Bioengineering of green-synthesized silver nanoparticles: In vitro physicochemical, antibacterial, biofilm inhibitory, anticoagulant, and antioxidant performance

Green-synthesized nanobiomaterials can be engineered as smart nanomedicine platforms for diagnostic and therapeutic purposes in medicine. Herein, we investigated the bioengineering of silver nanoparticles (AgNPs) and evaluated their physicochemical, antibacterial, biofilm inhibitory, anticoagulant, and antioxidant performance. Characterization of the AgNPs was performed utilizing UV-visible, transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FT-IR). The spherical shaped AgNPs were proven by TEM and SEM techniques. Moreover, the XRD diffraction patterns demonstrated that the nanoparticles were in a crystalline state. The DLS represented the hydrodynamic particle size of the NPs at 49.62 nm at a pH of 9. The calculated minimum inhibitory concentration (MIC) of AgNPs toward Staphylococcus aureus (ATCC 25923) was 8 μg mL-1, which was almost similar to tetracycline by the value of 4 μg mL-1. Moreover, the minimum bactericidal concentration (MBC) of AgNPs was 64 μg mL-1, which was significantly less than the determined value of 256 μg mL-1 for tetracycline. Considering the pathogenic and standard S. aureus, the evaluated concentrations of AgNPs and tetracycline showed significant biofilm inhibitory performance. Furthermore, the bioengineered AgNPs exhibited significant anticoagulant activity at 500 μg mL-1 compared to saline (P < 0.001). In addition, the biogenic AgNPs inhibited 69.73 ± 0.56% of DPPH free radicals at 500 μg mL-1, indicating considerable antioxidant potential.