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1.
Bull Environ Contam Toxicol ; 105(3): 372-380, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32705320

RESUMO

Quantum dots (QDs), such as cadmium selenide (CdSe) and lead selenide (PbSe) exhibit excellent optical, magnetic and chemical properties due to their extremely size (ca. 1-10 nm) and are attractive semiconductor nanomaterials for optical studies and energy storage. In this study, aqueous synthesis of CdSe and PbSe QDs in a size range of 2-10 nm was described. Synthesized QDs were characterized using SEM and TEM, DLS, zeta potential, FTIR, EDX and XRD. Highest accumulation (72.5 ± 5.8 mg L-1) of PbSe QDs occurred at 10 ppm suspensions. In general accumulation increased up to 48 h exposure then fluctuate tended to decline. For CdSe QDs, accumulation tended to decrease for 72 h exposure except that for 5 ppm groups. For the elimination period, in general, the elimination levels of PbSe and CdSe QDs from exposed individuals decreased (p < 0.05) even it has some fluctuate.


Assuntos
Artemia/fisiologia , Compostos de Cádmio/toxicidade , Chumbo/toxicidade , Pontos Quânticos/toxicidade , Compostos de Selênio/toxicidade , Animais , Artemia/efeitos dos fármacos , Compostos de Cádmio/química , Compostos de Cádmio/farmacologia , Nanoestruturas , Água/química
2.
Ecotoxicol Environ Saf ; 201: 110813, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32544745

RESUMO

The bioaccumulation potential and toxic effects of engineered nanomaterials (ENMs) to earthworms are poorly understood. Two studies were conducted following OECD TG 222 on Eisenia fetida to assess the effects of CdTe QDs with different coatings and soil ageing respectively. Earthworms were exposed to carboxylate (COOH), ammonium (NH4+), or polyethylene glycol (PEG) coated CdTe QDs, or a micron scale (bulk) CdTe material, at nominal concentrations of 50, 500 and 2000 mg CdTe QD kg-1 dry weight (dw) for 28 days in Lufa 2.2 soil. In the fresh soil study, earthworms accumulated similar amounts of Cd and Te in the CdTe-bulk exposures, while the accumulation of Cd was higher than Te during the exposures to CdTe QDs. However, neither the total Cd, nor Te concentrations in the earthworms, were easily explained by the extractable metal fractions in the soil or particle dissolution. There were no effects on survival, but some retardation of growth was observed at the higher doses. Inhibition of Na+/K+-ATPase activity with disturbances to tissue electrolytes, as well as tissue Cu and Mn were observed, but without depletion of total glutathione in the fresh soil experiment. Additionally, juvenile production was the most sensitive endpoint, with estimated nominal EC50 of values >2000, 108, 65, 96 mg CdTe kg-1 for bulk, PEG-, COOH- and NH4+-coated CdTe QDs, respectively. In the aged soil study, the accumulation of Cd and Te was higher than in the fresh soil study in all CdTe QD exposures. Survival of the adult worms was reduced in the top CdTe-COOH and -NH4+ QD exposures by 55 ±â€¯5 and 60 ±â€¯25%, respectively; and with decreases in growth. The nominal EC50 values for juvenile production in the aged soil were 165, 88, 78 and 63 mg CdTe kg-1 for bulk, PEG-, COOH- and NH4+-coated CdTe QDs, respectively. In conclusion, exposure to nanoscale CdTe QDs, regardless of coating, caused more severe toxic effects that the CdTe bulk material and the toxicity increased after soil ageing. There were some coating-mediated effects, likely due to differences in the metal content and behaviour of the materials.


