A biomedical laboratory in the United States has developed a way to potentially neutralize airborne viruses using food coloring sprays.
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This story originally appeared in The Conversation
Editor’s note: This research report provides a brief overview of interesting academic work.
From Young Kim, Purdue University;; Hee-Jae Jeon, Purdue University;; Jung Woo Leem, Purdue Universityand Yuhyun Ji, Purdue University
The big idea
Our biomedical engineering laboratory has developed a way to potentially neutralize airborne viruses using FDA-approved food coloring sprays. Aerosols are small pieces of solid or liquid substances that are suspended in the air.
Our idea was inspired by photodynamic therapy, which is also a medical treatment for certain types of cancer. Photodynamic therapy uses a photosensitizer, a chemical that reacts with oxygen in the presence of light to form free oxygen radicals. These radicals are highly reactive, which means they trigger other chemical reactions, including those that kill harmful pathogens.
Instead of using expensive medical photosensitizers, we’ve identified several FDA-approved food colors that can be used to create free radicals in visible light. We use ultrasound to create tiny sprays that contain the food coloring to allow the coloring to float and stay in the air. Sprays are barely visible and due to their small size and short shelf life, they do not stain surfaces.
We use this technique to make a device, the Photodynamic Airborne Cleaner, that disinfects airborne pathogens. To the best of our knowledge and belief, this is the first photodynamic therapy aerosol generator for disinfection in the air.
Why does it matter?
Viruses and bacteria are often transmitted through the air. A person infected with SARS-CoV-2, the virus that causes COVID-19, and who coughs or sneezes produces contaminated droplets and aerosols that are airborne and can cause disease.
Because of this risk, all types of indoor meetings are now limited. The ability to disinfect large amounts of indoor air for many people is important to reduce the chances of transmission.
What other research is being done in this area?
Photodynamic therapy was first demonstrated as a means of combating bacterial infections. Free oxygen radicals, especially singlet oxygen, can also inactivate viruses by damaging the nucleic acids, proteins, and lipids that make them up. Singlet oxygen, in particular, is effective in breaking down the lipid envelopes that form protective layers around many viruses. Most viruses harmful to humans, including SARS-CoV-2, have these envelopes.
Various other disinfection techniques are available, such as hydrogen peroxide spray, hydrogen peroxide vapor, ozone, steam, and UV-C or “deep UV” lighting. However, these are better suited for disinfecting surfaces than for deactivating pathogens in the air. In addition, they can be dangerous to humans. For example, deep ultraviolet rays are commonly used as disinfectants, but they are carcinogenic.
We are preparing to work with a federal research team to evaluate the effectiveness of our photodynamic air purifier in the air against the transmission of SARS-CoV-2 in the air.
FDA-approved food coloring sprays and their singlet oxygen generation don’t last long. These dye sprays are broken down in light and singlet oxygen is not generated without light. Although the food coloring is approved for consumption by the FDA, the safety of possible inhalation and oral ingestion must be assessed.
This article was translated by El Financiero.This article is republished by The Conversation under a Creative Commons license. Read the original article.