Fig. 5

Representative confocal images of OncoCilAir™ inserts 24 h after AGuIX^®-Cy5.5 exposure. a AGuIX^® NPs were preferentially observed in tumor areas. The GFP^+/++ tumor cells (green) and healthy tissues were labeled with ethidium bromide to show nuclei (blue). AGuIX^®-Cy5.5 NPs are represented in red. b Phalloidin staining (gray) revealed the organized healthy tissue compared to the chaotic tumor areas. c At higher magnification, the GFP/phalloidin colocalization confirmed AGuIX^® NP internalization inside tumor cells: the NPs were clustered into cytoplasmic vesicles. All images are orthogonal views presenting the XY, XZ and YZ planes. d Without cell fixation and permeabilization, AGuIX^®-Cy5.5 NPs were also observed inside live tumor cells with clear evidence of NP internalization in cytoplasmic vesicles. The two first insets of d are 3D projection, while the two last are orthogonal views with different zooms. e A zoom-in at the interface between tumor and normal surrounding tissue evidenced the NP’s behavior. The arrows indicated the presence of NP clusters in the normal tissue. Scale bar: 50 µm