Assuntos
Compostos de Cádmio/toxicidade , Oligoquetos/efeitos dos fármacos , Pontos Quânticos/toxicidade , Poluentes do Solo/toxicidade , Solo/química , Telúrio/toxicidade , Animais , Bioacumulação , Compostos de Cádmio/química , Compostos de Cádmio/metabolismo , Modelos Teóricos , Oligoquetos/metabolismo , Tamanho da Partícula , Pontos Quânticos/química , Pontos Quânticos/metabolismo , Reprodução/efeitos dos fármacos , Poluentes do Solo/química , Poluentes do Solo/metabolismo , Propriedades de Superfície , Telúrio/química , Telúrio/metabolismo , Fatores de Tempo
3.
Int J Nanomedicine ; 15: 2947-2955, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32425526

RESUMO

Introduction: ZnO quantum dots (QDs) have drawn much attention recently as they are Cd-free, low-cost, and have excellent optical properties. With the expanded production and application of ZnO nanoparticles, concerns about their potential toxicity have also been raised. Materials and Methods: We used RNA sequencing (RNA-seq) to analyze the global gene expression of liver and lung tissues after ZnO QDs treatment. Differentially expressed genes (DEGs) were screened, with a fold change >1.5 and padj <0.05. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed, and padj <0.05 was considered significantly enriched. The RNA-seq results were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Results: A total of 47 and 218 genes were significantly differentially expressed in the liver and lung. Eight GO terms were enriched in the liver and lung, and retinol metabolism and the peroxisome proliferator-activated receptor (PPAR) signaling pathway were shared in different tissues. Discussion: According to DEGs and pathway enrichment analyses, inflammation might be induced in liver and lung tissues after intravenous injection of ZnO QDs. These findings will be helpful for future research and application of ZnO QDs.


Assuntos
Fígado/efeitos dos fármacos , Proteínas de Neoplasias/efeitos dos fármacos , Proteínas Nucleares/efeitos dos fármacos , Pontos Quânticos/toxicidade , Ubiquitina-Proteína Ligases/efeitos dos fármacos , Óxido de Zinco/toxicidade , Animais , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Fígado/fisiologia , Masculino , Camundongos , Proteínas de Neoplasias/fisiologia , Proteínas Nucleares/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA , Testes de Toxicidade , Ubiquitina-Proteína Ligases/fisiologia
4.
Int J Nanomedicine ; 15: 1951-1965, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32256071

RESUMO

Introduction: Indium phosphide (InP) quantum dots (QDs) have shown a broad application prospect in the fields of biophotonics and nanomedicine. However, the potential toxicity of InP QDs has not been systematically evaluated. In particular, the effects of different surface modifications on the biodistribution and toxicity of InP QDs are still unknown, which hinders their further developments. The present study aims to investigate the biodistribution and in vivo toxicity of InP/ZnS QDs. Methods: Three kinds of InP/ZnS QDs with different surface modifications, hQDs (QDs-OH), aQDs (QDs-NH2), and cQDs (QDs-COOH) were intravenously injected into BALB/c mice at the dosage of 2.5 mg/kg BW or 25 mg/kg BW, respectively. Biodistribution of three QDs was determined through cryosection fluorescence microscopy and ICP-MS analysis. The subsequent effects of InP/ZnS QDs on histopathology, hematology and blood biochemistry were evaluated at 1, 3, 7, 14 and 28 days post-injection. Results: These types of InP/ZnS QDs were rapidly distributed in the major organs of mice, mainly in the liver and spleen, and lasted for 28 days. No abnormal behavior, weight change or organ index were observed during the whole observation period, except that 2 mice died on Day 1 after 25 mg/kg BW hQDs treatment. The results of H&E staining showed that no obvious histopathological abnormalities were observed in the main organs (including heart, liver, spleen, lung, kidney, and brain) of all mice injected with different surface-functionalized QDs. Low concentration exposure of three QDs hardly caused obvious toxicity, while high concentration exposure of the three QDs could cause some changes in hematological parameters or biochemical parameters related to liver function or cardiac function. More attention needs to be paid on cQDs as high-dose exposure of cQDs induced death, acute inflammatory reaction and slight changes in liver function in mice. Conclusion: The surface modification and exposure dose can influence the biological behavior and in vivo toxicity of QDs. The surface chemistry should be fully considered in the design of InP-based QDs for their biomedical applications.


