New research on nanodiamond-enhanced MRI

May 3 2017

Research by a collaboration of scientists in Australia and the United States demonstrates that using nanodiamonds somewhat like ‘tiny machines’ inside living patients has taken a quantum leap closer to reality.

The findings were published last night in Nature Communications.

Lead author, University of Sydney quantum physicist David Waddington said key to the new research was the demonstration of biocompatible nanodiamond contrast, overcoming a major challenge of competing techniques where nanodiamond must be prepared in freezing conditions before injection.

Lead author David Waddington, who completes his PhD this year, works out of the Australian Institute for Nanoscale Science and Technology (AINST) headquarters, the $150m Sydney Nanoscience Hub

“People are very interested in using nanoparticles for targeted delivery of vaccines and chemotherapy agents,” said Mr Waddington, who is completing his PhD this year.

Mr Waddington said the research was three years in the making and was initiated with a Fulbright Scholarship awarded early in his PhD at the University of Sydney, where he works in the team led by Professor David Reilly, in the new $150m Sydney Nanoscience Hub – the headquarters of the Australian Institute for Nanoscale Science and Technology (AINST), which launched last year.

Supported by Professor Reilly, Mr Waddington used the Scholarship to establish an ongoing collaboration with Associate Professor Matthew Rosen's lab in the Martinos Center at Massachusetts General Hospital – one of the world's most successful biomedical imaging centers – and Professor Ronald Walsworth's group at Harvard University.

“Key to researchers being able to determine the differences between successful and unsuccessful treatments is the ability to monitor the nanoparticles in vivo, as opposed to in a test tube, which is challenging with current approaches,” Mr Waddington said.

“In our manuscript, "Nanodiamond-enhanced MRI via in situ hyperpolarization", we detail a new technique we have developed and demonstrated for imaging nanoparticles. This technique is particularly promising as it will enable imaging of nanoparticles over the long timescales necessary for in vivo tracking.

Artist impression of nanodiamonds attached to cancer-targeting molecules, drawn up at the time of the previous 2015 research. The nanodiamonds act as lighthouses in an MRI, lighting up cancers that bind to the chemicals on their surfaces.

“As a result of our new research, we can repeatedly perform hyperpolarisation in a biocompatible environment, enabling nanodiamond imaging over indefinitely long periods of time and opening up the study of a range of diseases such as those affecting the brain and liver.”

Initial research published in Nature Communications in late 2015 led by Professor Reilly laid the groundwork for nanodiamond imaging based on a technique known as hyperpolarisation.  

Mr Waddington said: “Our close collaboration with the Rosen lab at the Martinos Center – world leaders in ultra-low field MRI – has been essential to the completion of this work, which began during the time I spent there on the Fulbright scholarship.”  

Professor Reilly, who leads a team that includes Mr Waddington and is focused primarily on developing quantum machines, said the nanodiamond finding was a great example of the benefits of experimental physics in generating unintended discoveries.

“It's estimated that such ultra-low field MRI scanners could be produced at a fraction of the cost of conventional MRI scanners, which could lead to this imaging technique being widely accessible in the future,” Professor Reilly said.

Details about the new research:

In this new publication, researchers have developed a technique that allows us to perform hyperpolarised imaging of nanodiamonds without cryogenic temperatures and microwaves. Essential to this is the use of ultra-low magnetic fields, which allow scientists to drive hyperpolarisation processes with biocompatible radiowaves at ambient temperatures using a technique known as the Overhauser effect.

Further, this study has required the use of a highly unusual ultra-low field MRI scanner. These scanners operate at a few hundredths of the magnetic field strength of conventional MRI scanners.