Coupling an MRI contrast agent, gadolinium, to a nanodiamond complex can increase signal intensity and image contrast, based on a study published online Dec. 28, 2009 in Nano Letters.
Thomas J. Meade, PhD, professor of chemistry, biochemistry and molecular and cell biology and radiology at Northwestern University in Chicago, led the study, along with Dean Ho, PhD, assistant professor of biomedical engineering and mechanical engineering at Northwestern.
The researchers found that Gadolinium (III)-nanodiamond complex represented a 10-fold increase in relaxivity when compared to the monomer Gd(III) complex and in turn, increased contrast enhancement and detection by MRI.
"Nanodiamonds have been shown to be effective in attracting water molecules to their surface, which can enhance the relaxivity properties of the Gd(III)-nanodiamond complex," said Ho. "This might explain why these complexes are so bright and such good contrast agents."
In addition to confirming the improved signal produced by the nanodiamond hybrid complex, the researchers found little impact on cellular viability and are currently exploring the pre-clinical applications in various animal models.
This study will pave the way for the clinical use of nanodiamonds to deliver therapeutics as well as remotely track the activity and location of the drugs, added Ho.
"The results are a leap and not a small one—it is a game-changing event for sensitivity," said Meade. "A nanodiamond is like a cargo ship—it gives us a nontoxic platform upon which to put different types of drugs and imaging agents."