Despite the wide range of diseases and conditions that can be diagnosed through a urine test, these tests have failed up till now in being able to detect blood clots. The terrible effects of blood clots include death so a cheap and easy detection method could save lives.
Now researchers at MIT have developed a simple urine test that can detect blood clots.The test centers around an iron oxide nanoparticle that is coated with peptides (short proteins) capable of detecting the enzyme thrombin, which is an indicator of blood clots.
In research published in the journal ACS Nano (“Nanoparticles That Sense Thrombin Activity As Synthetic Urinary Biomarkers of Thrombosis”), the MIT team demonstrated that the nanoparticle could be safely injected into mice and travel throughout their circulatory system. When the nanoparticle encounters the thrombin enzyme, the peptides on its surface break off, and then are excreted in the mice’s urine.
The urine sample is then treated with antibodies specific to the peptide tags used on the surface of the nanoparticle. The researchers discovered that the amount of peptide tags is directly proportional to the blood clotting present in the mice’s lungs.
“High levels of activation markers have been related to recurrent thrombosis, but they don’t have good sensitivity or specificity. Through application of the nanoparticles, if proven well-tolerated and nontoxic, alterations in the normal low levels of physiological thrombin generation might be easily detected,” said Henri Spronk, an assistant professor of biochemistry at Maastricht University in the Netherlands, who was not part of the research team, in the press release.
Sangeeta Bhatia, who was highlighted in an IEEE Spectrum article back in 2004 on how semiconductors are being used in drug delivery, and was the lead author on this research, believes that there are two potential applications for this test. In one version, the test could be used in an emergency room situation where a patient is complaining of symptoms that may indicate a blood clot. And in the other, it could be used in continual monitoring for those patients that are at a high risk of a blood clot.
“If a patient is at risk for thrombosis, you could send them home with a 10-pack of these sticks and say, ‘Pee on this every other day and call me if it turns blue,” Bhatia said in the press release.
Bhatia is so confident that this simple urine test has commercial potential that she is planning to launch a company based on it, which will be in part funded by the MIT’s Deshpande Center for Technological Innovation. If a blood clot test turns out not to have the market potential that they anticipate, it could also be adapted to detect cancer.
Illustration: Christine Daniloff/MIT
Dexter Johnson is a contributing editor at IEEE Spectrum, with a focus on nanotechnology.