A simple and sensitive test developed by i-sense engineers at Imperial College London, in collaboration with MIT, has produced a colour change in urine to signal growing tumours in mice.
Early stage diagnosis of cancer can increase survival and quality of life, however, cancer screening approaches can call for expensive equipment and trips to the clinic, which may not be feasible in rural or developing areas with little medical infrastructure. The emerging field of point-of-care diagnostic tools and technologies can provide cheaper, faster, and easier-to-use alternatives.
“By taking advantage of a chemical reaction that produces a colour change, this test can be administered without the need for expensive and hard-to-use lab instruments,” says Molly Stevens, Professor of Biomedical Materials and Regenerative Medicine at Imperial, and i-sense Deputy Director.
“The simple readout could potentially be captured by a smartphone picture and transmitted to remote caregivers to connect patients to treatment.”
How does the test work?
The technology works by injecting nanosensors, made of ultra-small gold nanoclusters, into mice. The nanosensors are then cut up by enzymes released by the tumour, known as proteases.
When the nanosensors are broken up by proteases, they pass through the kidney and can be seen with the naked eye through a colour change in the urine.
The researchers injected nanosensors into 14 healthy mice and 14 mice with colon tumours, and collected urine 1 hour after injection. The urine was treated with a chemical substrate and within 30 minutes, urine from tumour-bearing mice became bright blue.
“The gold nanoclusters we use are similar to materials already used in the clinic for imaging tumours, but here we are taking advantage of their unique properties to give us additional information about disease,” says Dr Colleen Loynachan, co-first author and Postdoctoral Research Associate in the i-sense Stevens group at Imperial.
“However, there’s still a lot of optimisation and testing needed before the technology can move beyond the lab.”
The team also designed the nanosensors to go ‘unseen’ by the immune system to prevent immune reactions or toxic side effects, and to prevent abundant serum proteins from sticking to them, which would make the nanosensors too large to be filtered by the kidneys.
The results from the fast, non-invasive test, developed by teams led by Imperial’s Professor Molly Stevens and MIT Professor and Howard Hughes Medical Institute investigator Sangeeta Bhatia, were recently published in Nature Nanotechnology.
Next stage research
Next, the team will continue to improve the study by testing in additional animal models to investigate diagnostic accuracy and safety.
“Proteases play functional roles in a number of diseases such as cancer, infectious diseases, inflammation, and thrombosis,” says co-first author Ava Soleimany, of Harvard and MIT.
“By designing versions of our sensors that can be cut by different proteases, we could apply this colour-based test to detect a diversity of conditions.”
The researchers are now working on a formulation that is easier to administer, and identifying ways to make the sensors responsive to multiple biomarkers in order to distinguish between cancers and other diseases.
For more information, please contact:
Caroline Brogan, Research Media Officer (Engineering)
Tel: +44(0)20 7594 3415
Out of hours duty media officer: +44 (0)7803 886 248
- “Renal clearable catalytic gold nanoclusters for in vivo disease monitoring” Nature Nanotechnology
- Authors: Colleen N. Loynachan, Ava P. Soleimany, Jaideep S. Dudani, Yiyang Lin, Adrian Najer, Ahmet Bekdemir, Qu Chen, Sangeeta N. Bhatia and Molly M. Stevens
- Imperial news piece
- Imperial Press Release
- Imperial College London
- Stevens group
- Massachusetts Institute of Technology