Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo


Unsupported browser: Your browser does not meet modern web standards. See how it scores »

{ action.text }

Using parts of living cells in a smart nanotechnology-based system, researchers in Switzerland have demonstrated a “nanocarrier” that can target specific types of cells and light up in response to conditions in their immediate environment.

The work is part of a growing effort by scientists worldwide to develop nano devices that can circulate in the bloodstream, slip stealthily past the body’s immune system, attach to cancer or inflammatory cells (an important ability in diseases such as atherosclerosis and arthritis), and deliver a deadly drug payload–destroying some of the toughest diseases without the often debilitating side effects that can accompany chemotherapy (see “Nanomedicine”).

Already, early versions of such nano-based treatments have been approved for breast cancer. But Patrick Hunziker, a physician at University Hospital Basel, and Wolfgang Meier, professor of chemistry at the University of Basel, are attempting to trigger the release of the drugs at more precise locations and at release rates adjusted to have the most effect on a particular disease.

One promising approach to achieving this goal is to develop nanocarriers that can respond to cues in their immediate environment, similar to how living cells can open and shut membrane pores. Hunziker and Meier have just reported in the journal Nano Letters on a system that incorporates bacterial proteins that form such pores.

The researchers first developed a type of polymer that self-assembles to form hollow spheres about 200 nanometers across. During the assembly process, they introduce the pore proteins, which form channels in the polymer spheres. As in bacteria, where the pores can close to protect cells from acidic environments, these channels also open and close in response to changes in pH.

The researchers then demonstrated that the resulting nanocarrier could control the location and duration of a fluorescent signal–an ability that could be useful in lab diagnostics. To do this, they added another biological molecule to the mix, encapsulating within the spheres an enzyme that breaks down certain compounds, causing them to glow. They then added the nanocarriers to a solution containing these compounds.

In experiments in which the researchers add the enzymes directly to the solution, without using the nanocarriers, the compounds glow diffusely and for only a few minutes. When using nanocarriers, though, the light is concentrated within the spheres, where the enzymes are sequestered, and the signal lasts many times longer–about three hours. Combined with the ability (demonstrated in an earlier paper) to make the nanocarriers latch onto specific cells, the system could be used to highlight the location of these cells in lab tests.

2 comments. Share your thoughts »

Tagged: Biomedicine, Materials

Reprints and Permissions | Send feedback to the editor

From the Archives


Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me