Bacteria-Killing Plastics Arise to Fight Infections in Hospitals

By Mike Howie & Mark Miller

When you’re sick and go to the hospital, you expect to get better, but that’s not always the case. The online research news resource ScienceDaily reports that 20 percent of patients that were hospitalized due to COVID-19 actually contracted the disease while in the hospital.

Illnesses like COVID-19 may spread in places thought to be exceptionally clean because of the ability for the bacterial microorganisms that can cause them to survive on plastic surfaces—which are practically everywhere in hospitals. According to ScienceDaily, “microorganisms can survive and remain infectious on abiotic surfaces, including plastic surfaces, for extended periods, sometimes up to several months.”

Two materials have been developed that may help shorten the lives of these germs. One is a coating developed at the University of Nottingham’s School of Pharmacy in the U.K. The other is a plastic developed by chemist Ethel Koranteng and a research team at University College London.

Uncommonly Effective

The scientists in Nottingham coated a polymer called acrylonitrile butadiene styrene (ABS) with chlorhexidine, a disinfectant and antiseptic commonly used by dentists. What they discovered was an uncommonly effective method for eliminating infectious microbes.

The researchers examined the coated ABS using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), a method that uses light to see what’s happening at the molecular level. It showed that the ABS not only killed microbes quickly, but after 45 minutes, the tested surfaces remained germ free. The coated ABS also worked for SARS-CoV-2, the virus that causes COVID-19, leaving no viral particles after 30 minutes, according to ScienceDaily.

In addition, the coating may help combat antimicrobial resistance—where bacteria can change over time and no longer respond to antibiotics. “This research offers an effective way to do this and the material could be added to plastic materials during manufacture, it could also potentially be used as a spray,” said study leader Felicity de Cogan, PhD, in the report.

Fighting Germs with Light

An article published in Science News Explores, explains that Koranteng and her team also used a common material—polyurethane. But the important part is what’s inside. The polyurethane is embedded with tiny semiconductor nanobits called quantum dots and a light-sensitive dye called crystal violet. Together, they use light to create a high-energy oxygen molecule that works as a potent antibiotic.

They tested their surface with impressive results. It killed 99.97 percent of the methicillin-resistant Staphylococcus aureus (MRSA) bacteria, which is immune to the antibiotic methicillin, and it did nearly as well at destroying another antibiotic-resistant bacteria, Escherichia coli or E. coli, according to Science News Explores.

Both team’s inventions could potentially reduce the risk and frequency of infections acquired in hospitals, which would make a meaningful difference in the lives of patients and doctors around the world.