Inactivation of SARS-CoV-2 by a chitosan/α-Ag2WO4 composite generated by femtosecond laser irradiation
Paula F. S. Pereira, Ana Carolina Alves de Paula e Silva, Bruna Natália Alves da Silva Pimentel, Ivo M. Pinatti, A.Z. Simões, Carlos Eduardo Vergani, Débora Ferreira Barreto-Vieira, Marcos Alexandre Nunes da Silva, Milene Dias Miranda, M. Monteiro, Amanda Resende Tucci, Carlos Doñate‐Buendía, Gladys Mı́nguez-Vega, Juán Andrés, E. Longo
Abstract
Abstract In the current COVID-19 pandemic, the next generation of innovative materials with enhanced anti-SARS-CoV-2 activity is urgently needed to prevent the spread of this virus within the community. Herein, we report the synthesis of chitosan/α-Ag 2 WO 4 composites synthetized by femtosecond laser irradiation. The antimicrobial activity against Escherichia coli , Methicilin-susceptible Staphylococcus aureus (MSSA), and Candida albicans was determined by estimating the minimum inhibitory concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC). To assess the biocompatibility of chitosan/α-Ag 2 WO 4 composites in a range involving MIC and MBC/MFC on keratinocytes cells (NOK-si), an alamarBlue™ assay and an MTT assay were carried out. The SARS-CoV-2 virucidal effects was analyzed in Vero E6 cells through viral titer quantified in cell culture supernatant by PFU/mL assay. Our results showed a very similar antimicrobial activity of chitosan/α-Ag 2 WO 4 3.3 and 6.6, with the last one demonstrating a slightly better action against MSSA. The chitosan/α-Ag 2 WO 4 9.9 showed a wide range of antimicrobial activity (0.49–31.25 µg/mL). The cytotoxicity outcomes by alamarBlue™ revealed that the concentrations of interest (MIC and MBC/MFC) were considered non-cytotoxic to all composites after 72 h of exposure. The Chitosan/α-Ag 2 WO 4 (CS6.6/α-Ag 2 WO 4 ) composite reduced the SARS-CoV-2 viral titer quantification up to 80% of the controls. Then, our results suggest that these composites are highly efficient materials to kill bacteria ( Escherichia coli , Methicillin-susceptible Staphylococcus aureus , and the yeast strain Candida albicans ), in addition to inactivating SARS-CoV-2 by contact, through ROS production.