Magnetic resonance imaging of pathogenic protozoan parasite XXXX labeled with superparamagnetic iron oxide nanoparticles.

@entity19 @entity2330 @entity9111
OBJECTIVES: The aim of this study was to establish a noninvasive tracking of the pathogenic parasite @entity2330 (Eh) after superparamagnetic iron oxide (SPIO) labeling by magnetic resonance imaging (MRI) on a single-cell level in vitro and in vivo in a @entity19 model for @entity9111 ( @entity9111 ). MATERIALS AND METHODS: Local institutional review committee on animal care approved all animal experiments. @entity2330 trophozoites were labeled with SPIO nanoparticles (SPIO-Eh). The uptake of SPIO by Eh was optimized using flow cytometry and visualized by bright field, fluorescence, and transmission electron microscopy. The viability of SPIO-Eh was assessed in vitro by determination of growth and ingestion rate of red blood cells. Migration of SPIO-Eh was proven by in vitro MRI in a preclinical 7 T MRI system using continually repeated MRI scans. In vivo distribution of SPIO-Eh within the @entity19 liver was assessed qualitatively and quantitatively by serial respiration-triggered T2*-weighted MRI, T2-weighted MRI, and R2* MR relaxometry up to 5 days after injection and correlated with immunohistology of the liver sections after removal. RESULTS: @entity2330 can be efficiently labeled with SPIO without influence on parasite growth rate or phagocytic capacity. In vitro dynamic MRI allowed real-time migration monitoring and determination of velocity of single SPIO-Eh. In vivo SPIO-Eh showed signal decrease in T2*-weighted and increase of R2* in @entity9111 formations. Motility of SPIO-Eh was necessary to induce @entity9111 formations. CONCLUSIONS: The present study demonstrates the feasibility of an efficient magnetic labeling and a noninvasive in vitro and in vivo MR tracking of the pathogenic protozoan Eh in a @entity19 model for @entity9111 , thus representing in future a noninvasive imaging tool to study parasite, as well as on host-specific pathomechanisms.
