Researchers Develop COVID Shield Coating
A team of Australian researchers has recently developed a sprayable coating capable of preventing the surface spread of infection from bacteria and viruses, including COVID-19.
Reported to be a first of its kind, the spray is made up of a combination of plastics strong enough to be considered an alternative to bullet-proof glass.
COVID Shield Research
Developed over a period of five years, the spray coating research was headed by co-lead author University of Sydney’s School of Biomedical Engineering Professor Antonio Tricoli and Director of the University of Melbourne's Graeme Clark Institute, Professor David Nisbet.
While COVID-19 was not a worldwide concern at the launch of the study, the authors note that research was funded and supported in part by Australian Research Council and NHMRC grants to mitigate the spread of viral and bacterial pathogens through contact with surfaces—a leading cause of infection worldwide.
Surface contamination is also reported to play a major role in the evolution of antibiotic-resistant bacterial strains.
According to the University of Sydney, the developed spray coating provides a more reliable alternative to standard disinfectants, which are becoming less effective and require regular reapplication, but it is the only permanent surface layer proven to protect surfaces from virus contamination.
Researchers note that the coating is also safer than existing alternatives to disinfectants, with no harmful side effects and more stable potency.
“Without a barrier, viruses such as coronaviruses can stay on surfaces and remain infectious for up to a week,” said Tricoli. “Other viruses such as reoviruses, which can cause colds or diarrhea, for instance, can remain on surfaces for several weeks, causing large outbreaks in health and aged care facilities.”
To develop the coating, the team tested the mechanical stability and surface energy of the coating, in addition to its ability to resist contamination from bacteria and viruses by subjecting it to high concentrations of both.
During the testing phase, coating samples were submerged for extended periods of time and the sprayed surfaces were purposely damaged.
“We have identified the mechanical processes underpinning how the spray works and quantified its effectiveness in different environments,” Nisbet said. “For this study, we tested metal surfaces. However, in the past we have shown the spray can be applied to any surface, for example, blotting paper, plastic, bricks, tiles, glass and metal.
“Our coating successfully prevented up to 99.85% and 99.94% of the bacteria strain growth. We also saw an 11-fold reduction in virus contamination.”
The research team further explained that the resulting coating works in two ways: it repels viruses and bacteria through air-filled barriers and is also capable of killing pathogens through microscopic materials, should a layer become damaged or submerged for extended periods.
“Like a lotus leaf, the surface spray creates a coating that repels water. Because the pathogens like to be in water, they remain trapped in the droplets and the surface is protected from contamination,” explained Tricoli. “If this mechanism fails, a secondary burst of ions is triggered by carefully designed nanomaterials dispersed in the coating.”
The conclusive coating can be spray-applied, in the same way as traditional spray paint. However, the team notes that smaller quantities are still needed. Once finalized, it is hoped that the coating can be applied to a variety of public surfaces such as lift buttons, stair rails, surfaces in hospitals, nursing homes, schools and restaurants.
“The coating has been engineered through a simple and scalable technique with a careful choice of materials to provide ultra-durability," Nisbet said. “We also believe our explanation of the mechanism behind the antimicrobial and antiviral effects could significantly advance research in antipathogen technologies that could see affordable manufacture of an effective surface spray to protect people from viruses and bacteria.”
Research on the coating has since been published in the journal Advanced Science. The team has also established a start-up company to aid the coating technology’s success. They hope that the coating will be commercially available within three years.
Recent Antibacterial Coating Research
Earlier this month, a team of researchers made up of Kuman University’s chemistry department faculty and others from the Atal Bihari Vajpayee Indian Institute of Information Technology and Management, Gwalior (ABV-IIITM Gwalior) were reported to develop a new anti-viral coating.
Using graphene, the paint spray is reported to have anti-viral properties generated from waste plastic.
Capable of killing several viruses, including COVID-19, the anti-viral coating claims to be a first of its kind and is notably cheap to make. Professor Nanda Gopal Sahoo, who led the study, explained to The Times of India that the graphene within the coating is extracted from discarded plastic, making the product very cost-effective.
Other materials making up the coating include special fatty acids, such as soap, zinc oxide and titanium-oxide-based nanoparticles. The anti-viral coating is also noted to utilize some other unnamed patented components as well.
The resulting combination not only protects surfaces from encountering viruses but can also kill already present viruses and stop their mutation, according to Sahoo.
In April, Russian researchers from Tomsk State University were reported to have developed a new paint designed to neutralize common pathogens and reduce nosocomial (hospital-acquired) infections.
Reportedly enhanced with biocidal nanoparticles, the new paint aims to neutralize a number of common pathogens and reduce nosocomial infections.
According to TSU, the paint Premia has two types of composition. Noted to be equal in effectiveness, only one of the paints has been tested and certified, while the second is an upgraded, cheaper version with the aim of making the paint more available to potential buyers.
In preliminary testing of both versions, developers added that the concentrated nanoparticles proved their effectiveness against a widespread collection of common nosocomial infections. Supported by a number of governmental programs, including the Priority 2030 program, the new coating is slated to be used on the walls of two Tomsk Region hospitals.
In March, a team of researchers from the Department of Nano-Bio Convergence of the Korea Institute of Materials Science reported that they’d developed a material that provides antibacterial and antiviral properties without changing the physical properties of various products that are commonly used.
According to the team, while antibacterial films and antibacterial coating products are widely used for elevator buttons, door handles and touch screens, they are difficult to maintain long-term antibacterial durability of the material because of the low transparency and damages caused by frequent use.
The application of antibacterial films and coatings also requires an additional process of attaching or producing a film to an existing product.
To mitigate this issue, the research team developed an antibacterial/antiviral additive capable of generating high metal ions. By about 1 to 2 weight percent (wt%) of the additive to various resins, the antibacterial properties reportedly increased to 99.99%, while the antiviral properties were reported to be more than 10 times in two hours without changing optical/mechanical/thermal properties of existing products.
The team reported that the antibacterial/antiviral additive is composed of non-toxic substances without organic antibacterial agents and nano compounds. In addition, when used as an additive, the material can carry out ultraviolet and heat curing processes without additional processing on existing products.
This research achievement was funded by the Ministry of Science and ICT and supported by KIMS. The research team is currently working on commercializing the technology by promoting the establishment of a research institute spin-off company.