NTU scientists develop probes that light up when kidney failure is detected

The team has filed a Singapore patent for the technology. PHOTO: NANYANG TECHNOLOGICAL UNIVERSITY, SINGAPORE
The team has filed a Singapore patent for the technology. PHOTO: NANYANG TECHNOLOGICAL UNIVERSITY, SINGAPORE
The team has filed a Singapore patent for the technology. PHOTO: NANYANG TECHNOLOGICAL UNIVERSITY, SINGAPORE

SINGAPORE - Imaging probes that light up when acute kidney failure is detected have been developed by local scientists, helping to spot the condition 1½ days faster than other real-time molecular imaging methods. The probes, which are injected into the bloodstream, light up due to a chemical reaction when they detect molecular changes caused by the onset of acute kidney failure.

Developed by scientists from the Nanyang Technological University (NTU), the probes have been tested on mice and will progress to human trials next year.

Acute kidney failure usually occurs in a few hours or a few days, and is most common among patients who are critically ill and need intensive care.

In 2015, there were 1,619 people diagnosed with kidney failure in Singapore, the main cause of this being diabetes.

Unlike the probes, current diagnostic platforms are unable to detect early stage, pre-morbid changes that underlie acute renal failure, said Associate Professor Pu Kanyi from the NTU School of Chemical and Biomedical Engineering.

These platforms include the serum creatinine test, which measures the level of creatinine in the blood and provides an estimate of how well the kidneys filter, and the blood urea nitrogen test, which measures the amount of urea nitrogen in the blood. Higher-than-normal urea nitrogen levels suggest that the kidneys or liver may not be working properly.

In contrast, the probes are sensitive enough to track changes in the biological processes triggered by the onset of acute kidney failure.

"For patients who are critically ill, like those in the intensive care unit, every minute is precious in reversing a condition like acute kidney failure, which can cause a patient's health to deteriorate rapidly," he said.

When tested on mice, the probes lit up 12 hours after cancer drug cisplatin was given at a level destructive to the kidneys - 1½ days faster than other real-time molecular imaging methods.

The findings were published in the scientific journal Nature Materials in May.

Prof Pu said there is also the possibility of developing the probes into test strips for urine samples, making it a non-invasive method of detecting acute kidney failure.

The NTU researchers found that the probe has high renal clearance - more than 97 per cent of the probes injected into mice flowed through the kidneys, and were excreted as part of urine.

When added to the urine sample and incubated for a few hours, the probes light up when exposed to UV light in the presence of biomarkers.

The team has filed a Singapore patent for the technology.

Their next phase of research will involve working with local and overseas medical institutions to further refine the probes using urine samples from patients in the intensive care unit by next year.

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