) and gold nanoparticles (GNPs) with Au-S covalent bonds. The colloid displayed improved stability in aqueous media and regular arrays in partial region. Moreover, these materials enhanced the contrast 9 times more than that of the corresponding uncoated Au compound when the Au mass content was only 0.15%. Therefore, these materials might have potential as dual-modality contrast agents for magnetic resonance imaging (MRI) and computed tomography (CT).