Bacterial-mediated Selenium Nanoparticles as Highly Selective Antimicrobial Agents with Anticancer Properties

The green synthesis of nanomaterials offers advantages over traditional chemical methods, such as the production of biocompatible nanostructures in an environmentally friendly and cost-effective manner. Among all of the available green synthesis routes, the use of bacteria offers a high-throughput and versatile synthesis of nanoparticles that can be used in a wide range of biomedical approaches. In this article, we present a controllable and versatile synthesis of selenium nanoparticles (SeNPs) using bacterial isolates of both Gram negative and Gram positive bacteria. The SeNPs were characterized in terms of their physicochemical properties and tested in both antimicrobial and cytotoxicity assays, showing a selective dose-dependent antibacterial activity in a selected range of concentrations (especially when SeNPs synthesized by a particular bacterial isolate were exposed to that isolate) and a mild cytotoxicity when exposed to human dermal fibroblasts. Furthermore, the SeNPs were tested for their anticancer activity by exposure to melanoma cells (skin cancer) in in vitro models, showing a significant dose¿response cytotoxic behavior that was associated to the production of reactive oxygen species. Therefore, this work presents a robust and versatile method to produce SeNPs using selected bacterial isolates for numerous biomedical applications.The authors from Tecnologico de Monterrey and CSIC thank the bilateral project BILTC22001 for funding. The authors from Tecnologico de Monterrey also thank the Department of Sciences – Chemistry and Nanotechnology at Tecnologico de Monterrey, campus Monterrey. TJW thanks Art Zaropoulo for funding. The authors acknowledge the service from the MiNa Laboratory at IMN, funded from CM (project SpaceTec, S2018/ NMT-4291 TEC2SPACE), MINECO (project CSIC13-4E-1794), and EU (FEDER, FSE)