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Filtering facepiece respirators (FFRs) protect wearers from inhalation of fine particulates and help prevent transmission of airborne viruses. Here, an FFR material is produced by successive deposition of contact drawn poly­(ethylene oxide) (PEO) fibers. Fibers are formed by immersing an array of pins in a highly viscous precursor solution of PEO and then rapidly removing the pins such that polymer entanglement occurs, forming multiple liquid bridges that rapidly dry as they extend. Tunable filtration is achieved by varying the number of PEO fiber elongation cycles. Placing the PEO textiles between two woven cotton cloths provides structural support and additional filtration capacity, achieving a maximum filtration efficiency of 95% with a corresponding initial pressure drop of 281 Pa. The entrapment of silver nanoparticles in the PEO fibers imparts virucidal properties to PEO-based textiles, as demonstrated by inactivation of a human coronavirus HCoV-OC43 and influenza A virus inoculum. The ability to tune filtration efficiency to application needs and provide advanced function through entrapment of active materials represents a versatile tool for limiting exposure to airborne particulates and pathogens.

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Chronic exposure to inorganic arsenic and trace metals has been linked to prostate cancer, and altered arsenic methylation capacity may have an important role in arsenic carcinogenesis. Biomarkers may be able to elucidate this role. Our objectives were to characterize profiles of arsenic species and metallome in toenails and urine samples, compare profiles between prostate cancer cases and controls, and determine the discriminant ability of toenail and urine biomarkers. Toenail samples (n = 576), urine samples (n = 152), and questionnaire data were sourced from the Atlantic Partnership for Tomorrow's Health (PATH) cohort study. Healthy controls were matched to prostate cancer cases (3:1 ratio) on sex, age, smoking status, and the province of residence. Metallome profiles and proportions of arsenic species were measured in toenail and urine samples. Analysis of covariance (ANCOVA) was used to compare the mean percent monomethylarsonic acid (%MMA), dimethylarsonic acid (%DMA), inorganic arsenic (%iAs), primary methylation index (PMI, MMA/iAs), and secondary methylation index (SMI, DMA/MMA). Multivariate analysis of covariance (MANCOVA) was used to compare selected metal concentrations. Mean %MMA was significantly lower and SMI was significantly higher in toenails from prostate cancer cases compared to controls in unadjusted and adjusted models. Proportions of arsenic species were correlated with total arsenic in toenails. Arsenic speciation in urine was not different between cases and controls, nor were metallome profiles in toenails and urine. Our results indicate that toenails are a viable biomarker for altered arsenic speciation in prostate cancer cases and may have greater utility than urine in this context.

Metrics & MoreArticle Recommendations * sı Supporting Information CONSPECTUS:The development of a highly effective, low-cost method for protection against direct transmission through infectious media associated with respiratory diseases has been considered to be a major challenge in the management of the pandemic outbreak. Currently, filtration in respirators and masks depends on the mesh size, raising safety concerns about direct contact with the virus-laden layers of masks and respirators during use and disposal. Also, conventional medical face masks and respirators are recommended for single use only because long-term use and reuse of masks increase the risk of contact transmission of pathogens. As a result, mask reusability has gained much attention in addressing the global problem of respirator and mask shortages during the COVID-19 pandemic. Furthermore, coinfection by influenza, SARS-CoV-2, and bacteria has been an ongoing issue in the current COVID-19 pandemic. In our response to the increasing demand for more convenient forms of disease control, our group has investigated antimicrobial technologies for respiratory devices against pandemic/epidemic diseases and developed two universal antimicrobial coating technologies: (1) nonwashable, reusable salt-coated fabrics and (2) washable, photopolymerizable polymer-coated fabrics which efficiently inactivate infectious viruses by contact with the filter. This is an opportune time to assess research efforts toward antimicrobial face mask technology for its expected impact on society and the economy.In this Account, we introduce the importance of respiratory devices for protection against respiratory diseases, decontamination methods, technical challenges for reuse and extended use, antimicrobial substances used in masks, antimicrobial functionalization strategies for mask fibers, and the characterization of antimicrobial performance and the limitations of the current procedure. Then, the major focus will be directed to discussing the continued efforts of our group to develop antimicrobial fabrics for face mask covers and face masks/respirators based on salt-coated polypropylene (PP) fibers. In the following sections of this Account, we will first discuss salt coating methods and pathogen inactivation mechanisms in salt-coated filters. Then, an overview of our recent progress in evaluating the antimicrobial performance of salt-coated PP fabrics against five different bacterial species, influenza viruses, and human coronaviruses will be presented. The technical challenges in the implementation of the technology will be highlighted in the last section. We believe that easy-to-implement antimicrobial respiratory devices would guarantee improved protection without decontamination processes and enable rapid responses to future pandemic/epidemic outbreaks.