- Melinda Murphy
New material repels blood
Researchers at the University of Pittsburgh have developed a coating that can be used to create textiles that repel viruses, along with bodily fluids such as saliva and blood. Interestingly, the coated textiles are reusable, and can be washed and scrubbed repeatedly without losing their virus-repelling properties. These characteristics may make them highly suited for use in reusable personal protective equipment (PPE) during the COVID-19 pandemic.
A shortage of PPE has made the response to the COVID-19 pandemic more difficult for healthcare staff. Most PPE items are not reusable, and, once potentially exposed to the virus, they must be discarded. Developing reusable PPE could make stocks last for longer and help healthcare staff to better protect themselves and their patients.
To address this, these researchers have developed a repellent coating for textiles that allows them to repel bodily fluids, and even viruses, making it easy to wash any contamination off. “Recently there’s been focus on blood-repellent surfaces, and we were interested in achieving this with mechanical durability,” said Anthony Galante, a researcher involved in the study. “We want to push the boundary on what is possible with these types of surfaces, and especially given the current pandemic, we knew it’d be important to test against viruses.”
The researchers’ solution involves polytetrafluoroethylene nanoparticles suspended in a solvent that is drop-casted onto the textile surface, and then exposed to heat to get the solution to bind to the textile fibers. The resulting coated textile is superhemophobic and antivirofouling. So far, the researchers have tested the coated textiles in their ability to repel adenoviruses, and intend to test it against coronaviruses in the future.
“As this fabric was already shown to repel blood, protein and bacteria, the logical next step was to determine whether it repels viruses. We chose human adenovirus types 4 and 7, as these are causes of acute respiratory disease as well as conjunctivitis,” said Eric Romanowski, another researcher involved in the study. “It was hoped that the fabric would repel these viruses similar to how it repels proteins, which these viruses essentially are: proteins with nucleic acid inside. As it turned out, the adenoviruses were repelled in a similar way as proteins.”
By subjecting the coated textiles to repeated rounds of ultrasonic washing and scrubbing with pads, the researchers demonstrated that the textile could be thoroughly washed and still maintain its repellent properties, suggesting its potential as a component of reusable PPE.
“The durability is very important because there are other surface treatments out there, but they’re limited to disposable textiles. You can only use a gown or mask once before disposing of it,” said Paul Leu, a third researcher involved in the project. “Given the PPE shortage, there is a need for coatings that can be applied to reusable medical textiles that can be properly washed and sanitized.”