title: The interaction and toxicity of multi-walled carbon nanotubes with Stylonychia mytilus.
abstract: The interaction of multi-walled carbon nanotubes (MWNTs) with living unicellular protozoan Stylonychia mytilus was studied. The results indicated that MWNTs were ingested largely by Stylonychia mytilus. Distribution of MWNTs in the cells, redistribution during dividing process of the cells, and excretion from the cells were observed successfully with optical microscope. The dependence of viability of Stylonychia mytilus was determined on the concentration of MWNTs, ranging from 0.1 microg/ml to 200 microg/ml. It was found that exposure of Stylonychia mytilus to the MWNTs with concentration higher than 1.0 microg/ml induced a dose-dependent growth inhibition to the cells and the damage occurred, by fluorescence microscopy, on the macronucleus and external membrane of the cells. The ultrastructure change by electron microscope revealed that the MWNTs exclusively localized to the mitochondria of the cells. It was proposed that the damage of macronucleus, micronucleus, and membrane of the cells, as well as growth inhibition of the cells might be a result of the damage of mitochondria, following this exclusive localization. Our finding provides important information on the bio-security of MWNTs and their migration in aqueous environment.
authors.affiliation: Laboratory of Nano-Biology and Medicine, Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.forename: Qunfen
authors.initials: Q
authors.lastname: Zhao
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Li
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Cai
authors.forename: Wenxin
authors.initials: W
authors.lastname: Li
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016798:Ciliophora / Q000737:chemistry* / Q000166:cytology* / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D007928:Lethal Dose 50; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000633:toxicity* / Q000648:ultrastructure; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014018:Tissue Distribution; D018675:Toxicity Tests
chemical_list: D037742:Nanotubes, Carbon