title: Toxic response of graphene nanoplatelets in vivo and in vitro.
abstract: With the development of nanotechnology, myriad types of novel materials have been discovered at the nanoscale, among which the most interesting material is graphene. However, the toxicity data available on graphene are extremely limited. In this study, we explored toxic response of commercially available graphene nanoplatelets (GNPs) in vivo and in vitro. The GNPs used in this study had a high surface area and feature considerably few defects. In mice, GNPs (2.5 and 5 mg/kg) remained in the lung until 28 days after a single instillation, and the secretion of inflammatory cytokines reached the maximal level at Day 14 and then decreased over time. In vitro study using BEAS-2B cells, a human bronchial epithelial cell line, GNPs located within autophagosome-like vacuoles 24 h after exposure. The GNPs (2.5, 5, 10, and 20 μg/mL) also dose-dependently reduced cell viability, which was accompanied by an increase in the portion of cells in the subG1 and S phases. Moreover, the GNPs down-regulated the generation of reactive oxygen species, suppressed ATP production, caused mitochondria damage, and elevated the levels of autophagy-related proteins. Based on these results, we suggest that GNPs provoked a subchronic inflammatory response in mice and that GNPs induced autophagy accompanying apoptosis via mitochondria damage in vitro.
authors: Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, Korea, pejtoxic@hanmail.net.
authors: Eun-Jung
authors: EJ
authors: Park
authors: Gwang-Hee
authors: GH
authors: Lee
authors: Beom Seok
authors: BS
authors: Han
authors: Byoung-Seok
authors: BS
authors: Lee
authors: Somin
authors: S
authors: Lee
authors: Myung-Haing
authors: MH
authors: Cho
authors: Jae-Ho
authors: JH
authors: Kim
authors: Dong-Wan
authors: DW
authors: Kim
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects; D001980:Bronchi / Q000166:cytology / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects* / Q000473:pathology; D006108:Graphite / Q000008:administration & dosage / Q000633:toxicity*; D006801:Humans; D007249:Inflammation / Q000139:chemically induced* / Q000473:pathology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008928:Mitochondria / Q000187:drug effects / Q000473:pathology; D053758:Nanoparticles / Q000008:administration & dosage / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors
chemical_list: D016207:Cytokines; D017382:Reactive Oxygen Species; D006108:Graphite