RESUMO
To address the challenge of the airborne transmission of SARS-CoV-2, photosensitized electrospun nanofibrous membranes were fabricated to effectively capture and inactivate coronavirus aerosols. With an ultrafine fiber diameter ([~] 200 nm) and a small pore size ([~] 1.5 {micro}m), the optimized membranes caught 99.2% of the aerosols of the murine hepatitis virus A59 (MHV-A59), a coronavirus surrogate for SARS-CoV-2. In addition, rose bengal was used as the photosensitizer for the membranes because of its excellent reactivity in generating virucidal singlet oxygen, and the membranes rapidly inactivated 98.9% of MHV-A59 in virus-laden droplets only after 15 min irradiation of simulated reading light. Singlet oxygen damaged the virus genome and impaired virus binding to host cells, which elucidated the mechanism of disinfection at a molecular level. Membrane robustness was also evaluated, and no efficiency reduction for filtering MHV-A59 aerosols was observed after the membranes being exposed to both indoor light and sunlight for days. Nevertheless, sunlight exposure photobleached the membranes, reduced singlet oxygen production, and compromised the performance of disinfecting MHV-A59 in droplets. In contrast, the membranes after simulated indoor light exposure maintained their excellent disinfection performance. In summary, photosensitized electrospun nanofibrous membranes have been developed to capture and kill airborne environmental pathogens under ambient conditions, and they hold promise for broad applications as personal protective equipment and indoor air filters. SynopsisPhotosensitized electrospun nanofibrous filters with excellent capture-and-kill performance against coronaviruses were designed and implemented to prevent the airborne transmission of COVID-19. Table of Contents O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=103 SRC="FIGDIR/small/454404v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@171d6corg.highwire.dtl.DTLVardef@18caad5org.highwire.dtl.DTLVardef@23b902org.highwire.dtl.DTLVardef@14746e4_HPS_FORMAT_FIGEXP M_FIG C_FIG
RESUMO
Airborne transmission of SARS-CoV-2 plays a critical role in spreading COVID-19. To protect public health, we designed and fabricated electrospun nanofibrous air filters that hold promise for applications in personal protective equipment and indoor environment. Due to ultrafine nanofibers ([~]300 nm), the electrospun air filters had a much smaller pore size compared to the surgical mask and cloth masks (a couple of microns versus tens to hundreds of microns). A coronavirus strain was used to generate aerosols for filtration efficiency tests, which can better represent SARS-CoV-2 than other agents used for aerosol generation in previous studies. The electrospun air filters showed excellent performance by capturing up to 99.9% of coronavirus aerosols, which outperformed many commercial face masks. In addition, since NaCl aerosols have been widely used in filtration tests, we compared the filtration efficiency obtained from the coronavirus aerosols and the NaCl aerosols. The NaCl aerosols were demonstrated as an eligible surrogate for the coronavirus aerosols in the filtration tests, when air filters and face masks with diverse pore sizes, morphologies, and efficiencies were used. Our work paves a new avenue for advancing air filtration by developing electrospun nanofibrous air filters for controlling SARS-CoV-2 airborne transmission. Moreover, the removal efficiency of the NaCl aerosols can be reasonably translated into understanding how air filters capture the coronavirus aerosols. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=148 SRC="FIGDIR/small/20249046v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@1a40a5eorg.highwire.dtl.DTLVardef@a4af7forg.highwire.dtl.DTLVardef@1fdd2c5org.highwire.dtl.DTLVardef@118a34e_HPS_FORMAT_FIGEXP M_FIG Table of Contents C_FIG
