Ecotoxicological effects and mechanism of CuO nanoparticles to individual organisms

Recent advances on environmental behavior of Cu-based nanomaterials in soil-plant system: A review

In recent years, copper-based nanomaterials (Cu-based NMs) have shown great potential in promoting agriculture development due to their special physicochemical characteristics. With the mass production and overuse of Cu-based NMs, there are potential effects on the soil-plant environment. Soil organisms, especially soil microorganisms, play a significant part in terrestrial or soil ecosystems; plants, as indirect organisms with soil-related Cu-based NMs, may affect human health through plant agricultural products. Understanding the accumulation and transformation of Cu-based NMs in soil-plant systems, as well as their ecotoxicological effects and potential mechanisms, is a prerequisite for the scientific assessment of environmental risks and safe application. Therefore, based on the current literature, this review: (i) introduces the accumulation and transformation behaviors of Cu-based NMs in soil and plant systems; (ii) focuses on the ecotoxicological effects of Cu-based NMs on a variety of organisms (microorganisms, invertebrates, and plants); (iii) reveals their corresponding toxicity mechanisms. It appears from studies hitherto made that both Cu-based NMs and released Cu2+ may be the main reasons for toxicity. When Cu-based NMs enter the soil-plant environment, their intrinsic physicochemical properties, along with various environmental factors, could also affect their transport, transformation, and biotoxicity. Therefore, we should push for intensifying the multi-approach research that focuses on the behaviors of Cu-based NMs in terrestrial exposure environments, and mitigates their toxicity to ensure the promotion of Cu-based NMs.

Copper-based nanomaterials: Opportunities for sustainable agriculture

The exponential growth of the global population has resulted in a significant surge in the demand for food worldwide. Additionally, the impact of climate change has exacerbated crop losses caused by pests and pathogens. The transportation and utilization of traditional agrochemicals in the soil are highly inefficient, resulting in significant environmental losses and causing severe pollution of both the soil and aquatic ecosystems. Nanotechnology is an emerging field with significant potential for market applications. Among metal-based nanomaterials, copper-based nanomaterials have demonstrated remarkable potential in agriculture, which are anticipated to offer a promising alternative approach for enhancing crop yields and managing diseases, among other benefits. This review firstly performed co-occurrence and clustering analyses of previous studies on copper-based nanomaterials used in agriculture. Then a comprehensive review of the applications of copper-based nanomaterials in agricultural production was summarized. These applications primarily involved in nano-fertilizers, nano-regulators, nano-stimulants, and nano-pesticides for enhancing crop yields, improving crop resistance, promoting crop seed germination, and controlling crop diseases. Besides, the paper concluded the potential impact of copper-based nanomaterials on the soil micro-environment, including soil physicochemical properties, enzyme activities, and microbial communities. Additionally, the potential mechanisms were proposed underlying the interactions between copper-based nanomaterials, pathogenic microorganisms, and crops. Furthermore, the review summarized the factors affecting the application of copper-based nanomaterials, and highlighted the advantages and limitations of employing copper-based nanomaterials in agriculture. Finally, insights into the future research directions of nano-agriculture were put forward. The purpose of this review is to encourage more researches and applications of copper-based nanomaterials in agriculture, offering a novel and sustainable strategy for agricultural development.

Bafi A1 inhibits nano-copper oxide-induced mitochondrial damage by reducing the release of copper from lysosomes

This study demonstrated that both copper oxide nanoparticles (CuO-NPs) and copper nanoparticles (Cu-NPs) can cause swelling, inflammation, and cause damage to the mitochondria of alveolar type II epithelial cells in mice. Cellular examinations indicated that both CuO-NPs and Cu-NPs can reduce cell viability and harm the mitochondria of human bronchial epithelial cells, particularly Beas-2B cells. However, it is clear that CuO-NPs exhibit a more pronounced detrimental effect compared with Cu-NPs. Using bafilomycin A1 (Bafi A1), an inhibitor of lysosomal acidification, was found to enhance cell viability and alleviate mitochondrial damage caused by CuO-NPs. Additionally, Bafi A1 also reduces the accumulation of dihydrolipoamide S-acetyltransferase (DLAT), a marker for mitochondrial protein toxicity, induced by CuO-NPs. This observation suggests that the toxicity of CuO-NPs depends on the distribution of copper particles within cells, a process facilitated by the acidic environment of lysosomes. The release of copper ions is thought to be triggered by the acidic conditions within lysosomes, which aligns with the lysosomal Trojan horse mechanism. However, this association does not seem to be evident with Cu-NPs.

Impact of nanopollution on plant growth, photosynthesis, toxicity, and metabolism in the agricultural sector: An updated review

Nanotechnology provides distinct benefits to numerous industrial and commercial fields, and has developed into a discipline of intense interest to researchers. Nanoparticles (NPs) have risen to prominence in modern agriculture due to their use in agrochemicals, nanofertilizers, and nanoremediation. However, their potential negative impacts on soil and water ecosystems, as well as plant growth and physiology, have caused concern for researchers and policymakers. Concerns have been expressed regarding the ecological consequences and toxicity effects associated with nanoparticles as a result of their increased production and usage. Moreover, the accumulation of nanoparticles in the environment poses a risk, not only because of the possibility of plant damage but also because nanoparticles may infiltrate the food chain. In this review, we have documented the beneficial and detrimental effects of NPs on seed germination, shoot and root growth, plant biomass, and nutrient assimilation. Nanoparticles exert toxic effects by inducing ROS generation and stimulating cytotoxic and genotoxic effects, thereby leading to cell death in several plant species. We have provided possible mechanisms by which nanoparticles induce toxicity in plants. In addition to the toxic effects of NPs, we highlighted the importance of nanomaterials in the agricultural sector. Thus, understanding the structure, size, and concentration of nanoparticles that will improve plant growth or induce plant cell death is essential. This updated review reveals the multifaceted connection between nanoparticles, soil and water pollution, and plant biology in the context of agriculture.

"From shadows to shores"-quantitative analysis of CuO nanoparticle-induced apoptosis and DNA damage in fish erythrocytes: A multimodal approach combining experimental, image-based quantification, docking and molecular dynamics

The usage of copper (II) oxide nanoparticles (CuO NPs) has significantly expanded across industries and biomedical fields. However, the potential toxic effects on non-target organisms and humans lack comprehensive understanding due to limited research on molecular mechanisms. With this study, by combining the 96 h in vivo exposure of crucian carp fish, Carassius carassius, to sub-lethal CuO NPs doses (0.5 and 1 mg/dL) with image-based quantification, and docking and molecular dynamics approaches, we aimed to understand the mechanism of CuO NPs-induced cyto-genotoxicity in the fish erythrocytes. The results revealed that both doses of copper NPs used were toxic to erythrocytes causing oxidative stress response and serious red blood cell morphological abnormalities, and genotoxicity. Docking and 10-ns molecular dynamics confirmed favorable interactions (ΔG = -2.07 kcal mol-1) and structural stability of Band3-CuO NP complex, mainly through formation of H-bonds, implying the potential of CuO NPs to induce mitotic nuclear abnormalities in C. carassius erythrocytes via Band3 inhibition. Moreover, conventional and multiple ligand simultaneous docking with DNA revealed that single, double and triple CuO NPs bind preferentially to AT-rich regions consistently in the minor grooves of DNA. Of note, the DNA-binding strength subtantially increased (ΔG = -2.13 kcal mol-1, ΔG = -4.08 kcal mol-1, and ΔG = -6.03 kcal mol-1, respectively) with an increasing number of docked CuO NPs, suggesting that direct structural perturbation on DNA could also count for the molecular basis of in-vivo induced DNA damage in C. carassius erythrocytes. This study introduces the novel term "erythrotope" to describe comprehensive red blood cell morphological abnormalities. It proves to be a reliable and cost-effective biomarker for evaluating allostatic erythrocyte load in response to metallic nanoparticle exposure, serving as a distinctive fingerprint to assess fish erythrocyte health and physiological fitness.

