Medical nanodevices could augment the immune system by finding and disabling unwanted bacteria and viruses. The immune device in the foreground of this image has found a virus; the other has touched a red blood cell.
It is useful to think in terms of medical nanomachines that resemble small submarines. Each of these is large enough to carry a nanocomputer as powerful as a mid-1980s mainframe, along with a huge database (a billion bytes), a complete set of instruments for identifying biological surfaces, and tools for clobbering viruses, bacteria, and other invaders.
Immune machines, with their onboard sensors and computers, will be able to react to the same molecular signals that the immune system does, but with greater discrimination. Before being sent into the body on their search-and-destroy mission, they could be programmed with a set of characteristics that lets them clearly distinguish their targets from everything else. The body's immune system can respond only to invading organisms that had been encountered by that individual's body. Immune machines, however, could be programmed to respond to anything that had been encountered by world medicine.
Immune machines can be designed for use in the bloodstream or the digestive tract. They could float and circulate, as antibiotics do, while searching for intruders to neutralize. To escape being engulfed by white blood cells making their own patrols, immune machines could display standard molecules on their surface—molecules the body knows and trusts already like a fellow police officer wearing a familiar uniform. |