Fig. 6

Cellular uptake and cytotoxicity of nrGO and nrGO/DOX. a Cellular uptake of nrGO/DOX in A549 cells by FCM assay. Cells were cultured with nrGO/DOX for 1, 2, 6, and 12 h respectively before FCM analysis. b Statistical results of cellular uptake of nrGO/DOX in A549 cells from three independent experiments. c Fluorescence images of living A549 cells cultured with nrGO/DOX. The adherent cells incubated with nrGO/DOX for 0, 1, 3, and 6 h were imaged by fluorescence microscope. d–f Dose-dependent cytotoxicity of nrGO with or without NIR irradiation on HepG2 (d), Huh7 (e), and A549 (f) cells. g Cytotoxicity of nrGO/DOX with heating or GSH treatment in A549 cells. *P < 0.05 and **P < 0.01, compared with the cells treated with nrGO/DOX alone