Acting on a conversation with doctors at the Vellore-based Christian Medical College over shortage of personal protective equipment (PPE), the Indian Institute of Science (IISc), Bengaluru, has developed an antiviral and antibacterial coating technology for three-layered masks that has the potential to destroy or inactivate the novel coronavirus that causes Covid-19.
In the absence of a vaccine, rapid manufacture of cost-effective multi-layered masks loaded with antiviral and antibacterial properties is vital because currently available masks are both expensive and inefficient in reducing viral transmission thereby putting the lives of high-risk groups such as health care workers in danger.
Researchers said their technology renders face masks more or as efficient, and cheaper, than N95 masks. As against N95 masks which costs in the range of Rs 400-Rs 600, the cost of the fabric for the three layer mask and coating material used in the novel technology (excluding incidental expenses) costs Rs 22.
“Technologically speaking, N95 and most other masks are based on a physical barrier approach that involves fine filters that prevent bacteria and viruses from entering the nasal cavity,” said Kaushik Chatterjee, associate professor, department of materials engineering, IISc. “Live viruses, however, can get transferred to healthcare workers during handling, removing and disposing PPE.”
While there are no anti-viral or antibacterial agents deposited on N95 masks, the fibres are electrostatically charged. “Most viruses have negative charge and when the virus or the bacteria come in contact with the mask, they get inactivated and unable to enter the respiratory tract,” said Suryasarathi Bose, associate professor, department of materials engineering, IISc.
{{/usCountry}}While there are no anti-viral or antibacterial agents deposited on N95 masks, the fibres are electrostatically charged. “Most viruses have negative charge and when the virus or the bacteria come in contact with the mask, they get inactivated and unable to enter the respiratory tract,” said Suryasarathi Bose, associate professor, department of materials engineering, IISc.
{{/usCountry}}Contrary to the N95 masks, the outer layer of the three-ply textile-based face masks comprises a nanofibrous polymer membrane that is deposited on the modified polyester. This membrane makes the first layer hydrophobic, meaning it resists the entry of any liquid drops containing the virus particles. The middle layer is also coated with the nanofibrous membrane, but loaded with antiviral and antibacterial agents which inactivate the virus or bacteria that may have been transferred through the first layer. The third and innermost layer is cotton fabric for an individual’s comfort. While the nanofibrous membranes are made of biodegradable polymer, antiviral and antibacterial agents used are USFDA approved.
“The hydrophobic nature of the upper layer delays the transmission of the droplets containing the virus on to the middle layer,” said Bose. “Once the virus particles are on the middle layer, the antiviral agents partially kill it in 30 minutes and completely within two hours.”
The industrially-scalable coating technology has undergone testing against viruses and bacteria at the institute’s laboratory with success. Currently a Bengaluru-based company has been identified to license their coating technology, while at the same time IISc will maintain non-exclusivity of their product owing to the magnitude of the epidemic’s outbreak.
The team including research scholars Monika Rajput, Tanyaradzwa Muzara and Ammanuel Gebrekrstos have filed a patent for ‘Antimicrobial composite fabric and method thereof’, which is not restricted to face masks since the coating technology can also be extended to other PPEs such as gloves, lab coats as well as surgical gowns and hospital apparels.