Researchers at North Carolina State University have developed a nanodecoy system that provides binding sites for the SARS-CoV-2 virus. The vesicles help prevent the virus from attaching to the lung cells and leading to their eventual destruction by the immune system. Nanodecs are derived from lung spheroid cells and contain on their surface the angiotensin 2 converting enzyme receptor (ACE2). The ACE2 receptor is the binding site and entry point of the SARS-CoV-2 virus into lung cells, so the vesicles essentially act as false binding sites, fooling the virus. Nanodecoys have been shown to be promising as an inhaled treatment in rodents and non-human primates, and may be useful as a COVID-19 treatment in humans.
Existing approaches to combat the SARS-CoV-2 virus have focused primarily on the virus itself. All of our vaccines are targeted against ear protein and one of the few direct treatments approved for COVID-19 (rather than treatments to treat symptoms) are monoclonal antibodies directed against the virus. However, as the new viral variants have shown, the virus is not a static target and these treatments could be made ineffective by viral mutations.
What is less likely to change is our body’s viral target: the ACE2 receptor. The latter treatment aims to overwhelm the viral particles in the lungs with binding sites, making it ineffective and making the immune system easily eliminated. Researchers hope the treatment can improve the body’s viral clearance, reduce symptoms and prevent the virus from damaging the lungs.
“If you think the spike protein is a key and the cell’s ACE2 receptor is a blocker, what we’re doing with nanodebots is overwhelming the virus with fake locks so it can’t find those that let it into the cells. Lung cells, ”Ke Cheng, a researcher involved in the study, said in a press release from North Carolina State University. “False locks bind and trap the virus, preventing it from infecting cells and reproducing, and the body’s immune system takes care of the rest.”
To date, researchers have shown that inhaled nanodebots stick to the lungs of mice for at least 72 hours and increase the elimination of a virus that mimics SARS-CoV-2. Another study in macaques showed that nanodecoys reduced inflammation and pulmonary fibrosis and increased viral clearance. Additional work is required to evaluate the potential of treatment for human patients.
“By focusing on the body’s defenses rather than a virus that will keep the mutation going, we have the potential to create a therapy that will be useful in the long run,” Cheng said. “As long as the virus needs to enter the lung cell, we can continue to fool it.”
Here’s an explanatory video from the state of North Carolina about the new technology:
Study a Nanotechnology of nature: Nanodecoys that mimic cells neutralize SARS-CoV-2 and mitigate lung damage in a non-human primate model of COVID-19