Assuntos
Pontos Quânticos/toxicidade , Animais , Análise Química do Sangue , Feminino , Índio/química , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Fosfinas/química , Pontos Quânticos/química , Sulfetos/química , Propriedades de Superfície , Distribuição Tecidual , Compostos de Zinco/química
5.
Ecotoxicol Environ Saf ; 196: 110569, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32278141

RESUMO

Cadmium-quantum dots (Cd-QDs) possess unique properties as optoelectronic devices for sensitive detection in food and biomedicine fields. However, the toxic effects of Cd-QDs to single cells is still controversial, due to the release mechanism of QDs to Cd2+in situ and the cytotoxic effects of QDs and Cd2+ respectively are still unclear. In this paper, the release rule of Cd2+ from CdTe QDs within single cells was investigated in situ by using flow cytometry method and the dose-response relationships were explored. Besides, an all-inclusive microscopy system was optimized for live cell imaging to observe the real-time entry process of CdTe QDs into cells. We found that intracellular CdTe QDs and Cd2+ contents were increased based on the dosage and exposing time. A dissociated saturation of Cd2+ from CdTe QDs was exist within cells. CdTe QDs induced more serious cytotoxicity on kidney cells than hepatocytes. The toxicity of oxidative stress, cell apoptosis effects induced by CdTe QDs and Cd2+ are also in consistent with this result. This research develops analytical method to quantify the uptake and release of Cd-QDs to primary cells in situ and can provide technical support in studying the cytotoxicity portion contributed by nanoparticles (NPs) and metal ions.


Assuntos
Compostos de Cádmio/toxicidade , Hepatócitos/efeitos dos fármacos , Rim/efeitos dos fármacos , Pontos Quânticos/toxicidade , Telúrio/toxicidade , Animais , Apoptose/efeitos dos fármacos , Compostos de Cádmio/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Rim/citologia , Masculino , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , Pontos Quânticos/química , Telúrio/química
6.
Chemosphere ; 251: 126440, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32169699

RESUMO

Carbon dots (CDs) are an emerging fluorescent nano-imaging probe due to their unique characteristics, such as good conductivity, carbon-based chemical composition, and photochemical stability, which sets up the potential of outperforming the classic metal-based quantum dots (QDs). It is a timely effort to proactively investigate the biocompatibility feature of CDs with a view to safely utilize this emerging nanomaterial in biological systems. In this study, we assessed the safety profile of an in-house synthesized CDs in hepatocyte-like Hepa 1-6 cells, which represents an important target organ for CDs exposure through either particle uptake and/or accumulation and elimination from primary exposure sites post particle administration. We not only demonstrated a dose- and time-dependent compromised cell viability, but also observed the induction of autophagy at high concentration (i.e. 400 µg mL-1), authenticated by the conversion of microtubule-associated protein light chain 3 (LC3)-I to LC3-II. We attributed these changes as the protective mechanism by which the cells used to compensate for CDs-induced apoptosis and cytotoxicity. The involvement of autophagy was further confirmed because the cytotoxicity profile can be increased or reduced by the use of 3-MA (autophagy inhibitor) and NAC (ROS inhibitor), respectively. Collectively, our findings revealed dose-dependent moderate cytotoxicity in Hepa 1-6 cells. Mechanistic understanding of autophagy during the cellular process revealed the homeostasis when liver cells deal with CDs as an external insult.


Assuntos
Pontos Quânticos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Autofagia , Carbono/química , Morte Celular , Sobrevivência Celular , Corantes Fluorescentes , Células HeLa , Hepatócitos/metabolismo , Humanos , Metais , Nanoestruturas , Pontos Quânticos/química
7.
Mar Environ Res ; 156: 104904, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32174334

