Effect Of CuNPs Research Articles

Synthesis and application of Cu-CaTiO3-GO ternary composite: A new visible-light active multifunctional photocatalyst efficient towards antibiotic cefixime degradation and H2 evolution reaction

To combat the issues of energy scarcity and environmental pollution, a visible-light responsive, ternary photocatalyst (Cu-CaTiO3-GO) was fabricated, by photo-depositing Cu nanoparticles over a CaTiO3-GO binary composite. The physicochemical characteristics of Cu-CaTiO3-GO were investigated using XRD, HR-TEM, FE-SEM, EDS-mapping XPS, Raman, FT-IR, BET, EIS, UV–vis DRS, and PL techniques. In comparison with pristine CaTiO3, and binary composites (Cu-CaTiO3, CaTiO3-GO), the ternary hybrid exhibited superior photocatalytic activity for H2generation as well as antibiotic cefixime (CFX) degradation. Under LED light, the rate of H2 generation over Cu-CaTiO3-GO accumulated to 57.69 mmolh−1, while the photodegradation efficiency for CFX reached 94.1 % in 100 min with 53.4 % of TOC removal. The upgraded performance is credited to synergistic effects of Cu NPs (SPR effect), CaTiO3 (specialized cuboid-like morphology), and GO (high conductivity), co-existing in the trio-hybrid, which resulted in a greatly increased surface area, an expanded spectral response range, a stronger adsorption property, efficient charge migration and separation extent. Ternary catalyst performed well even in the 4 recycling tests (retaining 79.4 % CFX removal and 52.51 mmolh−1 H2 evolution efficiency). In Cu-CaTiO3-GO system, the electron transport channel (Cu → CaTiO3 → GO) with adequate band potentials effectively supports both photocatalytic oxidation and reduction. Photoelectrons are enriched and transferred by plasmonic Cu, and then captured by GO, an e- sink. This maximizes composite photo redox capability, rapidly generating active radicals (OH), and (O2-), degrading CFX to simpler molecules and reducing proton to H2. The effectiveness of Cu-CaTiO3-GO was even tested in the real water matrices. Besides, degradation intermediates of CFX were elucidated using LC-MS, and the decomposition pathway was suggested. Finally, the probable photocatalytic reaction mechanism was deduced for both the degradation and H2 generation processes. The current study proposes a non-noble transition metal-based perovskite-type photocatalytic material for both clean energy generation and wastewater treatment.

Wound healing activity of green synthesized copper nanoparticles through cell proliferation-migration, antimicrobial effects, and nitric oxide triggering

The present experimental study was designed to evaluate the in vitro wound healing and anti-inflammatory effects of copper nanoparticles (CuNPs) green synthesized by the methanol extract Ferula macrecolea Boiss, as a plant with various pharmacological effects such as anti-inflammatory, and antimicrobial effects in traditional and modern medicine. The precipitation approach was used to green synthesis of CuNPs through mixing the methanol and copper sulfate solution. Cell viability and fibroblast proliferation assay were performed by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. The migration abilities of fibroblasts cells were evaluated using a cell scratch in vitro wound healing assay. Effects of CuNPs on iNOS expression genes were also performed by Real-time PCR. In vitro antibacterial susceptibility test of CuNPs was carried out according to the standards protocol of the National Committee for Clinical Laboratory Standards (NCCLS). The analysis of SEM revealed that the green synthesized CNP exhibited a globular shape with a size ranging from 15-90 nm; while their majority were at 40-60 nm. The results of the MTT assay showed that the calculated CC50 value of green synthesized CuNPs was 236.3 μg/mL. The optimum concentrations of the CuNPs which were selected based on the 50% cytotoxic concentration (CC50) value; whereas dose-dependently increased the proliferation of fibroblast cells. The CuNPs dose-dependently increased the rate of wound closure after 16 and 24 h. The results of the Real-Time PCR showed that CuNPs causes an upregulation in expression level of gene of nitric oxide synthesis (iNOS) in RAW 264.7 cells. CuNPs showed the promising antimicrobial effects against S. aureus, S. epidermidis and Ps. aeruginosa. The present study showed the high potency of CuNPs green synthesized by F. macrecolea for wound healing through their antimicrobial, proliferation of fibroblast cells, and provoking iNOS.