Advanced nanopesticides: Advantage and action mechanisms

The use of various chemical substances to control pests, diseases, and weeds in the field is a necessary part of the agricultural development process in every country. While the application of pesticides can improve the quality and yield of crops, plant resistance and the harm caused by pesticide residues to the environment and humans have led to the search for greener and safer pesticide formulations to improve the current situation. In recent years, nanopesticides (NPts) have shown great potential in agriculture due to their high efficiency, low toxicity, targeting, resistance, and controlled slow release demonstrated in the experimental stage. Commonly used approaches to prepare NPts include the use of nanoscale metal materials as active ingredients (AI) (ingredients that can play a role in insecticide, sterilization and weeding) or the construction of carriers based on commonly used pesticides to make them stable in nano-sized form. This paper systematically summarizes the advantages and effects of NPts over conventional pesticides, analyzes the formation and functions of NPts in terms of structure, AI, and additives, and describes the mechanism of action of NPts. Despite the feasibility of NPts use, there is not enough comprehensive research on NPts, which must be supplemented by more experiments in terms of biotoxicology and ecological effects to provide strong support for NPts application.

Biotic and Abiotic Interactions in Freshwater Mesocosms Determine Fate and Toxicity of CuO Nanoparticles

Transformation, dissolution, and sorption of copper oxide nanoparticles (CuO-NP) play an important role in freshwater ecosystems. We present the first mesocosm experiment on the fate of CuO-NP and the dynamics of the zooplankton community over a period of 12 months. Increasingly low (0.08-0.28 mg Cu L-1) and high (0.99-2.99 mg Cu L-1) concentrations of CuO-NP and CuSO4 (0.10-0.34 mg Cu L-1) were tested in a multiple dosing scenario. At the high applied concentration (CuO-NP_H) CuO-NP aggregated and sank onto the sediment layer, where we recovered 63% of Cu applied. For the low concentration (CuO-NP_L) only 41% of applied copper could be recovered in the sediment. In the water column, the percentage of initially applied Cu recovered was on average 3-fold higher for CuO-NP_L than for CuO-NP_H. Zooplankton abundance was substantially compromised in the treatments CuSO4 (p < 0.001) and CuO-NP_L (p < 0.001). Community analysis indicated that Cladocera were most affected (bk = -0.49), followed by Nematocera (bk = -0.32). The abundance of Cladocera over time and of Dixidae in summer was significantly reduced in the treatment CuO-NP_L (p < 0.001; p < 0.05) compared to the Control. Our results indicate a higher potential for negative impacts on the freshwater community when lower concentrations of CuO-NP (<0.1 mg Cu L-1) enter the ecosystem.

Bacterial cell permeability study by metal oxide and mixed metal oxide nanoparticles: analysis of the factors contributing to the antibacterial activity of nanoparticles

In this work, we investigate the nanoparticle-cell wall interaction by NiO and mixed metal oxide CuO-NiO nanoparticles. We have synthesized and characterized the nanoparticles using XRD, FESEM, EDS, UV vis. spectroscopy, FTIR, Zeta, and TEM analysis in our previous work. Furthermore, a preliminary antibacterial study showed that both the nanoparticles performed very well as antibacterial agents. In this extended work, we investigate the mechanism of interaction of NiO and CuO-NiO nanoparticles with S. aureus and E. coli cells as there are number of studies for antibacterial mechanism of CuO nanoparticles. The uptake of crystal violet dye in the outer bacterial membrane, the release of ß-galactosidase enzyme, and relative electric conductivity assay were used to investigate changes in the permeability and integrity of the cell membrane. Superoxide ions, which are produced intracellularly as ROS by nanoparticles, severely damage bacterial membranes. Zeta potential measurement, which resulted in surface charge neutralization, proved membrane instability. FTIR analysis was used to identify changes in the proteins, carbohydrates, and fatty acids that make up the chemical composition of cell surfaces. AFM imaging demonstrated extensive alteration of the nanomechanical and surface characteristics. Confocal microscopy examination supported the DNA fragmentation and nanoparticle-cell adhesion. Due to their enhanced antibacterial activity when compared to monometallic oxide nanoparticles, this study demonstrated that mixed metal oxides can be employed in the health and biomedical sectors.

A Review of the Antibacterial, Fungicidal and Antiviral Properties of Selenium Nanoparticles

The resistance of microorganisms to antimicrobial drugs is an important problem worldwide. To solve this problem, active searches for antimicrobial components, approaches and therapies are being carried out. Selenium nanoparticles have high potential for antimicrobial activity. The relevance of their application is indisputable, which can be noted due to the significant increase in publications on the topic over the past decade. This review of research publications aims to provide the reader with up-to-date information on the antimicrobial properties of selenium nanoparticles, including susceptible microorganisms, the mechanisms of action of nanoparticles on bacteria and the effect of nanoparticle properties on their antimicrobial activity. This review describes the most complete information on the antiviral, antibacterial and antifungal effects of selenium nanoparticles.

Copper oxide nanoparticles: In vitro and in vivo toxicity, mechanisms of action and factors influencing their toxicology

Copper oxide nanoparticles (CuO NPs) have received increasing interest due to their distinctive properties, including small particle size, high surface area, and reactivity. Due to these properties, their applications have been expanded rapidly in various areas such as biomedical properties, industrial catalysts, gas sensors, electronic materials, and environmental remediation. However, because of these widespread uses, there is now an increased risk of human exposure, which could lead to short- and long-term toxicity. This review addresses the underlying toxicity mechanisms of CuO NPs in cells which include reactive oxygen species generation, leaching of Cu ion, coordination effects, non-homeostasis effect, autophagy, and inflammation. In addition, different key factors responsible for toxicity, characterization, surface modification, dissolution, NPs dose, exposure pathways and environment are discussed to understand the toxicological impact of CuO NPs. In vitro and in vivo studies have shown that CuO NPs cause oxidative stress, cytotoxicity, genotoxicity, immunotoxicity, neurotoxicity, and inflammation in bacterial, algal, fish, rodents, and human cell lines. Therefore, to make CuO NPs a more suitable candidate for various applications, it is essential to address their potential toxic effects, and hence, more studies should be done on the long-term and chronic impacts of CuO NPs at different concentrations to assure the safe usage of CuO NPs.

Prepubertal exposure to copper oxide nanoparticles induces Leydig cell injury with steroidogenesis disorders in mouse testes

Copper oxide nanoparticles (CuONPs) are metallic multifunctional nanoparticles with good conductive, catalytic and antibacterial characteristics that have shown to cause reproductive dysfunction. However, the toxic effect and potential mechanisms of prepubertal exposure to CuONPs on male testicular development have not been clarified. In this study, healthy male C57BL/6 mice received 0, 10, and 25 mg/kg/d CuONPs by oral gavage for 2 weeks (postnatal day 22-35). The testicular weight was decreased, testicular histology was disturbed and the number of Leydig cells was reduced in all CuONPs-exposure groups. Transcriptome profiling suggested steroidogenesis was impaired after exposure to CuONPs. The steroidogenesis-related genes mRNA expression level, concentration of serum steroids hormones and the HSD17B3-, STAR- and CYP11A1-positive Leydig cell numbers were dramatically reduced. In vitro, we exposed TM3 Leydig cells to CuONPs. Bioinformatic analysis, flow cytometry analysis and western blotting analysis confirmed that CuONPs can dramatically reduce Leydig cells viability, enhance apoptosis, trigger cell cycle arrest and reduce cell testosterone levels. U0126 (ERK1/2 inhibitor) significantly reversed TM3 Leydig cells injury and testosterone level decrease induced by CuONPs. These outcomes indicate that CuONPs exposure activates the ERK1/2 signaling pathway, which further promotes apoptosis and cell cycle arrest in TM3 Leydig cells, and ultimately leads to Leydig cells injury and steroidogenesis disorders.