RESUMO

This study assesses the sex-specific effects induced by CdTe QDs, on the marine mussel Mytilus galloprovincialis in comparison to its dissolved counterpart. A 14 days exposure to CdTe QDs and dissolved Cd was conducted (10 µg Cd L-1), analysing Cd accumulation, oxidative stress, biotransformation, metallothionein and oxidative damage in the gonads. Both Cd forms caused significant antioxidant alterations, whereby QDs were more pro-oxidant, leading to oxidative damage, being females more affected. Overall, biochemical impairments on gonads of M. galloprovincialis demonstrate that the reproductive toxicity induced by CdTe QDs in mussels are sex-dependent and mediated by oxidative stress and lipid peroxidation. It is crucial to acknowledge how gametes are affected by metal-based nanoparticles, such as Cd-based QDs. As well as understanding the potential changes they may undergo at the cellular level during gametogenesis, embryogenesis and larval development potentially leading to serious impacts on population sustainability and ecosystem health.


Assuntos
Compostos de Cádmio/toxicidade , Gônadas/efeitos dos fármacos , Mytilus , Pontos Quânticos/toxicidade , Telúrio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Cádmio , Ecossistema , Peroxidação de Lipídeos , Estresse Oxidativo
8.
Chemosphere ; 251: 126174, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32151804

RESUMO

In this study, a model crop plant white mustard (Sinapis alba L.) was treated with an aqueous dispersion of silica-coated CdTe quantum dots (CdTe/SiO2 QDs) in a 72-h short-term toxicity test. The toxicity was established via measurements of (i) the root length and (ii) the chlorophyll fluorescence. These results were compared to two other sources of cadmium, free Cd ions (CdCl2) and prime un-shell nanoparticles CdTe QDs. Tested compounds were applied in concentrations representing 20 and 200 µM Cd. The uptake and translocation of Cd were investigated using inductively coupled plasma optical emission spectrometry (ICP-OES) and the spatial Cd distribution was investigated in detail applying laser induced breakdown spectroscopy (LIBS). The LIBS maps with a lateral resolution of 100 µm were constructed for the whole plants, and maps with a lateral resolution of 25 µm (micro-LIBS arrangement) were used to analyse only the most interesting parts of plants with Cd presence (e.g. root tips or a part crossing the root into the above-ground part). Our results show that the bioaccumulation patterns and spatial distribution of Cd in CdTe/SiO2 QDs-treated plants differ from the plants of positive control and CdTe QDs. Fluorescence microscopy photographs revealed that CdTe/SiO2 became adsorbed onto the plant surface in comparison to CdTe QDs. Further, a physico-chemical characterization of QDs before and after the test exposure showed only minor changes in the nanoparticle diameters and no tendencies of QDs for agglomeration or aggregation during the exposure.


Assuntos
Compostos de Cádmio/química , Pontos Quânticos/química , Adsorção , Bioacumulação , Cádmio , Compostos de Cádmio/toxicidade , Microscopia de Fluorescência , Pontos Quânticos/toxicidade , Dióxido de Silício/química , Sinapis/metabolismo , Cloreto de Sódio , Telúrio/química
9.
J Photochem Photobiol B ; 204: 111799, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32018156

RESUMO

CdSe/CdS core shelled quantum dots (QDs) were prepared by colloidal synthesis using a binary ligand system and a non-coordinating, reusable solvent n-octadecane (nOD). Both the synthesis of CdSe and CdSe/CdS core shelled quantum dots were achieved by hot injection technique at much lower temperatures than reported earlier. The use of binary ligand facilitated enough nucleation and growth. Red shift in absorption spectra, an enhanced crystallite and particle size is evidenced by XRD and TEM respectively, confirming the formation of core shell structure of CdSe/CdS. The synthesized core shells exhibited high fluorescence intensity, long term stability and good mono dispersion, making it a potential material for bio-imaging and sensing. Core shell QDs were modified with mercapto propionic acid (MPA) to impart aqueous solubility. Studies on cytotoxicity of shelled QDs reveal good bio compatibility with a very minimum toxicity of IC50 = 20 µg/L. These QDs were used for sensing E. coli. Ordinary glass slide, modified using plasma etching is surface modified through APTES aiding conjugation of antibodies. Anti- E. coli polyclonal antibody on glass matrix (slide) and antibody conjugated QDs were used for detection of E. coli in a typical sandwich model. The excellent optical transparency of glass and high emission of QDs lead to detection of E.coli with a limit of detection of 50 CFU/mL.


