Microcapsule Traps and Kills Harmful Bacteria

The traps attract and kill up to 95% of nearby bacteria, including microbes responsible for troublesome hospital-based infections. The scientists described their discovery as micro-sized "roach motels” for harmful bacteria.

In the study, Dr. David G. Whitten, from the University of New Mexico (Albuquerque, USA), and Dr. Kirk S. Schanze, from the chemistry department of the University of Florida (Gainesville, USA), working together with a team of faculty and graduate student collaborators, pointed out that bacterial contamination of medical devices causes up to 1.4 million deaths per year. Moreover, bacteria are becoming more resistant to conventional methods of disinfection. Scientists also are increasingly concerned about the possibility of intentional release of harmful bacteria by terrorists. As a result, researchers are attempting to develop new and improved methods of disinfection.

The New Mexico and Florida teams of researchers study involved the development of light-activated, hollow microcapsules composed of an organic conducting polymer. The antibacterial microcapsules can attract, capture, and destroy bacteria. In controlled laboratory tests, the researchers exposed the capsules to either Pseudomonas aeruginosa, one of the deadliest and most common hospital-based pathogens, or Cobetia marina, a type of bacterium that soils the hulls of ships and other marine equipment. After one hour of light exposure, the light-activated capsules killed more than 95% of the exposed bacteria, the researchers reported. The microcapsules can be applied to a variety of surfaces, including medical equipment, they added.

The scientists' study was published online, ahead of print, on November 24, 2008, in the first issue of a new journal, Applied Materials & Interfaces.

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