title: Lanthanide complexes on Ag nanoparticles: designing contrast agents for magnetic resonance imaging.
abstract: This paper describes colloidal particles that are designed to induce hyper-intensity contrast (T(1) 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 r(1) relaxivities of the of the surface bound complexes (obtained at 9.4 T and 25 degrees 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 Magnevist. Correspondingly, the respective whole particle relaxivities are 27927 and 13153 s(-1) mM(-1).
authors.affiliation: Department of Chemistry, New York University, New York, NY 10003, USA.
authors.forename: Talha S
authors.initials: TS
authors.lastname: Siddiqui
authors.forename: Ashish
authors.initials: A
authors.lastname: Jani
authors.forename: Florence
authors.initials: F
authors.lastname: Williams
authors.forename: Robert N
authors.initials: RN
authors.lastname: Muller
authors.forename: Luce
authors.initials: L
authors.lastname: Vander Elst
authors.forename: Sophie
authors.initials: S
authors.lastname: Laurent
authors.forename: Fang
authors.initials: F
authors.lastname: Yao
authors.forename: Youssef Zaim
authors.initials: YZ
authors.lastname: Wadghiri
authors.forename: Marc A
authors.initials: MA
authors.lastname: Walters
mesh_terms: D003287:Contrast Media / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D053768:Metal Nanoparticles; D046529:Microscopy, Electron, Transmission; D013056:Spectrophotometry, Ultraviolet
chemical_list: D003287:Contrast Media; D028581:Lanthanoid Series Elements; D006046:Gold