The journey to developing a coating effective against Covid-19

Prof. Angel Porgador, from the department of microbiology, immunology and genetics at Ben-Gurion University (BGU) and the National Institute of Biotechnology in the Negev (NIBN), and Dr. Mark Schvartzman, from the department of materials engineering at BGU, explains how they are developing a coating effective against Covid-19.

Certain metals which are not poisonous to humans, can be lethal even in small quantities for viruses and bacteria. Therefore, in proof of concept experiments, we 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. The findings showed that surfaces coated with copper nanoparticles are able to strongly block the infection of the cells by the virus. We believe that these ongoing experiments show a huge potential for copper ions in preventing surface-mediated infection with SARS-CoV-2.

Following these findings, we are developing anti-viral coatings that can be painted or sprayed on surfaces. The coatings are based on polymers, which are the starting materials of plastics and paints, and contain nanoparticles of copper and other metals. The polymers serve as binders, e.g. a matrix material in which the active component - metal nanoparticles - are embedded.

The nanoparticles embedded in the polymer will then enable the controlled release of metal ions onto the coated surface. This is because studies show that these ions have a strong anti-viral effect, which can eradicate virus particles that adhere to the surface. The release of ions is extremely slow, and so the coating can be effective for a long period of time - weeks and even months, reducing the infectivity of the virus particles by more than ten-fold.

This research activity is part of the coronavirus research task force, founded by Prof. Daniel Chamovitz, president of BGU. The research began when research funds were diverted in order to find rapid solutions for various challenges associated with the coronavirus pandemic. This invention also received the support of the Israel Innovation Authority.

In terms of challenges surrounding this research, the main challenge is to find the optimal formulation of the polymer with the embedded nanoparticles of different metals, which would provide the most effective elimination of the coronavirus on the surface.

Additionally, viruses are all different from each other by their size, structure, properties, as well as the way in which they interact with the environment. Therefore, nanoparticles of different size and chemical composition release active ions that interact with each type of virus through different pathways. This means that it is possible to optimize a nanoparticle based coating for one specific virus but formulating a coating that would satisfy multiple requirements stemming from diverse characteristics of different viruses is more challenging.

Another key challenge relates to the polymers used for the coatings. Polymers are required to provide strong adhesion to the surface the coating is applied on, and the ability to adhere depends on both the polymer and surface. This is why specific glues are used for different surfaces, and it is important to formulate a polymeric system which will universally stick to all surfaces.

Although the current research is focused on the coronavirus, we believe that since the mechanism behind the bioactivity of metal ions is universal, the developed coating will be effective against most viruses and bacteria.

Where is the research up to now? Currently, it is in the stage of transferring from a working prototype to a consumable product.