Antagonism toxicity of CuO nanoparticles and mild ocean acidification to marine algae

The toxicity of CuO nanoparticles (NPs) to marine microalgae (Emiliania huxleyi) under ocean acidification (OA) conditions (pHs 8.10, 7.90, 7.50) was investigated. CuO NPs (5.0 mg/L) caused significant toxicity (e.g., 48-h growth inhibition, 20%) under normal pH (8.10), and severe OA (pH 7.50) increased the toxicity of CuO NPs (e.g., 48-h growth inhibition, 68%). However, toxicity antagonism was observed with a growth inhibition (48 h) decreased to 37% after co-exposure to CuO NPs and mild OA (pH 7.90), which was attributed to the released Cu²⁺ ions from CuO NPs. Based on biological responses as obtained from RNA-sequencing, the dissolved Cu²⁺ ions (0.078 mg/L) under mild OA were found to increase algae division (by 17%) and photosynthesis (by 28%) through accelerating photosynthetic electron transport and promoting ATP synthesis. In addition, mild OA enhanced EPS secretion by 41% and further increased bioavailable Cu²⁺ ions, thus mitigating OA-induced toxicity. In addition, excess Cu²⁺ ions could be transformed into less toxic Cu₂S and Cu₂O based on X-ray absorption near-edge spectroscopy (XANES) and high-resolution transmission electron microscopy (HR-TEM), which could additionally regulate the antagonism effect of CuO NPs and mild OA. The information advances our knowledge in nanotoxicity to marine organisms under global climate change.

Nonmonotonic effect of CuO nanoparticles on medium-chain carboxylates production from waste activated sludge

The growing applications of CuO nanoparticles (NPs) in industrial and agriculture has increased their concentrations in wastewater and subsequently accumulated in waste activated sludge (WAS), raising concerns about their impact on reutilization of WAS, especially on the medium-chain carboxylates (MCCs) production from anaerobic fermentation of WAS. Here we showed that CuO NPs at 10-50 mg/g-TS can significantly inhibit MCCs production, and reactive oxygen species generation was revealed to be the key factor linked to the phenomena. At lower CuO NPs concentrations (0.5-2.5 mg/g-TS), however, MCCs production was enhanced, with a maximum level of 37% compared to the control. The combination of molecular approaches and metaproteomic analysis revealed that although low dosage CuO NPs (2.5 mg/g-TS) weakly inhibited chain elongation process, they displayed contributive characteristics both in WAS solubilization and transport/metabolism of carbohydrate. These results demonstrated that the complex microbial processes for MCCs production in the anaerobic fermentation of WAS can be affected by CuO NPs in a dosage-dependent manner via regulating microbial protein expression level. Our findings can provide new insights into the influence of CuO NPs on anaerobic fermentation process and shed light on the treatment option for the resource utilization of CuO NPs polluted WAS.

OsCERK1 Contributes to Cupric Oxide Nanoparticles Induced Phytotoxicity and Basal Resistance against Blast by Regulating the Anti-Oxidant System in Rice

CuO NPs (cupric oxide nanoparticles) are widely used in various fields due to their high electrical conductivity, electronic correlation effect, and special physical property. Notably, CuO NPs have good application prospects in agricultural production because of its antifungal activity to prevent crop diseases. However, the increasing release of CuO NPs into the environment has resulted in a serious threat to the ecosystem, including plants. Previous studies have reported the toxicity of CuO NPs on rice, but little is known about the underlying molecular mechanisms or specific genes involved in the response to CuO NPs. In this study, we found that the rice well-known receptor Chitin Elicitor Receptor Kinase 1 (OsCERK1), which is essential for basal resistance against pathogens, is involved in CuO NPs stress in rice. Knockout of OsCERK1 gene resulted in enhanced tolerance to CuO NPs stress. Furthermore, it was revealed that OsCERK1 reduces the tolerance to CuO NPs stress by regulating the anti-oxidant system and increasing the accumulation of H₂O₂ in rice. In addition, CuO NPs treatment significantly enhances the basal resistance against M. oryzae which is mediated by OsCERK1. In conclusion, this study demonstrated a dual role of OsCERK1 in response to CuO NPs stress and M. oryzae infection by modulating ROS accumulation, which expands our understanding about the crosstalk between abiotic and biotic stresses.

Clay Types Modulate the Toxicity of Low Concentrated Copper Oxide Nanoparticles Toward Springtails in Artificial Test Soils

Copper oxide nanoparticles (CuO-NPs) can be applied as an efficient alternative to conventional Cu in agriculture. Negative effects of CuO-NPs on soil organisms were found, but only in clay-rich loamy soils. It is hypothesized that clay-NP interactions are the origin of the observed toxic effects. In the present study, artificial Organisation for Economic Co-operation and Development soils containing 30% of kaolin or montmorillonite as clay type were spiked with 1-32 mg Cu/kg of uncoated CuO-NPs or CuCl₂ . We performed 28-day reproduction tests with springtails of the species Folsomia candida and recorded the survival, reproduction, dry weight, and Cu content of adults. In a second experiment, molting frequency and the Cu content of exuviae, as well as the biochemical endpoints metallothionein and catalase (CAT) in springtails, were investigated. In the reproduction assay, negative effects on all endpoints were observed, but only in soils containing montmorillonite and mostly for CuO-NPs. For the biochemical endpoints and Cu content of exuviae, effects were clearly distinct between Cu forms in montmorillonite soil, but a significant reduction compared to the control was only found for CAT activity. Therefore, the reduced CAT activity in CuO-NP-montmorillonite soil might be responsible for the observed toxicity, potentially resulting from reactive oxygen species formation overloading the antioxidant system. This process seems to be highly concentration-dependent, because all endpoints investigated in reproduction and biochemical assays of CuO-NP-montmorillonite treatments showed a nonlinear dose-response relationship and were constantly reduced by approximately 40% at a field-realistic concentration of 3 mg/kg, but not at 32 mg/kg. The results underline that clay-CuO-NP interactions are crucial for their toxic behavior, especially at low, field-realistic concentrations, which should be considered for risk assessment of CuO-NPs. Environ Toxicol Chem 2022;41:2454-2465. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Exogenous iron alters uptake and translocation of CuO nanoparticles in soil-rice system: A life cycle study

The abundant iron in farmland soil may affect the environmental fate of metal-based nanoparticles (MNPs). In this study, the effect of FeSO4 and nano-zero-valent iron (nZVI) as exogenous iron on the uptake and translocation of CuO nanoparticles (NPs) in soil-rice system was performed in a life cycle study. The results show that exogenous iron basically elevated the soil pH and electrical conductivity but lowered the redox potential. Moreover, the Cu bioavailability in soil was significantly increased by 86-269% with exogenous iron at the tillering stage, while was reduced by 15-45% with medium and high concentrations of Fe(II) at the maturation stage. Meanwhile, the addition of exogenous iron resolved the unfilling of grains caused by CuO NPs. Notably, except for highest Fe(II) treatment, both Fe(II) and nZVI reduced Cu accumulation from 31% to 84% in roots and leaves due to more iron plaque. Especially, medium Fe(II) level markedly decreased the Cu content in the brown rice. μ-XRF analysis suggests that high intensity of Cu was primarily located in the rice hull and embryo under Fe(II) treatment. The reduction of CuO NPs to Cu2O caused by Fe(II) can explain the positive effect of exogenous iron on controlling the environmental risk of MNPs.

Cell-Type-Dependent Dissolution of CuO Nanoparticles and Efflux of Cu Ions following Cellular Internalization

CuO nanoparticles (NPs) show promising applications in biosensors, waste treatment, and energy materials, but the growing manufacture of CuO NPs also leads to the concerns for their potential environmental and health risks. However, the cellular fates of CuO NPs such as Cu ion dissolution, transformation, and efflux remain largely speculative. In the present study, we for the first time combined the gold-core labeling and Cu ion bioimaging technologies to reveal the intracellular fates of CuO NPs in different cells following cellular internalization of NPs. We demonstrated that the dissolution rate of CuO NPs depended on the cell type. Following CuO dissolution, limited transformation of Cu(II) to Cu(I) occurred within the cellular microenvironment. Instead, Cu(II) was rapidly eliminated from the cells, and such rapid efflux in different cells was highly dependent on the GSH-mediated pathway and lysosome exocytosis. The labile Cu(I) level in the two cancerous cell lines was immediately regulated upon Cu exposure, which explained their tolerance to Au@CuO NPs. Overall, our study demonstrated a very rapid turnover of Cu in the cells following CuO internalization, which subsequently determined the cellular toxicity of CuO. The results will have important implications for assessing the health risk of CuO NPs.

