title: Toxicity of quantum dots and cadmium salt to Caenorhabditis elegans after multigenerational exposure.
abstract: To fully understand the biological and environmental impacts of nanomaterials requires studies that address both sublethal end points and multigenerational effects. Here, we use a nematode to examine these issues as they relate to exposure to two different types of quantum dots, core (CdSe) and core-shell (CdSe/ZnS), and to compare the effect to those observed after cadmium salt exposures. The strong fluorescence of the core-shell QDs allowed for the direct visualization of the materials in the digestive track within a few hours of exposure. Multiple end points, including both developmental and locomotive, were examined at QD exposures of low (10 mg/L Cd), medium (50 mg/L Cd), and high concentrations (100 mg/L Cd). While the core-shell QDs showed no effect on fitness (lifespan, fertility, growth, and three parameters of motility behavior), the core QDs caused acute effects similar to those found for cadmium salts, suggesting that biological effects may be attributed to cadmium leaching from the more soluble QDs. Over multiple generations, we commonly found that for lower life-cycle exposures to core QDs the parents response was generally a poor predictor of the effects on progeny. At the highest concentrations, however, biological effects found for the first generation were commonly similar in magnitude to those found in future generations.
authors.affiliation: Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
authors.forename: Elizabeth Q
authors.initials: EQ
authors.lastname: Contreras
authors.forename: Minjung
authors.initials: M
authors.lastname: Cho
authors.forename: Huiguang
authors.initials: H
authors.lastname: Zhu
authors.forename: Hema L
authors.initials: HL
authors.lastname: Puppala
authors.forename: Gabriela
authors.initials: G
authors.lastname: Escalera
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhong
authors.forename: Vicki L
authors.initials: VL
authors.lastname: Colvin
mesh_terms: D000818:Animals; D049628:Body Size / Q000187:drug effects; D019187:Cadmium Compounds / Q000032:analysis / Q000633:toxicity*; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000502:physiology; D005298:Fertility / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects; D008136:Longevity / Q000187:drug effects; D045663:Quantum Dots; D018036:Selenium Compounds / Q000032:analysis / Q000633:toxicity*; D013440:Sulfides / Q000032:analysis / Q000633:toxicity; D017967:Zinc Compounds / Q000032:analysis / Q000633:toxicity
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; C031238:zinc sulfide