title: Colorimetric Evaluation of the Viability of the Microalga Dunaliella Salina as a Test Tool for Nanomaterial Toxicity.
abstract: A diagnostic test system was developed to determine the toxicity of nanomaterials to the saltwater microalga Dunaliella salina through evaluation of cell death and changes in the culture growth rate at various toxicant concentrations, providing LC50 and other toxicological metrics. The viability of cells was shown to decrease with decreasing chlorophyll absorption of red light by damaged cells. This correlation was confirmed by independent fluorescence microscopic measurements of live and dead cells in the population. Two standard colorless pollutants, hydrogen peroxide and formaldehyde, were used to validate the colorimetric method. The method's performance is exemplified with three Ag-containing preparations (Ag nitrate, Ag proteinate, and 20-nm Ag nanoparticles) and with cetyltrimethylammonium bromide (CTAB) mixed with colloidal 15-nm Au and 20-nm Ag nanoparticles. The toxicity of the Ag-containing preparations to D. salina decreased in the order Ag nitrate ≥ Ag proteinate ≫ colloidal Ag. The toxicity of colloidal Au-CTAB mixtures was found to depend mostly on the content of free CTAB. The toxicity of colloidal Ag increased substantially in the presence of CTAB. The results suggest that our D. salina-based colorimetric test system can be used for simple and rapid preliminary screening of the toxicity of different nanomaterials.
authors: *Laboratory of Immunochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov 410049, Russian Federation.
authors: Alexander A
authors: AA
authors: Golubev
authors: Laboratory of Nanobiotechnology, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov 410049, Russian Federation.
authors: Artur Y
authors: AY
authors: Prilepskii
authors: *Laboratory of Immunochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov 410049, Russian Federation.
authors: Lev A
authors: LA
authors: Dykman
authors: Laboratory of Nanobiotechnology, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov 410049, Russian Federation Faculty of Nano- and Biomedical Technologies, Chernyshevsky Saratov State University, Saratov 410012, Russian Federation.
authors: Nikolai G
authors: NG
authors: Khlebtsov
authors: Laboratory of Nanobiotechnology, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov 410049, Russian Federation bog@ibppm.sgu.ru.
authors: Vladimir A
authors: VA
authors: Bogatyrev
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism*; D003102:Colloids; D003124:Colorimetry; D004305:Dose-Response Relationship, Drug; D006046:Gold / Q000633:toxicity*; D007928:Lethal Dose 50; D053768:Metal Nanoparticles / Q000633:toxicity*; D058086:Microalgae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008856:Microscopy, Fluorescence; D012834:Silver / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D015415:Biomarkers; D003102:Colloids; D002734:Chlorophyll; D012834:Silver; D006046:Gold
keywords: CTAB; fluorescence microscopy; plasmon-resonant particles; spectrophotometry; toxicology