Key points:
- A new bioadhesive shield acts like an “inner mask” to prevent viruses from reaching the lungs.
- In mice, the inhalable powder blocked SARS-CoV-2 with 75% efficiency in the first 4 hours.
- Researchers are investigating its use beyond viruses, such as for allergens and air pollution particles.
Rather than preventing a virus from turning harmful once inside your body, researchers at NC State have developed a “shied” to protect lungs from viruses like SARS-CoV-2 and influenza.
To infect, viruses need to penetrate the mucus to get to your lung cells, but the researchers’ bioadhesive prevent this.
The inhalable powder, called Spherical Hydrogel Inhalation for Enhanced Lung Defense, or SHIELD, reduced infection in both mouse and non-human primate models over a 24-hour period, and can be taken repeatedly without affecting normal lung function.
According to the study, published in Nature Materials, the inhalable powder microparticles are composed of gelatin and polyacrylic acid grafted with a non-toxic ester. When introduced to a moist environment, such as the respiratory tract and lungs, the microparticles swell and adhere to the mucosal layer, increasing the “stickiness” of the mucus.
The effects are most potent during the first eight hours after inhalation. After 48 hours, the SHIELD biodegrades, and is completely cleared from the body.
In a mouse model, SHIELD blocked SARS-CoV-2 pseudovirus particles with 75% efficiency four hours after inhalation, which fell to 18% after 24 hours. The researchers found similar results when testing against pneumonia and H1N1 viruses.
In a non-human primate model of both the original and Delta SARS-CoV-2 variants, SHIELD-treated subjects had reduced viral loads—from 50 to 300-fold less than control subjects—and none of the symptoms commonly associated with infection in primates, such as lung inflammation or fibrosis.
Additionally, the researchers noted no toxic side effects. In fact, 95% of cell cultures exposed to a high concentration of SHIELD remained healthy, and mice who were given daily doses for two weeks retained normal lung and respiratory function.
“SHIELD is easier and safer to use than other physical barriers or anti-virus chemicals,” said Ke Cheng, corresponding author. “It works like an ‘invisible mask’ for people in situations where masking is difficult, for example during heavy exercise, while eating or drinking, or in close social interactions. People can also use SHIELD on top of physical masking to have better protection.
The researchers are now looking at whether SHIELD could also be used to protect against things like allergens or even air pollution—essentially anything that invades and harms the lungs.
Information provided by NC State.