The virus responsible for the current COVID-19 pandemic is very tricky. As we all know by now, it is spread among people mainly via respiratory droplets, but it also remains stable on various surfaces for days. One of the first indications for this came from the Diamond Princess cruise ship, docked off the coast of Japan for almost a month with large numbers of infected passengers, where active virus particles were found even 17 days after the ship was evacuated.
In light of the possibility that the virus can spread through contaminated surfaces, it is important to be able to sterilize surfaces with high contamination potential, such as doorknobs, elevator buttons or handrails in public areas in general and especially in hospitals and clinics in particular. But commonly used disinfectants are mainly based on chemicals such as poisonous sodium hypochlorite (bleach) or alcohol, both of which provide only a temporary measure until the next exposure to the virus.
Prof. Angel Porgador from the department of microbiology, immunology and genetics at Ben-Gurion University (BGU) of the Negev in Beersheba and the National Institute of Biotechnology in the Negev (NIBN), and Dr. Mark Schvartzman, the department of BGU’s materials engineering are developing novel surface coatings that will have a long term effect and contain nanoparticles of safe metal ions and polymers with anti-viral and anti-microbial activity. The innovative surface coatings contain nanoparticles of anti-viral and anti-bacterial metal ions and polymers.
Doctoral students Yariv Greenshpan and Esti Toledo and postdoc Guillaume Le Saux participated in the research. The technology received financial support from the Israel Innovation Authority as part of a call for proposals for coping with the coronavirus
Certain metals can be lethal, even in small quantities, for viruses and bacteria and are not poisonous to humans. In proof-of-concept experiments, the research team assessed the effect of surfaces coated with nanoparticles of various metals on the infectivity of lentiviruses, which belong to the HIV family, in human cells. They discovered that surfaces coated with copper nanoparticles strongly block infection of the cells by the virus – thus offering a huge potential for copper ions in preventing surface-mediated infection with the coronavirus.
Based on these findings, the researchers are developing anti-viral coatings that can be painted or sprayed on surfaces. The coatings are based on polymers, which are the raw materials of plastics and paints, and contain nanoparticles of copper and other metals. The nanoparticles embedded in the polymer will enable controlled release of metal ions onto the coated surface. Studies show that these ions have a strong anti-viral effect that can eradicate virus particles that adhere to the surface. Because the release of ions is extremely slow, the coating can be effective for a long period of time – weeks and even months, and it will reduce the infectivity of the virus particles by more than 10-fold.
“The need to develop anti-viral coatings has greatly increased recently, with the pandemic, and this need will likely remain high even after the pandemic ends, due to increased awareness,” said Josh Peleg, chief executive officer of BGN Technologies, BGU’s technology company, which takes technological innovations from the lab to the market and fosters research collaborations and entrepreneurship among researchers and students.
“In addition, the product will be efficient as a general anti-viral and anti-bacterial coating. It can be applicable for medical settings, as an anti-pathogenic substance in places with increased risk of contamination, such as hospitals, but also for home use, and in public spaces such as schools, airports, public transportation and cinemas. We see a widespread and multidisciplinary academic commitment for finding solutions to currently medical and financial challenges as well as to the challenge of returning to normalcy once the pandemic wanes,” added Peleg.
The research activity by Porgador and Schvartzman is part of the coronavirus research task force founded by BGU president Prof. Daniel Chamovitz. Their invention received the support of the Israel Innovation Authority and is one of 27 proposals submitted to the authority by BGN Technologies.
“The current coronavirus is transmitted not only through droplet spray but also via various surfaces that can convey the virus from one person to another,” said Porgador. “There is a clear need for durable anti-viral coatings that can be sprayed or painted on surfaces, just like paint or varnish, and that will prevent viral transmission. These surfaces can include handles, buttons, railways or any other public surface that poses increased danger, in particular in places with a high concentration of potential carriers… It is important to remember that we are developing coatings that will be effective not only against the coronavirus but also against other viruses, as indicated in our proof of concept experiments, and also against bacteria, so they will be relevant for a wide range of applications.”
Schvartzman concluded: “The coating that we are developing is based on metals that are toxic for viruses or bacteria but completely human friendly. Until now, using such metals for anti-viral applications has encountered significant challenges due to the nature of the metals, such as the tendency to oxidize and corrode. Nanoparticles provide a solution to these obstacles. Another advantage of nanoparticles is the large surface area to volume ratio, which results in an efficient anti-viral surface area using a relatively small amount of metal. Additionally, nanoparticles of anti-viral metal can be easily embedded in a polymer that can coat the relevant surfaces for extended periods of time.”