The team identified a peptide that has a particular affinity to fibrin, the insoluble protein that’s contained in blood clots. Then they linked a radionuclide to the peptide. Radionuclides are unstable atoms that radioactively decay; they are detectable using PET imaging. By experimenting with different radionuclides and peptides, the team found the duo that exhibited the best PET visibility when bound to blood clots. “The probes all had a similar affinity to fibrin in vitro, but, in rats, their performances were quite different,” said Peter Caravan of Harvard’s Center for Biomedical Imaging in an American Chemical Society news release.
The top-performing probe, dubbed FBP8 (“fibrin binding probe #8”) uses copper-64 as the radionuclide. The next step is testing the blood clot probe in patients. If successful, the system would be a strong improvement over the use of various imaging paradigms in different body parts: ultrasound to look for the clot in the arteries of the legs, MRIs to scan the heart, and CT scans to inspect the lungs. “It’s a shot in the dark,” Caravan said in the news release. “Patients could end up being scanned multiple times by multiple techniques in order to locate a clot. We sought a method that could detect blood clots anywhere in the body with a single whole-body scan.”
Locating the clot quickly helps doctors decide the best course of therapy, including surgery or medication, so that they can remove the clot before if it breaks. A broken blood clot can cause recurrent strokes and complications by spreading fragments throughout the body.
REFERENCE: Fierce Medical Devices; 18 AUG 2015; Varun Saxena