Assuntos
Escherichia coli/efeitos dos fármacos , Vidro/química , Pontos Quânticos/química , Animais , Compostos de Cádmio/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Microscopia de Fluorescência , Pontos Quânticos/toxicidade , Compostos de Selênio/química , Sulfetos/química , Propriedades de Superfície
10.
Chemosphere ; 246: 125629, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31927360

RESUMO

In this study, a metabolomic analysis was used to reveal the neurotoxicity of the CdTe/ZnS QDs via microglia polarization. A gas chromatography-mass spectrometer (GC-MS) was applied to uncover the metabonomic changes in microglia (BV-2 cell line) after exposure to 1.25 µM CdTe/ZnS QDs. 11 annotated metabolic pathways (KEGG database) were significantly changed in all exposed groups (3 h, 6 h, 12 h), 3 of them were related to glucose metabolism. The results of the Seahorse XFe96 Analyzer indicated that the CdTe/ZnS QDs increased the glycolysis level of microglia by 86% and inhibited the aerobic respiration level by 54% in a non-hypoxic environment. In vivo study, 3 h after the injection of CdTe/ZnS QDs (2.5 mM) through the tail vein in mice, the concentration of the CdTe/ZnS QDs in hippocampus reached the peak (1.25 µM). The polarization level of microglia (Iba-1 immunofluorescence) increased 2.7 times. In vitro study, the levels of the extracellular TNF-α, IL-1ß and NO of BV-2 cells were all increased significantly after a 6 h or 12 h exposure. According to the results of the Cell Counting Kit-8, after a 6 h or 12 h exposure to the CdTe/ZnS QDs, the exposed microglia could significantly decrease the number of neurons (HT-22 cell line). This study proved that CdTe/ZnS QDs could polarize microglia in the brain and cause secondary inflammatory damage to neurons. There are potential risks in the application of the CdTe/ZnS QDs in brain tissue imaging.


Assuntos
Metabolômica/métodos , Microglia/efeitos dos fármacos , Pontos Quânticos/toxicidade , Animais , Compostos de Cádmio , Polaridade Celular/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Glicólise/efeitos dos fármacos , Hipocampo/patologia , Camundongos , Síndromes Neurotóxicas/etiologia , Pontos Quânticos/química , Sulfetos , Telúrio , Compostos de Zinco
11.
Food Chem ; 315: 126171, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31991253

RESUMO

A new-style white pepper derived dual-emission carbon dots (CDs) with a quantum yield of 10.4% was designed and facile constructed with one-pot solvothermal method. The green emission (520 nm) had an efficient and special "turn-on" fluorescence sensing of coenzyme A (CoA) with the aid of Cu2+, while red emission (668 nm) barely changed and worked as reference. In the concentration range (0-150 µM), relative fluorescence intensity ratios (F520/F668) showed excellent linear correlation with concentrations of CoA, and detection limit was as low as 8.75 nm. Moreover, the strategy has been successfully applied for label-free detection of CoA in real pig liver samples with good recoveries (93.3-108.0%). Notably, the synthesized CDs had durable fluorescence, low cytotoxicity, and good biocompatibility for cellular imaging, which demonstrated wide and promising applicability for biosensing and bioimaging in the future.


Assuntos
Carbono/química , Coenzima A/análise , Imagem Molecular/métodos , Piper nigrum/química , Pontos Quânticos/química , Animais , Fluorescência , Química Verde , Células HeLa , Humanos , Limite de Detecção , Fígado/química , Imagem Molecular/instrumentação , Pontos Quânticos/toxicidade , Suínos , Testes de Toxicidade
12.
Nanotoxicology ; 14(3): 372-387, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31909648

