title: Noncovalent functionalization of carbon nanotubes with amphiphilic gd3+ chelates: toward powerful t1 and t2 MRI contrast agents.
abstract: An amphiphilic gadolinium (III) chelate (GdL) was synthesized from commercially available stearic acid. Aqueous solutions of the complex at different concentrations (from 1 mM to 1 microM) were prepared and adsorbed on multiwalled carbon nanotubes. The resulting suspensions were stable for several days and have been characterized with regard to magnetic resonance imaging (MRI) contrast agent applications. Longitudinal water proton relaxivities, r1, have been measured at 20, 300, and 500 MHz. The r1 values show a strong dependence on the GdL concentration, particularly at low field. The relaxivities decrease with increasing field as it is predicted by the Solomon-Bloembergen-Morgan theory. Transverse water proton relaxation times, T2, have also been measured and are practically independent of both the frequency and the GdL concentration. An in vivo feasibility MRI study has been performed at 300 MHz in mice. A negative contrast could be well observed after injection of a suspension of functionalized nanotubes into the muscle of the leg of the mouse.
authors: Unité de Pharmacologie Chimique et Génétique; CNRS, UMR 8151, Paris. cyrille.richard@univ-paris5.fr
authors: Cyrille
authors: C
authors: Richard
authors: Bich-Thuy
authors: BT
authors: Doan
authors: Jean-Claude
authors: JC
authors: Beloeil
authors: Michel
authors: M
authors: Bessodes
authors: Eva
authors: E
authors: Tóth
authors: Daniel
authors: D
authors: Scherman
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D003287:Contrast Media; D005682:Gadolinium / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D037742:Nanotubes, Carbon
chemical_list: D002614:Chelating Agents; D003287:Contrast Media; D037742:Nanotubes, Carbon; D005682:Gadolinium