Fig. 6

a Cellular uptake of Sk-Br-3 after 4 h incubation with either 5 µM free Ce6 or the same concentration of Ce6 but in the MSN-Ce6 conjugate form. b Viability results of Sk-Br-3 cells incubated for 4 h with 5 µM free Ce6 or the same concentration of Ce6, but in the MSN-Ce6 conjugate form followed by irradiation using 665 nm for various durations. c Representative fluorescence images of U87 control cells and cells incubated for 4 h with 5 µM Ce6 in the MSN-Ce6 conjugate form showing the nuclei stained with Hoechst 33258, Ce6 fluorescence and the merge of both. d Cellular uptake of HF-5 after 4 h incubation with either 5 µM free Ce6 or same concentration of Ce6 but in the MSN-Ce6 conjugate form. e Viability results of HF-5 cells incubated for 4 h with 5 µM free Ce6 or the same concentration of Ce6, but in the MSN-Ce6 conjugate form followed by irradiation using 665 nm for various durations. Experiments were repeated at least 3 times and presented are mean and standard deviation