Friday, April 6, 2007

UMD researchers explore nanotechnology

Cell-like ‘factories’ in the body may prevent and cure illnesses

E-mail this article \ Print this article

ANNAPOLIS — Imagine not having to go to the doctor when you are sick. No medicine, no popping pills. Instead, tiny cell-like machines in your body would already be at work manufacturing medicine and delivering it exactly where it is needed.

University of Maryland researchers say these ‘‘nanofactories” may not be that far away.

Nanofactories are pseudo-cells that are swallowed, inhaled or absorbed through the skin, and travel to a specific location in the body. What’s unique about the tiny biochemical factories is that they could potentially use materials already in the body to manufacture medicine at the first sign of infection or disease.

‘‘You actually take components and make something that wasn’t there before,” said Gary Rubloff, a professor and director of the University of Maryland NanoCenter in College Park. ‘‘It takes things from their environment and puts them through the factory and generates something important.”

The nanofactory could potentially ward off disease and infection by interfering with what is known as the quorum sensing process. In this process, bacteria ‘‘talk” to each other, as scientists put it, to coordinate their attack on the body.

The bacteria communicate by sending signals, and use receptors to detect the signals. Scientists say the bacteria communicate about the availability of food and how to protect themselves from harmful substances such as a response from the human immune system.

‘‘Quorum sensing determines the outcome of the bacteria,” said William Bentley, chairman of the bioengineering department. ‘‘Typically they establish a biofilm. That’s a big problem because people with cystic fibrosis have biofilm ... once you have a biofilm there, it’s hard to kill because it’s hard for the antibiotics to get to it.”

The more bacteria communicating with each other, the greater the chance that they can overpower the human immune system and create biofilms.

‘‘A lot of their activities are coordinated by this communication,” Bentley said. ‘‘The network [of cells] determines how well they attach to other surfaces.”

It takes many bacteria to create a biofilm. Collectively, they create a sticky substance that enables them to attach to a surface. Bacteria can create biofilms in the body, which can lead to common ailments such as ear infections, gingivitis or urinary tract infections. Biofilms can also have a role in fatal illnesses such as cystic fibrosis.

University of Maryland researchers said the nanofactories may be able to deter the harmful effects of E. coli. In experiments, researchers have attached the nanofactories to E. coli, and the process showed potential for the nanofactories to neutralized E. coli cells.

The concept of using nanotechnology to deliver drugs in the body isn’t new, Rubloff said.

But the new nanofactory technology would deliver the drug to a specific site in the body before it is even needed. Then, the factory would generate drugs using materials already in the body or intercept communication between the bacteria.

‘‘There’s a fair amount of this going on,” Rubloff said. ‘‘What is unusual here is the notion that you look at constructs of biology with man-made nanotechnology as something very active ... as a system.”

When an individual takes an antibiotic, the drug travels all over the body. It goes to the site where the bacteria are communicating as well as other places where it is not needed. When drugs are delivered to unnecessary sites in the body, this can cause side effects.

The nanofactory would prevent side effects by delivering the drug to only the infection site instead of the entire body.

‘‘This technology would allow you to pinpoint the drug where it needs to be,” Bentley said. ‘‘You don’t need a lot of drug. It treats those specific cells and nothing else. You wouldn’t have all sorts of interactions with everything else.”

Now the researchers are working on how to control the factory from outside the body. They can turn it on, but can’t turn it off. And they are working on a way to disguise the nanofactories so that the body doesn’t think they are foreign and attack them.