Imbed Biosciences Inc., a closely-held biotech that makes a product for pain and infections in complex wounds, says a reformulation of its biggest product as a nasal spray could help prevent the spread of Covid-19.

The Madison, Wisconsin-based company says it has developed an antiviral formulation of silver nanoparticles, based on its already U.S. approved Microlyte Matrix wound therapy, which could be used to prevent the early spread of Covid-19. The company hopes to start testing the spray in patients soon.

“We have collected data from an independent viral lab that shows it has efficacy against not only Covid but other viruses such as influenza,” Dr. Michael Schurr, an Asheville, North Carolina surgeon and one of Imbed’s six co-founders, said in a phone interview. The nanoparticles bind with Covid viruses and prevent the molecules from taking over human cells, disrupting the entire pathway for viruses that attack the body’s cells, Schurr added.

Imbed’s nanoparticles were found to inactivate or kill about 99.9% of SARS-Cov-2 viruses in an experimental study run by Virology Research Services of London, according to a report seen by Bloomberg. To be sure, those results came from a study in a controlled lab and have not yet been replicated in a follow-on or human trial.

The nanoparticles could be administered through a nasal spray to prevent the Covid-19 viruses from entering the body. Another way would be as a therapeutic for patients with Covid symptoms or those that have tested positive, the company said.

Studies of small doses of the nanoparticles in animals showed the therapy is safe and doesn’t cause any adverse side effect, according to Imbed Chief Executive Officer Ankit Agarwal.