Nanobots and atherosclerosis. Artwork of nanorobots inside a blood vessel as they carry out treatment of atherosclerosis. Blood vessels can become blocked or narrowed by the build-up of fatty plaques (atheromatous plaques, yellow), a condition known as atherosclerosis. This reduces blood flow to the areas served by the blood vessel. This can cause conditions such as angina, a heart attack, or a stroke. One of the aims of nanotechnology is to develop microscopically small probes for insertion into the body to treat medical conditions.