Fig. 3

In vitro cytotoxicity of Nir-Ir NPs. A-D) Cell viabilities of HCT116 (A), SW480 (B), HCT8 (C) and HCT8/V (D) cells after various treatments (control, Ir, Nir Nir/Ir mixture and Nir-Ir NPs) for 72 h. E, F) Immunostaining (E) of γH2AX and Rad51 and numbers of each foci (F) in HCT8/V cells after various treatments for 24 h. Images were representative of three independent samples. Data were presented as mean values ± SD (n = 3 independent samples). *P < 0.05, **P < 0.01, ***P < 0.001 from two-tailed student’s t test indicated statistical difference compared to the Ir group. G) Immunoblotting of the protein expression status of MRP1 in HCT8/V cells after various treatments for 48 h. H, I) Representative flow cytometric plot (H) and apoptotic percentages (I) of tumor cells after various treatments for 48 h using an Annexin V-FITC/PI kit in HCT116 and HCT8/V cells. Data were presented as mean values ± SD (n = 3 independent samples). **P < 0.01 from the two-tailed student’s t test indicated statistical difference compared to the Ir group. J) Immunoblot analysis of apoptosis-related proteins expression after various treatments for 48 h (relative expression, fold of α-tubulin )