How New Plastic Repels Bacteria
An array of thousands of plastic dots researchers tested to see if they resistant bacteria.
CREDIT: From New bacteria resistant materials discovered by NottmUniversity on YouTube
Several newly discovered plastics act like a nonstick surface for bacteria, according to a new study. Bacteria don't seem to like to attach to the new materials, which could be used as a coating for medical devices — a kind of Teflon for catheters and other hospital equipment whose contaminated surfaces can give patients infections, the researchers write in their paper, published Aug. 12 in the journal Nature Biotechnology.
"In a hospital, bacteria attach to glass or silicone," said Chien-Yi Chang, a biologist at the University of Nottingham in the U.K. who worked on the study. "The bacteria just love the glass. They hate our material, but that's a good thing."
Bacteria often like to gather and stick to surfaces in communities called biofilms. The new plastics resist biofilm formation. The body's immune system is more easily able to attack free-floating bacteria than these films, so devices coated in the biofilm Teflon might help the body ward off infections on its own, said Morgan Alexander, a University of Nottingham materials scientist who led the study.
Chang, Alexander and their team, including scientists in the U.K. and the U.S., discovered the biofilm-repelling plastics by testing thousands of plastic drops they arranged on small glass rectangles. When team members found plastics that seemed able to repel bacteria, they coated catheters with the materials and stuck the catheters in a soup with bacteria including E. coli and the bacterium that causes staph infections.
The researchers then compared their catheters with state-of-the-art, silver-coated catheters used in hospitals today. Medical devices now often incorporate silver in their coatings because silver kills bacteria. Yet the new plastics-coated catheters harbored 96.7 percent less bacteria than silver-coated catheters.
A plastic-coated catheter may have another advantage over silver-coated ones, too, the researchers said. The new plastics work by avoiding biofilm buildup without killing bacteria, so they may not lead bacterial populations to develop resistance the way antibiotic use can lead to resistant infections, Alexander told the University of Nottingham.
The team has also implanted their plastic-coated devices in mice and found the mice's immune systems are able to resist infections.
The next step is to find a cheaper, easier way to manufacture the promising plastics — an essential step to getting device companies to try the new materials, Alexander said.