Particulate Respirators Functionalized with Silver Nanoparticles Showed Excellent Real-Time Antimicrobial Effects against Pathogens

Abstract

Particulate respirators designed to filtrate fine particulate matters usually do not possess antimicrobial functions. The current study aimed to functionalize particulate respirators with silver nanoparticles (nanosilver or AgNPs), which have excellent antimicrobial activities, utilizing a straightforward and effective method. We first enhanced the nanosilver-coating ability of nonwoven fabrics from a particulate respirator through surface modification by sodium oleate. The surfactant treatment significantly improved the fabrics' water wet preference where the static water contact angles reduced from 122° to 56°. Both macroscopic agar-plate tests and microscopic scanning electron microscope (SEM) characterization revealed that nanosilver functionalized fabrics could effectively inhibit the growth of two model bacterial strains (i.e., Staphylococcus aureus and Pseudomonas aeruginosa). The coating of silver nanoparticles would not affect the main function of particulate respirators (i.e., filtration of fine air-borne particles). Nanosilver coated particulate respirators with excellent antimicrobial activities can provide real-time protection to people in regions with severe air pollution against air-borne pathogens.

A comprehensive review on antimicrobial face masks: an emerging weapon in fighting pandemics

“…In these situations, an unexpected danger arises due to the reaerosolisation of the settled particles during intense sneezing or coughing by the wearer. 16 Microbial survival and re-growth on conventional face masks aer usage and improper storage can also lead to secondary infections in humans. 14,15 So, face masks are typically discarded aer a single-use to avoid the inoculation and spread of highly infectious pathogens.…”

“…Compared to physical attachment through a dip (soak) coating and spray coating, the surface modication mediated coating renders long-term attachment of AgNPs. 16,134,135,137 In a study, the surface of an N95 respirator was treated with a surfactant, sodium oleate, which imparted carboxylic functionalities to the surface. 16 The carboxylic sites are reported to be responsible for improved hydrophilicity and served as reaction sites for attachment for AgNPs.…”

“…16,134,135,137 In a study, the surface of an N95 respirator was treated with a surfactant, sodium oleate, which imparted carboxylic functionalities to the surface. 16 The carboxylic sites are reported to be responsible for improved hydrophilicity and served as reaction sites for attachment for AgNPs. Microscopic observations of the fabric using Field Emission SEM aer the spread plate tests revealed that the material effectively inhibited the growth of two model airborne bacterial strains, S. aureus and Pseudomonas aeruginosa (P. aeruginosa).…”

“…[8][9][10][11][12] Realising the fact, most of the countries have enforced or advised its citizen to wear face masks in public places. 13 However, there are several concerns associated with the use of conventional face masks such as the survivability of microorganisms on the face mask surface, 14,15 re-aerosolisation of settled particles, 16 safe management and disposal of used face masks, 17 and fomite transmission. 18 Some of these concerns have led to the development of face masks with inherent antimicrobial properties to impart surface contact killing/ deactivation property in addition to particle ltration.…”

Survival of Microorganisms on Filtering Respiratory Protective Devices Used at Agricultural Facilities

“…Zheng et al (2016) enhanced the nanosilver-coating ability of nonwoven fabrics from a particulate respirator through surface modification by sodium oleate (the surfactant improved the fabrics’ water wet preference). Developed by the authors, functionalized particulate respirators with silver nanoparticles had excellent antimicrobial activities against Staphylococcus aureus and Pseudomonas aeruginosa [17].…”