Integrin-dependent activity of Pt(IV) NP-cRGD. (A)
In vitro cytotoxicities of cisplatin, Pt(IV) or Pt(IV) NPs with different densities of the cRGD ligand in the SKOV3 cells, IC50: 50% growth inhibitory concentration. (B)
In vitro confocal laser scanning microscopy (CLSM) images of RB-labeled Pt(IV) NPs (RB NPs) and RB-labeled Pt(IV) NP-cRGD (RB NP-cRGD) uptake in SKOV3 and A2780 cells, RB: Rhodamine B. The cells were incubated with the respective nanoparticle solutions (20 μg/mL RB) for 1 h and 4 h at 37 °C. All pictures show merged images, which include the nuclei (blue) and nanoparticles (red). Scale bar 20 μm. (C, D) Quantitative analysis of the internalized nanoparticles in the SKOV3 (C) and A2780 cells (D) based on the CLSM images. (E) Flow cytometric analysis of integrin expression. (a) SKOV3 cells and (b) αv integrin-downregulated SKOV3 cells. Alexa Flour 488-labeled mouse IgG: control, black; Alexa Flour 488-labeled anti-αvβ3 integrin antibody: red; and Alexa Flour 488-labeled anti-αvβ5 integrin antibody: blue. (F)
In vitro cytotoxicities of cisplatin, Pt(IV) NPs and Pt(IV) NP-cRGD in αv integrin-downregulated SKOV3 cells. The data are presented as the mean ± SD of three independent experiments. Statistical significance in (A) was calculated by one-way ANOVA with Tukey's post hoc test. Statistical significance in (C), (D) and (F) was calculated by two-way ANOVA with Tukey's post hoc test. *P < 0.05, **P < 0.01, ***P < 0.005, NS indicates P > 0.05.