1. Noncovalent Functionalization of Carbon Nanotubes with Amphiphilic Gd3+ Chelates: Toward Powerful T1 and T2 MRI Contrast Agents
- Author
-
Jean-Claude Beloeil, Michel Bessodes, Éva Tóth, Daniel Scherman, Bich-Thuy Doan, and Cyrille Richard
- Subjects
Materials science ,Gadolinium ,Inorganic chemistry ,Contrast Media ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Nuclear magnetic resonance ,law ,Amphiphile ,General Materials Science ,Chelation ,Chelating Agents ,Aqueous solution ,Nanotubes, Carbon ,Mechanical Engineering ,Relaxation (NMR) ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Magnetic Resonance Imaging ,0104 chemical sciences ,chemistry ,Surface modification ,Stearic acid ,0210 nano-technology - 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.
- Published
- 2007