Monica Ferraris

During the current pandemic of COVID-19 caused by the new Coronavirus SARS-CoV-2, the confinement measures slowed down the contagion, but did not completely avoid the disease diffusion for health workers, patients and the remaining population. The individual protection equipment (e.g. facial masks), filters for air conditioning systems and for medical respiratory devices do not possess an intrinsic antimicrobial/virucidal action and they are susceptible to microbial/viral colonization. An efficient antimicrobial/virucidal technology on air filtering media is crucial for maintaining a safe air environment and protecting people, in particular when lockdown is eased. This short communication reports about the virucidal effect, preliminary verified towards Coronavirus SARS-CoV-2, of a silver nanocluster/silica composite sputtered coating, directly applicated on a FFP3 mask.

New antiviral drugs and new preventive antiviral strategies are a target of intense scientific interest. Thanks to their peculiar properties, nanomaterials play an important role in this field, and, in particular, among metallic materials, silver nanoparticles were demonstrated to be effective against a wide range of viruses, in addition to having a strong antibacterial effect. Although the mechanism of antiviral action is not completely clarified, silver nanoparticles can directly act on viruses, and on their first steps of interaction with the host cell, depending on several factors, such as size, shape, functionalization and concentration. This review provides an overview of the antiviral properties of silver nanoparticles, along with their demonstrated mechanisms of action and factors mainly influencing their properties. In addition, the fields of potential application are analyzed, demonstrating the versatility of silver nanoparticles, which can be involved in several devices and applications, including biomedical applications, considering both human and animal health, environmental applications, such as air filtration and water treatment, and for food and textile industry purposes. For each application, the study level of the device is indicated, if it is either a laboratory study or a commercial product.