Fabrication of chitosan-based nanocomposites reinforced with zeolite and gold nanoparticles for enhanced bactericidal efficiency

The development of novel antibacterial biomaterials is urgently needed to address infection, which is a key global issue that threatens human health. For this purpose, polymer-based nanocomposites augmented with nanoparticles have drawn attention as effective materials for antibacterial goals, offering bactericidal effectiveness and durability. This study presents a novel chitosan-based polymer nanocomposite augmented with zeolite and gold (Au) nanoparticles. The nanocomposite was prepared via a direct synthesis method. A thorough structural and morphological characterization was conducted on the nanocomposite. The findings demonstrated the interactions between the components and, in turn, the successful preparation of the nanocomposite. The bactericidal efficiency of the synthesized samples was assessed through the number of colony-forming units per millimetre (CFU/ml). The results confirmed the bactericidal activity of the synthesized samples against S. mutans. The samples synthesized in experiment 7 (chitosan 6 mg/ml, zeolite 3 mg/ml and Au 4.5 mg/ml) presented the lowest survival rate of S. mutans bacteria (0.24 log10 CFU/ml). Analysis of variance (ANOVA) revealed a contribution percentage of 51.28% for Au nanoparticles, which shows that Au nanoparticles contributed the most to the antibacterial performance of the nanocomposite. This was followed by 24.32% and 16.84% for chitosan and zeolite, respectively. The interaction effects further verified that the combination of third-level Au nanoparticles and chitosan had the most synergistic effects, which led to a 23.29% reduction in the survival rate of S.mutans. Overall, this nanocomposite holds significant potential in dental applications as an antibacterial agent. Nonetheless, toxicology assessments in vitro and in vivo are warranted, ensuring their biocompatibility before their clinical application.