RESUMO

The annual increase in the production and the use of engineering quantum dots (QDs) have led to concern about exposure and safety of QDs. To resolve the risk of Cd release from QDs, a series of Cd-free QDs, represented by CuInS2/ZnS QDs, has been developed in recent years. However, the toxicological profile of CuInS2/ZnS QDs has not been fully elucidated, especially, their immunotoxicity. Here, we performed a detailed in vitro cytotoxicity study on PEGylated CuInS2/ZnS QDs using the DC2.4 cell line and investigated their in vivo immunotoxicity using BALB/c mice. In vitro experiments showed that CuInS2/ZnS QDs were taken up by cells, promoted cell viability, enhanced release of tumor necrosis factor-α, and decreased the level of interleukin (IL)-6 in response to lipopolysaccharide stimulation. More than 5000 genes at the transcriptome level were observed by high-throughput RNA sequencing after CuInS2/ZnS QD exposure. In vivo study showed that CuInS2/ZnS QDs increased the levels of IL-4 on day 1 and enhanced the levels of IL-10 and IL-13 on day 28 in mice. There was no obvious difference in the number of spleen-derived lymphocytes, organic index, hematology and immune organ histology on days 1 and 28 after treatment. These findings demonstrated that PEGylated CuInS2/ZnS QDs disturbed the function of DC2.4 immune cells in vitro, but caused no obvious toxicity to immune system in vivo, suggesting that PEGylated CuInS2/ZnS QDs are biocompatible and have potential for bioapplication in the future.


Assuntos
Cobre/toxicidade , Sistema Imunitário/efeitos dos fármacos , Índio/toxicidade , Polietilenoglicóis/química , Pontos Quânticos/toxicidade , Sulfetos/toxicidade , Compostos de Zinco/toxicidade , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Feminino , Sistema Imunitário/imunologia , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Pontos Quânticos/química , Baço/efeitos dos fármacos , Baço/imunologia , Timo/efeitos dos fármacos , Timo/imunologia , Transcriptoma/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
13.
J Photochem Photobiol B ; 202: 111734, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31837584

RESUMO

A simple and one-step microwave digestion method was utilized to synthesize the highly photoluminescent glucosamine derived nitrogen and zinc doped carbon dots (N, Zn-CDs) with a bluish-green luminescence property. The synthesized N, Zn-CDs inherited a good photoluminescence property with a quantum yield of 74% and which were characterized by XPS, XRD, TEM, FT-IR, UV-Vis, and fluorescence spectrometry. More importantly, N, Zn-CDs served as a fluorescence sensor for the detection of Fe3+ ions, under optimal conditions, a good linear relationship was established in the concentration range of 0.25-125 µM. Also, the experimental results showed the detection limit of N, Zn-CDs against Fe3+ was 0.15 µM, this could be a promising assay for sensing Fe3+ ions. Also, the role of zinc doping was explored by conducting the detection under similar experimental conditions in the absence of zinc, and reports revealed that the reason for high photoluminescence was due to the zinc doping. Along with the sensing application, our group had investigated the bactericidal property of synthesized N, Zn-CDs against gram-negative (Escherichia coli), and gram-positive pathogens (Staphylococcus aureus). N, Zn-CDs displayed good bactericidal activity against both pathogens under light conditions, but Escherichia coli, even under the dark condition proved its activity. Besides, the morphology of both the strains was displayed before and after the treatment via a scanning electron microscopic images. Also, a plausible mechanism for bactericidal activity was also explained. The reported synthesis method could provide a novel approach for the design of high photoluminescent N, Zn-CDs with good sensing and bactericidal property towards Fe3+ ions, gram-negative and positive bacterial strains.


