Background: Until now, there is no available efficient vaccine against toxoplasmosis, and the current
medications have adverse side effects. Therefore, the search for prophylactic strategies against
toxoplasmosis is mandatory.
Objective: To evaluate the immunoprotection potential activity of the immunogenic T. 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).
Material and Methods: This study was carried out on 50 Swiss albino mice that were equally divided
into 5 groups: negative and positive controls, ID immunized with SAG1, IN immunized with SAG1-loaded
MNPs, and ID immunized with SAG1-loaded MNPs. Brain cyst counting, histopathological examination,
and measurement of immunoglobulins G, and A, and interleukins 10, and 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 are a promising effective delivery tool for SAG1. Since IN route is a needlefree
method of administration, it is preferred than ID route.