Figure 3.

In vitro antitumor effects of PPNs mediated chemotherapy and photodynamic therapy. (A) Cytotoxicity of empty PPNs and the antitumor effects of PPNs-DOX in SKOV-3 ovarian cancer cells, compared with free DOX. (B) Cell viability of SKOV-3 cancer cells after 2 hrs incubation with PPNs followed by exposure of 30 mW/cm² NIR light for 15 s, 30 s, 1 min, 2 min and 4 min. (C) Cell killing effect of DOX combined with PPNs mediated photo-therapy. SKOV-3 cancer cells were treated with PPNs, free DOX, and PPNs-DOX for 6 hrs. Cells were irradiated with light for 2 min, and cell viability was measured by MTS assay after 72 hrs (P<0.05). (D) ROS production was quantified by flow cytometry in SKOV-3 cancer cells treated with different concentrations of PPNs for 2 hrs, followed by 30 mW/cm² laser irradiation for 2 min. (E) SKOV-3 cancer cells were incubated with 100 µg/mL PPNs for 2 hrs followed by light irradiation for 2 min. 24 hrs later, cells were stained with 40 nM DiOC₆(3) (Green, mitochondrial membrane potential), propridium iodide (PI, red, dead cells) and Hoechst 33342 (blue, nucleus). (F) SKOV-3 cancer cells were treated with different concentrations of PPNs for 2 hrs followed by PDT. Cleaved caspase-3 expression was measured by western blot analysis 24 h later. (G) Cell morphology of SKOV-3 cancer cells after PDT was evaluated by Hema 3 staining.