Tuesday, August 31, 2010

Scientists Create MRSA-Killing Nanotech Coating

    Scientists Create MRSA-Killing Nanotech Coating
  • A team of researchers at the Rensselaer Polytechnic Institute has developed a material that safely kills MRSA bacteria on contact. The material could be used to coat surgical equipment, hospital walls and other high-risk surfaces.
  • A team of researchers at the Rensselaer Polytechnic Institute has developed a material that safely kills MRSA bacteria on contact. The material could be used to coat surgical equipment, hospital walls and other high-risk surfaces.

    Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous infection caused by an antibiotic-resistant strain of staph bacteria. Sometimes called a "super bug," MRSA can be life-threatening and is especially common in hospitalized patients who have undergone surgical procedures. As occurrences of the deadly infection are on the rise in hospitals, doctors and scientists are desperate for preventative measures. In an exciting breakthrough, a team of researchers at the Rensselaer Polytechnic Institute has developed a nanoscale coating that safely and effectively kills MRSA bacteria upon contact.

    The material, which is based on an enzyme found in nature, showed remarkable results in trial studies, in which latex paint was laced with it and painted onto a surface: 100 percent of MRSA bacteria were killed within 20 minutes of contact.

    MRSA is especially dangerous because it is resistant to antibiotics. Currently, no standard treatment path exists (source: CDC).

    "We're building on nature," said Jonathan S. Dordick, the Howard P. Isermann Professor of Chemical and Biological Engineering, and director of Rensselaer's Center for Biotechnology & Interdisciplinary Studies, according to the university's statement. "Here we have a system where the surface contains an enzyme that is safe to handle, doesn't appear to lead to resistance, doesn't leach into the environment, and doesn't clog up with cell debris. The MRSA bacteria come in contact with the surface, and they're killed."

    In the material, carbon nanotubes are combined with lysostaphin, a naturally occurring enzyme that non-MRSA strains of staph use to defend against the bacteria. The nanotube-enzyme mixture can be combined with many different types of surface coatings, such as paint.

    "We asked ourselves: Were there examples in nature where enzymes can be exploited that have activity against bacteria?" Dordick said.

    The nanoscale material pictured here is a mixture of carbon nanotubes and lysostaphin, a naturally occurring enzyme that fights MRSA (source: Rensselaer/Ravindra C.Pangule and Shyam Sundhar Bale).

    The answer to this search was lysostaphin, which is produced by non-pathogenic strains of staph that are harmless to humans.

    "It's very effective. If you put a tiny amount of lysostaphin in a solution with Staphylococcus aureus, you'll see the bacteria die almost immediately," said Ravi Kane, a professor in the Department of Chemical and Biological Engineering at Rensselaer.

    "Lysostaphin is exceptionally selective," Dordick said. "It doesn't work against other bacteria, and it is not toxic to human cells."


    Combining the enzyme with carbon nanotubes increases its ability to reach the harmful bacteria. "The more the lysostaphin is able to move around, the more it is able to function." Dordick explained.

    The coating, which can be painted onto various hospital surfaces, kills 100 percent of MRSA bacteria on contact (source: Rensselaer/Ravindra C.Pangule).

    Most antimicrobial agents lack effectiveness or are dangerous. Some leach into the environment, posing harmful side effects, while others clog up and lose their effectiveness over time. The anti-MRSA coating does neither.

    "We spent quite a bit of time demonstrating that the enzyme did not come out of the paint during the antibacterial experiments. Indeed, it was surprising that the enzyme worked as well as it did while remaining embedded near the surface of the paint," Dordick said.

    Although MRSA is resistant to man-made antibiotics, it is unlikely to become resistant to lysostaphin. "Lysostaphin has evolved over hundreds of millions of years to be very difficult for Staphylococcus aureus to resist," Kane said. "It's an interesting mechanism that these enzymes use that we take advantage of."

    The researchers envision all high-risk hospital surfaces coated with the material, which can be washed repeatedly and has a dry storage shelf life of six months. The coating could save lives and reduce hospital stays for thousands of patients.


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