This paper describes colloidal particles that are designed to induce hyper-intensity contrast (T1 relaxation) in MRI. The contrast agents consist of discrete gadolinium complexes tethered to 10 nm diameter silver nanoparticles. The gadolinium complexes (1) [Gd(DTPA-bisamido cysteine)]2- and (2) [Gd(cystine-NTA)2]3-, undergo chemisorption to particle surfaces through thiol or disulfide groups, respectively, to form two new contrast agents. The resulting nanoparticulate constructs are characterized on the basis of their syntheses, composition, spectra and contrast enhancing power. The average r1 relaxivities of the of the surface bound complexes (obtained at 9.4 T and 25 °C) are 10.7 and 9.7 s-1 mM-1, respectively, as compared to 4.7 s-1 mM-1 for the clinical agent MagnevistTM. Correspondingly, the respective whole particle relaxivities are 27927 and 13153 s-1 mM-1.
- Longitudinal relaxation
- Monolayer protected
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry