Study of anti-Toxoplasma gondii effect of mPEG–PCL copolymeric loaded with pyrimethamine, in vitro

The discovery of new drugs with minimal toxicity is crucially important in the search for effective treatments for toxoplasmosis. The study aimed to assess the effectiveness of pyrimethamine-loaded mPEG-PCL copolymeric nanoparticles (mPEG-PCL-Pyr) against Toxoplasma gondii (T. gondii) tachyzoites. The nanoparticles were fabricated using a nano-precipitation method and characterized using DLS and AFM. Through MTT assay, the anti-toxoplasmic activity was gauged. Healthy and infected cell viability, infection index, proliferation index, plaque count, and size were evaluated. Results indicated a maximum drug loading capacity of 11.23% in the nanoparticles. Toxicity testing on Vero cells infected with tachyzoites revealed notable cytotoxic effects at pyrimethamine-equivalent concentrations of 20 and 40 mg/mL in the mPEG-PCL copolymeric nanoparticle formulation. However, as the results indicated, the administration of mPEG-PCL-Pyr resulted in the reduction of intracellular proliferation, infection index, and the number and size of plaques in comparison to uninfected treated cells (P < 0.05). The synthesized Nano drug exhibited slightly better performance than pyrimethamine, despite the lack of statistical significance in the observed distinction (p > 0.05). The study demonstrated that mPEG-PCL copolymeric nanoparticles containing pyrimethamine effectively impede the in vitro replication of T. gondii. The study demonstrated that mPEG-PCL copolymeric nanoparticles containing pyrimethamine effectively impede the in vitro replication of T. gondii. The impact of pyrimethamine resembled that of the synthesized nano-drug on T. gondii tachyzoites, suggesting the potential of these nanoparticles as a promising avenue for toxoplasmosis treatment.