Chitosan nanoconjugates loaded with Sophora flavescens phytochemicals for enhanced antimicrobial and antibiofilm activity against nosocomial pathogens

This study describes the preparation of chitosan nanoparticles (ChNPs) and a Sophora flavescens -loaded nanoconjugate using TPP-mediated ionic gelation and their preliminary evaluation against clinically relevant nosocomial pathogens. Nanoconjugate formation was characterized using spectroscopic, physicochemical, and electron microscopic techniques, which confirmed modified physicochemical properties following phytochemical incorporation. The developed nanoconjugate exhibited a reduced hydrodynamic diameter (432.6 nm), lower particle-size heterogeneity (PDI = 0.355), and a positive surface charge (> +40 mV) compared with unloaded ChNPs. Biological evaluation demonstrated concentration-dependent antimicrobial and antibiofilm activities against bacterial and Candida pathogens, with bactericidal and fungicidal effects observed at 1–2 mg/mL. Membrane permeability and protein leakage assays further suggested membrane-associated antimicrobial effects. In addition, the nanoconjugate showed high cytocompatibility toward L929 fibroblast cells (>90% viability) and low hemolytic activity under the tested conditions. Overall, the findings indicate that incorporation of S. flavescens phytochemicals into chitosan nanoparticles may enhance the antimicrobial and antibiofilm performance of the developed nano system. However, the present work represents a preliminary in vitro investigation, and further studies using advanced biological models and in vivo systems are required to confirm its biomedical potential.