In this paper, a novel photoelectrochemical sensor based on doped quantum dots (QDs) without enzymes was designed for direct detection of H 2 O 2 and indirect detection of glucose. First, the ...fabrication processes of doped QDs based sensors were described. Second, doped QDs based sensors were tested under different applied potentials and light sources to optimize the measurement conditions. Third, the sensing properties of doped QDs on H 2 O 2 were given, which have been compared with the results from other QDs. Cu doped QDs showed better sensing properties. Finally, detection of glucose was achieved by doped QDs based photoelectrochemical sensors. From the experimental results, it can be concluded that the doped QDs based sensors designed by us can be used to detect H 2 O 2 and glucose.
Abstract Anaplastic thyroid carcinoma (ATC) is one of the most aggressive human malignancies. The aggressive behavior of ATC and its resistance to traditional treatment limit the efficacy of ...radiotherapy, chemotherapy, and surgery. The purpose of this study is aimed at enhancing the therapeutic efficacy of radiotherapy (RT) combined with photothermal therapy (PTT) in murine orthotopic model of ATC, based on our developed single radioactive copper sulfide (CuS) nanoparticle platform. We prepare a new dual-modality therapy for ATC consisting of a single-compartment nanoplatform, polyethylene glycol-coated 64 CuCuS NPs, in which the radiotherapeutic property of64 Cu is combined with the plasmonic properties of CuS NPs. Mice with Hth83 ATC were treated with PEG-64 CuCuS NPs and/or near infrared laser. Antitumor effects were assessed by tumor growth and animal survival. We found that in mice bearing orthotopic human Hth83 ATC tumors, micro-PET/CT imaging and biodistribution studies showed that about 50% of the injected dose of PEG-64 CuCuS NPs was retained in tumor 48 h after intratumoral injection. Human absorbed doses were calculated from biodistribution data. In antitumor experiments, tumor growth was delayed by PEG-64 CuCuS NP-mediated RT, PTT, and combined RT/PTT, with combined RT/PTT being most effective. In addition, combined RT/PTT significantly prolonged the survival of Hth83 tumor-bearing mice compared to no treatment, laser treatment alone, or NP treatment alone without producing acute toxic effects. These findings indicate that this single-compartment multifunctional NPs platform merits further development as a novel therapeutic agent for ATC.
The structure of copper(ii) complexes formed with triethanolamine (TEA) core poly(amidoamine) (PAMAM) dendrimers from generation 0 (G0) to 4 (G4) were investigated by the electron paramagnetic ...resonance (EPR) technique and molecular simulations. Different square planar coordination modes were detected as a function of copper(ii) concentration, whose dynamic evolution relates to the high structural flexibility peculiar to this dendrimer family. Modulated by generation and solvation effects, copper(ii) complexation begins at the dendrimer core and progresses to the dendrimer periphery. Differently from the ethylenediamine (EDA) core PAMAM dendrimers, the copper complexes involving the TEA core showed high mobility and saturation of the internal sites above the 1 : 1 molar ratio between the dendrimers and the ions. Therefore, by combining EPR and molecular simulations for the first time, ultimately we obtained unique information on structure, dynamics and copper interacting ability of these dendrimers which could be successfully exploited in biomedical applications.
Nano- and microscale copper oxide particles (CuO NP, CuO MP) are applied for manifold purposes, enhancing exposure and thus the potential risk of adverse health effects. Based on the pronounced in ...vitro cytotoxicity of CuO NP, systematic investigations on the mode of action are required. Therefore, the impact of CuO NP, CuO MP and CuCl
on the DNA damage response on transcriptional level was investigated by quantitative gene expression profiling via high-throughput RT-qPCR. Cytotoxicity, copper uptake and the impact on the oxidative stress response, cell cycle regulation and apoptosis were further analysed on the functional level.
Cytotoxicity of CuO NP was more pronounced when compared to CuO MP and CuCl
in human bronchial epithelial BEAS-2B cells. Uptake studies revealed an intracellular copper overload in the soluble fractions of both cytoplasm and nucleus, reaching up to millimolar concentrations in case of CuO NP and considerably lower levels in case of CuO MP and CuCl
. Moreover, CuCl
caused copper accumulation in the nucleus only at cytotoxic concentrations. Gene expression analysis in BEAS-2B and A549 cells revealed a strong induction of uptake-related metallothionein genes, oxidative stress-sensitive and pro-inflammatory genes, anti-oxidative defense-associated genes as well as those coding for the cell cycle inhibitor p21 and the pro-apoptotic Noxa and DR5. While DNA damage inducible genes were activated, genes coding for distinct DNA repair factors were down-regulated. Modulation of gene expression was most pronounced in case of CuO NP as compared to CuO MP and CuCl
and more distinct in BEAS-2B cells. GSH depletion and activation of Nrf2 in HeLa S3 cells confirmed oxidative stress induction, mainly restricted to CuO NP. Also, cell cycle arrest and apoptosis induction were most distinct for CuO NP.
The high cytotoxicity and marked impact on gene expression by CuO NP can be ascribed to the strong intracellular copper ion release, with subsequent copper accumulation in the cytoplasm and the nucleus. Modulation of gene expression by CuO NP appeared to be primarily oxidative stress-related and was more pronounced in redox-sensitive BEAS-2B cells. Regarding CuCl
, relevant modulations of gene expression were restricted to cytotoxic concentrations provoking impaired copper homoeostasis.
