This tiny sensor can be injected into the body during a biopsy to keep a constant vigil on tumor growth. Developed at MIT, the device is packed with magnetic nanoparticles and proteins that bind to particular molecules that are associated with certain cancers. The device is "read" via MRI scan but a future sensor may be interrogated with a magnetic wand waved over the body. The system may also have applications in heart disease. From New Scientist:
In another study with mice, (researcher Michael) Cima transformed the tumour-monitoring device into a heart-attack detector by lining the inside of the capsule with antibodies that bind to three different proteins released by heart muscle cells when they burst open.After embedding the devices in the rodents' skin and inducing heart attacks, Cima was able to precisely measure the severity of damage: the more protein accumulated in the monitor, the worse the heart attack and the stronger the MRI signal.
Such a device would be especially useful for people who experience silent heart attacks – which usually present little pain or obvious symptoms – as well as those at risk of a second heart attack.
"Implantable sensor tracks cancer in the body"