2024-03-29T10:22:59Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1754772019-02-08T01:56:32Zcom_10261_14com_10261_8col_10261_393
00925njm 22002777a 4500
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Sendra, Marta
author
Moreno-Garrido, Ignacio
author
Yeste, María Pilar
author
Gatica, José Manuel
author
Blasco, Julián
author
2016-09
Titanium dioxide nanoparticles (TiO2 NPs) has become a part of our daily life in the form of drug delivery systems, therapeutics and biosensors, cosmetics, production of paints, coatings, plastics, skin care products, foods, water remediation devices and pharmaceuticals, and the predicted environmental concentrations are the highest in aquatic ecosystems. Although TiO2 has got a limited reactivity, under UV-A radiation can increase adverse effects on organisms, due to its photocatalytic properties; and the occurrence at nanoscale level change its physicochemical properties and toxicity. Phytoplankton is a key trophic level in aquatic ecosystems, and the toxicity provoked by these nanoparticles can affect structure and function of the ecosystems. Two microalgae species, from freshwater (Chlamydomonas reinhardtii) and seawater (Phaeodactylum tricornutum) have been selected for testing toxicity of TiO2 NPs and TiO2 bulk form. Due to their photo-catalytic properties, UV-A effect was checked, also. TiO2 NPs and bulk TiO2 showed a relation between the size of agglomerates (homoagglomerates) and time in freshwater and saltwater but not in ultrapure water. Under both, UV-A and no UV-A treatments, NPs triggered higher cytotoxic responses than conventional bulk material. TiO2 NPs produced higher increasing in ROS production, damage to membrane and quantum yield. The marine microalgae species (P. tricornutum) showed to be more sensitive than the selected freshwater species and higher Ti internalization was reported. Exopolymeric substances (EPS) in the culture media are produced in presence of TiO2 NPs and bulk from microalgae, pointing out a possible defense mechanism, enhancing homoagglomeration and settling processes and reducing bioavailability. In order to assess environmental risk assessment in realistic conditions, UV radiation should be considered as key element in toxicity assay guidelines.
30th ESCPB Congress (2016)
http://hdl.handle.net/10261/175477
http://dx.doi.org/10.13039/501100003329
http://dx.doi.org/10.13039/501100000780
http://dx.doi.org/10.13039/501100011011
Toxicity of TIO2 nanoparticles and bulk in freshwater and marine microalgae, under visible light and UV-A-radiation