title: In vivo assessment of CdSe-ZnS quantum dots: coating dependent bioaccumulation and genotoxicity.
abstract: Semiconductor nanocrystals, or Quantum Dots (QDs), have gained considerable attention due to their unique size-dependent optical and electronic properties that make them attractive for a wide range of applications, including biology and nanomedicine. Their widespread use, however, poses urgent questions about their potential toxicity, especially because of their heavy metal composition that could cause harmful effects to human health and environment. In this work, we evaluated in vivo the long-term toxicity of CdSe-ZnS QDs with different surface coatings, probing oral administration in the model system Drosophila melanogaster. In particular, we found that all the differently coated QDs significantly affect the lifespan of treated Drosophila populations and induce a marked increase in reactive oxygen species (ROS) levels. Furthermore, we observed that these QDs induce severe genotoxic effects and increased rate of apoptosis in Drosophila haemocytes. These toxic effects were found to be mainly related to the in vivo degradation of QDs with consequent release of Cd(2+) ions, while the coating of QDs can modulate their bioaccumulation in the organism, partly decreasing their overall toxicity.
authors.affiliation: Istituto Italiano di Tecnologia (IIT), Center for Bio-Molecular Nanotechnologies@UniLe, Via Barsanti - 73010, Arnesano, Lecce, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Galeone
authors.forename: G
authors.initials: G
authors.lastname: Vecchio
authors.forename: M A
authors.initials: MA
authors.lastname: Malvindi
authors.forename: V
authors.initials: V
authors.lastname: Brunetti
authors.forename: R
authors.initials: R
authors.lastname: Cingolani
authors.forename: P P
authors.initials: PP
authors.lastname: Pompa
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002104:Cadmium / Q000032:analysis / Q000493:pharmacokinetics; D019187:Cadmium Compounds / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D016923:Cell Death / Q000187:drug effects; D004331:Drosophila melanogaster; D006434:Hemocytes / Q000187:drug effects; D020287:In Situ Nick-End Labeling; D008136:Longevity / Q000187:drug effects; D009152:Mutagenicity Tests; D045663:Quantum Dots; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism; D018036:Selenium Compounds / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D013440:Sulfides / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D013499:Surface Properties; D017967:Zinc Compounds / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity
chemical_list: D019187:Cadmium Compounds; D017382:Reactive Oxygen Species; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D002104:Cadmium; C058667:cadmium selenide; C031238:zinc sulfide