Assuntos
Carbono/química , Compostos Férricos/análise , Nitrogênio/química , Pontos Quânticos/química , Espectrometria de Fluorescência , Zinco/química , Catálise , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Água Doce/análise , Íons/química , Luz , Limite de Detecção , Micro-Ondas , Pontos Quânticos/toxicidade , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
14.
Chemosphere ; 240: 124856, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31568945

RESUMO

The differential mechanisms of CdS QDs (Quantum Dots) and Cd ion toxicity to Arabidopsis thaliana (L.) Heynh were investigated. Plants were exposed to 40 and 60 mg L-1 for CdS QDs and 76.9 and 115.2 mg L-1 CdSO4·7H2O and toxicity was evaluated at 5, 20, 35 (T5, T20, T35) days after exposure. Oxidative stress upon exposure was evaluated by biochemical essays targeting non-enzymatic oxidative stress physiological parameters, including respiration efficiency, total chlorophylls, carotenoids, ABTS and DPPH radicals reduction, total phenolics, GSH redox state, lipid peroxidation. Total Cd in plants was measured with AAS. Root and leaf morphology and element content were assessed in vivo utilizing low-vacuum Environmental Scanning Electron Microscopy (ESEM) with X-ray microanalysis (EDX). This integrated approach allowed identification of unique nanoscale CdS QDs toxicity to the plants that was distinct from CdSO4 exposure. The analyses highlighted that CdS QDs and Cd ions effects are modulated by the developmental stage of the plant, starting from T20 till T35 the plant development was modulated by the treatments, in particular CdS QDs induced early flowering. Both treatments induced Fe accumulation in roots, but at different intensities, while CdS QDs was associated with Mn increase into plant leaf. CdSO4 elicited higher levels of oxidative stress compared with QDs, especially the former treatment caused more intense respiration damages and reduction in chlorophyll and carotenoids than the latter. The two types of treatments impact differently on root and leaf morphology.


Assuntos
Arabidopsis/efeitos dos fármacos , Arabidopsis/fisiologia , Compostos de Cádmio/toxicidade , Pontos Quânticos/toxicidade , Sulfetos/toxicidade , Cádmio/farmacocinética , Cádmio/toxicidade , Clorofila/metabolismo , Microanálise por Sonda Eletrônica , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas , Pontos Quânticos/química
15.
Anal Chim Acta ; 1095: 204-211, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31864624

RESUMO

The abnormal expression of sialic acids (SAs) on cells and tissues is closely related to various pathophysiological states. Here we applied phenylboronic acid (PBA) functionalized graphitic carbon nitride fluorescent quantum dots (PCQDs) with sizes from 3 to 5 nm in efficient and selective labeling SAs on the surface of living cells and tissues. With abundant PBA in their structure, the water soluble PCQDs showed the relative SA level on the cell surface via selectively and efficiently staining different cell lines in 30 min and revealed that M1 macrophages may express more SAs on their surfaces compared with M0 and M2. The distinct demarcation of cancerous and para-noncancerous areas on cancer tissue sections was showed by PCQDs staining. PCQDs with their high selectivity, stable photoluminescence, low cost, and nontoxicity can be an ideal SA fluorescent probe for living cells and tissues.


Assuntos
Corantes Fluorescentes/química , Grafite/química , Ácido N-Acetilneuramínico/análise , Compostos de Nitrogênio/química , Pontos Quânticos/química , Animais , Ácidos Borônicos/química , Ácidos Borônicos/toxicidade , Linhagem Celular Tumoral , Corantes , Corantes Fluorescentes/toxicidade , Grafite/toxicidade , Humanos , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Ácido N-Acetilneuramínico/metabolismo , Compostos de Nitrogênio/toxicidade , Pontos Quânticos/toxicidade , Células RAW 264.7 , Coloração e Rotulagem
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 229: 117792, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31865110

RESUMO

The paper by the authors Hau and Liu (Spectrochim Acta A Mol Biomol Spectrosc. 2019 Sep 5;220:117104) showed the effects of mercaptopropionic acid- CdTe quantum dots to the antioxidant enzymes catalase and superoxide dismutase molecules and then demonstrates the subsequent quantum dots toxic effects at a cellular level, and they proposed a mechanism of QD induced apoptosis and cell death involving oxidative stress, revealing their potential risk in the biomedical applications. QD concentrations were not determined according to the Cd concentrations in the QD that could be measured via ICP-MS. In conclusion, since cell viability above 80% as non-toxic based on ISO 10993-5, CdTe QDs cannot be considered as toxic. Also, according to the literature only CAT and SOD enzyme activities are not enough to claim oxidative stress formation.


