Engineering news
Although current coating formulations made of pure copper are antibacterial and self-sanitising, they kill types of bacteria with thicker cell walls (gram-positive) slower than bacteria with thinner cell walls (gram-negative).
Led by materials engineer Dr Amanda Clifford, a team of researchers from the University of British Columbia (UBC) in Canada designed a new nano-copper coating that includes bacteria-killing nanoscale features and zinc. The nanoscale features are tiny bumps that can kill bacteria by rupturing their cell wall, while the zinc – which is also antibacterial – selectively oxidizes in the presence of copper and helps kill bacteria quicker than pure copper alone.
“Use of our coating could significantly reduce the incidence of contracting bacterial infections from high-touch surfaces in healthcare facilities, such as doorknobs and elevator buttons, since it kills bacteria using multiple approaches,” said Dr Clifford. “As it contains less copper than other existing coatings or whole copper parts, it would also be cheaper to make.”
The material took just one hour to kill 99.7% of Staphylococcus aureus (MRSA) – a Gram-positive pathogen commonly responsible for hospital-acquired infections – compared with two hours for pure copper, the researchers said.
“Not only does this coating kill pathogens faster than pure copper, it helps ensure antibiotics remain effective,” said Dr Clifford. “By using this new formulation, we’re killing pathogens before patients become infected and need to use antibiotics against them, slowing the rise of antibiotic resistance.”
The team has filed a provisional patent for the coating and fabrication process, which is described in a new paper in Advanced Materials Interfaces.
“This is currently targeted for hospitals and healthcare settings, because these locations are where the antibiotic-resistant pathogens, such as methicillin-resistant Staphylococcus aureus, are an issue. We also don’t want to be at a place where we can't use antibiotics,” said Dr Clifford.
The researchers plan to further evaluate the material against other pathogens, such as viruses, and hope to eventually commercialise their coating.
The work was funded in partnership with Teck Resources Limited, which has installed copper surfaces on high-contact surfaces in the faculty of applied science buildings at UBC.
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