The development, evaluation, and field validation of biocide functionalized nanofiber material for the application of disposable personal protective equipment
Creators: name: Wei, Michelle
Publisher: name: University of Iowa
Year: 2027
Subjects: electrospinning nanofiber layers
hydrophobic and antimicrobial
livestock production facilities
pathogen elimination
repeated aerosol exposures
self-decontaminating PPE
Occupational safety

description: Disposable personal protective equipment (PPE) such as surgical masks and protective clothing is not designed to be antimicrobial and requires decontamination for reuse. In this work, we aimed to improve protections for workers in biosecurity settings (e.g., livestock facilities) and minimize disease transmission from contaminated personal protective equipment (PPE) for healthcare workers by developing, evaluating, and field validating nanofiber materials with antimicrobial properties for use in PPE.
description: First, we fabricated polystyrene nanofibers (PS) functionalized with biocides including silver nanoparticles (AgNPs) in two sizes (20 and 35 nm) and a quaternary ammonium compound tetrabutylammonium bromide (TBAB) at 0.1 wt.% and 1 wt.% either individually or combined, via electrospinning. We investigated their antimicrobial efficacy by exposing these nanofiber layers to bioaerosols containing either Escherichia coli (E. coli) or bacteriophage MS2 for 15 minutes then evaluating their antibacterial/antiviral efficacy after an additional 10-, 60-, 120-, and 180-minute of contact time. We identified that the PS based formulation containing 1 wt.% AgNPs (20 nm) and 1 wt.% TBA20B achieved the highest antibacterial and antiviral efficacy after 120-minute contact time as compared to the conventional materials used in a Tyvek® laboratory coat and surgical mask, as well as nonfunctionalized PS.
description: Second, we fabricated the same formulation from a 1.5 mL and a 0.3 mL precursor solution to make relatively thick and thin nanofiber layers, respectively, exposed these thick and thin nanofiber layers repeatedly to two different loadings of bioaerosols containing either E. coli (1.8 × 1010 and 5.8 × 107 CFU/mL) or bacteriophage MS2 (8.7 × 1013 and 1.7 × 109 PFU/mL) for a 15 minute exposure duration followed with 120 minute contact time, and then evaluated their antibacterial and antiviral efficacy. We found that both thick and thin nanofiber layers sustained more than 3 additional log-units reduction relative to a polypropylene surgical mask when exposed to bioaerosols containing 5.8 × 107 CFU/mL of viable E. coli repeatedly for 10 repeated exposure periods. The same nanofiber layers also sustained 3 - log units of additional reduction relative to the material used in a N-95 respirator when exposed to bioaerosols containing 8.7 × 1013 PFU/mL viable bacteriophage MS2 repeatedly for seven repeated exposure periods. Furthermore, we found that the thick nanofiber layers were more efficacious against repeated exposures to bacteriophage MS2 than that of thin nanofiber layers.
description: Finally, using the same methodology as we used in the laboratory, we tested the antimicrobial efficacy of the thick and thin nanofiber layers at a swine production facility. When repeatedly exposed to bioaerosols at the swine production facility for up to 15 exposure periods, we found that both thick and thin nanofiber layers eliminated E. coli growth and sustained more than 3-log units of additional reduction relative to a polypropylene surgical mask and an unfunctionalized PS nanofiber layer. In fact, overall, performance at the swine production facility matched expectations from laboratory studies.
description: Collectively, our data suggests that our biocide-functionalized nanofibers may be suitable for either extended use or reuse as self-decontaminating material for PPE development. The outcome of this study may help to further protect workers in biosecurity settings and reduce disease transmission from contaminated PPE for healthcare workers.