By Lee PickeringOct 4 2019North Carolina State University researchers have reported that they have developed an elastic, self-sterilizing polymer able to kill a wide variety of superbugs, including methicillin-resistant Staphylococcus aureus (MRSA).
Alternate Weapon for Drug-resistant Pathogens
“We were exploring a different approach for creating antimicrobial materials when we observed some interesting behavior from this polymer and decided to explore its potential in greater depth,” said Rich Spontak, an NC State chemical and biomolecular engineering professor and co-corresponding author of a paper on the work.
“What we found is extremely promising as an alternate weapon to existing materials-related approaches in the fight against drug-resistant pathogens,” Spontak said. “This could be particularly useful in clinical settings – such as hospitals or doctor’s offices – as well as senior-living facilities, where pathogen transmission can have dire consequences.”
Unique Molecular Architecture
The polymer’s unique molecular architecture attracts water to a sequence of repeat units that are chemically modified (or functionalized) with sulfonic acid groups.
“When microbes come into contact with the polymer, water on the surface of the microbes interacts with the sulfonic acid functional groups in the polymer – creating an acidic solution that quickly kills the bacteria,” said Reza Ghiladi, an associate professor of chemistry at NC State and co-corresponding author of the paper.
“These acidic solutions can be made more or less powerful by controlling the number of sulfonic acid functional groups in the polymer.”
archers testing the polymer against six types of bacteria, including antibiotic-resistant strains such as MRSA, vancomycin-resistant Enterococcus faecium, and carbapenem-resistant Acinetobacter baumannii. When 40% or more of the relevant polymer units contained sulfonic acid groups, the polymer was able to kill almost all each strain of bacteria within 5 minutes.
New Polymer Fully Destroys the Influenza and Rabies
The researchers also pitting the polymer against some viruses. “The polymer was able to fully destroy the influenza and the rabies analog within 5 minutes,” said Frank Scholle, an associate professor of biological sciences at NC State and co-author of the paper. “While the polymer with lower concentrations of the sulfonic acid groups had no practical effect against human adenovirus, it could destroy 99.997% of that virus at higher sulfonic acid levels.”
One potential challenge related to the polymer is that its antimicrobial effect could progressively worsen over time, as positively charged ions (cations) in water neutralize sulfonic acid groups. But the researchers think it’s possible to get the polymer “recharged” through exposure to an acid solution.
“In laboratory settings, you could do this by dipping the polymer into a strong acid,” Ghiladi said. “But in other settings — such as a hospital room — you could simply spray the polymer surface with vinegar.
Source: https://www.ncsu.edu/