In vivo phytotoxic effect of yttrium-oxide nanoparticles on the growth, uptake and translocation of tomato seedlings (Lycopersicon esculentum)

The potential toxicity and ecological risks of rare-earth nanoparticles in the environment have become a concern due to their widespread application and inevitable releases. The integration of hydroponics experiments, partial least squares structural equation modeling (PLS-SEM), and Transmission Electron Microscopy (TEM) were utilized to investigate the physiological toxicity, uptake and translocation of yttrium oxide nanoparticles (Y₂O₃ NPs) under different hydroponic treatments (1, 5, 10, 20, 50 and 100 mg·L^-1 of Y₂O₃ NPs, 19.2 mg·L^-1 Y(NO₃)₃ and control) in tomato (Lycopersicon esculentum) seedlings. The results indicated that Y₂O₃ NPs had a phytotoxic effect on tomato seedlings' germination, morphology, physiology, and oxidative stress. The Y₂O₃ NPs and soluble Y^III reduced the root elongation, bud elongation, root activity, chlorophyll, soluble protein content and superoxide dismutase and accelerated the proline and malondialdehyde in the plant with increasing concentrations. The phytotoxic effects of Y₂O₃ NPs on tomato seedlings had a higher phytotoxic effect than soluble Y^III under the all treatments. The inhibition rates of different levels of Y₂O₃ NPs in shoot and root biomass ranged from 0.2% to 6.3% and 1.0-11.3%, respectively. The bioaccumulation and translocation factors were less than 1, which suggested that Y₂O₃ NPs significantly suppressed shoot and root biomass of tomato seedlings and easily bioaccumulated in the root. The observations were consistent with the process of concentration-dependent uptake and translocation factor and confirmed by TEM. Y₂O₃ NPs penetrate the epidermis, enter the cell wall, and exist in the intercellular space and cytoplasm of mesophyll cells of tomato seedlings by endocytic pathway. Moreover, PLS-SEM revealed that the concentration of NPs significantly negatively affects the morphology and physiology, leading to the change in biomass of plants. This study demonstrated the possible pathway of Y₂O₃ NPs in uptake, phytotoxicity and translocation of Y₂O₃ NPs in tomato seedlings.

One-step Green Fabrication of Antimicrobial Surfaces via In Situ Growth of Copper Oxide Nanoparticles

Microorganisms such as pathogenic bacteria, fungi, and viruses pose a serious threat to human health and society. Surfaces are one of the major pathways for the transmission of infectious diseases. Therefore, imparting antipathogenic properties to these surfaces is significant. Here, we present a rapid, one-step approach for practical fabrication of antimicrobial and antifungal surfaces using an eco-friendly and low-cost reducing agent, the extract of Cedrus libani. Copper oxide nanoparticles were grown in situ on the surface of print paper and fabric in the presence of the copper salt and extract, without the use of any additional chemicals. The morphology and composition of the grown nanoparticles were characterized using field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction techniques. The analysis revealed that the grown particles consist of mainly spherical CuO nanoparticles with an average size of ∼14 nm and its clusters with an average size of ∼700 nm. The in situ growth process enables strong bonding of the nanoparticles to the surface, resulting in enhanced durability against wear and tear. Moreover, the fabricated surface shows excellent growth inhibition ability and bactericidal activity against both gram-negative and gram-positive bacteria, Escherichia coli and Staphylococcus aureus, as well as antifungal activity against Candida albicans, a common pathogenic fungus. The ability to grow copper oxide nanoparticles on different surfaces paves the way for a range of applications in wound dressings, masks, and protective medical equipment.

Synthesis of CuO nanoparticles stabilized with gelatin for potential use in food packaging applications

In the present study, a method for the synthesis of gelatin-stabilized copper oxide nanoparticles was developed. Synthesis was carried out by direct chemical precipitation. Copper sulfate, chloride, and acetate were used as precursors for the copper oxide synthesis. Gelatin was used as a stabilizer. It was found that the formation of monophase copper oxide II only occurred when copper acetate was used as a precursor. Our results showed that particles of the smallest diameter are formed in an aqueous medium (18 ± 6 nm), and those of th largest diameter—in an isobutanol medium (370 ± 131 nm). According to the photon correlation spectroscopy data, copper oxide nanoparticles synthesized in an aqueous medium were highly stable and had a monomodal size distribution with an average hydrodynamic radius of 61 nm. The study of the pH effect on the colloidal stability of copper oxide nanoparticles showed that the sample was stable in the pH range of 6.8 to 11.98. A possible mechanism for the pH influence on the stability of copper oxide nanoparticles is described. The effect of the ionic strength of the solution on the stability of the CuO nanoparticles sol was also studied, and the results showed that Ca²⁺ ions had the greatest effect on the sample stability. IR spectroscopy showed that the interaction of CuO nanoparticles with gelatin occurred through the hydroxyl group. It was found that CuO nanoparticles stabilized with gelatin have a fungicidal activity at concentration equivalent 2.5 · 10⁻³ mol/L and as a material for food nanopackaging can provide an increase in the shelf life of products on the example of strawberries and tomatoes. We investigated the possibility of using methylcellulose films modified with CuO nanoparticles for packaging and storage of hard cheese “Holland”. The distribution of CuO nanoparticles in the methylcellulose film was uniform. We found that methylcellulose films modified with CuO nanoparticles inhibited the growth and development of QMAFAM, coliforms, yeast and mold in experimental cheese sa mples. Our research has shown that during the cheese storage in thermostat at 35 ± 1 °C for 7 days, CuO nanoparticles migrated to the product from the film. Nevertheless, it is worth noting that the maximum change in the concentration of copper in the experimental samples was only 0.12 µg/mg, which is not a toxic concentration. In general, the small value of migration of CuO nanoparticles confirms the high stability of the developed preparation. Our results indicated that the CuO nanoparticles stabilized with gelatin have a high potential for use in food packaging – both as an independent nanofilm and as part of other packaging materials.

Behavior and toxicity assessment of copper nanoparticles in aquatic environment: A case study on red swamp crayfish

With the wide use of copper nanoparticles (CuNPs) in various industrial and commercial applications, they inevitably enter the aquatic environment. However, their behavior in the aquatic environment and potential toxicity to aquatic organisms remain little known. In this study, we investigated the behavior of CuNPs in freshwater, as well as the toxicity and bioaccumulation of CuNPs and copper sulfate (CuSO₄), used as a positive control for copper ions toxicity, in red swamp crayfish (Procambarus clarkii). The results showed that CuNPs released copper ions into freshwater and aggregated rapidly in freshwater, and their release of copper ions and aggregation slowed down at a higher concentration of CuNPs. The calculated 72-h LC₅₀ values for crayfish were 1.18 and 0.54 mg/L for CuNPs and CuSO₄, respectively. Cu accumulation in the gill and hepatopancreas from CuSO₄ treatments was significantly higher than that from CuNPs, and the highest Cu bioaccumulation level in crayfish was found in the gill, followed by hepatopancreas and muscle with the exposure of copper. The activities of the antioxidative enzymes in the crayfish significantly decreased after exposure to CuNPs for 48 h, compared to the control (without CuNPs or CuSO₄). Histological examination revealed that there was no significant alteration of hepatopancreas in the crayfish exposed to CuNPs. Meanwhile, the growth of crayfish was not significantly inhibited by CuNPs. These results suggested that CuNPs exposure can induce oxidative stress in the crayfish, gill is the main tissue for their accumulation, and their toxicity is mainly caused by the released copper ions.

Copper II oxide nanoparticles (CuONPs) alter metabolic markers and swimming activity in zebra-fish (Danio rerio)

The present study aimed to compare the metabolic effects caused by using copper oxide nanoparticles with two distinct morphologies nanorods and nanosphere. The CuONPs in the form of nanorods were characterized in the order of 500 nm, on a scale of 20, 100, and 500 nm. Meanwhile, the nanosphere CuONPs were characterized in the order of 5 nm, on a 30 nm scale. The analysis of metabolic rate was performed using the closed respirometry technique, specific ammonia excretion, and swimming ability as biomarkers, the physiological effects on Danio rerio were investigated. For the experiments, 88 fish were used, exposed for 24 h at concentrations of 0, 50, 100, and 200 μg/L of copper oxide nanoparticles in the form of nanospheres and nanorods, respectively. The tests carried out with the nanorods demonstrated metabolic alterations in fish, with an increase of 294% and 321% in the metabolic rate at concentrations of 100 μg/L and 200 μg/L, respectively. Furthermore, there was a decrease in specific ammonia excretion by 34% and 83% and in swimming capacity by 34% and 55% at concentrations of 100 and 200 μg/L, respectively, when compared to the control. The tests performed with nanospheres did not show significant changes compared to the control. These experiments showed that different morphological structures of the same copper oxide nanoparticle caused different effects on fish metabolism. It is concluded that the characterization of nanoparticles is essential to understand their effects on fish, since their structural forms can cause different toxic effects on D. rerio.

