Sustainable streptomycin-based Ag nanoparticle synthesis and study of the cytotoxicity

Antibiotic resistance is one of the major problems of our time, which can be addressed by the use of different nanoparticles synthesized using antibiotics. The interaction between nanoparticles and biological systems is dynamic, which makes them extremely powerful for applications in the biomedical field. In this work, silver nanoparticles (Ag NPs) were synthesized with streptomycin and characterized by TEM, XRD, and UV-VIS. The synthesis resulted in the formation of spherical particles in the size range of 10-20 nm, which did not show any signs of aggregation after several days, facilitating their ease of use. Cytotoxicity studies of the synthesized AgNPs were performed by flow cytometry on A549 lung cancer cells after 24 h of exposure. At a concentration of 0.02 mM AgNP, the live cell ratio did not differ significantly from the control, but LC₅₀ value was between 1.7 and 1.9 mM. The change in mitochondrial activity was examined after 4 h of exposure, and the results showed that AgNPs synthesized with streptomycin induce a decrease in mitochondrial activity at concentrations as low as 0.01 mM Ag NP. In this study, we have shown that antibiotic-streptomycin-stabilized nanoparticles play a dual role by both reducing and stabilizing silver nanoparticles without the need for any undesirable additive. Nanostructured silver particles synthesized with antibiotics were effective against the cancer cell line used. This is most probable because damage to the mitochondria induces the production of free radicals leading to severe cell damage. The research contributes to a deeper understanding of the effects of nanoparticles on cancer cells. The ability to stabilize silver nanoparticles with antibiotic-loaded nanoparticles could enhance therapeutic efficacy and open new opportunities for the design and development of nanomedicines for use in various biomedical fields such as wound healing, drug delivery, and antimicrobial coatings.