Antimicrobial Surface Coatings to Reduce COVID-19 Spread

Abstract

The Air Force has identified an urgent need to reduce COVID 19 contaminant loads in environments where Airmen operate (e.g., patient transfer mobility aircraft) and thus decrease transmission likelihood. Physical Sciences Inc. (PSI) and National Emerging Infectious Disease Laboratories at Boston University (NEIDL/BU) are developing an antimicrobial coating and demonstrate its effectiveness on evacuation litter products and blood pressure monitoring equipment. PSI is coating multiple medical equipment materials with a permanently attached, broad spectrum antimicrobial technology. The coating was previously demonstrated on textile, metal and plastic surfaces for strong attachment and broad spectrum antimicrobial activity against bacteria, spores, fungi and viruses. The coating efficacy for the target surfaces is being demonstrated against a virus panel and other pathogens of interest. The coating is being optimized to achieve high levels of viral reduction within a short amount of time. The robustness of coating in litter operation is being evaluated upon weathering, abrasion, and cleaning. The coating was developed based on prior PSI studies that demonstrated broad spectrum antimicrobial activity of fabric and metal surfaces against bacteria, spores, fungi and viruses. Greater than 99 99.999% kill efficiency was demonstrated against: (a) antibiotic resistant bacteria: C. Diff. both vegetative cells and spores), MRSA , b) sterilization resistant spores ( Bacillus, sp. sp.), (c) clean room bacteria B. atrophaeus ), (d) Gram positive bacteria S. Aureus, S. Epidermis ), (e) Gram negative bacteria ( E.Coli ), (f) fungus C. Albicans ) and (g) non enveloped viruses ( MS2 ). Biocompatibility of fabric coupons was also demonstrated with no cytotoxicity or skin irritation. Results to date indicate strong attachment of the antimicrobial coating to surfaces of NATO evacuation litter and blood pressure cuff materials. The coating process was optimized to provide uniform and high density coverage across all materials. Formulations for both bath and spray coating processes have been developed. All coated materials showed antiviral activity high efficacy (up to 5.5 log reduction, >99.999% kill efficiency) against a COVID 19 surrogate, Vesicular stomatitis virus (VSV). The antiviral efficacy was demonstrated by qualitative microscopy/imaging experiments as well as by quantitative plague forming assays. Various surfaces including litter bedding, litter poles, litter handles, litter straps and blood pressure cuff fabrics were demonstrated for antiviral activity with high efficacy.