Construction of Zr-Metal-Organic Frameworks-Based Composite Materials toward Anhydrous Proton Conduction and Photocatalytic CO2 Reduction.

Metal-organic frameworks constructed from Zr usually possess excellent chemical and physical stability. Therefore, they have become attractive platforms in various fields. In this work, two families of hybrid materials based on ZrSQU have been designed and synthesized, named Im@ZrSQU and Cu@ZrSQU, respectively. Im@ZrSQU was prepared through the impregnation method and employed for proton conduction. Im@ZrSQU exhibited terrific proton conduction performance in an anhydrous environment, with the highest proton conduction value of 3.6 × 10-2 S cm-1 at 110 °C. In addition, Cu@ZrSQU was synthesized via the photoinduction method for the photoreduction of CO2, which successfully promoted the conversion of CO2 into CO and achieved the CO generation rate of up to 12.4 μmol g-1 h-1. The photocatalytic performance of Cu@ZrSQU is derived from the synergistic effect of Cu NPs and ZrSQU. Based on an in-depth study and discussion toward ZrSQU, we provide a versatile platform with applications in the field of proton conduction and photocatalysis, which will guide researchers in their further studies.

Synthesis and Characterization of Citrus limonum Copper Nanoparticles and its in vitro Evaluation of Cytotoxicity against JURKAT Cells

Background Biosynthesized copper nanoparticles (CuNPs) are eco-friendly, cost-effective, and biocompatible agents reported for extensive biomedical and bioengineering applications. Different chemical synthesis approaches have been established recently, with challenges of higher toxicity and high cost involved in the synthesis process. Green synthesized nanoparticles emerged and was extensively reported to address the challenges faced by traditional chemical synthesis processes. However, the high toxicity remains a significant challenge for translating the green synthesized nanoparticles into clinically valuable products. Purpose To synthesize, characterize, and evaluate the citrus extract-based CuNps cytotoxicity against JURKAT cell lines. Materials and Methods An aqueous extract of the citrus fruit was used as a reducing agent, and the CuNps were synthesized. Fourier Transform Infra-Red (FTIR), scanning electron microscopy (SEM), dynamic light scattering (DLS), Ultraviolet-visible (UV-vis) spectrophotometry, and X-ray diffraction (XRD) were used to confirm the synthesis of CuNp and its structure. Furthermore, the effect of CuNPs on cell viability and toxicity was evaluated by mitochondrial toxicity tests (MTT) and LDH assays against the JURKAT cell lines. Results and Conclusion The synthesized nanoparticle’s size ranged from 40 to 70 nm, as confirmed through nanoparticle tracking analysis (NTA) and SEM. The synthesized nanoparticles were confirmed to be anti-proliferative with a high percent of cytotoxicity as found from MTT and LDH leakage assays. The size and shape of the synthesized CuNPs as studied by SEM were found to be 30–70 nm and more or less spherical. MTT reported 64.87% inhibition at 320 µg/mL with an IC50 value of 80.78 µg/mL ( p < 0.05). Cytotoxicity as measured by the LDH assay was found to be 53.12 ± 0.89% at 320 µg/mL with an IC50 of 23.12 ± 0.39 when compared to the positive control (11.21 ± 0.15 µg/mL). Green-synthesized CuNPs exhibited potential anti-cancerous activity in JURKAT cell lines, as evidenced by the LDH and MTT assays.

