title: Threshold Dose of Three Types of Quantum Dots (QDs) Induces Oxidative Stress Triggers DNA Damage and Apoptosis in Mouse Fibroblast L929 Cells.
abstract: Although it has been reported that fluorescent quantum dots (QDs) have obvious acute toxic effects in vitro, their toxic effects at low doses or threshold doses are still unknown. Therefore, we evaluated the biological histocompatibility and in vitro toxicity of three types of QDs at threshold doses. Also, we compared the toxic effects of QDs with different raw chemical compositions and sizes. The results showed that low concentrations of QDs (≤7 μg/mL) had no obvious effect on cell viability and cell membrane damage, oxidative damage, cell apoptosis or DNA damage. However, QD exposure led to a significant cytotoxicity at higher doses (≥14 μg/mL) and induced abnormal cellular morphology. In addition, when comparing the three types of QDs, 2.2 nm CdTe QDs exposure showed a significantly increased proportion of apoptotic cells and significant DNA damage, suggesting that size and composition contribute to the toxic effects of QDs. Based on these discussions, it was concluded that the concentration (7 μg/mL) may serve as a threshold level for these three types of QDs only in L929 fibroblasts, whereas high concentrations (above 14 μg/mL) may be toxic, resulting in inhibition of proliferation, induction of apoptosis and DNA damage in L929 fibroblasts.
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. zhangting@seu.edu.cn.|Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210009, China. zhangting@seu.edu.cn.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. wyq336@126.com.|Wuxi Center for Disease Control and Prevention, Wuxi 214023, China. wyq336@126.com.
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. konglu@seu.edu.cn.
authors.forename: Lu
authors.initials: L
authors.lastname: Kong
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. yyxue@seu.edu.cn.
authors.forename: Yuying
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. tm@seu.edu.cn.|Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210009, China. tm@seu.edu.cn.
authors.forename: Meng
authors.initials: M
authors.lastname: Tang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D019187:Cadmium Compounds / Q000008:administration & dosage / Q000633:toxicity; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage; D005347:Fibroblasts / Q000187:drug effects*; D006461:Hemolysis; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects*; D010316:Particle Size; D045663:Quantum Dots / Q000008:administration & dosage / Q000633:toxicity*; D018036:Selenium Compounds / Q000008:administration & dosage / Q000633:toxicity; D013691:Tellurium / Q000008:administration & dosage / Q000633:toxicity; D018675:Toxicity Tests
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; C058667:cadmium selenide; D013691:Tellurium; C028337:cadmium telluride
keywords: DNA damage; apoptosis; cytotoxicity; oxidative stress; threshold doses