Application of Copper Iodide Nanoparticle-Doped Film and Fabric To Inactivate SARS-CoV-2 via the Virucidal Activity of Cuprous Ions (Cu ⁺ )

Abstract

As a result of the novel coronavirus disease 2019 pandemic, strengthening control measures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become an urgent global issue. In addition to antiviral therapy and vaccination strategies, applying available virucidal substances for SARS-CoV-2 inactivation is also a target of research to prevent the spread of infection. Here, we evaluated the SARS-CoV-2 inactivation activity of a copper iodide (CuI) nanoparticle dispersion, which provides Cu + ions having high virucidal activity, and its mode of actions. In addition, the utility of CuI-doped film and fabric for SARS-CoV-2 inactivation was evaluated. The CuI dispersion exhibited time-dependent rapid virucidal activity. Analyses of the modes of action of CuI performed by western blotting and real-time reverse transcription polymerase chain reaction targeting viral proteins and the genome revealed that CuI treatment induced the destruction of these viral components. In this setting, the indirect action of CuI-derived reactive oxygen species contributed to the destruction of viral protein. Moreover, the CuI-doped film and fabric demonstrated rapid inactivation of the SARS-CoV-2 solution in which the viral titer was high. These findings indicated the utility of the CuI-doped film and fabric as anti-SARS-CoV-2 materials for the protection of high-touch environmental surfaces and surgical masks/protective clothes. Throughout this study, we demonstrated the effectiveness of CuI nanoparticles for inactivating SARS-CoV-2 and revealed a part of its virucidal mechanism of action. IMPORTANCE The COVID-19 pandemic has caused an unprecedented number of infections and deaths. As the spread of the disease is rapid and the risk of infection severe, hand and environmental hygiene may contribute to suppressing contact transmission of SARS-CoV-2. Here, we evaluated the SARS-CoV-2-inactivation activity of CuI nanoparticles, which provide the Cu + ion, as an antiviral agent, and provided advanced findings of the virucidal mechanisms of action of Cu + . Our results showed that the CuI dispersion as well as CuI-doped film and fabric rapidly inactivated SARS-CoV-2 with a high viral titer. We also demonstrated the CuI’s virucidal mechanisms of action, specifically, the destruction of viral proteins and the genome by CuI treatment. Protein destruction largely depended on CuI-derived reactive oxygen species. This study provides novel information about the utility and mechanisms of action of promising virucidal material against SARS-CoV-2.

Aluminium Gauze Reduces SARS-CoV-2 Viral Load in Non-Woven Masks Worn by Patients with COVID-19

“…Numerous researchers have studied several materials to inactivate SARS-CoV-2 [6]. Copper iodide nanoparticles, copper-silver nanohybrids, silver nanocluster/silica com-posites, titanium dioxide, and aluminium reduce SARS-CoV-2 survival in experimental settings [4,[7][8][9]. It is not known which materials are better at decreasing SARS-CoV-2 survival in clinical settings.…”

Disinfection and decontamination in the context of SARS‐CoV‐2‐specific data

“…Additives to plastics, metals, ceramics, and other surfaces have shown antiviral efficacy to the extent that these surfaces may have inhibitory effects after initial viral deposition. Several copper‐based products have especially attracted attention 118–131 . Some of the latter surfaces have included protective gear 121,129 .…”

“…Several copper‐based products have especially attracted attention. 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 Some of the latter surfaces have included protective gear. 121 , 129 It is not clear how much other foreign substances may interfere with antiviral efficacy on these coated surfaces.…”

Virucidal PVP-Copper Salt Composites against Coronavirus Produced by Electrospinning and Electrospraying

“…Researchers theoretically demonstrated that the release of Cu (II) ions causes the destruction of viral proteins and genomes; in addition, inactivation of the virus by Cu (II) may be related to direct and indirect activity with viral surfaces via production of reactive oxygen species (ROS) [ 25 ]. Copper interferes with important virus proteins, causing their inactivation [ 26 ].…”