Toxicological assessment of TiO2 nanoparticles by recombinant Escherichia coli bacteria
Toxicological assessment of TiO2 nanoparticles by recombinant Escherichia coli bacteria
复制标题
DOI：
10.1039/c0em00499e
复制
发表时间：
2011-01-01
影响因子：
--
通讯作者：
He, Tiande
中科院分区：
文献类型：
--
作者：
Jiang, Guoxiang;Shen, Zhenyao;He, Tiande
快速和有效的方法来评估纳米颗粒的毒性是目前的研究所需的。在这里，我们表明，大肠杆菌标记的绿色荧光蛋白可以是一个很好的模式细菌用于评估的急性毒性的二氧化钛（约50%的抑制率后，135分钟的曝光）。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）结果表明，纳米TiO 2颗粒（NPs）对重组菌中某些蛋白的表达有影响，在30/40、10/20 μ g mL（-1）处理的重组菌中分别观察到明显的抑制表达和提高表达的效果。然而，GFP表达（27 kD）不受引入的TiO 2纳米颗粒的影响。荧光强度的变化可能是由于产生的活性氧导致GFP翻译后修饰的折叠和发色团形成受损所致。此外，由于聚集，较高浓度的TiO 2 NPs降低了它们的毒性。20 μ g mL（-1）的腐殖酸（HA）引入到培养基中可以降低荧光抑制，这是由于它在NP和细胞之间提供了空间位阻屏障。
Rapid and efficient methods to assess nanoparticle toxicity are desired in current research. Here we showed that Escherichia coli labeled by green fluorescent protein can be a good model bacterium for assessing acute toxicity of TiO2 (about 50% inhibition ratios after 135 min exposure). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that TiO2 nanoparticles (NPs) can influence certain protein expression in the recombinant bacterium, and the obvious effects in repressed expression and elevated expression were observed in 30/40, 10/20 mu g mL(-1) treated cells, respectively. However, the GFP expression (27 kD) was not influenced by introduced TiO2 NPs. The change of the fluorescence intensity may be caused by the damage in folding and chromophore formation of the GFP post-translational modification due to generated reactive oxygen species. Furthermore, TiO2 NPs at higher concentrations decreased their toxicity because of aggregation. 20 mu g mL(-1) humic acid (HA) introduced to the medium can decrease the fluorescent inhibition owing to the barrier of steric hindrance it provides between NPs and cells.