Improving Selenium Nanoparticles Bioproduction by Gamma Irradiated Endophytic Fungi and Their Cytotoxic and Wound Healing Activities.

In view of the rapidly expanding applications of selenium nanoparticles (SeNPs) across industrial and agricultural sectors, this study investigated the potential of endophytic fungi as biological nano factories for SeNP biosynthesis. The development of optimized microbial processes for nanomaterial production and their subsequent scale up represent a promising and sustainable strategy for future industrial applications. This work focused on refining fermentation conditions to enhance SeNP yield from four endophytic fungal strains. A systematic evaluation of cultivation parameters, including physicochemical and physiological factors, was performed to determine their influence on nanoparticle synthesis. Gamma irradiation was further applied to improve fungal performance and increase SeNP production. To elucidate the role of proteins in nanoparticle formation and stabilization, we examined the reduction of selenite to elemental selenium and characterized protein–nanoparticle interactions. SDS-PAGE analysis revealed distinct protein bands and subunits associated with SeNPs. Additionally, bioactive secondary metabolites produced by the fungi were profiled using Gas Chromatography–Mass Spectrometry (GC–MS). Cytotoxicity assays demonstrated that SeNPs synthesized by Aspergillus ochraceus, A. quadrilineatus, A. terreus, and Fusarium equiseti exhibited significant activity against MCF 7 breast cancer cells. Furthermore, these nanoparticles accelerated the wound healing process, highlighting their potential biomedical applications.