Fig. 4

Biodistribution of Biweekly MnNP Treatment in TBR5 Model. MnNP biodistribution in the TBR5 ovarian tumor model was examined via flow cytometry. A Cy5-MnNPs demonstrated significant increase in uptake in CD45+ immune cells in both the ascites and solid tumor compared to the CD45- populations (n = 5, ##p < 0.001). MnNPs were also associated with over 89% of CD45+ cells in the ascites and 30% of CD45+ cells in the solid tumor (**p < 0.001). B Direct comparison of the different organs for macrophages, monocytes, and other immune cells revealed targeted delivery to the tumors and ascites with minimal off-target delivery to the spleens (n = 5, **p < 0.001). Macrophages displayed significantly elevated %MnNP+ levels compared to most other immune cells in the (C) tumor, (D) ascites, and (E) spleen. The %MnNP+ macrophage population was significantly higher than all other immune cell subtypes in the tumor, and higher than all other subtypes except monocytes in the ascites and spleen (n = 5, *p < 0.05, **p < 0.001)