Figure 1: Cell viability study in vitro with MCF-7: untreated cells (C), nanoparticle-treated cells (C+N), Bcl-2 siRNA-treated cells (C+N+BCL2), IGF-1R siRNAtreated cells (C+N+IGFR), IGF-1R siRNA- and p53-treated cells (C+N+IGFR+p53), IGF-1R siRNA- and Bcl-2 siRNA-treated cells (C+N+IGFR+BCL2), Bcl-2 siRNA- and p53-treated cells (C+N+BCL2+p53), IGF-1R/Bcl-2 siRNAs- and p53-treated cells (C+N+IGFR+BCL2+p53). IGF-1R siRNA-, Bcl-2 siRNA- and/or p53 plasmid-loaded carbonate apatite particles were generated by exogenous addition of 4 μl of 1 M calcium chloride, siRNA (40 nM) and/or plasmid (100 ng) to 1 mL bicarbonate-buffered DMEM (pH7.4), followed by incubation at 37°C for 30 min and supplementation with 10% FBS prior to incubation with MCF-7 cells for a consecutive period of 48 h. MTT as say was s u b s e q u e n t l y performed with the absorbance being taken at wave length of 570 nm with reference to 630 nm. Vertical bars represent standard error, *P<0.05 vs control (untreated cells) or **P<0.05 vs control (nanoparticle-treated cells).