Alternatively, zinc salts have been successfully used as antimicrobial agents from research up to clinical trials for viral warts.60,61 More recently, ZnO nanoparticles (ZnONPs) were developed for the treatment of HSV-2. ZnONPs were prepared with a tetrapod morphology.62 The results showed that they can mimic cell surface interacting with the HS present on the viral capsid. Additionally, these particles have been used for photocatalysis showing to efficiently destroy the viral proteins upon UV irradiation.62 Besides all these interesting examples, in vivo applications are still needed to validate this therapeutic modality. Due to the generation of high levels of ROS, the toxicity of copper nanoparticles has been widely debated. The antiviral activity of copper nanoparticles is generally associated with the release of Cu+ ions in solution, thus the leakage of cytotoxic cationic species can be modulated by surface functionalization before in vitro and in vivo applications. On the other side, the use of nanomaterials generating ROS can find applications in textile and surface coating. The general broad virucidal efficiency of copper oxide nanoparticles shown for H1N1 pandemic influenza57 should be tested on SARS-Cov-2 and might be used for improving mask protection efficiency.