CuO nanoparticles decorated on hydroxyapatite/ferrite magnetic support: photocatalysis, cytotoxicity, and antimicrobial response

Photocatalysts supported in magnetic nanocomposites for application in environmental remediation processes have been evaluated for removing contaminants due to easy recovery and low toxicity to the ecosystem. In this work, copper oxide (CuO) nanoparticles with photocatalytic properties were decorated on magnetic support constituted by hydroxyapatite (HAP) and ferrite to achieve efficiency in contaminated water remediation under visible light irradiation. First, nanomaterials were obtained by precipitation route, allowing fast and straightforward synthesis. Then, CuO nanoparticles with 6 nm diameter were efficiently decorated on magnetic support (25 nm), showing a high ability to absorb visible light irradiation (bandgap) to promote electronic transition and charge separation. Under visible irradiation, CuO promotes the H₂O₂ reduction in the conduction band (BC) to form hydroxyl radicals (^•OH), which are responsible for rhodamine B (RhB) dye degradation (> 90% in 60 min). Magnetic hysteresis assays confirmed the magnetic properties of HAP/ferrite support, which enabled the recovery and reuse of the magnetic photocatalyst efficiently up to 3 cycles. Due to low Cu²⁺ leaching after the photocatalytic application stage, cytotoxicity assay for the Allium cepa seeds did not exhibit abnormal cells other than those commonly found. Furthermore, the CuO-decorated nanoparticles showed bactericidal activity against S. aureus (Gram-positive) and E. coli (Gram-negative) microorganisms, being more significant for the first one. Thus, the developed nanocomposite of CuO nanoparticles decorated on the magnetic support surface showed to be a complete system for water remediation, acting in contaminant degradation under visible light irradiation and bactericidal control with environmentally friendly characteristics.Graphical abstract CuO nanoparticles decorated on hydroxyapatite/ferrite magnetic support acting as a photocatalytic and bactericidal system.

X-ray spectrometry imaging and chemical speciation assisting to understand the toxic effects of copper oxide nanoparticles on zebrafish (Danio rerio)

Currently, copper nanoparticles are used in various sectors of industry, agriculture, and medicine. To understand the effects induced by these nanoparticles, it is necessary to assess the environmental risk and safely expand their use. In this study, we evaluated the toxicity of copper oxide (nCuO) nanoparticles in Danio rerio adults, their distribution/concentration, and chemical form after exposure. This last assessment had never been performed on copper-exposed zebrafish. Such evaluation was done through the characterization of nCuO, acute exposure tests and analysis of distribution and concentration by microstructure X-ray fluorescence spectroscopy (µ-XRF) and atomic absorption spectroscopy (GF-AAS). Synchrotron X-ray absorption spectroscopy (XAS) was performed to find out the chemical form of copper in hotspots. The results show that the toxicity values of fish exposed to nCuO were 2.4 mg L^-1 (25 nm), 12.36 mg L^-1 (40 nm), 149.03 mg L^-1 (80 nm) and 0.62 mg L^-1 (CuSO₄, used as a positive control). The total copper found in the fish was in the order of mg kg^-1 and it was not directly proportional to the exposure concentration; most of the copper was concentrated in the gastric system. However, despite the existence of copper hotspots, chemical transformation of CuO into other compounds was not detected.

Exposure of adult sand dollars (Scaphechinus mirabilis) (Agassiz, 1864) to copper oxide nanoparticles induces gamete DNA damage

The increase in the number of products containing nanoparticles (NPs) poses a real threat to the environment. Recently, more evidence has been added to predictive models about the presence of NPs in various natural and anthropogenic systems. The acute toxicity of most aquatic NPs has now been well documented. However, data such as the ecotoxicological significance of the long-lasting effects of NPs on the reproductive system and gamete quality of aquatic organisms are still relatively scarce. Therefore, a 10-day experiment was carried out on the sand dollar Scaphechinus mirabilis (Agassiz, 1864) exposed to low (20 and 40 μg/L) concentrations of copper oxide nanoparticles (CuO NPs). An accumulation of copper in tissues and a significant increase in lipid peroxidation product concentrations after exposure to NP were observed. A significant decrease in the fertilization rate was shown at 40 μg/L. No significant changes in embryonic or larval development were found. However, comet analysis results showed a significant increase in DNA damage in spermatozoa exposed to CuO NPs, which may further manifest as negative effects at later developmental stages or in subsequent generations.

Impact of the Arbuscular Mycorrhizal Fungus Funneliformis mosseae on the Physiological and Defence Responses of Canna indica to Copper Oxide Nanoparticles Stress

Copper oxide nanoparticles (nano-CuO) are recognized as an emerging pollutant. Arbuscular mycorrhizal fungi (AMF) can mitigate the adverse impacts of various pollutants on host plants. However, AMF’s mechanism for alleviating nano-CuO phytotoxicity remains unclear. The goal of this study was to evaluate how AMF inoculations affect the physiological features of Canna indica seedlings exposed to nano-CuO stress. Compared with the non-AMF inoculated treatment, AMF inoculations noticeably improved plant biomass, mycorrhizal colonization, leaf chlorophyll contents, and the photosynthetic parameters of C. indica under nano-CuO treatments. Moreover, AMF inoculation was able to significantly mitigate nano-CuO stress by enhancing antioxidant enzyme activities and decreasing ROS levels in the leaves and roots of C. indica, thus increasing the expression of genes involved in the antioxidant response. In addition, AMF inoculation reduced the level of Cu in seedlings and was associated with an increased expression of Cu transport genes and metallothionein genes. Furthermore, AMF inoculations increased the expression levels of organic acid metabolism-associated genes while facilitating organic acid secretion, thus reducing the accumulation of Cu. The data demonstrate that AMF–plant symbiosis is a feasible biocontrol approach to remediate nano-CuO pollution.

Acute iron oxide nanoparticles exposure induced murine eosinophilic airway inflammation via TLR2 and TLR4 signaling

Iron oxide nanoparticles (Fe₂ O₃ NPs) is the main component of air pollution particles in urban rail transit environment. People are more exposed to Fe₂ O₃ NPs, however, the studies on relationship between Fe₂ O₃ NPs and respiratory health are limited. In the present study, acute airway inflammation caused by Fe₂ O₃ NPs and its possible mechanism were investigated. BALB/c mice were intratracheally challenged with different concentrations of Fe₂ O₃ NPs. Fe₂ O₃ NPs induced bronchial epithelial barrier function damage, infiltration of neutrophils and lymphocytes into the airway submucosa, secretion of mucus in the airway epithelium and elevated expression of eosinophil major basic protein (EMBP) in lungs. Compared with the control group, Fe₂ O₃ NPs increased eosinophils by 20 times in bronchoalveolar lavage fluid (BALF), and markedly increased eosinophils related cytokines and chemokines, including interleukin (IL) -5, IL-33, thymic stromal lymphopoietin (TSLP), monocyte chemotactic protein (MCP)-3, eotaxin, tumor necrosis factor (TNF)-α, keratinocyte chemoattractant (KC). Furthermore, Fe₂ O₃ NPs up-regulated levels of IL-5, MCP-3, eotaxin, and KC in serum. In vitro studies showed that Fe₂ O₃ NPs increased the genes and proteins expression of Toll-like receptors (TLR)-2, TLR4, TNF receptor associated factor 6 (TRAF6), myeloid differentiation factor 88 (MyD88), nuclear factor (NF)-κB, and TNF-α in RAW267.4 cells. The downstream inflammatory cytokine protein expression and release such as TNF-α was significantly decreased after using TLR2/TLR4 inhibitor OxPAPC, but not MyD88 inhibitor ST2825. These results suggest that TLR2 and TLR4 played important role in Fe₂ O₃ NPs inducing acute eosinophilic airway inflammation in the murine lung.

