Silver Nanoparticles–Polyethyleneimine-Based Coatings with Antiviral Activity against SARS-CoV-2: A New Method to Functionalize Filtration Media

Abstract

The use of face masks and air purification systems has been key to curbing the transmission of SARS-CoV-2 aerosols in the context of the current COVID-19 pandemic. However, some masks or air conditioning filtration systems are designed to remove large airborne particles or bacteria from the air, being limited their effectiveness against SARS-CoV-2. Continuous research has been aimed at improving the performance of filter materials through nanotechnology. This article presents a new low-cost method based on electrostatic forces and coordination complex formation to generate antiviral coatings on filter materials using silver nanoparticles and polyethyleneimine. Initially, the AgNPs synthesis procedure was optimized until reaching a particle size of 6.2 ± 2.6 nm, promoting a fast ionic silver release due to its reduced size, obtaining a stable colloid over time and having reduced size polydispersity. The stability of the binding of the AgNPs to the fibers was corroborated using polypropylene, polyester-viscose, and polypropylene-glass spunbond mats as substrates, obtaining very low amounts of detached AgNPs in all cases. Under simulated operational conditions, a material loss less than 1% of nanostructured silver was measured. SEM micrographs demonstrated high silver distribution homogeneity on the polymer fibers. The antiviral coatings were tested against SARS-CoV-2, obtaining inactivation yields greater than 99.9%. We believe our results will be beneficial in the fight against the current COVID-19 pandemic and in controlling other infectious airborne pathogens.

Electrospun nanofibers for medical face mask with protection capabilities against viruses: State of the art and perspective for industrial scale-up

“…As seen so far, a proper optimization of the ES process allows a stable and uniform distribution of NPs as well as for other active materials at single fiber surface level. This method can be beneficial compared to other recent approach adopted to functionalize commercial face mask, which may result instead in a coating instability for the surface functionalization over the time with an undesired effect on antimicrobial and antiviral properties [ [236] , [237] , [238] ]. Additionally, recent studies proved that several NPs materials with antimicrobial and antiviral properties, including MgO and CuO, are compatible when embedded in electrospun membranes based on natural polymers, such as CA and poly(ε-caprolactone) (PCL) [ 239 , 240 ].…”

Amine-Functionalized Silver Nanoparticles: A Potential Antiviral-Coating Material with Trap and Kill Efficiency to Combat Viral Dissemination (COVID-19)

“…Recently, Baselga et al developed a mask by coating silver nanoparticles and taking PEI as an anchor molecule that binds the Ag-NPs and cotton fabric via electrostatic interaction (Fig. 5 ) [ 126 ]. The stability of the binding of the Ag-NPs to the fibres was corroborated using polypropylene, polyester viscose, and polypropylene-glass-spun-bonded mats as substrates, obtaining very low amounts of detached Ag-NPs in all cases.…”

“…The stability of the binding of the Ag-NPs to the fibres was corroborated using polypropylene, polyester viscose, and polypropylene-glass-spun-bonded mats as substrates, obtaining very low amounts of detached Ag-NPs in all cases. The antiviral coatings were tested against SARS-CoV-2, and obtained inactivation was 99.9% [ 126 ]. These face masks are reusable, durable, and have better filtration and antiviral efficiency.…”

“…B Determination of the infective viral load (a) in materials coated with silver nanoparticles and the control after 2 h and (b) is coated spunbond after 10 min, after 2 h after infection, and after 4 h after infection with the SARS-CoV-2 virus at room temperature. Adapted with permission from [ 126 ] under a common creative attribution licence …”

“…Recently, Baselga et al developed a mask by coating silver nanoparticles and taking PEI as an anchor molecule that binds the Ag-NPs and cotton fabric via electrostatic interaction (Fig. 5) [126].…”