Design of gold nanoparticles for magnetic resonance imaging

Molecular complexes containing the element gadolinium are proven agents for increasing the diagnostic utility of magnetic resonance imaging (MRI), but their use in detecting small tumors is limited by the relatively weak signal these agents produce.

In order to produce a more powerful MRI contrast agent, investigators at the Université Claude Bernard Lyon in France, have developed a method for attaching multiple gadolinium atoms to the surface of gold nanoparticles.

Reporting its work in the journal Advanced Functional Materials, a research team led by Stéphane Roux, Ph.D., and Olivier Tillement, Ph.D., describes the chemical method it used to prepare gold nanoparticles capable of binding strongly to gadolinium. This method produces a multilayered nanoparticle containing an average of 150 gadolinium binding sites covering the 2-nanometer-diameter gold particles. The dense packing of the gadolinium-binding molecule on the nanoparticle surface appears to stabilize the construct under physiological conditions.

Magnetic resonance experiments showed that this nanoparticle-based agent produces a magnetic signal nearly 200 times stronger than that produced by typical gadolinium complexes. Based on these results, the investigators are now modifying their formulation methods in order to add tumor-targeting agents to the nanoparticle surface. They also note that it may be possible to use these gadolinium-coated gold nanoparticles as both imaging and heat-producing therapeutic agents.

This work is detailed in a paper titled, “Design of gold nanoparticles for magnetic resonance imaging.” An abstract of this paper is available at the journal’s website. View abstract.