Sustainable biosynthesis and characterization of optimized silver nanoparticles using Apis mellifera Syriaca bread with antimicrobial and biocompatibility evaluation

Silver nanoparticles (AgNPs) were green-synthesized using Syrian bee bread (SBB) extract as a natural reducing and stabilizing agent. Optimal reaction conditions were established at 1% extract concentration, 1 mM silver nitrate, pH 9.5, and room temperature. Dynamic light scattering (DLS) analysis revealed a hydrodynamic diameter (ZA) of 61.95 nm with a polydispersity index (PDI) of 0.347, while the zeta potential measured − 25.2 mV, indicating good colloidal stability. UV–Vis spectroscopy showed a characteristic absorption peak at 437 nm, and field emission scanning electron microscopy (FESEM) confirmed predominantly spherical nanoparticles with an average size of ~ 30 nm. Atomic force microscopy (AFM) showed smooth, uniform surfaces with an average size of ~ 36 nm of spherical AgNPs. The synthesized SBB-AgNPs displayed notable antimicrobial activity, with inhibition zones of 20, 20, 22, 21, 20, and 25 mm against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, and Candida albicans, respectively. The minimum inhibitory concentrations (MICs) values ranged from 20 to 25 µg/mL, while the minimum inhibitory concentrations (MBCs) were 40–50 µg/mL demonstrating effective bactericidal potential. Cytotoxicity assessment on normal human dermal fibroblasts (NHDF) revealed that doses up to 50 µg/mL were relatively safe and maintained high cell viability, whereas higher concentrations induced dose-dependent cytotoxicity, with an IC50 value of 192.3 µg/mL, indicating good biocompatibility. This study reports, for the first time, the use of SBB for nanoparticle synthesis, underscoring its potential as a sustainable natural source for producing eco-friendly nanomaterials. These findings demonstrate the promise of SBB-AgNPs for biomedical applications by balancing antimicrobial efficacy with cellular safety.