New Delhi: Scientists from the University of Pennsylvania have developed a chewing gum that can reduce SARS-CoV-2 transmission, by acting as a “trap” for the novel coronavirus. The gum is laced with a plant-grown protein that can potentially decrease the viral load of the SARS-CoV-2 infection in saliva, and reduce its transmission, according to the study published recently in the journal 'Molecular Therapy'.
The study was carried out in collaboration with researchers from The Wistar Institute and Fraunhofer, USA.
In a statement issued by the University of Pennsylvania, Henry Daniell, lead author of the study, said that the SARS-CoV-2 replicates in the salivary glands, and when an infected person sneezes, coughs, or speaks, some of the virus may be expelled and can reach others. He added that the gum offers an opportunity to neutralise the virus in the saliva, giving people a simple way to possibly cut down on a source of disease transmission.
Though vaccines have played a major role in changing the course of the pandemic, they have not ruled out transmission of Covid-19. Even people who have been fully vaccinated can become infected with the SARS-CoV-2 virus, and can carry a viral load similar to the unvaccinated, according to recent research.
Researchers Studied ACE2 Protein To Develop The Chewing Gum
Daniell had been growing a particular protein with a therapeutic potential in his lab, even before the onset of the pandemic. The protein, called angiotensin-converting enzyme 2 (ACE2), was being studied to understand its potential to treat hypertension, and was grown in the lab using a patented plant-based production system.
Coincidentally, the ACE2 receptor on human cells serves as the binding site for the SARS-CoV-2 spike protein. Also, injections of ACE2 can reduce viral load in people with severe infections, according to some studies.
The scientists bombarded the plant material with the DNA of target proteins, so that the plant chloroplasts could take up the DNA, and begin growing the proteins, the peer-reviewed study said. The plant material could be used as a means of delivering the protein, and was freeze-dried and ground-up. Protein drug synthesis is usually an expensive production and purification process, but the plant-based system helped the scientists overcome a lot of obstacles, the study stated.
Another group of researchers from the University of Pennsylvania were developing a chewing gum infused with plant-grown proteins to disrupt dental plaque. Daniell and his colleagues combined their research on ACE2 with the chewing gum technology. They infused a gum with plant-grown ACE2 proteins, to test its potential to neutralise SARS-CoV-2 in the oral activity.
Ronald Collman, another researcher at the University of Pennsylvania, said Daniell approached him to know whether one can internally validate the level of SARS-CoV-2 virus in the saliva samples. Collman said that Daniell’s approach of making the proteins in plants and using them orally is inexpensive and hopefully scalable.
ACE2 Incorporated Into Cinnamon-flavoured Gum Tablets
The researchers tested the chewing gum by growing ACE2 in plants, and paired it with another compound that enables the protein to cross mucosal barriers and facilitates binding, the study said. The scientists incorporated the resulting plant-material into cinnamon-flavoured gum tablets.
They also incubated samples obtained from nasopharyngeal swabs from Covid-19 infected patients with the gum, and observed that the ACE2 present could neutralise SARS-CoV-2 viruses, the study stated. The gum largely prevented the viral particles from entering cells, either by blocking the ACE2 receptor on the cells, or by binding directly to the spike protein, the study said.
The team of researchers exposed samples from Covid-19 patients to the ACE2 gum, and found that levels of viral RNA fell so dramatically that it became almost undetectable, the authors noted in the study.
The scientists intend to conduct a clinical trial to evaluate whether the approach is safe and effective when tested in people infected with SARS-CoV-2, and are seeking permission for the same. The chewing gum could be given to patients whose infection status is unknown, or even for dental check-ups, if the clinical trial proves the gum to be safe and effective.
The gum could reduce the likelihood of passing the virus to caregivers, the authors noted in the study. Daniell said the gum could be used as an additional tool, along with physical barriers such as masks, to reduce the chance of SARS-CoV-2 transmission.