Intranasal versus intradermal immunoprotective effect of maltodextrin nanoparticles loaded with SAG1 against toxoplasmosis in murine model

Background: Until now, there is no available satisfactory vaccine against human toxoplasmosis and the current medications have adverse side effects so the search for prophylactic strategies against toxoplasmosis is mandatory. Objectives: To evaluate the immunoprotection activity of the immunogenic antigen as Toxoplasma gondii Surface Antigen 1 (SAG1) combined with maltodextrin nanoparticles (MNPs) against toxoplasmosis. A secondary objective is to assess the most efficient route of administration, intranasal (IN) or intradermal (ID). Materials and methods: This study was carried out on 50 Swiss albino mice that were divided into negative control group, positive control group, ID immunized group with SAG1, IN immunized group with SAG1-loaded MNPs, and ID immunized group with SAG1-loaded MNPs. positive control group, IN immunized group, and SAG1-loaded MNPs ID immunized group. Brain cyst counting, histopathological examination, and measurement of immunoglobulins (IgG, IgA), and interleukin (IL-10, IL-12) levels were used to assess the immunoprotective effects SAG1-loaded MNPs. Results: The efficacy of immunization with SAG1 was enhanced after loading it on MNPs with significant reduction rate of brain cyst count 89.76% in the ID immunized group and 77.46% in the IN immunized group . Moreover, SAG1-loaded MNPs IN immunized group showed the least pathological changes and the highest levels of anti-T. gondii IgG with the highest levels of cytokines IL-10 and IL-12. Conclusion: Maltodextrin NPs nanoparticles could be used as an are a promising effective nanocarrier delivery tool for SAG1. Since IN route is as a needle-free method of administration, it is preferred than ID route.