TORONTO -- A new "self-cleaning" plastic developed by a team of scientists can prevent bacteria and viruses from sticking and proliferating on its surface, McMaster University said on Friday.
The material is similar to the conventional thin, transparent plastic wraps many use to keep food fresh, but its surface is textured with microscopic wrinkles and chemically treated so that everything that comes into contact with it -- from bacteria to a drop of blood -- simply bounces off.
"It has, at the microscopic and molecular level, some structure that helps it to repel all kinds of contaminants, including multi-drug resistant bacteria," engineering physicist Leyla Soleymani said in an interview. "We have nanoscale features - these are a billion times smaller than a metre."
The surface was tested with two forms of particularly antibiotic-resistant bacteria, Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas, considered critical and high priority pathogens by the World Health Organization because of the very limited treatment options for those who are infected and the public health threat they pose. The effectiveness of the material in repelling the bugs was captured through electron microscope images that showed "virtually no bacteria" on the surface.
The research and development of this particular plastic took three years and was a collaborative effort led by Soleymani and mechanical engineering assistant professor Tohid Didar, who teamed up with Eric Brown from McMaster’s Institute for Infectious Disease Research and Kathryn Grandfield with the McMaster-based Canadian Centre for Electron Microscopy.
Didar had already been working on repellent surfaces for some time when discussions began with colleagues in microbiology.
"They basically said, if you can take these structures and put it on a platform that’s useful, not just a laboratory scale prototype that’s not flexible … and show that it really repels the bugs that they’re really scared of, then this would be something that’s really critically needed and groundbreaking," said Soleymani.
In theory, even if the material were immersed in water, for example, there would be a microscopic air bubble layer, invisible to the naked eye, that would form between its surface and the water, Soleymani explained.
Inspired by the water-repellent lotus leaf, the team said the material can be applied in a number of different situations such as food packaging to stop the spread of Salmonella, E. coli, listeria, and other bacteria from raw meats and other foods.
The material is flexible, durable, and inexpensive, they added, and can be shrink-wrapped on to surfaces like IV stands, door handles, and railings, where dangerous bacteria is commonly found.
The team hopes to work with a commercial partner to produce the material and might start with a hospital before working towards everyday consumers, Soleymani said.
