Chitosan-Coated Azithromycin-Loaded PLGA Nanoparticles: Characterization and Potential for Enhanced Antibacterial Activity

Tóm tắt

Recent studies have introduced azithromycin (AZT) in multiple formulations that implement nanoparticles (NPs) to enhance its antibacterial efficacy and prevent bacterial resistance. However, the impact of chitosan (CS) coating on AZT–poly(lactic-co-glycolic acid) (PLGA) NPs remains underexplored. This study developed and characterized AZT–PLGA NPs with and without CS coating, focusing on physicochemical properties, in-vitro release, and antibacterial properties (against Staphylococcus aureus). The uncoated and CS-coated NPs exhibited mean particle sizes below 200 nm with narrow polydispersity (PDI < 0.3). CS coating reversed the surface charge from negative to positive values (app. 30 mV), confirming successful deposition. SEM and FTIR analyses indicated a PLGA-rich core with drug–polymer interactions, and a CS layer in coated NPs. In vitro release studies revealed that CS-coated NPs showed a more sustained release profile compared to uncoated NPs. Antibacterial evaluation demonstrated that all NP formulations had lower minimum inhibitory concentrations (MIC) than raw AZT, with PLGA-based formulations achieving approximately fourfold MIC reduction. CS-coated NPs showing comparable or slightly lower MBC values than the same formulation without CS. This work presents a new aspect of CS-coated PLGA NPs, offering a potential platform for macrolide antibiotics.