Synergistic Interactions of Oxidized Amylose Silver Nanoparticles and Topically Applicable Antibiotics Against Staphylococcus aureus.

Staphylococcus aureus causes serious infections that are increasingly difficult to treat due to antibiotic resistance. In this study, we synthesized oxidized amylose silver nanoparticles (OAAgNPs) and evaluated their synergistic potential with topical antibiotics against multidrug-resistant (MDR) S. aureus. OAAgNPs were synthesized and characterized using spectroscopic and microscopic techniques, confirming their nanoscale structure (5-10 nm) and chemical composition. Antibacterial testing against 50 clinical MDR isolates showed that OAAgNPs alone inhibited bacterial growth. More importantly, combinations with gentamicin (GEN), ciprofloxacin, mupirocin (MUP), or fusidic acid (FA) significantly enhanced antibacterial efficacy. Synergy was strongest with GEN and consistently observed with MUP and FA-antibiotics for which such nanoparticle synergy has rarely been documented. Cytotoxicity assays on mammalian cells demonstrated low toxicity at therapeutically relevant concentrations. Overall, this study highlights the potential of OAAgNP-antibiotic combinations as a promising strategy for managing MDR skin infections. Further research toward clinical formulation development is warranted.