What if you could put on personal protective equipment (PPE), and viruses — like the coronavirus — just bounced off of it?
This could soon be a reality, thanks to research at Pitt’s Laboratory for Advanced Materials at Pittsburgh (LAMP). The lab has created a textile coating that not only repels liquids like blood and saliva but can also prevent viruses from adhering to the surface. It’s also durable and washable.
Current masks, gowns and other PPE can absorb and carry viruses and bacteria — and inadvertently spread the disease that the user is trying to contain. PPE are also still in short supply in many places.
“We were initially testing repellency of proteins from blood,” says professor Paul W. Leu, who directs LAMP. “This is important because blood can carry various pathogens, and the proteins can degrade materials. Afterward, we came up with the idea to repel viruses since the outside layers of viruses also consist of proteins.”
It’s quite a difficult problem.
“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,” says Leu.
“It’s challenging to create surfaces that repel a wide range of fluids such as blood, urine and saliva. The main difficulty in making these coatings is ensuring that they are mechanically durable and wash stable.”
The coating, simply put, repels liquid droplets and prevents them from penetrating the fabric.
“Virus particles in liquid droplets have significantly less surface area to attach to on coated fabric,” explains Leu.
“It is the first demonstration of virus repellency for textiles. Another unique demonstration is the durability of the coating with regard to mechanical abrasion and washing.”
The coated materials were put to the test — running them through dozens of ultrasonic washes, scouring them with a Scotch-Brite scrubbing pad, even scraping them with a sharp razor blade.
The coating remained effective after each test.
Then they tested it on adenoviruses.
“We collaborated with researchers at the University of Pittsburgh Medical Center to test adenoviruses using plaque assays,” explains Leu. “Adenoviruses are a common virus that spread through respiratory droplets. We used what are called plaque-forming assays. Both treated and untreated textiles were submerged in a medium with the virus for 30 minutes. Any viruses that were attached to the textiles were removed and quantified by these plaque assays.”
Adenoviruses were repelled in the same way as fluids like blood and saliva.
These coatings could be used on everything from hospital gowns to waiting room chairs. Right now, the coating is applied using drop casting — which saturates the material with a solution from a syringe, then uses a heat treatment. Eventually, researchers think it can be applied with a spraying or dipping method, and scaled up for production.
The next steps involve more and more testing.
“We are trying to work with textile manufacturers and healthcare providers to realize this coating for actual application,” says Leu. “We will be testing it with beta coronaviruses, which are not quite as dangerous to work with as SARS-CoV-2. We would like to evaluate SARS-CoV-2 as well, eventually.”
This research was recently published in the journal ACS Applied Materials and Interfaces.