When you think that the diameter of a human hair is 75,000 nanometres, it’s hard to imagine how Professor David Reilly from the University of Sydney Nano Institute is able to achieve so much with nanodiamonds that are a mere 2.5 nanometres in size.
In collaboration with Harvard University, our researchers have discovered that nanoscale diamonds can light up early-stage cancers in MRI scans, potentially identifying tumours before they become life-threatening.
The name ‘nanodiamonds’ is descriptive. They are literally diamonds in composition, being carbon crystals, but they have qualities that could offer a revolution in targeted drug delivery and medical imaging.
First the nanodiamonds have to be magnetised, which isn’t easy.
“In fact, it’s basically impossible,” says Professor Reilly. “You can only do this on the quantum scale, a place of such atomic smallness that the usual laws of physics don’t apply.”
This has allowed researchers in a range of fields to contemplate transformative new technologies, but for Professor Reilly and his team, it also means they’ve had to leave behind accepted practice and look at physics in a new way.
The question is, why would you want to magnetise a nanodiamond in the first place?
The goal is to cause nanodiamonds to light up in the human body in a way that a magnetic resonance imaging (MRI) machine can see. This would allow more detailed images to be captured.
“Unlike other substances used to enhance MRIs, nanodiamonds are largely non-toxic and in small concentrations, they’re easily removed by the body,” says Professor Reilly. “They can act as a beacon that can also ferry pharmaceuticals to where they’re needed.”
The beacon effect would allow clinicians using an MRI to watch nanodiamonds travel through the body in real time. If they were attached to molecules that are attracted to cancer cells, you could see exactly where the cancer cells were, and do this while the cancer cells were still undetectable by other methods.
Then there is the drug delivery capability of nanodiamonds. “There’s a lot of knowledge about the surface chemistry of diamonds, so we can attach basically any molecule we like,” explains Professor Reilly.
“This makes nanodiamonds like rafts travelling through the bloodstream carrying whatever drug you want, for targeted imaging or chemotherapy delivery.”
Drug dosages are reduced and accuracy enhanced. The same nanodiamond principles could also see the big, cumbersome and expensive MRI machines themselves, become much smaller.
“You could have an MRI the size of a motorcycle helmet that takes an MRI of your brain while you’re in the ambulance,” says Professor Reilly.
When Professor Reilly and his team first proposed that it might be possible to magnetise nanodiamonds by manipulating their electrons, it was a hope based on reasoning. Since then, they have demonstrated that the technique works and works well.
“There’s a good story to be told here about what we’re doing and where we’re going,” says Professor Reilly. “We’re engaging with the world’s biggest industries and having impacts on the global stage.”
Diameter of human hair in nanometres
Size of a nanodiamond in nanometers