The Effects of TiO(2) Nanoparticles on Cisplatin Cytotoxicity in Cancer Cell Lines

There have been many studies on improving the efficacy of cisplatin and on identifying safe compounds that can overcome multi-drug resistance (MDR) acquired by cancer cells. Our previous research showed that polyethylene glycol-modified titanium dioxide nanoparticles (TiO(2) PEG NPs) affect cell membrane receptors, resulting in their aggregation, altered localization and downregulation. TiO(2) PEG NPs may affect P-glycoprotein (P-gp), a membrane efflux channel involved in MDR. In this study, we investigated the effect of TiO(2) PEG NPs on cisplatin cytotoxicity. We used HepG2 cells, which highly express P-gp and A431 cells, which show low expression of P-gp. The results showed that 10 µg/mL 100 nm TiO(2) PEG NPs increased intracellular cisplatin levels and cytotoxicity in HepG2 cells but not in A431 cells. TiO(2) PEG NPs treatment decreased the expression level of P-gp in HepG2 cells. Our findings indicate that TiO(2) PEG NPs enhance cisplatin cytotoxicity by down regulating P-gp and that TiO(2) PEG NPs are promising candidates for inhibiting P-gp and reversing drug resistance acquired by cancer cells.