Mechanism of quantum dots facilitating Cu2+-induced hepatic L02 cells toxicity: possible trojan-horse role of QDs]

Concerns regarding the potential environmental impact of quantum dots (QDs) are raised for its extensive use. Understanding the influences of QDs on original environmental pollutants induced toxicity and obtaining information about the mechanism is crucial to evaluate potential ecological hazards posed by QDs. The effects of QDs on Cu2+ induced Hepatic L02 cells toxicity and the mechanisms were investigated. IC10 value of 2 microg/mL QDs and IC10-IC50 value of 2.5-20 microg/mL of CU2+ was used in this study. Firstly Luminescence emission spectrum of QDs showed 10 nm red shifts with addition of Cu2+ provide the interaction possibility of QDs and Cu2+, the further X-ray energy dispersive spectroscopy (EDX) analysis indicated binding of Cu2+ on QDs surface. Then the intracellular Cu2+ concentrations showed increase with addition of QDs, which is accompanied by loss of cell viability and morphology changes. The mechanism was therefore assumed as interaction of QDs-Cu2+ improved the intracellular Cu2+ level then cytotoxicity. QDs seemed to serve as Trojan-horse taking much more Cu2+ into cells via cheating cell membrane recognition, which imply the possible interactions with heavy metal ions will pose a significant influence on environment and human body.