The War On Disease Goes Miniature

The future of medicine is vast--and it's also amazingly small. One day in the next century, thanks to the burgeoning field of nanotechnology, you could walk out of the doctor's office with a prescription for cancer detectors so tiny you can't see them. In this Lilliputian world, units are measured in nanometers--10,000 times smaller than the diameter of a single human hair. The idea is that if we can build new drugs and devices molecule by molecule, the way the tissues and organs in our own bodies are formed, we can make them much more targeted and effective.

One of the hottest areas of nanoresearch is better drug delivery. Scientists are now working on a miniaturized sensor for diabetics that mimics the glucose-detection system in a healthy body. The device, possibly implanted under the skin, would monitor blood-sugar levels, then release insulin as needed. And researchers at MIT recently made a prototype for an entire mini-pharmacy: a microchip (implanted or swallowed) with as many as 1,000 tiny reservoirs--each the size of a pinprick--that can hold 25 nanoliters of anything from painkillers to antibiotics. MIT's Robert Langer says the chip, now the size of a dime, can be made even smaller. And he plans to make it "smart" by adding a sensor that will know when to release a drug and what the dose should be.

Going small could also mean killing off cancer cells early, before they grow into life-threatening tumors. At the University of Michigan, Dr. James R. Baker Jr. is designing a kind of smart bomb that would target cancer cells by reading their chemical "signatures" and be small enough (about 20 nanometers) to get inside an individual cell and blast it away. Be patient: work on the device has just begun, and preliminary testing in humans won't start for at least five years.

Nanomedicine isn't just about getting rid of the bad--it's about enhancing the good. Imagine artificial red blood cells containing tiny nanopumps that would compress oxygen, allowing each cell to carry more than 200 times as much as its human counterpart. Are you at high risk of having a coronary? Doctors would inject you with an army of nanocells. Even if your heart shut down during an attack, you'd continue to be nourished with lifesaving oxygen.

Don't call your doctor for a nanoprescription just yet. Nanopump cells are only on the drawing board, and many other drugs and devices are more than a decade away. There are also plenty of unknowns. What, exactly, will nanoparticles be made of? And will the body accept them? But scientists are working hard to turn all this sci-fi into medical reality. One day, the smaller the medicine cabinet, the more powerful it may turn out to be.