Skip to main content
Move the World.
These “Nanotraps” Capture SARS-CoV-2 for the Immune System to Kill

Lead Image Courtesy of Huang Lab

Researchers at the University of Chicago have developed a surprise they hope will curtail SARS-CoV-2: virus traps. Studded with "bait," these tiny particles trap the virus and then call in reinforcements from the immune system to destroy it.

"Since the pandemic began, our research team has been developing this new way to treat COVID-19," Pritzker School of Molecular Engineering assistant professor Jun Huang, whose lab the Nanotraps were made in, said in a release.

"We have done rigorous testing to prove that these Nanotraps work, and we are excited about their potential."

Trapping a virus: The team's approach, published in Matter, was inspired by cancer cells, according to postdoc researcher Min Chen. Cancer cells release little cargo carriers, called exosomes, that can suppress the immune system.

"A lot of T cells (a type of immune cell) are going to be attracted by those cancer exosomes," Chen tells me, inhibiting the body's immune response; think of the chaff a fighter pilot releases to keep a guided missile off their tail.

The team, led by Chen and cancer biology graduate student Jill Rosenberg, looked to create their own decoys, aimed at fooling viruses, rather than the immune system. 

The idea is delightfully intuitive. Their "Nanotraps" are nanoparticles covered in proteins that bind to SARS-CoV-2's spike protein. The proteins can be ACE2 (the protein that the virus latches onto to enter human cells) or neutralizing antibodies the body creates to disable the virus.

The viruses then get stuck to the Nanotraps, which use a signaling molecule to call in immune cells, called macrophages, that devour the Nanotraps, viruses and all.

"We have a very high density of ACE2 or the neutralizing antibodies on these nanoparticles," Chen says. This allows the nanoparticles to "easily" outcompete human cells at attracting viruses, Chen says.

Of the two forms of bait, the neutralizing antibodies may actually have an edge, says Huang.

"The binding affinity is much higher than the ACE2," Huang says — meaning the neutralizing antibodies, specially designed to seek out and glom on to the spike protein of the virus, are much stickier.

The team envisions the Nanotraps being administered via nasal spray, or perhaps as eye drops.

ACE2, however, is a more universal target. Because it is key to the virus' replication, variants of SARS-CoV-2 are always going to need a way to bind to it, whereas some antibodies can have a harder time sticking to new variants.

The hope is that Nanotraps may be effective against various strains of coronaviruses.

Much smaller than a human cell, the Nanotraps are made of phospholipids and polymers already approved by the FDA, and mouse studies found no evidence of toxicity. 

The team envisions them being administered via nasal spray, or perhaps as eye drops, with the goal of treating COVID-19 — although it could perhaps prove to be a preventative measure as well.

In labs and lungs: After testing the Nanotraps' safety in mice, the team needed to see if the viruses actually took the bait.

They tested the Nanotraps against a pseudovirus — a SARS-CoV-2 stand-in that lacks the ability to replicate, because it is safer than working with the real thing.

In cell tissue cultures, they found that the Nanotraps stopped the pseudovirus from infecting lung cells completely. Using a pair of lungs and a machine to keep them alive (donated by a deceased patient and the surgical department), they also found the Nanotraps could stop the pseudovirus in a real lung environment.

Of course, that doesn't mean the same will hold true with the real SARS-CoV-2. To test the Nanotraps against the bonafide agent behind COVID-19, the team worked with Argonne National Laboratory to test the Nanotraps in human cell culture against the real deal. 

To test their Nanotraps, the team used lungs donated from the University of Chicago surgical department. Inside the lungs, which were not healthy enough for transplant and hooked to machines to keep them alive, the Nanotraps proved effective at snapping up a pseudovirus stand-in for SARS-CoV-2.

To test their Nanotraps, the team used lungs donated from the University of Chicago surgical department. Inside the lungs, which were not healthy enough for transplant and hooked to machines to keep them alive, the Nanotraps proved effective at snapping up a pseudovirus stand-in for SARS-CoV-2. Credit: Photo by Jill Rosenberg

In that test, the lab found that the nanoparticles were 10 times better at stopping the virus than dumping in ACE2 proteins or neutralizing antibodies alone. 

The fact that the Nanotraps can be loaded up with thousands, or even tens of thousands, of antibodies may be the reason why they outperform the proteins on their own, Chen says.

Next steps: Research is still in the early stages; you won't be able to find Nanotraps in your pharmacy before human clinical trials are performed.

