Researchers from the Max Planck Institute for Intelligent Systems in Stuttgart have discovered a novel MRI contrast agent that could become an alternative to the widely used gadolinium. Initial testing revealed that diamond dust enhances signals and continues functioning as intended days after injection.
Gadolinium has been the standard signal-enhancing material used for over 30 years to improve MRI detection of tumors. While gadolinium does enhance signals of the affected areas being imaged, it also travels to surrounding health tissues once injected into a patient's bloodstream. Additionally, gadolinium persists in the brain and kidneys of patients for months to years after administration with long-term effects still unknown.
In the research, published in Advanced Materials, researchers from the Max Planck Institute for Intelligent Systems in Stuttgart describe the potential benefits of diamond dust as an alternative imaging enhancer. Initially discovered by accident, Dr. Jelena Lazovic Zinnanti was researching methods to rupture drug-delivery capsules and turned to nanometer-sized diamond dust particles to achieve this.
“I had intended to use the dust only to heat up the drug carrying capsules,” said Zinnanti. “I used gadolinium to track the dust particles’ position. I intended to learn if the capsules with diamonds inside would heat up better. While performing preliminary tests, I got frustrated, because gadolinium would leak out of the gelatin – just as it leaks out of the bloodstream into the tissue of a patient. I decided to leave gadolinium out. When I took MRI images a few days later, to my surprise, the capsules were still bright. Wow, this is interesting, I thought! The diamond dust seemed to have better signal enhancing properties than gadolinium. I hadn’t expected that.”
To confirm her findings, Zinnanti injected the diamond dust into chicken embryos, ultimately discovering that while gadolinium diffused throughout the embryo diamond dust nanoparticles stayed within the blood vessels and shone brightly during MRI scanning. While diamond dust in conjunction with gadolinium has been used in the past to improve magnetic resonance imaging, the use of diamond dust alone as a contrast agent has never been demonstrated.
“Why the diamond dust shines bright in our MRI still remains a mystery to us,” said Zinnanti. “I think the tiny particles have carbons that are slightly paramagnetic. The particles may have a defect in their crystal lattice, making them slightly magnetic. That’s why they behave like a T1 contrast agent such as gadolinium. Additionally, we don’t know whether diamond dust could potentially be toxic, something that needs to be carefully examined in the future.”
Zinnanti believes should diamond dust prove to be nontoxic and well tolerated by patients, it has the potential to become a new contrast agent that improves localized MRI scanning and protects a patient's healthy tissues.