Biology and nanotechnology are moving ever closer together. Ars recently wrote about the use of nanoparticles to aid delivery of stem cells in cardiac therapy. Now, Swiss researchers have developed nanoparticles that can detect, and one day could combat, viruses.

When viruses enter the human body, the immune system responds to their presence. This triggers a sophisticated chain of events that leads to production of antibodies specific to the virus. Depending on the swiftness and effectiveness of the response, there are usually three possibilities: viruses are eliminated before they cause damage, they are eliminated after the person suffers a bout of sickness, or, in the worst case scenario, the virus spreads uncontrolled.

One option for combating viral infections is to develop “artificial” antibodies. These antibodies can have two uses: they can be used to detect infections and, if produced at large enough scale, they can be used to combat infections.

That’s what Patrick Shahgaldian and his colleagues at the University of Applied Sciences and Arts Northwestern Switzerland have been working on. Their solution is relatively simple. Find the virus that causes infection; imprint copies of it on a nanoparticle; then use this “mold” to trap the virus.

There are several steps to creating the imprinted nanoparticle. Step one involves sticking the virus on a silica nanoparticle (SNP) using binding chemicals. (Just to be clear, these binding chemicals are too toxic to be used in the body.) In step two, the SNP is coated with a layer of polymer (organosiloxane). Next, the “virus imprinted particle” (VIP) is subjected to ultrasound which dislodges the virus.

After optimizing the thickness of the polymer layer, Shahgaldian and his team tested these VIPs in a virus-infected solution of human blood serum. After 30 minutes of exposure to the VIPs, they found that they were able to trap up to 88 percent of all viruses even at very low (65 picomolar, or 10^-12) concentration. Their effectiveness in clearing a virus-containing water solution was even higher.

According to Shahgaldian, these VIPs will be first used as a diagnostic tool—expose humans to a small amount of VIPs, and then find out if any of them contain trapped viruses. Of course, clinical trials will be needed to find out if it is safe to inject so many nanoparticles at once.

The next step, says Shahgaldian, is to use VIPs for therapy. But that will require additional developments, like mass manufacturing of these nanoparticles. If it were to be used to fight a new strain of virus, like the coronavirus that’s making many nervous, then a method that will produce these artificial antibodies quickly and at a large scale will be needed.

Nature Communications, 2013. DOI: 10.1038/ncomms2529 (About DOIs).