•Antiviral activities were comparatively evaluated using copper and silver compounds.•Solid-state Cu2O showed superior activity against enveloped and non-enveloped viruses.•Exposure to Cu2O ...preferentially inactivated infection ability of influenza viruses.•Cu2O has a unique antiviral mechanism mediated by direct contact.
Antiviral activities of insoluble solid-state and soluble ionic copper and silver compounds were evaluated against influenza A virus (A/PR8/H1N1) possessing a viral envelope and bacteriophage Qβ lacking an envelope. The viral solutions were exposed on glass samples uniformly loaded with copper and silver compounds. Exposure to solid-state cuprous oxide (Cu2O) efficiently inactivated both influenza A virus and bacteriophage Qβ, whereas solid-state cupric oxide (CuO) and silver sulfide (Ag2S) showed little antiviral activity. Copper ions from copper chloride (CuCl2) had little effect on the activity of bacteriophage Qβ in spite of the fact that copper ions strongly inactivate influenza A in previous studies. Silver ions from silver nitrate (AgNO3) and silver(I) oxide (Ag2O) in solution showed strong inactivation of influenza A and weak inactivation of bacteriophage Qβ. We also investigated the influence of the compounds on the function of two influenza viral proteins, hemagglutinin and neuraminidase. Silver ions from AgNO3 and Ag2O remarkably decreased enzymatic activity of neuraminidase through the breakage of disulfide (SS) bonds, corresponding to the selective inactivation of influenza A virus. By contrast, exposure to Cu2O markedly reduced the activity of hemagglutinin rather than neuraminidase. These findings suggest that solid-state Cu2O disrupts host cell recognition by denaturing protein structures on viral surfaces, leading to the inactivation of viruses regardless of the presence of a viral envelope.
Metal-binding natural products contribute to metal acquisition and bacterial virulence, but their roles in metal stress response are underexplored. We show that a five-enzyme pathway in
synthesizes a ...small-molecule copper complex, fluopsin C, in response to elevated copper concentrations. Fluopsin C is a broad-spectrum antibiotic that contains a copper ion chelated by two minimal thiohydroxamates. Biosynthesis of the thiohydroxamate begins with cysteine and requires two lyases, two iron-dependent enzymes, and a methyltransferase. The iron-dependent enzymes remove the carboxyl group and the α carbon from cysteine through decarboxylation, N-hydroxylation, and methylene excision. Conservation of the pathway in
and other bacteria suggests a common role for fluopsin C in the copper stress response, which involves fusing copper into an antibiotic against other microbes.
Single-crystalline Cu2ax Se nanowires with high aspect ratio on copper substrate have been achieved by a simple hydrothermal route. Based on in situ TEM studies, while utilizing integrated STM holder ...measuring their electrical conductivities, it is confirmed that single-crystalline Cu2ax Se nanowire was very good match the semiconducting characteristic. An electron source device using as-prepared Cu2ax Se nanowires on the Cu substrate has been first fabricated, which shows excellent field emission (FE) properties: the emitting current density as high as 0.83 I14A/cm2 at an applied field of 5.5 V/ mu m, suggesting that the Cu2ax Se nanowire may be potentially applied in the vacuum microelectronics industry.
In this study, the effect factors and mechanisms of doxycycline hydrochloride (DOX) adsorption on copper nitrate modified biochar (Cu-BC) was investigated. Cu-BC absorbent was synthesized through ...calcination of peanut shells biomass at 450°C and then impregnation with copper nitrate. The Cu-BC has exhibited excellent sorption efficiency about 93.22% of doxycycline hydrochloride from aqueous solution, which was double higher than that of the unmodified biochar. The experimental results suggest that the adsorption efficiency of DOX on the Cu-BC is dominated by the strong complexation, electrostatic interactions between DOX molecules and the Cu-BC samples. Comprehensively considering the cost, efficiency and the application to realistic water, the Cu-BC hold the significant potential for enhancing the effectiveness to remove DOX from water.
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•Biochar derived from agricultural wastes were low-cost.•Cu(II) modified biochar exhibited excellent sorption efficiency compared with pristine biochar.•Efficiency of DOX removal was greatly pH dependent.•Cu(II) strongly enhanced the sorption of DOX species through complexation.
The aim of the study was to investigate the effect of two forms (CuCO3 (CuS); and Cu nanoparticles (CuNP)) and dosages (standard 6.5 mg/kg (H), half of the standard (L)) of additional dietary Cu ...administered to growing rats on gastrointestinal and hepatic function and morphology. Copper in the form of CuNP vs CuS caused lower Cu faecal/urinal excretion and increased Cu accumulation in the brain tissue. Hepatic high-grade hydropic degeneration and necrotic lesions were observed only in the CuNP-H animals. In the lower gut, the dietary application of CuNP stifled bacterial enzymatic activity of caecal gut microbiota and resulted in lower SCFA production. That diminishing effect of CuNP on caecal microbiota activity was accompanied by a relative increase in the secretion of glycoside hydrolases by bacterial cells. The results showed that in comparison to Cu from CuCO3, Cu nanoparticles to a greater extent were absorbed from the intestine, accumulated in brain tissue, exerted antimicrobial effect in the caecum, and at higher dietary dose caused damages in the liver of rats.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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