Green synthesis, characterization, acaricidal, larvacidal, and repellent activities of copper nanoparticles of Astragalus sinicus against Hyalomma anatolicum

Objective: To green synthesize and characterize copper nanoparticles (CuNPs) using Astragalus sinicus, as well as evaluate the acaricidal, larvacidal, and repellent activities of CuNPs against Hyalomma anatolicum (H. anatolicum), one of the most prevalent ticks infesting cattle in Saudi Arabia. Methods: CuNPs were green synthesized by adding the Astragalus sinicus extract to a copper sulfate solution. The acaricidal, larvicidal, and repellent activities of CuNPs against H. anatolicum were assessed via the adult immersion test, the larval packet test, and the vertical movement behavior of tick larvae, respectively. The effects of CuNPs on acetylcholinesterase as well as oxidative enzyme activities were examined. Results: The green synthesized CuNPs displayed a spherical form with a size range of 15-75 nm. After exposure of adult H. anatolicum to different concentrations of CuNPs, the viability rate of adult H. anatolicum and the mean number, weight, and hatchability of eggs were noticeably reduced, in comparison to the control group (P<0.001). In addition, the viability rate of larvae considerably declined (P<0.001) with the LC50 and LC90 values of 11.30 and 20.34 μg/mL, respectively. The maximum repellent activity of CuNPs was observed at 50, 100, and 200 μg/mL with complete repellent activity after 60, 120, and 180 min of exposure, respectively. CuNPs, mainly at ½LC50 and LC50 concentrations, markedly suppressed the acetylcholinesterase activity of the larval stage of H. anatolicum (P<0.001). Moreover, CuNPs, mainly at LC50 dose, significantly elevated malondialdehyde level while declining glutathione-S-transferase level in H. anatolicum larvae (P<0.001). Conclusions: CuNPs show potent acaricidal, larvicidal, and repellent activities against adults and larvae of H. anatolicum. However, further studies must be performed to clarify the precise mechanisms and the efficacy of CuNPs in practical use.

Copper nanoparticles lead to reproductive dysfunction by affecting key enzymes of ovarian hormone synthesis and metabolism in female rats

Studies on the general toxicity of copper nanoparticles (Cu NPs) have been conducted extensively, but their effects on reproductive toxicity remain unclear. In this study, we evaluated the toxic effect of Cu NPs on pregnant rats and their litter. The comparative in vivo toxicity of Cu ions, Cu NPs, and Cu microparticles (MPs) was studied in a 17-day repeated oral-dose experiment at the doses of 60, 120, and 180 mg/kg/day in pregnant rats. The pregnancy rate, mean live litter size, and number of dams decreased when exposed to Cu NPs. Moreover, Cu NPs caused a dose-dependent increase in ovarian Cu levels. The metabolomics results showed that Cu NPs caused reproductive dysfunction by altering sex hormones. In addition, in vivo and in vitro experiments showed that the ovarian cytochrome P450 enzymes (CYP450), responsible for hormone production, were significantly upregulated, whereas the enzymes responsible for hormone metabolism were significantly inhibited, resulting in a metabolic imbalance in some ovarian hormones. Furthermore, the results revealed that the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways significantly participated in the regulation of ovarian CYP enzyme expression. Overall, the results of the in vivo and in vitro toxicity experiments with Cu ions, Cu NPs, and Cu MPs suggested that toxicity from nanoscale Cu particles poses a more serious reproductive threat than microscale Cu as Cu NPs could directly damage the ovary and affect the metabolism of ovarian hormones.

The Effect of Copper and Copper Oxide Nanoparticles on Rainbow Trout (Oncorhynchus mykiss W.) Spermatozoa Motility after Incubation with Contaminants.

