Development and Characterization of Chi-tosan-Polyvinylpyrrolidone Nanoparticles for Antimicrobial Drug Delivery Applications

Chitosan (CS) and Polyvinylpyrrolidone (PVP)-based nanoparticles (NPs) are promis-ing candidates for developing drug delivery systems due to their biocompatibility, bi-odegradability, and antimicrobial activity. This study aims to evaluate the potential of these NPs for controlled release and biological activity by encapsulating synthetic compounds (bis-THTT, JH1, and JH2) and natural antimicrobials (Honey bee and Propolis). NPs were synthesized using ionic gelation, optimizing the CS:PVP and CS-PVP: sodium tripolyphosphate (TPP) ratios. Encapsulation of the selected com-pounds was carried out, followed by physicochemical characterization using FTIR, TGA, XRD, and AFM. Biological activity was assessed via antimicrobial tests against Escherichia coli and Staphylococcus aureus, and cytotoxicity was evaluated using the MTT assay on 3T3 mouse fibroblasts. Drug release profiles were studied in artificial gastric fluid (pH 1.78). The optimal CS:PVP ratio was found to be 1:0.5, ensuring homogeneous NPs without aggregation. Encapsulation efficiencies ranged between 75–90%, depend-ing on the compound. Antimicrobial assays demonstrated significant inhibition zones for JH1, JH2, Honey bee, and Propolis NPs against E. coli. Cytotoxicity evaluations re-vealed no toxic effects at concentrations of 5 and 10 µg/ml. Controlled release studies confirmed a sustained release of over 180 minutes for all encapsulated compounds. CS-PVP-based nanoparticles effectively encapsulate both synthetic and natural com-pounds, enhancing their stability, antimicrobial efficacy, and controlled release poten-tial. These findings highlight the versatility of CS-PVP-based NPs as innovative plat-forms for drug delivery in biological therapies.