Fig. 4

Flow cytometry results of nanoparticles internalization tests onCCD-18Co fibroblast-like, healthy colorectal cells and HT-29 CRC malignant cells at A) 5 h and B) 24 h after NPs treatment. C Spinning disk fluorescence microscopy of HT-29 cells untreated (Control) or treated with L-ZnO or YSA-ZnO. Multiple images were taken for each sample, to obtain a Z-stack; the projection of the 3D reconstructed image is visible in the right and bottom part of each panel. Nuclei were stained with Hoechst (blue) and cell membrane with WGA-647 (red). ZnO cores were stained with ATTO-550 (yellow) and the lipidic shell were labelled with DiO (green). D Reconstructed fluorescence microscopy 3D image of HT-29 cells treated with YSA-L-ZnO. *p < 0.0332, **p < 0.0021, ***p < 0.0002, ****p < 0.0001