The study aimed to analyse the effect of copper nanoparticles of similar particle size of Cu and CuO and copper ions (CuSO4) on the motility parameters of rainbow trout spermatozoa after long-term exposure and compare its harmful effect. Nanoproducts of Cu and CuO (Cu NPs, CuO NPs) of primary particle size around 50 nm and ionic solution of CuSO4 were used for the study. Suspension of concentrations 0, 1, 5, 10, 25, and 50 mg Cu·L−1 of Cu NPs, CuO NPs, and CuSO4 was dissolved in an artificial seminal plasma. Milt was mixed with the prepared solution and stored in a fridge, at 6 °C, for 96 h. At the defined incubation time, spermatozoa were activated for movement, and six motility parameters were evaluated using an automated system (CASA). Increasing concentrations of Cu NPs, CuO NPs, and CuSO4 in an incubation medium in parallel decreased the percentage of motile sperm (MOT). The effect of Cu NPs and ionic copper on MOT was more deleterious than that of CuO NPs. Copper products slightly increased the velocity (VCL) compared to the control, particularly up to 24 h of storage. Linearity (LIN) was improved by three tested products, particularly CuO NPs. Generally, the motility duration was prolonged when the sperm was incubated with copper products compared to the control. Nanoproducts made from different compounds of the same elements of similar particle size have a different effect on cells. Cu NPs were more harmful than CuO NPs. The effect of Cu NPs was similar to an ionic form of CuSO4. When incubated, the copper nanoproducts and ionic form exert a slightly positive effect on spermatozoa velocity, linearity, and motility duration, particularly up to 24 h of storage.

Hetero-aggregation behaviour of green copper nanoparticles: Course interactions with environmental components

In this work, the hetero-aggregation behaviour of well-characterized copper nanoparticles (Cu-Nps) prepared by Koelreuteria apiculata seed extract, was investigated on the soil via sorption studies. Fate on sand was determined by the introduction of suspended particles in the form of pulse in Plexiglas column packed with fully saturated sand. Photo-degradation study was conducted in visible light for ensuring the stability of the formed Cu-Nps. For ensuring their biological incongruity, the effect of Cu-Nps were investigated against Staphylococcus aureus, Escherichia coli, and Salmonella typhi. The antifungal activity was manoeuvred on Laurilia taxodi for manifesting its status against fungal community. The impact of Cu-Nps on Chlorella sp. was ameliorated with the increasing chlorophyll content from 34% to 43% with the concentrations of 100 mg/L to 5000 mg/L respectively. The genetic effect of 2500 mg/L of Cu-Nps was divulged to be nearly negligible with the value of 0.004 as chromosomal aberration index, on the newly emerged root tips of Allium cepa. Cu-Nps played a pivotal role in enhancing chlorophyll accumulation and enzymatic activity in the seeds of Cicer arietinum with the 100% germination rate. All the studies covering biotic and abiotic parameters inferred the biocompatible nature of the Cu-Nps beforehand, thus paving their way to nature without any disquiet regarding their detrimental temperament.

Geometry effect of copper nanoparticles and nanowires on polyetheretherketone-matrix nanocomposites: Thermal conductivity, dynamic mechanical properties and wear resistance

Polyetheretherketone (PEEK)-matrix nanocomposites filled with copper nanowires (Cu NWs) and copper nanoparticles (Cu NPs) were prepared by hot compaction method. The effects of Cu NWs and Cu NPs on the thermal conductivity, dynamic mechanical performance, and tribological property of PEEK-matrix nanocomposites were investigated. Results indicate that Cu NPs and Cu NWs with different geometry exhibit different influences on the crystallization behavior, melting behavior, dynamic mechanical properties, and friction and wear behavior of PEEK matrix. Namely, Compared to Cu NPs, Cu NWs can more efficiently better dissipate heat and transfer stress at PEEK/nanofiller interface. Moreover, the friction and wear behavior of the PEEK-matrix nanocomposites is also related to the geometry of the Cu nanofillers to some extent. This is because Cu NPs can act as roll bearings to reduce friction; and Cu NWs with a high thermal conductivity can prevent softening of PEEK matrix and increase the wear resistance via well dissipating friction heat away from the sliding interface. In one word, the comprehensive properties of PEEK-matrix nanocomposites are closely related to the geometry effect of Cu NPs and Cu NWs, which could be of significance for revealing the relation between the micro morphology and the macro application of inorganic nanofillers.

