title: Specific nanotoxicity of graphene oxide during zebrafish embryogenesis.
abstract: Graphene oxide (GO) has shown great potential for biological, medical, energy and electronic applications. As a consequence of these diverse applications, GO release into the ecosystem is inevitable; however, the corresponding risks are largely unknown, particularly with respect to the critical period of embryogenesis. This study revealed that GO adhered to and enveloped the chorion of zebrafish embryos mainly via hydroxyl group interactions, blocked the pore canals of the chorionic membrane, and caused marked hypoxia and hatching delay. Furthermore, GO spontaneously penetrated the chorion, entered the embryo via endocytosis, damaged the mitochondria and primarily translocated to the eye, heart and yolk sac regions, which are involved in the circulatory system of zebrafish. In these organs, GO induced excessive generation of reactive oxygen species and increased oxidative stress, DNA damage and apoptosis. Graphene oxide also induced developmental malformation of the eye, cardiac/yolk sac edema, tail flexure and heart rate reduction. In contrast to the common dose-effect relationships of nanoparticles, the adverse effects of GO on heart rate and tail/spinal cord flexure increased and then decreased as the GO concentration increased. These findings emphasize the specific adverse effects of GO on embryogenesis and highlight the potential ecological and health risks of GO.
authors.affiliation: a Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education) , Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin , China.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Chen
authors.affiliation: a Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education) , Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin , China.
authors.forename: Xiangang
authors.initials: X
authors.lastname: Hu
authors.affiliation: a Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education) , Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin , China.
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.affiliation: a Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education) , Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin , China.
authors.forename: Qixing
authors.initials: Q
authors.lastname: Zhou
mesh_terms: D000818:Animals; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D047108:Embryonic Development / Q000187:drug effects*; D006108:Graphite / Q000633:toxicity*; D008928:Mitochondria / Q000187:drug effects; D053758:Nanoparticles / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D010087:Oxides / Q000633:toxicity; D015027:Zebrafish / Q000196:embryology
chemical_list: D010087:Oxides; D006108:Graphite
keywords: Hatching delay; malformation; mitochondrial dysfunction; oxidative stress; uptake