Researchers eye non-gadolinium MRI contrast agent

Researchers from Stony Brook University, Stony Brook, N.Y., have developed an effective, and potentially safer, nanoparticle-based MRI contrast agent, according to the results of a preclinical study published June 7 in the journal PLoS ONE.

The new contrast agent is graphene-based, offering an alternative to gadolinium-based agents most commonly used today.

“A graphene-based contrast agent can allow the same clinical MRI performance at substantially lower dosages,” Balaji Sitharaman, PhD, assistant professor in the department of biomedical engineering at Stony Brook University, said in a release.

Gadolinium-based contrast agents can have harmful side effects in some patients, such as nephrogenic systemic fibrosis, prompting the FDA to restrict the clinical use of gadolinium and spurring the need for an MRI contrast agent that demonstrates lower toxicity. Further, most MRI contrast agents are not suitable for extended-residence-intravascular (blood pool), or tissue (organ)-specific imaging, and do not allow molecular imaging.

In the current study, Sitharaman and colleagues demonstrated that potassium permanganate-based oxidative chemical procedures used to synthesize graphene nanoparticles leads to the confinement of trace amounts of Mn²⁺ ions between the graphene sheets.

“The results indicate that confinement (intercalation) of paramagnetic metal ions within graphene sheets, and not the size, shape or architecture of the graphitic carbon particles is the key determinant for increasing relaxivity, and thus, identifies nano confinement of paramagnetic ions as novel general strategy to develop metal-ion graphitic-carbon complexes as high relaxivity MRI [contrast agents],” wrote the authors.

Sitharaman said the technology will lower healthcare costs by reducing the cost per dose and the number of doses required.