Effects of copper oxide nanoparticles on Salix growth, soil enzyme activity and microbial community composition in a wetland mesocosm

A model wetland with Salix was established to investigate the effects of CuO nanoparticles (NPs; the equivalent amount of Cu at 0, 100 and 500 mg/kg) on plant, soil enzyme activity and microbial community. Ionic Cu (100, 500 mg/kg) and bulk-sized CuO particles (BPs, 500 mg/kg) were included as controls. The results suggested the CuO NPs at 500 mg/kg and ionic Cu treatments inhibited the plant growth, while CuO NPs at 100 mg/kg and CuO BPs at 500 mg/kg played a facilitating role. CuO NPs significantly decreased the activities of peroxidase and polyphenol oxidase, while ionic Cu treatments increased peroxidase activity, BPs and ionic Cu (500 mg/kg) increased the polyphenol oxidase activity. Bacterial community richness and diversity were reduced in all Cu treatments; however, CuO NPs and BPs at 500 mg/kg significantly increased the richness and diversity of fungal community.Soil microbial community was significantly altered by Cu types and dose. In comparison with ionic Cu and CuO BPs, CuO NPs uniquely enriched the microbial community and the fungal families.Overall, it demonstrate that both particle size and dose regulate the impact of CuO on wetland ecology, which deepens our understanding on the ecological risks of CuO NPs in freshwater forested wetland.

The dichotomy of nanotechnology as the cutting edge of agriculture: Nano-farming as an asset versus nanotoxicity

The unprecedented setbacks and environmental complications, faced by global agro-farming industry, have led to the advent of nanotechnology in agriculture, which has been recognized as a novel and innovative approach in development of sustainable farming practices. The agricultural regimen is the "head honcho" of the world, however presently certain approaches have been imposing grave danger to the environment and human civilization. The nano-farming paradigm has successfully elevated the growth and development of plants, parallel to the production, quality, germination/transpiration index, photosynthetic machinery, genetic progression, and so on. This has optimized the traditional farming into precision farming, utilising nano-based sensors and nanobionics, smart delivery tools, nanotech facets in plant disease management, nanofertilizers, enhancement of plant adaptive potential to external stress, role in bioenergy conservation and so on. These applications portray nanorevolution as "the big cheese" of global agriculture, mitigating the bottlenecks of conventional practices. Besides the applications of nanotechnology, the review identifies the limitations, like possible harmful impact on environment, mankind and plants, as the "Achilles heel" in agro-industry, aiming to establish its defined role in agriculture, while simultaneously considering the risks, in order to resolve them, thus abiding by "technology-yes, but safety-must". The authors aim to provide a significant opportunity to the nanotech researchers, Botanists and environmentalists, to promote judicial use of nanoparticles and establish a secure and safe environment.

Effect of Copper Nanoparticles and Ions on Epididymis and Spermatozoa Viability of Chinese Soft-Shelled Turtles Pelodiscus sinensis

Copper nanoparticles (CuNPs) have been widely used in various industrial and commercial applications, which become a potential threat to aquatic organisms. Nevertheless, their potential toxicity to the epididymis and sperm remains little known. In this study, we evaluated the effect of CuNPs and copper ions (CuSO4) on the spermatozoa viability, epididymal structure, antioxidant enzyme activity, and inflammatory cytokines in cauda epididymis of the Chinese soft-shelled turtle. Results showed that the spermatozoa viability of Chinese soft-shelled turtles decreased significantly with an increase in CuNPs or Cu ions concentrations. The epithelial cells of the epididymal duct of the Chinese soft-shelled turtles with the treatment of 5 mg kg−1 CuNPs were slightly swollen, and the connective tissue between the epididymal ducts was loose. The epithelial structure of the epididymal tube was severely damaged with an increase in Cu ion concentrations. Compared to the control, the antioxidative enzymes activities and the expression of IL-1β, TNF-α, and IL-6 mRNA in the epididymis significantly increased with the treatment of CuNPs or CuSO4. The present study revealed that Cu ions exert more harmful effect on the epididymis and spermatozoa viability of Chinese soft-shelled turtles than copper nanoparticles.

Copper Nanoparticles: Synthesis and Characterization, Physiology, Toxicity and Antimicrobial Applications

Metallic nanoparticles are a new class of materials with applications in medicine, pharmaceutical and agriculture. Using biological, chemical and physical approaches, nanoparticles with amazing properties are obtained. Copper is one of the most-found elements and plays an important part in the normal functioning of organisms. Coper nanoparticles have superior antibacterial properties when comparing them to present day antibiotics. Moreover, apart from their antibacterial role, antifungal, antiviral and anticancer properties have been described. Although the mechanism of actions is not completely understood, copper nanoparticles can become a viable alternative in fighting multi-resistant bacteria strains. We hereby review the already existing data on copper nanoparticle synthesis, effects and mechanisms of action as well as toxicity.

Joint effects of carbon nanotubes and copper oxide nanoparticles on fermentation metabolism towards Saccharofermentans acetigenes: Enhancing environmental adaptability and transcriptional expression

In this study, the joint effects of widely used copper oxide nanoparticles (CuO NPs) and multi-walled carbon nanotubes (MWCNTs) on the fermentation metabolism of a model acetogenic bacterium Saccharofermentans acetigenes were investigated and the underlying mechanisms were further explored. The presence of sole CuO NPs or MWCNTs severely inhibited the acetate generation, while their co-existences did not further decrease the acetate yield as expected. Further analysis indicated the joint effects facilitated the enhancement of bacterial stimulus response to the environment and interspecies communication, which improved adaptive capacity to the adverse environment involved in nanomaterials. Meanwhile, the co-existence reduced inhibitory effects of sole nanomaterial on the gene expressions and catalytic activities of key enzymes involved in glycolysis and pyruvate metabolism. Therefore, the joint effects could enhance environmental adaptation of S. acetigenes and transcriptional expressions of key enzymes for acetic acid production-related processes, alleviating the inhibition of CuO NPs to acetate production.

Features of Bioaccumulation and Toxic Effects of Copper (II) Oxide Nanoparticles Under Repeated Oral Exposure in Rats

BACKGROUND

Currently, the range of copper (II) oxide nanoparticles' (CuO NPs) applications is expanding and the global production of CuO NPs is increasing. In this regard, the risk of exposure of the population to this nanomaterial increases.

OBJECTIVE

The aim of the study is to investigate the patterns of bioaccumulation and toxic effects of CuO NPs after multiple oral exposures.

METHODS

The particle size was determined by scanning electron microscopy and dynamic laser light scattering. Specific surface area was measured by the method of Brunauer, Emmett, Teller. Total pore volume - by the method of Barrett, Joyner, Khalenda. Twenty-four hours after the final exposure, blood samples were taken for biochemical and hematological analysis, and internal organs were taken to determine their mass, copper concentration and histological analysis. The study was carried out in comparison with copper (II) oxide microparticles (CuO MPs).

RESULTS

In terms of size, surface area, and pore volume, the studied copper (II) oxide sample is a nanomaterial. The median lethal dose of CuO NPs was 13187.5 mg/kg of body weight. Bioaccumulation occurs in the stomach, blood, intestines, liver, lungs, kidneys and brain. Pathomorphological changes in the liver are manifested in the form of necrosis, degeneration, hepatitis; kidney - proliferation of mesangial cells, dystrophy; stomach - gastritis; small intestine - hyperplasia, enteritis; large intestine - colitis; lungs - hyperplasia, abscess, pneumonia, bronchitis, vasculitis. Clumps of brown pigment were detected in the kidneys, stomach and lungs. The mass of the stomach and intestines increased, the mass of the liver, kidneys and lungs decreased. Pathomorphological changes in organs are likely to cause an increase in the levels of activity of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, amylase, malondialdehyde concentration and a decrease in plasma antioxidant activity. The proportion of segmented neutrophils, the number of leukocytes are raised, the proportion of lymphocytes is reduced.

CONCLUSION

The degree of bioaccumulation and toxicity of CuO NPs are more expressed in relation to CuO MPs.

