Analysis of copper nanoparticles toxicity based on a stress-responsive bacterial biosensor array

Abstract

The rapid development in nanoparticle production and application during the past decade requires an easy, rapid, and predictive screening method for nanoparticles toxicity assay. In this study, the toxicological effects and the source of toxicity of copper nanoparticles (CuNPs) are investigated based on a stress-responsive bacterial biosensor array. According to the responses of the biosensing strains, it is found that CuNPs induce not only oxidative stress in E. coli, but also protein damage, DNA damage, and cell membrane damage, and ultimately cause cell growth inhibition. Through enzyme detoxification analysis, the toxicological effects of CuNPs are traced to H(2)O(2) generation from CuNPs. Rapid copper release from CuNPs and Cu(I) production are observed. The oxidation of the released Cu(I) has a close relation to H(2)O(2) production, as tris-(hydroxypropyltriazolylmethyl) amine, the specific Cu(I) chelator, can largely protect the cells from the toxicity of CuNPs. In addition, the TEM study shows that CuNPs can be adsorbed and incepted fast by the cells. Comparatively, copper microparticles are relatively stable in the system and practically non-toxic, which indicates the importance of toxic estimation of materials at the nanoscale. In addition, the Cu(II) ion can induce protein damage, membrane damage, and slight DNA damage only at a relatively high concentration. The current study reveals the preliminary mechanism of toxicity of CuNPs, and suggests that the stress-responsive bacterial biosensor array can be used as a simple and promising tool for rapid screening in vitro toxicity of nanoparticles and studying the primary mechanism of the toxicity.

Comparative environmental fate and toxicity of copper nanomaterials

“…Exposure to Cu NPs resulted in oxidative stress (measured by biotic reactive oxygen species (ROS) generation) for E. coli and L. brevis, but there was no effect from CuCl 2 , CuSO 4 , μCu or μCuO at the concentrations studied ([Cu] up to 250 mg/L) (Kaweeteerawat et al, 2015). These results are in line with previous work indicating that exposure to Cu NPs caused cellular oxidative stress in bacterial cells (Li et al, 2013), yeast cells (Kasemets et al, 2013), and mammalian cells (Liu et al, 2014). Exposure to ionic and nano-and micro-scale Cu particles resulted in DNA damage (using an in-vitro plasmid assay), but while nCu and μCu induced complete degradation of plasmid DNA, both n-Cu(OH) 2 converted the supercoiled plasmid to open circular (single-strand breaks) and linearized plasmid (double-strand breaks) (Kaweeteerawat et al, 2015).…”

Microscopic and Spectroscopic Analyses of Selected Agricultural Formulations Containing Various nanostructures

“…At concentrations of 40-60 mg/ml, it is toxic to various organisms such as algae, bacteria, crustaceans, and fish [36]. The type and application mode of these compounds are important, as the global production of Ag and Cu in the form of NPs is estimated at more than 500 tons per year [37], and their industrial and agricultural use is constantly increasing [38].…”

Dissolution and aggregation of Cu nanoparticles in culture media: effects of incubation temperature and particles size

“…For instance, Chen et al (2006) found that CuNPs could induce more severely pathological injuries to the kidney, liver, and spleen of mice compared to copper at micrometer size. On the other hand, a few studies have shown that copper ions could induce protein damage, membrane damage, slight DNA damage, and cell death (Li et al 2013). Therefore, it is essential to determine the changes in physicochemical properties (e.g., size, dissolution, and aggregation) of NPs during toxicological exposure to correctly interpret the doseresponse relationships and to avoid inaccurate dose estimation and the misinterpretation of toxicity results.…”