Biodegradable Nanohybrid Materials as Candidates for Self-Sanitizing Filters Aimed at Protection from SARS-CoV-2 in Public Areas

Abstract

The COVID-19 pandemic has raised the problem of efficient, low-cost materials enabling the effective protection of people from viruses transmitted through the air or via surfaces. Nanofibers can be a great candidate for efficient air filtration due to their structure, although they cannot protect from viruses. In this work, we prepared a wide range of nanofibrous biodegradable samples containing Ag (up to 0.6 at.%) and Cu (up to 20.4 at.%) exhibiting various wettability. By adjusting the magnetron current (0.3 A) and implanter voltage (5 kV), the deposition of TiO2 and Ag+ implantation into PCL/PEO nanofibers was optimized in order to achieve implantation of Ag+ without damaging the nanofibrous structure of the PCL/PEO. The optimal conditions to implant silver were achieved for the PCL-Ti0.3-Ag-5kV sample. The coating of PCL nanofibers by a Cu layer was successfully realized by magnetron sputtering. The antiviral activity evaluated by widely used methodology involving the cultivation of VeroE6 cells was the highest for PCL-Cu and PCL-COOH, where the VeroE6 viability was 73.1 and 68.1%, respectively, which is significantly higher compared to SARS-CoV-2 samples without self-sanitizing (42.8%). Interestingly, the samples with implanted silver and TiO2 exhibited no antiviral effect. This difference between Cu and Ag containing nanofibers might be related to the different concentrations of ions released from the samples: 80 μg/L/day for Cu2+ versus 15 µg/L/day for Ag+. The high antiviral activity of PCL-Cu opens up an exciting opportunity to prepare low-cost self-sanitizing surfaces for anti-SARS-CoV-2 protection and can be essential for air filtration application and facemasks. The rough cost estimation for the production of a biodegradable nanohybrid PCL-Cu facemask revealed ~$0.28/piece, and the business case for the production of these facemasks would be highly positive, with an Internal Rate of Return of 34%.

Virucidal PVP-Copper Salt Composites against Coronavirus Produced by Electrospinning and Electrospraying

“…Manakhov et al [ 47 ] reported that the increased antiviral activity of copper-containing nanofibers was the result of the release of ions that offered high antiviral activity against the SARS-CoV-2 virus strain. Thus, our study results suggest that this virucidal action occurs as a result of the release of Cu 2+ ions from copper sulfate dissociation into the culture medium of the virucidal test, which can promote an electrostatic interaction of Cu 2+ ions with the viral model, leading to the destruction of the coronavirus.…”

The role of ion dissolution in metal and metal oxide surface inactivation of SARS-CoV-2

“…Despite antimicrobial properties of silver being widely reported (19), we show that a silver surface did not exhibit extensive SARS-CoV-2 inactivation. Others have also reported silver materials to lack antiviral activity against SARS-CoV-2 and other viruses (14,16,20,21) and the poor antiviral activity has been proposed to be due to low levels of Ag ion dissolution (14,20). In contrast, positive reports of silver antiviral activity generally relate to silver-containing nanoparticles (22)(23)(24)(25)(26).…”

Design and fabrication of a biodegradable face shield by using cleaner technologies for the protection of direct splash and airborne pathogens during the COVID-19 pandemic

“…Zywicka et al developed novel, sustainable filters based on bacterial cellulose (BC) functionalized with low-pressure argon plasma (LPP-Ar) which has >99% bacterial and viral filtration efficiency ( Żywicka et al, 2022 ). Manakhov et al prepared a wide range of nanofibrous biodegradable Self-Sanitizing Filters containing Ag (up to 0.6 at.%) and Cu (up to 20.4 at.%) for the protection against SARS-CoV-2 in Public Areas ( Manakhov et al, 2022 ).…”