We have completed maintenance on DiscoverMagazine.com and action may be required on your account. Learn More

Big Cures Come in Small Packages

By Fenella Saunders
Sep 1, 2001 5:00 AMNov 12, 2019 5:37 AM


Sign up for our email newsletter for the latest science news

Nanotechnology has become shorthand for gee-whiz miniature devices that may never find practical uses. At Rice University in Texas, however, tiny constructions called nanoshells have shown promise for fighting cancer and administering drugs. The devices are simple enough: beads about three millionths of an inch wide, with an outer metal wall and an inner silicon core. But by varying the size ratio between wall and core, electrical and computer engineer Naomi Halas and her Rice colleagues can tune the shells precisely to absorb or scatter specific wavelengths of light. "Small particles of gold absorb green light very strongly and look red," says Halas. "It's partly because of the metal and partly because of the shape, so we're controlling the shells' color by changing the shape."

Growth process of a nanoshell, as captured by an electron microscope.Photograph courtesy of Rice University

Working with Rice bioengineer Jennifer West, Halas found she could design gold-encased nanoshells to absorb infrared or visible light and convert it to heat. That raised the possibility of fighting cancer by selectively binding the shells to malignant cells. Infrared rays would pass harmlessly through soft tissue but generate lethal heat where they strike the nanoshells. In lab tests, Halas and West have used this selective heating to cook tumor cells without harming surrounding healthy ones. "This eliminates toxic chemotherapy drugs, so we predict it should result in lower side effects," Halas says. In a similar way, nanoshells could trigger implanted, temperature sensitive drug-delivery devices, releasing a dose only when illuminated with a specific infrared wavelength. Halas even envisions using the shells as miniature beacons for instant diagnostic tests, as they could emit telltale infrared signals in the presence of certain pathogens.

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!


Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2024 Kalmbach Media Co.