title: Cellular uptake, elimination and toxicity of CdSe/ZnS quantum dots in HepG2 cells.
abstract: In this work, the cellular uptake, elimination and toxicity of CdSe/ZnS QDs in HepG2 cells were comprehensively studied using inductively coupled plasma mass spectrometry (ICP-MS), MTT assay, AO/EB staining, and glutathione level and gene expression analysis. ICP-MS analytical results showed that the uptake efficiency of CdSe QDs by HepG2 cells was lower than that of Cd(II) and Se(IV), and the uptake was dose- and time-dependent. The uptake amount was related to the physicochemical properties of QDs, and NH2-QDs with smaller size were more easily taken up by cells. In combination with various biochemical methodologies, a systematic and thorough quantitative analysis of the in vitro effects of CdSe/ZnS QDs with different coatings was conducted, along with that of Cd (II) and Se (IV). Although Cd(II) above 8.9 μM exhibited obvious toxicity to the cells, no obvious toxicity of four CdSe/ZnS QDs was observed within the tested concentration range (10-100 nM), most likely due to the protection of the ZnS shell and the PEG coating. From the molecular level's point of view, QDs at concentration of 100 nM exhibit obvious impact on the cells, such as increased gene expression (MT1A and CYP1A1), which was positively correlated with the intracellular concentration of QDs.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Peng
authors.forename: Man
authors.initials: M
authors.lastname: He
authors.forename: Beibei
authors.initials: B
authors.lastname: Chen
authors.forename: Qiumei
authors.initials: Q
authors.lastname: Wu
authors.forename: Zhiling
authors.initials: Z
authors.lastname: Zhang
authors.forename: Daiwen
authors.initials: D
authors.lastname: Pang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
mesh_terms: D001692:Biological Transport; D019187:Cadmium Compounds / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D056945:Hep G2 Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D045663:Quantum Dots / Q000737:chemistry / Q000378:metabolism*; D018036:Selenium Compounds / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity; D013440:Sulfides / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity; D017967:Zinc Compounds / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; C031238:zinc sulfide
keywords: CdSe/ZnS quantum dots; Elimination; HepG2 cells; Inductively coupled plasma mass spectrometry; The cellular uptake; Toxicity