Untargeted metabolomics and molecular docking studies on green silver nanoparticles synthesized by Sarocladium subulatum: Exploring antibacterial and antioxidant properties.

The biological synthesis of silver nanoparticles (Ag-NPs) with fungi has shown promising results in antibacterial and antioxidant properties. Fungi generate metabolites (both primary and secondary) and proteins, which aid in the formation of metal nanoparticles as reducing or capping agents. While several studies have been conducted on the biological production of Ag-NPs, the exact mechanisms still need to be clarified. In this study, Ag-NPs are synthesized greenly using an unstudied fungal strain, Sarocladium subulatum AS4D. Three silver salts were used to synthesize the Ag-NPs for the first time, optimized using a cell-free extract (CFE) strategy. Additionally, these NPs were assessed for their antimicrobial and antioxidant properties. Various spectroscopic and microscopy techniques were utilized to confirm Ag-NP formation and analyze their morphology, crystalline properties, functional groups, size, stability, and concentrations. Untargeted metabolomics and proteome disruption were employed to explore the synthesis mechanism. Computational tools were applied to predict metabolite toxicity and antibacterial activity. The study identified 40 fungal metabolites capable of reducing silver ions, with COOH and OH functional groups playing a pivotal role. The silver salt type impacted the NPs' size and stability, with sizes ranging from 40 to 52 nm and zeta potentials from -0.9 to -30.4 mV. Proteome disruption affected size and stability but not shape. Biosynthesized Ag-NPs using protein-free extracts ranged from 55 to 62 nm, and zeta potentials varied from -18 to -27 mV. Molecular docking studies and PASS results found no role for the metabolome in antibacterial activity. This suggests the antibacterial activity comes from Ag-NPs, not capping or reducing agents. Overall, the research affirmed the vital role of specific reducing metabolites in the biosynthesis of Ag-NPs, while proteins derived from biological extracts were found to solely affect their size and stability.

Comparative molecular docking and toxicity between carbon-capped metal oxide nanoparticles and standard drugs in cancer and bacterial infections.

Introduction: Nanoparticles (NPs) are of great interest in the design of various drugs due to their high surface-to-volume ratio, which result from their unique physicochemical properties. Because of the importance of examining the interactions between newly designed particles with different targets in the case of various diseases, techniques for examining the interactions between these particles with different targets, many of which are proteins, are now very common. Methods: In this study, the interactions between metal oxide nanoparticles (MONPs) covered with a carbon layer (Ag2O3, CdO, CuO, Fe2O3, FeO, MgO, MnO, and ZnO NPs) and standard drugs related to the targets of Cancer and bacterial infections were investigated using the molecular docking technique with AutoDock 4.2.6 software tool. Finally, the PRO TOX-II online tool was used to compare the toxicity (LD50) and molecular weight of these MONPs to standard drugs. Results: According to the data obtained from the semi flexible molecular docking process, MgO and Fe2O3 NPs performed better than standard drugs in several cases. MONPs typically have a lower 50% lethal dose (LD50) and a higher molecular weight than standard drugs. MONPs have shown a minor difference in binding energy for different targets in three diseases, which probably can be attributed to the specific physicochemical and pharmacophoric properties of MONPs. Conclusion: The toxicity of MONPs is one of the major challenges in the development of drugs based on them. According to the results of these molecular docking studies, MgO and Fe2O3 NPs had the highest efficiency among the investigated MONPs.

Biosynthesis of Quantum Dots and Their Therapeutic Applications in the Diagnosis and Treatment of Cancer and SARS-CoV-2.

Quantum dots (QDs) are semiconductor materials that range from 2 nm to 10 nm. These nanomaterials (NMs) are smaller and have more unique properties compared to conventional nanoparticles (NPs). One of the unique properties of QDs is their special optoelectronic properties, making it possible to apply these NMs in bioimaging. Different size and shape QDs, which are used in various fields such as bioimaging, biosensing, cancer therapy, and drug delivery, have so far been produced by chemical methods. However, chemical synthesis provides expensive routes and causes serious environmental and health issues. Therefore, various biological systems such as bacteria, fungi, yeasts, algae, and plants are considered as potent eco-friendly green nanofactories for the biosynthesis of QDs, which are both economic and environmentally safe. The review aims to provide a descriptive overview of the various microbial agents for the synthesis of QDs and their biomedical applications for the diagnosis and treatment of cancer and SARS-CoV-2.