A bioactive coating developed by a Quebec-Brazilian team would allow surgical masks not only to block viruses, but also to destroy them.
The researchers tested three different coatings, including one which destroyed almost all of the viruses deposited on the surface of the mask in less than a minute.
“We deposit a very thin layer of a few dozen layers of atoms,” Professor Diego Montovani, who directs the Biomaterials and Bioengineering Laboratory at Laval University, explained to La Presse Canadienne. We change the way the material interacts with the environment. »
Right now, he said, surgical masks act as a barrier that traps most, but not all, bacteria and viruses.
In addition, certain viruses, such as COVID-19, can survive for several hours on the surface of the mask. And coughing, talking, sneezing or having a runny nose can reduce the filtration capacity of the masks, hence the importance of replacing them after a few hours.
The Quebec-Brazilian research team therefore tested three molecules recognized for their bioactive properties in the laboratory. These molecules were attached, using plasma technology, to samples of surgical mask fabrics contaminated with a coronavirus.
The researchers tested a coating of polyethyleneimine (PEI), a polymer found particularly in detergents; a coating of PEI and lauric acid, a fatty acid found in coconut; and a coating of PEI and copper sulfate.
The abundance of viruses deposited on the first two coatings had melted by 99% after two hours. But in the case of the third coating, 99.99% of the viruses were destroyed after less than a minute, possibly because the copper had pierced the virus membrane and allowed the PEI to enter inside.
The bioactive coating had been added to the external surface of the masks, to intercept viruses at the time of inspiration. It could in theory also be added to the internal surface of the mask, to prevent the wearer from contaminating their environment, but further testing will be needed before getting to that, Professor Montovani said.
“As they are natural materials, it probably would not have a very long lifespan, we would not be able to use the mask for several days,” he said. But for an interaction of a few hours, I think it’s a product that could be considered. »
The researcher believes that such masks could be particularly useful in environments where the risk of contamination is high, such as in the emergency room of a hospital, during a concert in a crowded amphitheater or on the occasion of a plane trip.
In large-scale production, adding the coating would only increase the cost of each mask by about ten cents, the researchers estimate.
The results of this study were published by the journal Applied Surface Science.