Drug-free nasal spray prevents infections by trapping viruses in the nose

Nobody wants to get a respiratory infection like COVID-19 or the flu, but vaccines are not 100% effective, and constantly taking preventative medication can be problematic. This is where a special nasal spray could help, as it has been shown (in mice) to prevent such diseases without the use of drugs.

Respiratory viruses usually enter our bodies in droplets exhaled by infected people and inhaled through the nose. These viruses continue to multiply as they infect the cells that line our nasal passages. When we subsequently sneeze or even just exhale, their progeny are expelled in liquid droplets and infect more people.

To capture and neutralize viruses in the nose, scientists at Harvard-affiliated Brigham and Women's Hospital turned to the U.S. Food and Drug Administration. Specifically, they looked for ingredients that had previously been used in FDA-approved nasal sprays or were on the FDA's list of generally recognized as safe preparations.

The resulting substance is known as Pathogen Capture and Neutralizing Spray (PCANS) and does not contain any medication.

Instead, the spray forms a gel that lines the inside of the nose. While this gel does not affect the user's breathing, it captures any viruses or bacteria that are subsequently inhaled into the nose and immobilizes them until they die.

In laboratory tests, the spray protected mice from a mouse-adapted form of the H1N1 flu virus, even when that virus was administered at a dose 25 times the lethal dose. In addition, the concentration of the virus in the animals' lungs was reduced by over 99.99% compared to an untreated control group of mice. The spray remained in the rodents' noses for up to eight hours and effectively blocked the infection for at least four hours.

Although PCANS has not yet been tested on humans, has was used in a 3D printed model of a human nose, where it captured twice as many microbe-containing droplets as mucus alone.

“It blocked and neutralized nearly 100% of all viruses and bacteria we tested, including influenza, SARS-CoV-2, RSV, adenovirus, K pneumonia and more,” says Dr. John Joseph, lead author of the study.

The research is described in an article that recently appeared in the journal Advanced materialsAnd if you suffer from allergies, beware: Scientists believe the spray could one day be used daily to capture and neutralize allergens.

Source: Brigham and Women's Hospital