Histopathological and calreticulin changes in the liver and gill of Takifugu fasciatus demonstrate the effects of copper nanoparticle and copper sulphate exposure

Copper nanoparticles (Cu-NPs) are water pollutants, which has significant toxic environmental effects. However, the effects of Cu-NPs on Takifugu fasciatus are still relatively unknown. Compared with the control (no add CuSO4 and Cu-NPs). This study aims to describe the pathological changes in the gill and liver of pufferfish exposed to CuSO4 (Cu2+ for short) and Cu-NPs dissolved at a concentration of either 20 or 100 μg/L, in a semi-static waterborne exposure regime for 28 days. All Cu treatments resulted in organ injuries, and the pathologies observed following exposure to Cu-NPs were broadly of the same type as those observed following exposure to Cu2+. In the gill, these included lamellar fusion, clubbed tips, and mucocytes swollen, and in the liver included oedema, aggregation of blood cells, and necrosis. Furthermore, enzyme activity assays revealed that Ca2+ -ATP activity significantly increased under the influence of Cu, whilst Na+-K+-ATPase activity was significantly inhibited. In this study, the CRT in T. fasciatus (referred to as TfCRT) was identified and full-length cDNA sequences were characterized. Subsequently, RT-PCR and western blot analysis were carried out to assess the expressions of TfCRT in the gill and liver at both the mRNA and protein levels. Under both the Cu-NPs and Cu2+ treatments, both the mRNA and protein expressions of TfCRT were considerably higher in the gill and liver compared to that of the control treatment. Furthermore, there were no significant differences between Cu-NPs and Cu2+ treatment (at the same treatment concentration) in the expressions of TfCRT at the mRNA or protein levels. Overall, both Cu2+ and Cu-NPs had negative effects on T. fasciatus, and Cu-NPs had the toxic effects similar to dissolved Cu. Our results provide the ecological safety data service of Cu-NPs in water, and provide a reference for the health T. fasciatus aquaculture.

Oral exposure of pregnant rats to copper nanoparticles caused nutritional imbalance and liver dysfunction in fetus

Copper nanoparticles (Cu NPs) are increasingly used as an animal feed additive in China. In previous studies, it was determined that Cu NPs can penetrate the placental barrier, however, its toxic effects on the fetus have not yet been elucidated. Therefore, in this study, we investigated the potential fetal toxic effects of Cu NPs. Cu NPs were orally administered to pregnant Sprague-Dawley rats from gestation days (GDs) 3–18 at a dose of 60, 120, and 180 mg/kg/day. Cesarean sections were conducted on GD 19. During fetal examination, no toxicities were observed regarding general clinical signs, however, Cu NPs significantly decreased fetal body weight, body length, and liver weights. Cu ions and Cu MPs exhibited similar effects on the fetal development. Cu NPs increased the liver concentration of Cu, and decreased protein levels and Fe in fetuses. Cu NPs also increased oxidative stress and inflammation in the fetus after pregnant rats were exposed to high doses of Cu NPs. Oral exposure to Cu NPs during pregnancy increased Cu concentrations in the fetus, which not only affected fetal development, but also significantly induced oxidative stress and inflammatory responses in fetal liver. Taken together, these findings are valuable to evaluate fetal risk assessment after oral exposure of Cu NPs during pregnancy. Additional comprehensive toxicity studies are deemed necessary to clarify the underlying mechanisms involved.

