| Summary: | 碩士 === 國立屏東科技大學 === 生物科技系所 === 103 === Over the decades, nanotechnology has become a rapidly developing industry, therefore nanoparticles concentration increased in the air, causing potential risk to organisms. TiO2-NPs have been widespread used in consumer products, such as cosmetics, sunscreens and building paints. According to statistics, manufacturing products containing TiO2-NPs stand at 5000 t/a for the current production. The phototoxicity of titanium dioxide nanoparticles (TiO2-NPs) can produce reactive oxygen species (ROS) when TiO2-NPs absorb ultraviolet (UV) radiation. Pteris vittata L can absorb arsenic in the soil, making it potential for phytoremediation. The study focuses on the effect of exposure to TiO2 nanoparticles in zebrafish and Pteris vittata L.
The zebrafish exposed to TiO2-NPs (concentration at 10 mg/L), under ambient laboratory light and simulated solar radiation (SSR) through a short-term of acute toxicity test for 6 days, shows that SSR have effect on the behavior of zebrafish. Using the analysis of two way ANOVA confirm that TiO2-NPs and SSR have interaction. However, using the AmpliteTM Colorimetric Acetylcholinesterase Assay kit has exclude factors of neurological injury, and also that behavioral effect was not based on the concentration change of Acetylcholinesterase (AChE). The TiO2 did not affect related antioxidant enzymes activities and production of lipid peroxidation (MDA). For 6 days, using a fluorescence method to analyze the relative levels of apoptosis based on densitometric techniques by AO (Acridine Orange) stain, found that exposed to TiO2-NPs will reduce apoptosis, in contrast exposed to TiO2-NPs with SSR which significantly increased the levels of apoptosis.
Prothallus of Pteris vittata L was exposed to TiO2-NPs (concentration at 10, 100, and 1000 mg/L) for toxicity test for six days; observation was done once every two days. It was found that TiO2-NPs induced prothallium chlorosis, chloroplast morphological changes and cellular acidification on Pteris vittata L following observed after three times, but did not affect the cell viability. We also analyzed the TiO2 effects on photosynthesis pigment of Pteris vittata L by Thin Layer Chromatography (TLC), it was found that exposed to TiO2-NPs will reduce chlorophyll a content on 1000 mg/L concentration. To learn more about TiO2-NPs effect on Pteris vittata L, comparative proteomic to protein variable were exposed to TiO2-NPs for six days. The proteins were identified by LC-MS/MS. TiO2-NPs 1000 mg/L concentration was found to cause arsenate reductase expression to diminished, whileTiO2-NPs 10、100 mg/L concentration induced putative arsenate reductase expression. Exposed TiO2-NPs induced Oxygen-evolving enhancer protein 1 protein expression, which ATP-binding cassette transporter and ATP synthase beta chain found at TiO2-NPs 100 mg/L. Kinesin-like protein for actin-based chloroplast movement 1 was found in control. We also culture the prothallus of Pteris vittata L on a solid medium for growth toxicity test for five weeks. Using the analysis of statistics software , it was found that TiO2-NPs can significantly inhibit Pteris vittata L growth, when exposed to TiO2-NPs at concentration 10、1000 mg /L. In contrast, Pteris vittata L exposed to TiO2-NPs at concentration of 100 mg/L cause growth. It was found that TiO2-NPs induced cellular acidification on Pteris vittata L, but did not affect the cell viability、chloroplast morphological、photosynthesis pigment. We used comparative proteomic to protein variable expose to TiO2-NPs for five weeks. Found that TiO2-NPs exposure can cause protochlorophyllide oxidoreductase A (PORA) expression diminished, however, on the ribulose-1, 5-bisphosphate carboxylase/oxygenase large subunit, partial (RUBL) expression was induced.
Our study also demonstrated phototoxicity of TiO2-NPs effect on zebrafish behavior by TiO2-NPs with SSR interaction. In addition, we investigate the suitability of Pteris vittata L for the phytoremediation of a wide range of aquatic environment with TiO2. We showed that Pteris vittata L could clean TiO2 of aquatic environment as a tool of phytoremediation, and improve to behavioral effects of TiO2 on zebrafish.
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