title: Effects of TiO2 nanoparticles on ROS production and growth inhibition using freshwater green algae pre-exposed to UV irradiation.
abstract: This study investigated the possibility that titanium dioxide nanoparticles (nano-TiO2) toxicity in Pseudokirchneriella subcapitata involves reactive oxygen species (ROS) production, using the dichlorodihydroﬂuorescein (DCF) assay. Algae were exposed to nano-TiO2 under laboratory fluorescent lamps supplemented with UV irradiation for 3h, with or without a UV filter. Results showed that nano-TiO2 increased ROS production in UV-exposed cells, with or without a UV filter (LOEC values were 250 and 10mg/L, respectively). Sublethal effects of nano-TiO2 on UV pre-exposed algae were also examined. Toxicity studies indicated that exposure to nano-TiO2 agglomerates decreased algal growth following 3h pre-exposure to UV, with or without a UV filter (EC50s were 8.7 and 6.3mg/L, respectively). The present study suggests that the growth inhibitory effects of nano-TiO2 in algae occurred at concentrations lower than those that can elevate DCF fluorescence, and that ROS generation is not directly involved with the sublethal effects of nano-TiO2 in algae.
authors: State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, Jilin 130117, PR China; School of Life Science and Technology, Nanyang Normal University, Nanyang, Henan 473061, PR China.
authors: Ling
authors: L
authors: Fu
authors: National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada.
authors: Mahsa
authors: M
authors: Hamzeh
authors: National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada.
authors: Sabine
authors: S
authors: Dodard
authors: State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, Jilin 130117, PR China. Electronic address: zhaoyh@nenu.edu.cn.
authors: Yuan H
authors: YH
authors: Zhao
authors: National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada; Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec H9X 3V9, Canada. Electronic address: geoffrey.sunahara@mcgill.ca.
authors: Geoffrey I
authors: GI
authors: Sunahara
mesh_terms: D000460:Chlorophyta / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D005618:Fresh Water; D053768:Metal Nanoparticles / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014025:Titanium / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium
keywords: Pseudokirchneriella subcapitata; Reactive oxygen species (ROS); TiO(2) nanoparticle; Toxicity mechanism