While the nanoparticles have not shown any toxic effects yet, further research in small and large animal models, as well as phase 1 human trials, will be needed to ensure the Nanotrap's safety, Rosenberg says via email.

The team envisions their Nanotraps as not just a SARS-CoV-2 therapy or even prophylactic, but as a platform with the potential to be used for other viruses. By switching out the trap's bait, you could theoretically capture and clear lots of other viruses.

We'd love to hear from you! If you have a comment about this article or if you have a tip for a future Freethink story, please email us at [email protected]

Up Next

If you want to understand a problem, talk to the people working on solutions. Join us as we meet the people and explore the ideas on the frontlines of an unprecedented global response.

Public Health
“That Is Insane”: The Strange, Deadly Coronavirus Immune Response
coronavirus immune response
Public Health
“That Is Insane”: The Strange, Deadly Coronavirus Immune Response
Research suggests the coronavirus immune response is different than with other viruses. It may help inform treatments and our understanding of COVID-19.

Research suggests the coronavirus immune response is different than with other viruses. It may help inform treatments and our understanding of COVID-19.

Uprising
What's Special About Cancer-Killing Nanobots? Precision.
medical nanobots
Uprising
What's Special About Cancer-Killing Nanobots? Precision.
These tiny, robotic machines can deliver drugs directly to infected cells, and they're changing the future of medicine.

These tiny, robotic machines can deliver drugs directly to infected cells, and they're changing the future of medicine.

Coronavirus
Trees and Insects Helped Create Novavax’s COVID-19 Vaccine
Novavax’s COVID-19 Vaccine
Coronavirus
Trees and Insects Helped Create Novavax’s COVID-19 Vaccine
Novavax’s COVID-19 vaccine was nearly 90% effective in a U.K. trial — and the ingredients for the promising subunit vaccine came from insects and trees.

Novavax’s COVID-19 vaccine was nearly 90% effective in a U.K. trial — and the ingredients for the promising subunit vaccine came from insects and trees.

Coronavirus
Ghost Kitchens Are Saving Restaurants During the Pandemic
ghost kitchens
Coronavirus
Ghost Kitchens Are Saving Restaurants During the Pandemic
Ghost kitchens are thriving during the pandemic, as more restaurants rely on online delivery orders for their income.

Ghost kitchens are thriving during the pandemic, as more restaurants rely on online delivery orders for their income.

Coronavirus
Pain Relief From Coronavirus May Be Helping It Spread
Pain Relief From Coronavirus
Coronavirus
Pain Relief From Coronavirus May Be Helping It Spread
Rather than feeling sick, some people may be getting pain relief from coronavirus — a discovery that could impact both the pandemic and the opioid epidemic.

Rather than feeling sick, some people may be getting pain relief from coronavirus — a discovery that could impact both the pandemic and the opioid epidemic.

Coronavirus
Gates Foundation Backs a $3 Coronavirus Vaccine
$3 Coronavirus Vaccine
Coronavirus
Gates Foundation Backs a $3 Coronavirus Vaccine
The Gates Foundation is spending $150 million to help with the manufacturing and distribution of a $3 coronavirus vaccine in lower-income nations.

The Gates Foundation is spending $150 million to help with the manufacturing and distribution of a $3 coronavirus vaccine in lower-income nations.

Coronavirus
New Air Filter for COVID-19 Could Lower Risk of Being Indoors
Air Filter for COVID-19
Coronavirus
New Air Filter for COVID-19 Could Lower Risk of Being Indoors
A new air filter for COVID-19 heats up to nearly 400 degrees Fahrenheit to kill the coronavirus in aerosols.

A new air filter for COVID-19 heats up to nearly 400 degrees Fahrenheit to kill the coronavirus in aerosols.

Public Health
FDA Approves First Saliva Test for Coronavirus
Saliva Test for Coronavirus
Public Health
FDA Approves First Saliva Test for Coronavirus
The FDA has granted a saliva test for coronavirus emergency use authorization, giving health officials a new way to diagnose COVID-19.

The FDA has granted a saliva test for coronavirus emergency use authorization, giving health officials a new way to diagnose COVID-19.

Healthcare
New Tool Seeks to Protect Those Reusing Coronavirus Masks
Coronavirus Masks
Healthcare
New Tool Seeks to Protect Those Reusing Coronavirus Masks
A group of researchers launched a website that teaches healthcare workers everything they need to know about reusing coronavirus masks as safely as possible.

A group of researchers launched a website that teaches healthcare workers everything they need to know about reusing coronavirus masks as safely as possible.