Microfluidic-Synthesized Chitosan Nanoparticles Loaded with Azithromycin: Impact on Toxoplasma gondii Tissue Cysts in Mouse Model.

Background: We aimed to investigate the effect of chitosan nanoparticles loaded azithromycin on reducing the number of Toxoplasma gondii tissue cysts in the brain of a mouse model.

Methods: Chitosan nanoparticles and azithromycin loaded nanoparticles were synthesized using microfluidic system and characterized using dynamic light scattering (DLS) and TEM images. Forty BALB/c mice after infection with a cyst forming T. gondii strain, were divided into four groups daily receiving PBS, 10 mg/kg azithromycin, 10 mg/kg chitosan nanoparticles, and 10 mg/kg chitosan nanoparticles loaded azithromycin, respectively, for 10 days. Immediately after end of the treatment, the mice were sacrificed and the tissue cyst burden in their brain was investigated using an optical microscope and compared by ANOVA statistical test.

Results: The average particle size and dispersion index for chitosan nanoparticles were 193.66 nm and 0.43, and for nanoparticles containing azithromycin drug, they were 233.66 nm and 0.21, respectively. The amount of drug loading was 1.8% and the drug release was more than 90% after less than 48 hours. The stability of nanoparticles did not change significantly after 28 days of observation. Toxoplasma tissue cyst numbers obtained in a range of 1.48 to 1.95 in 10 ul brain suspension with no significant differences among the groups of treated mice.

Conclusion: The synthesis of chitosan nanoparticles loaded with azithromycin by microfluidic system could make the particles with more uniformity and stability and high loading of the drug with low cost and more convenient conditions.