Environmental risk of nanomaterials and nanoparticles and EPR technique as an effective tool to study them-a review

Nanotechnologies and different types of nanomaterials belong in present day to intensively studied materials due to their unique properties and diverse potential applications in, e.g., electronics, medicine, or display technologies. Together with the investigation of their desired beneficial properties, a need to investigate and evaluate their influence on the environment and possible harmful effects towards living organisms is growing. This review summarizes possible toxic effects of nanomaterials on environment and living organisms, focusing on the possible bioaccumulation in organisms, toxicity, and its mechanisms. The main goal of this review is to refer to potential environmental risks rising from the use of nanomaterials and the necessity to deal with the possible toxic effects considering the growing interest in the wide-scale utilization of these materials. Electron paramagnetic resonance spectroscopy as the only analytical technique capable of detecting radical species enables detection, quantification, and monitoring of the generation of short-lived radicals often coupled with toxic effects of nanomaterials, which makes it an important method in the process of nanotoxicity mechanism determination.

The toxic effect of CuO of different dispersion degrees on the structure and ultrastructure of spring barley cells (Hordeum sativum distichum)

Nowadays, nanotechnology is one of the most dynamically developing and most promising technologies. However, the safety issues of using metal nanoparticles, their environmental impact on soil and plants are poorly understood. These studies are especially important in terms of copper-based nanomaterials because they are widely used in agriculture. Concerning that, it is important to study the mechanism behind the mode of CuO nanoparticles action at the ultrastructural intracellular level. It is established that the contamination with CuO has had a negative influence on the development of spring barley. A greater toxic effect has been exerted by the introduction of CuO nanoparticles as compared to the macrodispersed form. A comparative analysis of the toxic effects of copper oxides and nano-oxides on plants has shown changes in the tissue and intracellular levels in the barley roots. However, qualitative changes in plant leaves have not practically been observed. In general, conclusions can be made that copper oxide in nano-dispersed form penetrates better from the soil into the plant and can accumulate in large quantities in it.

Soil properties can evoke toxicity of copper oxide nanoparticles towards springtails at low concentrations

Copper oxide nanoparticles (CuO-NP) are used as an efficient alternative to conventional Cu in agriculture and might end up in soils. They show a high toxicity towards cells and microorganisms, but only low toxicity towards soil invertebrates. However, most existing soil ecotoxicological studies were conducted in a sandy reference soil and at test concentrations ≥100 mg Cu/kg soil. Therefore, there is a knowledge gap concerning the effect of soil texture on the toxicity of CuO-NP at lower, more realistic test concentrations. In our study, a sandy reference soil and three loamy soils were spiked with CuO-NP at up to four concentrations, ranging from 5 to 158 mg Cu/kg. We investigated 28-day reproduction as well as weight and Cu content after 14-day bioaccumulation and subsequent 14-day elimination for the springtail Folsomia candida. For the first time we analysed the size distribution of CuO-NP in aqueous test soil extracts by single particle-ICP-MS which revealed that the diameter of CuO-NP significantly increased with increasing concentration, but did not vary between test soils. Negative effects on reproduction were only observed in loamy soils, most pronounced in a loamy-acidic soil (-61%), and they were always strongest at the lowest test concentration. The observed effects were much stronger than reported by other studies performed with sandy soils and higher CuO-NP concentrations. In the same soil and concentration, a moderate impact on growth (-28%) was observed, while Cu elimination from springtails was inhibited. Rather than Cu body concentration, the diameter of the CuO-NP taken up, as well as NP-clay interactions might play a crucial role regarding their toxicity. Our study reports for the first time toxic effects of CuO-NP towards a soil invertebrate at a low, realistic concentration range. The results strongly suggest including lower test concentrations and a range of soil types in nanotoxicity testing.

Antibacterial Cotton Fabric Functionalized with Copper Oxide Nanoparticles

Textiles functionalized with cupric oxide (CuO) nanoparticles have become a promising option to prevent the spread of diseases due to their antimicrobial properties, which strongly depend on the structure and morphology of the nanoparticles and the method used for the functionalization process. This article presents a review of work focused on textiles functionalized with CuO nanoparticles, which were classified into two groups, namely, in situ and ex situ. Moreover, the analyzed bacterial strains, the resistance of the antimicrobial properties of textiles to washing processes, and their cytotoxicity were identified. Finally, the possible antimicrobial mechanisms that could develop in Gram-positive and Gram-negative bacteria were described.

Abatement of the Stimulatory Effect of Copper Nanoparticles Supported on Titania on Ovarian Cell Functions by Some Plants and Phytochemicals

The application of nanoparticles has experienced a vertiginous growth, but their interaction with food and medicinal plants in organisms, especially in the control of reproduction, remains unresolved. We examined the influence of copper nanoparticles supported on titania (CuNPs/TiO2), plant extracts (buckwheat (Fagopyrum esculentum) and vitex (Vitex agnus-castus)), phytochemicals (rutin and apigenin), and their combination with CuNPs/TiO2 on ovarian cell functions, using cultured porcine ovarian granulosa cells. Cell viability, proliferation (PCNA accumulation), apoptosis (accumulation of bax), and hormones release (progesterone, testosterone, and 17β-estradiol) were analyzed by the Trypan blue test, quantitative immunocytochemistry, and ELISA, respectively. CuNPs/TiO2 increased cell viability, proliferation, apoptosis, and testosterone but not progesterone release, and reduced the 17β-estradiol output. Plant extracts and components have similar stimulatory action on ovarian cell functions as CuNPs/TiO2, but abated the majority of the CuNPs/TiO2 effects. This study concludes that (1) CuNPs/TiO2 can directly stimulate ovarian cell functions, promoting ovarian cell proliferation, apoptosis, turnover, viability, and steroid hormones release; (2) the plants buckwheat and vitex, as well as rutin and apigenin, can promote some of these ovarian functions too; and (3) these plant additives mitigate the CuNPs/TiO2's activity, something that must be considered when applied together.

Nanotechnology in soil remediation - applications vs. implications

Engineered nanomaterials (ENMs) and nanotechnology have shown great potential in addressing complex problems and creating innovative approaches in soil remediation due to their unique features of high reactivity, selectivity and versatility. Meanwhile, valid concerns exist with regard to their implications towards the terrestrial environment and the ecosystem. This review summarizes: (i) the applications and the corresponding mechanisms of various types of ENMs for soil remediation; (ii) the environmental behavior of ENMs in soils and their interactions with the soil content; (iii) the environmental implications of ENMs during remedial applications. The overall objective is to promote responsible innovations so as to take optimal advantage of ENMs and nanotechnology while minimizing their adverse effects to the ecological system. It is critical to establish sustainable remediation methods that ensure a healthy and safe environment without bringing additional risk.

Impact of copper oxide nanoparticles on the germination, seedling growth, and physiological responses in Brassica pekinensis L

Wide application of nanoparticles causes considerable environmental, health, and safety problems. However, their potential impact and mechanisms on plant growth are not completely clear. In the present study, the effects of different concentration of copper oxide nanoparticles (nCuO) on seed germination and seedling growth, as well as physiological parameters of Brassica pekinensis L., were investigated. The seeds were exposed to 10-, 100-, and 1000-mg L-1 nCuO suspensions and 0.8-mg L-1 Cu2+ released from 1000-mg L-1 nCuO for 7 day. The results showed that nCuO did not affect the germination rate, germination potential, and germination index of B. pekinensis but significantly affected the vitality index. The growth of roots and shoots of B. pekinensis was promoted at 10-mg L-1 nCuO, while they were inhibited under 1000-mg L-1 nCuO and Cu2+ ion treatments, and roots suffered more damage than shoots. Cu content in shoots and roots of B. pekinensis increased with increasing concentrations of nCuO, which is significantly higher in roots as compared with shoots. Roots and shoots accumulated more Cu under nCuO treatments compared with Cu2+ ion treatment. nCuO treatments led to significant lignification in roots of B. pekinensis. Furthermore, nCuO increased in the contents of soluble sugar and protein in shoots, while nCuO at 1000 mg L-1 significantly inhibited the content of soluble protein in roots. In addition, concentration-dependent augmentation of lipid peroxidation, hydrogen peroxide and superoxide generation, and antioxidant enzyme activity were noticed in shoots and roots of B. pekinensis seedlings under nCuO and Cu2+ ion treatments. Altogether, the results strongly suggested that the phytotoxicity of nCuO in B. pekinensis was caused by both the nanoparticles itself and the released Cu2+ ions.

