U87 cells were seeded at a density in 1×10 /well in a 6-well plate 24h before addition of nanorods or NPs in growth medium. Before flow cytometry analysis, adhesive cells were first stained with fluorescein diacetate and Hoechst 33342. Then, live cells were washed once with warm DPBS and then detached with trypsin-EDTA treatment for 5 min at 37 °C, centrifuged, and resuspended in 500 µL of a solution of BSA 1% in DPBS. This suspension was passed through a 50 µm nylon mesh filter and kept on ice until analysis. For the experiment, the cells were analyzed using a MACSQuant® VYB flow cytometer. The detectors were calibrated in by the light scattering and fluorescence using MACSQuant® fluorescent calibration beads.