A laboratory study in mice demonstrates that a colour-change urine test based on nanosensors could help detect colon cancer / bowel cancer.
Researchers at Imperial College London, UK and Massachusetts Institute of Technology (MIT) in the US developed the new technology to enable early cancer identification.
The existing screening methods for cancer require costly equipment and clinic visits, which are not always practical.
The new point-of-care diagnostic approach involves the injection of nanosensors, which will be dismantled by tumour enzymes called matrix metalloproteinases (MMPs).
The broken nanosensors pass through the kidney and can be identified with the naked eye when a blue colour change occurs in a urine test.
When assessed in a total of 28 mice, urine samples obtained from animals with colon cancer become bright blue compared to those from healthy mice.
Imperial College London departments of materials and bioengineering professor Molly Stevens said: “By taking advantage of this chemical reaction that produces a colour change, this test can be administered without the need for expensive and hard-to-use lab instruments.
“The simple readout could potentially be captured by a smartphone picture and transmitted to remote caregivers to connect patients to treatment.”
Researchers created the nanosensors from ultra-small nanoclusters (AuNCs) linked to a protein carrier known as neutravidin via linkers broken by the MMP9 enzyme.
To avoid immune reactions, toxic side effects and sticking of abundant serum proteins to AuNCs, the team masked the AuNC surfaces from the body’s immune system.
A follow-up after four weeks of nanosensor administration found that the mice did not exhibit any side effects or evidence of protein-sensor complex or free AuNCs.
Researchers are planning to evaluate the diagnostic accuracy and safety of the sensors in other animal models to improve their specificity and sensitivity.
Before human application of the new technology, the sensors require further optimisation and testing. However, researchers believe that it could help to detect various conditions, including cancer and infectious diseases.