The role of surface modification in the interactions between CdTe quantum dots and ABC transporters in lung cancer cells.

This paper aimed to investigate the role of surface modification on the potential interaction between CdTe quantum dots (QDs) and ABC transporters in doxorubicin-resistant lung cancer (A549/DOX) cells. For this purpose, CdTe QDs modified with -glutathione (GSH), -carboxy (COOH), and -amino (NH2) were applied, with the former two QDs exhibiting negative potentials and the latter ones being positive. All the three QDs reduced cell viability in a concentration-dependent manner, with NH2-CdTe QDs being more toxic. Such phenomena might be due to the adherence of NH2-CdTe QDs to negative cell membrane and thereby causing an enhanced accumulation. Addition of transporter inhibitors significantly enhanced the intracellular accumulation and toxicity of negative QDs, but such phenomena were barely found or even reversed for NH2-CdTe QDs, indicating that ABC transporters mainly excreted negative QDs. All the QDs caused little effects on the mRNA expression of ABC transporters, which should be due to the fact that the induction effects of QDs have been attenuated by the disruption of cell membrane. Overall, these results reveal the mechanism by which ABC transporters are involved in the efflux of CdTe QDs with different surface modifications, which could help the detoxification of QDs in the environment.