Different toxicity mechanisms between bare and polymer-coated copper oxide nanoparticles in Lemna gibba

2014 ◽  
Vol 185 ◽  
pp. 219-227 ◽  
Author(s):  
François Perreault ◽  
Radovan Popovic ◽  
David Dewez
2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
François Perreault ◽  
Abdallah Oukarroum ◽  
Laura Pirastru ◽  
Louka Sirois ◽  
William Gerson Matias ◽  
...  

Copper oxide nanoparticles (CuO NPs), used in antifouling paints of boats, are released in the environment and can induce toxicity to aquatic organisms. In this report, we used chlorophyll a fluorescence imaging to evaluate CuO NPs toxicity in Lemna gibba. This approach allowed to evaluate the differential effect of CuO NPs on photosynthesis of whole L. gibba plants. Exposure to 0.1 to 0.4 g/L CuO NPs during 48h induced strong inhibition of photosynthetic processes resulting in a decrease of plant growth. By using fluorescence imaging, different photosynthetic parameters were evaluated simultaneously in microplate conditions. Imaging of FO fluorescence yield showed the decrease of leaf photosynthetic active surface for whole plants exposed to CuO NPs. This method showed that CuO NPs inhibited photosystem II maximal, photosystem II operational quantum yields, and photochemical quenching of fluorescence associated with electron transport. Nonphotochemical fluorescence quenching as an indicator of energy dissipation not used in photosynthesis was shown to be increased by the effect of CuO NPs. Such approach in microplate conditions provides synchronous high repetition measurements for numerous plants. This study may give a reliable methodological approach to evaluate toxicity risk of NPs in aquatic ecosystems.


2021 ◽  
Vol 22 (7) ◽  
pp. 3688
Author(s):  
Tiantian Xiong ◽  
Shasha Zhang ◽  
Zhuangzhuang Kang ◽  
Ting Zhang ◽  
Shaoshan Li

Understanding the complex mechanisms involved in plant response to nanoparticles (NPs) is indispensable in assessing the environmental impact of nano-pollutants. Plant leaves can directly intercept or absorb NPs deposited on their surface; however, the toxicity mechanisms of NPs to plant leaves are unclear. In this study, lettuce leaves were exposed to copper oxide nanoparticles (CuO-NPs, 0, 100, and 1000 mg/L) for 15 days, then physiological tests and transcriptomic analyses were conducted to evaluate the negative impacts of CuO-NPs. Both physiological and transcriptomic results demonstrated that CuO-NPs adversely affected plant growth, photosynthesis, and enhanced reactive oxygen species (ROS) accumulation and antioxidant system activity. The comparative transcriptome analysis showed that 2270 and 4264 genes were differentially expressed upon exposure to 100 and 1000 mg/L CuO-NPs. Gene expression analysis suggested the ATP-binding cassette (ABC) transporter family, heavy metal-associated isoprenylated plant proteins (HIPPs), endocytosis, and other metal ion binding proteins or channels play significant roles in CuO-NP accumulation by plant leaves. Furthermore, the variation in antioxidant enzyme transcript levels (POD1, MDAR4, APX2, FSDs), flavonoid content, cell wall structure and components, and hormone (auxin) could be essential in regulating CuO-NPs-induced stress. These findings could help understand the toxicity mechanisms of metal NPs on crops, especially NPs resulting from foliar exposure.


Author(s):  
Haider Qassim Raheem ◽  
Takwa S. Al-meamar ◽  
Anas M. Almamoori

Fifty specimens were collected from wound patients who visited Al-Hilla Teaching Hospital. The samples were grown on Blood and MacConkey agar for 24-48 hr at 37oC. The bacterial isolates which achieved as a pure and predominant growth from clinical samples as Pseudomonas fluorescens, were identified using morphological properties and Vitek2 system. The anti-bacterial activity of copper oxide nanoparticles (CuO NPs) against was tested by (disk diffusion assay) using dilutions of (400, 200, 100, 50, 25, and 12.5‎µ‎g/ml). The (MIC and MBC) of each isolate was determined. CuO NPs shows wide spectrum antibacterial activity against tested bacteria with rise zone of inhibition diameter that is proportionate with the increase in nanoparticle concentration. The MIC of CuO NPs extended from 100-200‎µ‎g/ml and the MBC ranged from 200-400‎µ‎g/ml. The antibiotic profile was determined by Viteck 2 compact system (Biomérieux). CuO NPs‎ found highly effective and safe in P. fluorescens wounds infections comparing with used antibiotics.


2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Hemalatha D ◽  
Saraswath S

In material science, green method for synthesis of nanomaterials is feasible, cheaper and eco-friendly protocol. To accomplish this phenomenon, present study was aimed to synthesize Copper oxide nanoparticles using leaf extract of Aloevera with two different precursors CuCl2.2H2O (Cupric chloride) and CuSo4.5H2O (Cupric sulfate). The extraction of Aloevera is employed as reducing and stabilizing agent for this synthesis.Copper oxide Nanoparticles is effective use of biomedical application due to their antibacterial function. The synthesized Copper oxide nanoparticles were characterized by X-Ray Diffraction Spectroscopy (XRD), Energy Dispersive Spectroscopy (EDX), FourierTransform Infrared Spectroscopy (FT- IR) and Scanning Electron Microscope(SEM). XRD studies reveal the crystallographic nature of Copper oxide nanoparticles. Furthermore the Copper oxide nanoparticles have good Antibacterial activity against both gram negative (E.Coli, Klebsiella pneumonia) and gram positive (Bacillus cereus, Staphylococcus aureus)bacteria.


Author(s):  
Monika Vats ◽  
Shruti Bhardwaj ◽  
Arvind Chhabra

Background & Objective: Nanoparticles are used in cosmetic and dermatologic products, due to better skin penetration properties. Incorporation of natural products exhibiting medicinal properties in nano-preparations could significantly improve efficacy of these products and improve the quality of life without the side effects of synthetic formulations. Methods: We here report green synthesis of Copper Oxide nanoparticles, using Cucumber extract, and their detailed biophysical and bio-chemical characterization. Results: These Copper Oxide-Cucumber nanoparticles exhibit significant anti-bacterial and anti-fungal properties, Ultra Violet-radiation protection ability and reactive-oxygen species inhibition properties. Importantly, these nanoparticles do not exhibit significant cellular toxicity and, when incorporated in skin cream, exhibit skin rejuvenating properties. Conclusion: Our findings have implications for nanoparticle-based cosmetics and dermatologic applications.


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