Radioactive Antibody Fragment May Help Scientists Identify Artery Deposits

Apr 11, 2012 by Journal of Clinical Toxicology

The researchers created radioactive antibody fragments called nanobodies that attached to particles in artery plaque called vascular cell adhesion molecule-1 (VCAM1).
“Nanobodies constitute a promising new class of radiotracers for cardiovascular imaging,” Broisat said. Ongoing inflammation in a plaque deposit is a crucial sign that the plaque may rupture, and VCAM1 plays a major role in the inflammation process. In laboratory tests, the radioactive nanobodies were attracted to VCAM-1.
In animal tests, researchers injected a solution containing the radioactive particles into the blood stream of mice with artery plaques. They then used a single-proton emission computed tomography (SPECT/CT) imaging scan to detect the radioactive particles.
The nanobodies attached to VCAM-1 expressing tissues. Following radiolabeling, some of the nanobodies remained stable in the laboratory and in mouse blood for six hours. This allowed imaging of the mice up to three hours after nanobody injection. These scans revealed plaques in the animals’ aortic arches. If approved for human use, physicians can inject nanobodies into patients to determine if they are at risk of plaque rupture.