Research Article

Quantification of Nanoparticle Enhancement in Polarized Breast Tumor Macrophage Deposits by Spatial Analysis of MRI and Histological Iron Contrast Using Computer Vision

Figure 3

Characterization of endogenous and contrast-enhanced macrophage iron deposit polarization. Fields of paraffin-embedded tumor cross sections from control (left, −USPIO) and iron nanoparticle-injected (right, +USPIO) mice showing deposits of (a) Prussian blue iron+ macrophages and colocalized (b) AIF1, (c) CD68, (d) CD206, and (e) merged immunofluorescent markers. (f) Absolute count of CD68+ macrophages per mm2 tumor cross section and (g) frequency of total M1-like (AIF1) and M2-like (CD206) macrophages determined by whole tumor cross section ROI analysis of immunofluorescent images in control (−USPIO) and nanoparticle-injected (+USPIO) cohorts (mean ± SEM shown, tumors/group, , two-tailed Student’s -test). Frequency of total iron+ macrophage calculated as (h) iron+CD68+/CD68+, (i) iron+AIF1+/AIF1+, (j) iron+CD206+/CD206+, and (k) iron+CD206+AIF1+/CD206+AIF1+ cells (mean ± SEM shown, tumors/group, , , two-tailed Student’s -test). Scale bar is shown for all images.