<i>Khargia iranica</i> <i>KH</i>.<i>T</i>.<i>2</i>-Mediated Synthesis of Gold and Silver Nanoparticles: Optimization, Characterization, and Inhibitory Efficiency Against Malignant and Bacterial Cells

Metallic nanoparticles (NPs) are effective in various biological processes. In particular, gold (Au) and silver (Ag) NPs have unique properties that make them ideal candidates for therapeutic applications. This study aimed to explore the potential of a new isolate, <i>Khargia iranica</i> <i>KH</i>.<i>T</i>.<i>2</i>, for the extracellular synthesis of Au- and AgNPs and to evaluate their anticancer and antibacterial activities. The cyanobacteria were isolated and morphologically and genetically identified; their chemical constituents were detected using LC-QTOF-MS. <i>K. iranica</i> <i>KH</i>.<i>T</i>.<i>2</i> mediated the syntheses of Au and Ag NPs using two methods (cell-free media and cell biomass extracts). The syntheses were optimized by controlling various parameters, such as the concentration, temperature, illumination, and pH, to obtain small and stable LC_Bio@AgNPs, LC_Sup@AgNPs, LC_Sup@AuNPs, and LC_Bio@AuNPs. The NPs were physicochemically characterized, and their antibacterial and anticancer activities were studied. Au and Ag NPs were successfully synthesized by <i>K. iranica</i> <i>KH</i>.<i>T</i>.<i>2,</i> suggesting that their peptides, amino acids, polysaccharides, and fatty acids were the main reagent-mediated synthesis. LC_Bio@AgNPs, LC_Sup@AgNPs, LC_Sup@AuNPs, and LC_Bio@AuNPs are small and negatively charged, enabling them to be used as antibacterial and anticancer agents. <i>K. iranica</i> <i>KH</i>.<i>T</i>.<i>2</i> represented a novel source for synthesizing Au and Ag NPs, and these NPs have been demonstrated to be effective therapeutic agents.