MSNs bind preferentially to bladder cancer cells relative to normal bladder epithelia in vivo as shown in a series of renderings of T2-weighted MRI scans acquired before (A-C) and after (D-F) intravascular instillation of Gd2O3–TRITC–MSN. (A, D) 2D grayscale view, T: tumor. (B, E) Three-dimensional (3D) rendering images. (C, F) The tumor is segmented and rendered with a pseudo color map. Finger-like projections are revealed which are not observed before the injection of particles (C). Histology confirms anatomical observations and particle penetrations in the structures within the tumor: bright field (G) and fluorescent microscopy (H). Scale bars 1 mm (A-F); 250 μm (G, H). Reproduced with permission from Ref180.