title: Toxicity of Graphene Quantum Dots in Zebrafish Embryo.
abstract: OBJECTIVE
  To evaluate the bio-safety of graphene quantum dots (GQDs), we studied its effects on the embryonic development of zebrafish.
  
  
  METHODS
  In vivo, biodistribution and the developmental toxicity of GQDs were investigated in embryonic zebrafish at exposure concentrations ranging from 12.5-200 μg/mL for 4-96 h post-fertilization (hpf). The mortality, hatch rate, malformation, heart rate, GQDs uptake, spontaneous movement, and larval behavior were examined.
  
  
  RESULTS
  The fluorescence of GQDs was mainly localized in the intestines and heart. As the exposure concentration increased, the hatch and heart rate decreased, accompanied by an increase in mortality. Exposure to a high level of GQDs (200 μg/mL) resulted in various embryonic malformations including pericardial edema, vitelline cyst, bent spine, and bent tail. The spontaneous movement significantly decreased after exposure to GQDs at concentrations of 50, 100, and 200 μg/mL. The larval behavior testing (visible light test) showed that the total swimming distance and speed decreased dose-dependently. Embryos exposed to 12.5 μg/mL showed hyperactivity while exposure to higher concentrations (25, 50, 100, and 200 μg/mL) caused remarkable hypoactivity in the light-dark test.
  
  
  CONCLUSIONS
  Low concentrations of GQDs were relatively non-toxic. However, GQDs disrupt the progression of embryonic development at concentrations exceeding 50 μg/mL.
authors.affiliation: School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, Gansu, China.
authors.forename: Zhen Guo
authors.initials: ZG
authors.lastname: Wang
authors.affiliation: Department of Heavy Ion Irradiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000, Gansu, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhou
authors.affiliation: School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, Gansu, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Jiang
authors.affiliation: School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, Gansu, China.
authors.forename: Jing E
authors.initials: JE
authors.lastname: Song
authors.affiliation: School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, Gansu, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Heavy Ion Irradiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000, Gansu, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Si
authors.affiliation: School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, Gansu, China.
authors.forename: Yun Ping
authors.initials: YP
authors.lastname: Chen
authors.affiliation: Department of Heavy Ion Irradiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000, Gansu, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Heavy Ion Irradiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000, Gansu, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Gan
authors.affiliation: College of Life Sciences, Northwest Normal University, Lanzhou 730070, Gansu, China.
authors.forename: Jian Zhen
authors.initials: JZ
authors.lastname: Li
authors.affiliation: Department of Heavy Ion Irradiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000, Gansu, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, Gansu, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000187:drug effects*; D006108:Graphite / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D045663:Quantum Dots / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D015027:Zebrafish / Q000196:embryology*
chemical_list: D006108:Graphite
keywords: Developmental toxicity; Embryo; Graphene quantum dots; Zebrafish