Tiny microscopic spheres can trap and kill harmful bacteria

Washington, November 25 : American researchers have developed tiny microscopic spheres that can trap and kill harmful bacteria in the same manner as "roach motels" snare and destroy cockroaches.

Researchers at the University of Florida and the University of New Mexico say that their research may lead to new coatings that will disinfect common surfaces, combat bio-terrorism or sterilize medical devices, reducing the devices' responsibility for an estimated 1.4 million infection-related deaths each year.

"The bacteria get in there, they get stuck, and then they get killed," said Kirk Schanze, a UF professor of chemistry and one of eight authors of the paper.

In a research paper published in the American Chemical Society journal ACS Applied Materials and Interfaces, Schanze and his colleagues have revealed that the spheres are far from the only such "biocide" on the market or under development, but they are unique in their materials and booby-trap action.

That, according to the researchers, could prove important as bacteria evolve to become increasingly resistant to standard disinfectants.

"The first novelty is the material we are using - these conducting polymers. The second novelty is the roach motel concept," Schanze said.

He said that the coatings imbued with the spheres could potentially be applied to doorknobs or other surfaces where bacterial diseases are often transferred.

Schanze joined forces with David Whitten, a professor of chemical engineering and associate director of University of New Mexico Center for Biomedical Engineering, to develop the tiny traps based on electricity-conducting polymers they have worked on for the past decade.

The researchers say that the polymers have a unique trait: When they are exposed to light, they produce a "very reactive form of oxygen" that is highly toxic to bacteria - much like bleach or other potent sterilizers.

Building on the research team's hypothesis that the polymers could be used to keep surfaces cleansed, UF doctoral student Jonathan Sommer developed a method to shape them into microscopic spheres - ranging in size from 1 to 5 microns.

UNM doctoral student Thomas Corbitt and his co-workers have already tested the spheres using a relatively safe bacteria that is closely related to Pseudomonas aeruginosa, a common, persistent and lethal bacteria in hospitals.

Though initial experiments revealed that the spheres could wipe out over 95 per cent of the bacteria after exposure to light for about an hour, Schanze admits that more studies are required to nail down their potency.

However, since none of the materials used in the spheres are exotic or expensive, Schanze says that they have good potential to be produced at industrial scales.

ANI