In Vitro Antibacterial Activity of Chitosan/ZnO/Ag Ternary Nanocomposites against Clinical Wound Isolates

Chitosan is a biodegradable, linear, biocompatible natural polymer. By adding silver (Ag) and zinc oxide (ZnO) nanoparticles to a gel, a bandage with antibacterial, antimicrobial, and anti-inflammatory effects can be formed. In this study, the antibacterial efficacy of pure chitosan nanoparticles and Cs/ZnO/Ag nanocomposite solutions against both Gram-positive and Gram-negative bacteria was investigated. Staphylococcus aureus was the most frequently detected bacterium at 16%. Klebsiella pneumoniae ranked second at 11%, and Escherichia coli ranked third at 5%. The inhibition zones in millimeters around agar wells containing pure chitosan nanoparticle solutions and Cs/ZnO/Ag nanocomposite solutions were measured in this study. The inhibition zones against S. aureus were 5, 8 and 10 mm respectively for pure solutions of chitosan nanoparticles and 5, 7 and 10 mm respectively for E. coli. Similarly, the inhibition zones for K. pneumoniae were 5, 8, and 10 mm, respectively. The Cs/ZnO/Ag nanocomposites were tested in solution at different ZnO:Ag ratios. It was observed that the antibacterial activity increased when CS/ZnO/Ag nanocomposites were applied at different ratios (ZnO:Ag = 1:1, 2:1, and 3:1; 0.15% by weight). In this group, inhibition zones for S. aureus were measured as 9, 9, and 10 mm; for E. coli as 8, 10, and 10 mm; and for K. pneumoniae as 9, 10, and 11 mm. In conclusion, enriching chitosan-based nanocomposites with ZnO and silver nanoparticles significantly increases their antibacterial efficacy against both Gram-positive and Gram-negative bacteria. These findings suggest that CS/ZnO/Ag nanocomposites can be used as a potential biomaterial in the control of wound infections.