Fig. 6
Fluorescence microscopy images of particle cellular uptake and subsequent intracellular DOXO release in breast MDA-MB-231 cancer cells. Free DOXO and (PSS/DOXO-coated GNRs@HSA/CS NPs are shown at different time points in the presence and absence of NIR light illumination (0.5 W/cm2 at 808 nm for 5 min). Red channel was from DOXO fluorescence (λexc = 488 nm); blue channel from cell nuclei stained with DAPI (λexc = 355 nm); bright field channel and merged images are also shown. Scale bar is 10 µm. The plot represents the average normalized measured intensity values (in the region if interest, nuclei) of doxorubicin per cell (in the region of interest, nuclei, of several cells). The intensity was made in relation to the fluorescent intensity signal at the longest incubation time (24 h)