Self-Sterilizing Polymer to Reduce Healthcare-Acquired Infections

Researchers from North Carolina State University have developed a new nanostructured polymer that can kill many different strains of bacteria and viruses within minutes. Their work demonstrates that the unique chemical modifications on the polymer allow it to kill bacteria like E. coli, along with the “superbug” methicillin-resistant Staphylococcus aureus (MRSA), and that the polymer can be exposed to bacteria multiple times and still remain effective. This exciting development can be used as a method to actively disinfect surfaces to help reduce hospital-acquired infections, which kill over 25,000 Americans each year.

Currently, there are a variety of methods to reduce hospital-acquired infections (HAIs). Ultraviolet light, bleach, or hydrogen peroxide can be used to disinfect a surface, but this can damage the same surface or cause health problems for those handling the materials. Other approaches include using copper, silver, gold, or metal oxide nanoparticles embedded in healthcare surfaces. These approaches are limited by bacteria becoming resistant to these metals, and they can contaminate the food chain by leaching into the environment. To address these limitations, the NC State researchers developed a new auto-disinfecting surface by using materials chemistry.

The way the technology works is by imparting chemical modifications on a polymer known as TESET, which is currently used for water purification, among other uses. The modification creates a sulfonic acid chemical group linked to the surface of the polymer. When microbes interact with the surface, a small amount of water hydrates the sulfonic acid, leading to a very sudden drop in pH, killing the bacteria. The researchers optimized the chemistry, and can tune the potency of the material by changing the number of sulfonic acid groups on the surface.

The team tested the system by exposing different bacteria to the surface and quantified how many bacteria survived over time. They found that for various types of bacteria, including MRSA, their lead formulation killed 99.9999% of bacteria within five minutes. They also demonstrated that after multiple exposures to bacteria, the polymer still remains highly potent.

“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,” says Rich Spontak, co-corresponding author of a paper on the work. “And what we found is extremely promising as an alternate weapon to existing materials-related approaches in the fight against drug-resistant pathogens. 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.”

“And this work focused on only one polymer series manufactured by Kraton Polymers,” Spontak added. “We are very eager to see how we can further modify this and other polymers to retain such effective and fast-acting antimicrobial properties while improving other attributes that would be attractive for other applications.”

The publication in Material Horizons: Inherently Self-Sterilizing Charged Multiblock Polymers That
Kill Drug-Resistant Microbes In Minutes

Via: NC State