Metal oxide nanoparticles facilitate the accumulation of bifenthrin in earthworms by causing damage to body cavity

In this study, we explored the influence of two metal oxide nanoparticles, nano CuO and nano ZnO (10, 50, 250 mg/kg), on accumulation of bifenthrin (100 μg/kg) in earthworms (Eisenia fetida) and its mechanism. The concentrations of bifenthrin in earthworms from binary exposure groups (bifenthrin + CuO and bifenthrin + ZnO) reached up to 23.2 and 28.9 μg/g, which were 2.65 and 3.32 times of that in bifenthrin exposure group without nanoparticles, respectively, indicating that nanoparticles facilitated the uptake of bifenthrin in earthworms. The contents of biomarkers (ROS, SOD, and MDA) in earthworms indicated that nanoparticles and bifenthrin caused damage to earthworms. Ex vivo test was utilized to investigate the toxic effects of the pollutants to cell membrane of earthworm coelomocytes and mechanism of increased bifenthrin accumulation. In ex vivo test, cell viability in binary exposure groups declined up to 30% and 21% compared to the control group after 24 h incubation, suggesting that coelomocyte membrane was injured by the pollutants. We conclude that nanoparticles damage the body cavity of earthworms, and thus lead to more accumulation of bifenthrin in earthworms. Our findings provide insights into the interactive accumulation and toxicity of nanoparticles and pesticides to soil organisms.

Phytotoxicity Assessment of Copper Oxide Nanoparticles on the Germination, Early Seedling Growth, and Physiological Responses in Oryza sativa L

The increasing utilization of copper oxide nanoparticles (CuO NPs) and their release into the environment has made it imperative to elucidate their impact on the ecological system including plants. However, their potential toxic impact and mechanisms on plant growth are still unclear. The aim of this study was to investigate the effects of CuO NPs and released Cu ions on seed germination and early seedling growth, as well as physiological and biochemical parameters of Oryza sativa. The results showed that CuO NPs at high concentration significantly inhibited seed germination and early seedling growth. The toxicity of CuO NPs originated from the particulate NPs rather than the released Cu²⁺. The phytotoxicity of CuO NPs to rice seed germination and seedling growth probably induced by high Cu accumulation along with the lignification and oxidative damage. The work presented here will increase our knowledge of phytotoxicity of CuO NPs.

Effect of morphology and support of copper nanoparticles on basic ovarian granulosa cell functions

The aim of this survey is to explore the possible effects of unsupported and supported copper nanoparticles (CuNPs) of different morphologies on basic ovarian cell functions. For this purpose, we have compared the activity of unsupported spherical, triangular, and hexagonal CuNPs, as well as of spherical CuNPs supported on titania, zeolite Y and activated charcoal (0, 1, 10, or 100 ng/mL) on cultured porcine ovarian granulosa cells. Cell viability, proliferation (accumulation of proliferating cell nuclear antigen, PCNA), apoptosis (accumulation of Bcl-2-associated X protein, bax) and release of steroid hormones progesterone, testosterone, and 17β-estradiol have been analyzed by the Trypan blue test, quantitative immunocytochemistry, and ELISA, respectively. Cell viability decreased after treatment with hexagonal CuNPs, whilst all the other CuNPs increased it. Unsupported spherical and hexagonal CuNPs, and spherical CuNPs/titania reduced PCNA accumulation; in contrast, an increase was noted for unsupported triangular CuNPs and CuNPs/zeolite Y. Bax accumulation was not affected by hexagonal CuNPs, whereas CuNPs/zeolite Y promoted it and all the other CuNPs depleted it. The release of all steroid hormones was inhibited by CuNPs/titanium dioxide and stimulated by CuNPs/charcoal, whilst CuNPs/zeolite Y promoted the testosterone and 17β-estradiol output, but not that of progesterone. These results demonstrate the direct, mainly stimulatory, impact of CuNPs on basic ovarian cell functions. The character of the CuNPs' action depends on their shape and support. Therefore, CuNPs with appropriate chemical modification could be potentially useful for the control of reproductive processes and treatment of reproductive disorders.

Hormesis Effects of Nano- and Micro-sized Copper Oxide

The concerns about the possible risk of manufactured nanoparticles (NPs) have been raised recently. Nano- and micro-sized copper oxide (CO and CONP) are widely used in many industries. In this regard, in-vitro studies have demonstrated that CONP is a toxic compound in different cell lines. Despite their unique properties, NPs possess unexpected toxicity profiling relative to the bulk materials. This study was designed to examine and compare the toxic effects of CO and CONPs in-vivo and in isolated rat mitochondria. Male Wistar albino rats received 50 to 1000 mg/kg CO or CONP by gavage and several toxicological endpoints including biochemical indices and oxidative stress markers. Then, the pathological parameters in the multiple organs such as liver, brain, spleen, kidney, and intestine were assessed. Mitochondria were isolated from the rat liver and several mitochondrial indices were measured. The results of this study demonstrated that CO and CONP exhibited biphasic dose-response effects. CONPs showed higher toxicity compared with the bulk material. There were no significant changes in the results of CONP and CO in isolated rat liver mitochondria. The present studies provided more information regarding the hormetic effects of CO and CONPs in-vivo and in isolated rat mitochondria.

Short-term exposure to low concentrations of copper oxide nanoparticles can negatively impact the ecological performance of a cosmopolitan freshwater fungus

In the past few decades, the use of nano-based products has been expanding, subsequently increasing the risk of aquatic contamination by nanoparticles (NPs). Consequently, it is important to assess the potential risks of environmentally realistic concentrations of NPs. Leaf litter decomposition, a fundamental ecological process in headwater streams, is governed mainly by fungi. In this study, copper oxide nanoparticles (CuO NPs) were synthesised, and the influence of short term exposure to low concentrations of copper oxide nanoparticles on leaf litter decomposition and fungal reproduction (sporulation) was assessed. A cosmopolitan aquatic fungal decomposer species Articulospora tetracladia was used to assess litter decomposition upon exposure to CuO NPs (0.00, 0.04, 0.08 and 0.12 mg L-1) for a short time period (1, 2, 3 and 4 days). Concentrations and exposure time of NPs affected both leaf litter decomposition and sporulation. A significant difference in leaf litter decomposition and fungal sporulation was observed between the control (0.0 mg L-1) and all concentrations tested but not between 0.04, 0.08 and 0.12 mg L-1 of NPs. All the exposure time points (1, 2, 3 and 4 days) had a significant impact on sporulation; however a significant difference in leaf litter mass loss was seen between all time points except for between 2 and 3 days. Overall, our study provides a novel insight into the potential risk of short-term exposure to environmentally realistic concentrations of CuO NPs on the ecological performance of a cosmopolitan freshwater fungus.

A sub-individual multilevel approach for an integrative assessment of CuO nanoparticle effects on Corbicula fluminea

Because they are widely used, copper oxide nanoparticles (CuO NPs) are likely to enter the aquatic environment and then reach the sediment. We have examined the effect of CuO NPs in the freshwater endobenthic bivalve Corbicula fluminea. Some previous studies have investigated effects at biochemical and physiological levels, but molecular endpoints are still poorly studied despite they are sensitive in early detection of NPs effect. In the present study, we have investigated short-term effects (96 h) of CuO NP (12, 30 nm; 0, 20 and 100 μg/L) using molecular endpoints as well as more conventional biochemical and physiological markers. The expression of antioxidant (CuZnSOD, MnSOD, Cat, Se-GPx, Trxr) and antitoxic (GST-Pi, HSP70, MT, Pgp, MRP1) related genes was measured at the mRNA level while antioxidant (SOD, TAC) and antitoxic (GST, ACP) defenses, energetic reserves and metabolism (ETS, Tri, LDH), and cellular damages (LPO) were assessed using a biochemical approach. The filtration rate measured at 96 h provided information at the physiological scale. Gene expression and filtration rate were responsive to CuO NPs but the effects differed according to the NP size. The results suggest that defense mechanisms may have been set up following 30 nm-NP exposure. The response to 12 nm-NP was lower but still showed that exposure to 12 nm-NP led to activation of cellular elimination mechanisms. The lowering of the filtration rate may have protected the organisms from the contamination. However, this raised the question of further repercussions on organism biology. Together, the results (i) indicate that CuO NP may exert effects at different levels even after a short-term exposure and (ii) point out the precocity of molecular response.