Fig. 5.

Cell penetrating peptide effect for photodynamic therapy. a, b Live (green, FITC)/dead (red, Texas Red) assays with confocal microscopy for adherent HeLa cells after 30 min illumination under different polarization conditions for NP dimers (without cell penetrating peptides labeled on the NP surface and denoted by without TAT) with 532 nm photons (a) and NR dimers (without cell penetrating peptides labeled on the NR surface and denoted by without TAT) with 660 nm photons (b), respectively. c, d The death ratio of HeLa cells incubated with (c) NP dimers, (d) NR dimers under different polarized light irradiation determined by MTT assay. The NP or NR dimers with/without cell penetrating peptides modified on the surface were denoted by with TAT/without TAT. Scale bar: 200 μm. The error bars correspond to the standard error of the mean (n = 3)