Biodistribution and toxicity assessment of copper nanoparticles in the rat brain

AimsThe increase in the usage of copper nanoparticles (Cu NPs) in the industrial and medical fields has raised concerns about their possible adverse effects. The present study aims to investigate the potential adverse effects of Cu NPs on the brain of adult male Wistar rats through the estimation of some oxidative stress parameters and acetylcholinesterase (AChE) activity. Basic proceduresCu NPs were prepared and characterized using different techniques: Dynamic Light Scattering, X-Ray Diffraction, Transmission and Scanning Electron Microscopy, Fourier transform Infrared Spectroscopy, in addition to Energy Dispersive X-ray Spectroscopy. Rats were divided into two groups: Cu NPs-treated group (IV injected with 15 mg/kg ˷ 13 nm Cu NPs for 2 successive days) and a control group (injected with saline). Rats of the 2 groups were decapitated simultaneously after 48 h of the last injection. The Cu content in different brain areas was analyzed using inductively coupled plasma mass spectrometry. Moreover, the effect of Cu NPs on brain edema was evaluated. The behavior of rats in an open-field was also examined 24 h post the last injection. Main findingsSignificant increases of Cu content in the cortex, cerebellum, striatum, thalamus and hippocampus were found. Moreover, Cu NPs lead to the induction of oxidative stress condition in the thalamus, hypothamaus and medulla. In addition, Cu NPs induced significant increases in AChE activity in the medulla, hippocampus, striatum besides midbrain. Cu NPs-injected rats showed also decreased exploratory behaviour. Principal conclusionThe results obtained in the present study point to the importance of toxicity assessments in evaluating the efficiency of Cu NPs for the safe implementation in different applications.

Long-term effects of copper nanoparticles on granule-based denitrification systems: Performance, microbial communities, functional genes and sludge properties

The widespread use of copper nanoparticles (CuNPs) has attracted increasing concern because of their potential effects on biological wastewater treatment. However, their effect on granule-based denitrification systems is unclear. Hence, the effects of CuNPs on denitrifying granules were investigated during long-term operation. The results showed that 51.9% of nitrogen removal capacity was lost after exposure to 5 mg L−1 CuNPs, with the amount of Cu(II) gradually increasing with elevating CuNP levels. Moreover, the relative abundance of denitrifying bacteria (Castellaniella) and denitrifying functional genes (nirK, napA, narG and nosZ) obviously decreased. Meanwhile, the specific denitrification activity, the content of extracellular polymeric substances and dehydrogenase activity decreased by 44.0%, 15.2% and 99.9%, respectively, compared to their values in the initial sludge. Considering the downtrend in the abundance of copper resistance genes, it was deduced that the toxicity of CuNPs was mainly or at least partially due to the release of Cu(II).

Effects and mechanisms of sub-chronic exposure to copper nanoparticles on renal cytochrome P450 enzymes in rats

Copper nanoparticles (Cu NPs) have widespread application because of their special physicochemical characteristics, however we need to more clearly study the toxicity mechanism of Cu NPs to ensure its safe use in pharmaceutical and animal feed. Thus, the aim of this study was to evaluate the effects and mechanisms of sub-chronic exposure to Cu NPs on renal CYP450 s of rats. In this study, we investigated the effects of Cu NPs on renal oxidative stress, cytokines and histopathology of rats. We found that Cu NPs (200 mg/kg) significantly disordered the function and structure of the kidney and caused a dose-dependent increase in oxidative stress and cytokines, which significantly decreased the levels of mRNA, protein, and activity of CYP450 s. Micro-coppers (Cu MPs) and Cu ions have similar effects, but their effects on CYP450 s were weaker than Cu NPs. The expression of nuclear receptors were inhibited and the expression of Akt, STAT3/5, CREB, p70S6K, NF-κB, P38 and ERK1/2 were activated when the inhibition effects of CYP450 s activity were observed in renal of rats. Therefore, we believe that Cu NPs can activate the STAT, NF-κB and MAPK signaling pathways to down-regulate the expression and activity of CYP450 s by inducing oxidative stress and inflammatory response in rat kidney.

