Figure 7

Increased drug-sensitivity of chemotherapeutics on MDR ovarian cancer cells in the presence of siRNA@PLGA NPs. Suppression of cell growth of SKOV3 parent and resistant cell lines (A) or A2780 parent and resistant cell lines (B) under incremental concentrations of paclitaxel (PTX) or cisplatin (CP) in the absence or in the presence of siRNA@PLGA NPs. MDR cancer cells were pretreated with siRNA@PLGA NPs (0.28 mg/mL) containing MDR1 and BCL2 siRNA (37.5 nM respectively), and 24 h later, treated with paclitaxel or cisplatin for 48 h. Cell viability was assessed by an MTT assay. IC₅₀ values of chemotherapeutics were estimated by using nonlinear regression analysis of Origin 8 data analysis software. Each IC₅₀ value is presented beside the corresponding plot. Data were represented as mean ± s.d. from three independent experiments. Any marked promotion of drug-sensitivity on both SKOV3 and A2780 parent cell lines was not seen and a higher dosage of siRNA@PLGA NPs, ranging from 0.4 mg/mL to 0.9 mg/mL, did not yield any notable difference in IC₅₀ (data not shown).