New agent to spy clogged arteries
By Janet Raloff
From Chicago, at the American Chemical Society Meeting
High-density lipoproteins (HDLs) are referred to as the good cholesterol because they can penetrate artery-clogging plaque and carry away some of the bad cholesterol. Now, researchers in New York City have designed a nanoparticle, modeled on HDL particles, to improve the detection of such arterial plaques.
Like HDLs, the new contrast agent enters fatty deposits on vessel walls. Under magnetic resonance imaging (MRI), the new molecule shines brightly and highlights cholesterol buildups in partially blocked arteries.
Current MRI contrast agents “have no affinity for the cholesterol plaque,” notes medicinal chemist David Cormode of the Mt. Sinai School of Medicine. His team created the new plaque-seeking agent by binding atoms of gadolinium—an excellent MRI contrast agent—to a shortened, synthetic analog of the HDL protein. The researchers canceled gadolinium’s normal toxicity by attaching other molecules to the metal.
In tests on seven mice, the new agent improved the detection of arterial plaques by almost 80 percent, compared with MRI using a conventional contrast agent. Within a few weeks, the agent will be tested in rabbits.
If the synthetic HDL works as well in people, Cormode says, the new contrast agent will improve physicians’ ability to track the effectiveness of plaque-busting treatments.
