Effects of TiO2 nanoparticles on ROS production and growth inhibition using freshwater green algae pre-exposed to UV irradiation.
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.
['Fu|Ling|L|', 'Hamzeh|Mahsa|M|', 'Dodard|Sabine|S|', 'Zhao|Yuan H|YH|', 'Sunahara|Geoffrey I|GI|']
D000460:Chlorophyta D004305:Dose-Response Relationship, Drug D005618:Fresh Water D053768:Metal Nanoparticles D017382:Reactive Oxygen Species D014025:Titanium
Pseudokirchneriella subcapitata Reactive oxygen species (ROS) TiO(2) nanoparticle Toxicity mechanism