Copper-polyaniline nanocomposite: Role of physicochemical properties on the antimicrobial activity and genotoxicity evaluation

Copper nanoparticles (Cu NPs) have proven to own excellent antimicrobial efficacy, but the problems of easy oxidation and aggregation limit their practical application. Here, nanocomposite based on polyaniline (PANI) and Cu NPs solved this problem and brought additional physicochemical properties that are markedly advantageous for antimicrobial applications. Current work exploits this potential, to examine its time- and concentration-dependent antimicrobial activity, employing E. coli, S. aureus, and C. albicans as a model microbial species. Regarding the presence of polaronic charge carriers in the fibrous polyaniline network, effects of Cu NPs' size and their partially oxidized surfaces (the data were confirmed by HRTEM, FESEM, XRD, Raman and XPS analysis), as well as rapid copper ions release, Cu-PANI nanocomposite showed efficient bactericidal and fungicidal activities at the concentrations ≤1 ppm, within the incubation time of 2 h. Beside the quantitative analysis, the high levels of cellular disruption for all tested microbes were evidenced by atomic force microscopy. Moreover, the minimum inhibitory and bactericidal concentrations of the Cu-PANI nanocomposite were lower than those reported for other nanocomposites. Using such low concentrations is recognized as a good way to avoid its toxicity toward the environment. For this purpose, Cu-PANI nanocomposite is tested for its genotoxicity and influence on the oxidative status of the human cells in vitro.

Copper nanoparticles induce early fibrotic changes in the liver via TGF-β/Smad signaling and cause immunosuppressive effects in rats

Copper nanoparticles (Cu NPs) have various uses, including as additives in polymers/plastics, lubricants for metallic coating, and biomedical applications. We investigated the role of transforming growth factor (TGF)-β1 signaling in hepatic damage caused by Cu NPs and explored the effects of a 28-day repeated oral administration to Cu NPs on the immune response. The exposure to Cu NPs caused a dose-dependent increase in Cu levels in the liver and spleen. Cu NPs caused hepatic damage and markedly increased oxidative stress in liver tissues. Cu NPs induced activation of TGF-β1/Smad signaling by induction of vascular endothelial growth factor and matrix metalloproteinase-9. Exposure to Cu NPs also induced activation of Smad-independent pathways, phosphorylation of mitogen-activated protein kinases (MAPKs) and Akt/FoxO3. Consistent with the activation of TGF-β1/Smad-dependent and -independent pathways, Cu NPs markedly increased the deposition and induction of extracellular matrix components, α-smooth muscle actin, and collagens in liver tissues. In addition, repeated exposure to Cu NPs suppressed the proliferation of mitogenically stimulated T- or B-lymphocytes and decreased CD3+ (particularly, CD3+CD4+CD8−) and CD45+ population, followed by decreased levels of immunoglobulins and Th1/Th2 type cytokines. Collectively, Cu NPs caused hepatic damage and induced pro-fibrotic changes, which were closely related to the activation of oxidative stress-mediated TGF-β1/Smad-dependent and -independent pathways (MAPKs and Akt/FoxO3). We confirmed the immunosuppressive effect of Cu NPs via the inhibition of mitogen-stimulated spleen-derived lymphocyte proliferation and suppression of B- or T-lymphocyte-mediated immune responses.

A comparison of the effects of copper nanoparticles and copper sulfate on Phaeodactylum tricornutum physiology and transcription

Copper nanoparticles (CuNPs) have been used in a broad range of applications. However, they are inevitably released into the marine environment, making it necessary to evaluate their potential effects on marine phytoplankton. In this study, the short-term (96h) effects of CuNPs and CuSO4 on Phacodactylum tricornutum growth, photosynthesis, reactive oxygen species production and transcription were assessed. It was found that high concentrations (40μM) of CuNPs and CuSO4 significantly inhibited the growth, photosynthesis and induced oxidative stress of P. tricornutum, while lower concentrations caused a hormetic response as indicated by a slight stimulation in algal growth. The high percentage of dissolved Cu (78–100%) in culture medium suggested that the dissolved Cu was the main driver of toxicity during CuNPs treatment. The algal cells upregulated electron transport chain-related genes to produce more energy and restore photosynthesis after 96h of treatment with CuNPs and CuSO4. This study delineates the cellular mechanism behind the toxicity of CuNPs and CuSO4 on marine diatoms.

