Construction of Baicalein-Loaded Chitosan Nanoparticles for Staphylococcus aureus-Induced Lung Infection Remission.

PURPOSE: In this study, we constructed baicalein (a traditional Chinese medicine)-loaded chitosan nanoparticles (a drug-delivery system) with great biocompatibility for the remission of Staphylococcus aureus-induced lung infection. METHODS: The nanoparticles were prepared via a one-step reaction. Baicalein-release rates were studied via ultraviolet absorption assays. Morphology was characterized using AFM and TEM. The antibacterial mechanism of the nanoparticles was studied through ONPG, crystal violet staining, and live/dead bacterial staining assays, anti-inflammatory performance investigated via ELISA and WB assays, and in vivo anti-lung-infection capacity studied via H&E staining and ELISA kits. RESULTS: The average size of the nanoparticles was uniform (~200 nm), and the zeta potential was about 18.5 ± 0.3 mV. The encapsulation efficiency was about 40%. The release of baicalein was >80% under different temperatures and pH. Dry nanoparticles were also stable. The minimum inhibitory concentration against S. aureus was about 15 μg/mL. The maximum tolerable dose in vivo was 300 μg/kg. The nanoparticles exhibited outstanding anti-inflammatory and anti-lung-infection performance. CONCLUSION: The in vitro and in vivo results demonstrate that our drug-delivery system could be an efficient platform for the remission of bacterium-induced lung infection.