Small Wonders: Micro-Machines in Medicine

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Smalley tells WebMD that nanotechnology is already used in medicine in the form of man-made molecules that are coupled with toxic chemicals or radioactive particles. These molecules, which do not exist in nature, can deliver drugs or lethal doses of radiation to cancerous tumors, for example. From there, it's not much of a leap, he says, to imagine drug delivery using micromanufactured tubes, so-called nanotubes.

In testimony before Congress in 1999, Smalley forecast other uses for nanotechnology in medicine. They include rapid genetic analysis that would allow diagnosis and treatment customized to fit an individual patient based on his or her genetic profiles; more durable artificial organs that would be less likely to be rejected by the recipient's immune system; and "sensing systems, which will allow the detection of emerging disease in the living body, and will ultimately shift the focus of patient care from disease treatment to early detection and/or prevention," he says.

Other medical applications of nanotechnology that at first seem to be far out in left field are in fact coming pretty close to home, says Leslie Rubinstein, president of Renaissance Technologies in Lexington, Ky. In an interview with WebMD, he describes the use of practical nanorobots for treatment of various medical problems. The minimedic machines could be built using existing technology -- such as that used to make tiny computer chips. The robots themselves would be designed to boldly go where no robot has gone before -- that is, into areas of the body that are hard to reach -- and where the goal is to get rid of something that shouldn't be there.

Similar work is being performed at the Massachusetts Institute of Technology in Cambridge, where Ian Hunter, PhD, professor of mechanical engineering and bioengineering and his colleagues are developing "nanowalkers" that would do for medicine what robotic probes have done for space exploration. The nanowalkers could crawl over, around, or through the body to image and diagnose diseases that lie hidden from conventional scanning techniques, deliver drugs to tumors, or repair organs without the need for surgery.

There are those who worry that once we've started down the path to fashioning self-assembling robots, there may be no turning back, and that one day, we may wake up and find that the robots have multiplied and taken on life of their own.

"They start talking to one another and pretty soon what you've really got is a wholly alien artificial life form, a true Franken-thing. And I agree that would be terrifying if it were true, but I deny even the possible existence of this thing," says Smalley.

"We're so far away from anything remotely resembling a self-assembling robot that it's silly to worry about it right now."