Biogenic copper nanoparticles promote the growth of pigeon pea ( Cajanus cajan L.)

Environmental pollution and toxicity have been increasing due to the overuse of chemical fertilisers, which has encouraged nanotechnologists to develop eco-friendly nano-biofertilisers. The authors demonstrated the effect of biogenic copper nanoparticles (CuNPs) on the growth of pigeon pea (Cajanus cajan L.). The UV–visible analysis showed absorbance at 615 nm. Nanoparticle tracking and analysis revealed particle concentration of 2.18 × 108 particles/ml, with an average size of 33 nm. Zeta potential was found to be −16.7 mV, which showed stability. X-ray diffraction pattern depicted the face centred cubic structure of CuNPs; Fourier transform infrared spectroscopy demonstrated the capping due to acidic groups, and transmission electron micrograph showed nanoparticles with size 20–30 nm. The effect of CuNPs (20 ppm) on plant growth was studied, for the absorption of CuNPs by plants on photosynthesis, which was evaluated by measuring chlorophyll a fluorescence using Handy-Plant Efficiency Analyser. CuNPs treatment showed a remarkable increase in height, root length, fresh and dry weights and performance index of seedlings. The overall growth of plants treated with CuNPs after 4 weeks was recorded. The results revealed that inoculation of CuNPs contribute growth and development of pigeon pea due to growth promoting activity of CuNPs.

Effects of phytogenic copper nanoparticles on fermentative hydrogen production by Enterobacter cloacae and Clostridium acetobutylicum

Copper nanoparticles (Cu-NPs) were synthesized using Murraya koenigii leaf extract as reducing agent and characterized. TEM images show that the Cu-NPs were mostly cuboid shaped with an average size of about 97 nm. The influence of phytogenic Cu-NPs on biohydrogen production from glucose was studied using Enterobacter cloacae and Clostridium acetobutylicum, and its effects were compared with CuSO4. The effects of Cu-NPs and CuSO4 (2.5, 5.0, 7.5, 10.0 and 12.5 mg/L) on biohydrogen production using E. cloacae at pH 7.0 and C. acetobutylicum at pH 6.0 were performed in batch mode. Both Cu-NPs and CuSO4 supplementation inhibited the biohydrogen production in a dose dependent manner. The Cu-NPs were found to have more inhibitory effect on biohydrogen production of E. cloacae and C. acetobutylicum than CuSO4.

Toxicity of engineered copper (Cu0) nanoparticles to the green alga Chlamydomonas reinhardtii

Environmental context Engineered copper nanoparticles are presently under development for various uses and may thus be finally released into the aquatic environment. Copper is well known to be both an essential and a toxic element for aquatic organisms. Here, we investigate the toxicity of copper nanoparticles to a green alga and compare it with the toxicity of dissolved copper. Abstract The toxicity of carbon-coated copper nanoparticles (CuNPs) to the unicellular green alga Chlamydomonas reinhardtii was investigated and compared with effects of dissolved Cu2+. The CuNPs with an original size of 6–7nm rapidly agglomerated in the medium to average particle sizes of 140–200nm. Dissolved Cu from CuNPs increased over 2h to 1–2% of total Cu. The photosynthetic yield of C. reinhardtii strongly decreased after exposure for 1 or 2h to dissolved CuII in the concentration range 0.1–10μM, whereas this decrease occurred in the total Cu concentration range 1–100μM after exposure to CuNPs. Effects of CuNPs were compared with those of dissolved CuII on the basis of dissolution experiments. CuNP effects on photosynthetic yield were similar or somewhat stronger for the same dissolved Cu2+ concentration. Addition of EDTA as a strong ligand for CuII suppressed the toxicity of dissolved CuII and of CuNPs. These results thus indicate effects on the algae are mostly from free Cu2+.