Assuntos
Ácido 3-Mercaptopropiônico/toxicidade , Compostos de Cádmio/toxicidade , Catalase/metabolismo , Hepatócitos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Pontos Quânticos/toxicidade , Superóxido Dismutase/metabolismo , Telúrio/toxicidade , Animais , Células Cultivadas , Hepatócitos/efeitos dos fármacos , Humanos , Células MCF-7 , Camundongos
18.
Int J Nanomedicine ; 14: 9513-9524, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819447

RESUMO

Background: Early diagnosis of renal cell carcinoma is extremely significant for the effective treatment of kidney cancer. The development of AS1411 aptamer modified Mn-MoS2 QDs provides a promising fluorescence/magnetic resonance (MR) dual-modal imaging probe for the precise diagnosis of renal clear cell carcinoma. Methods: In this work, Mn-MoS2 QDs were synthesized through a simple "bottom-up" one-step hydrothermal method. AS1411 aptamer was modified on the Mn-MoS2 QDs to improve the specificity to renal cell carcinoma. The characteristics of Mn-MoS2 QDs were confirmed by transmission electronic microscopy (TEM), atomic force microscope (AFM), X-ray photoelectron spectrometer (XPS), photoluminescence (PL) emission spectra, etc. Cellular fluorescence labelling was investigated using the Mn-MoS2 QDs and AS1411-Mn-MoS2 QDs. The T1-weighted MR imaging was assessed by the in vitro MR cell imaging and in vivo MR imaging. Finally, the long-term toxicity of Mn-MoS2 QDs was investigated by the hematology and histological analysis. Results: The prepared Mn-MoS2 QDs exhibited excellent aqueous property, intense fluorescence, low toxicity, high quantum yield of 41.45% and high T1 relaxivity of 16.95 mM-1s-1. After conjugated with AS1411 aptamer, the AS1411-Mn-MoS2 QDs could specifically fluorescently label the renal carcinoma cells and present a specific MRI signal enhancement in the tumor region of mice bearing renal carcinoma tumors. Furthermore, Mn-MoS2 QDs revealed low toxicity to the mice via hematology and histological analysis. Conclusion: These results demonstrated the potential of AS1411-Mn-MoS2 QD as a novel nanoprobe for targeted MR imaging and fluorescence labelling of renal cell carcinoma.


Assuntos
Aptâmeros de Nucleotídeos/química , Carcinoma de Células Renais/diagnóstico por imagem , Dissulfetos/química , Imagem por Ressonância Magnética , Manganês/química , Molibdênio/química , Oligodesoxirribonucleotídeos/química , Pontos Quânticos/química , Coloração e Rotulagem , Animais , Morte Celular , Linhagem Celular Tumoral , Dissulfetos/toxicidade , Feminino , Fluorescência , Humanos , Neoplasias Renais/diagnóstico por imagem , Manganês/toxicidade , Camundongos , Molibdênio/toxicidade , Pontos Quânticos/toxicidade , Pontos Quânticos/ultraestrutura
19.
Mikrochim Acta ; 186(12): 851, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31776683

RESUMO

A rapid, sensitive, and selective fluorometric assay is described for the determination of chromium(VI) in real waters and living cells. The method is making use of nitrogen, phosphorus, and sulfur tri-doped carbon dots (NPS-CDs) which have absorption/emission maxima at 360/505 nm/nm. Cr(VI) has an absorption maximum at 350 nm and causes an inner filter effect (IFE) on the blue fluorescence of the NPS-CDs. The NPS-CDs were hydrothermally synthesized using p-aminobenzenesulfonic acid and tetrakis(hydroxymethyl)phosphonium chloride as precursors. The NPS-CDs were characterized by transmission electron microscopy, X-ray diffraction, and several spectroscopic methods. They are biocompatible and negligibly cytotoxic when tested with HeLa cells and MCF-7 cells even after 48 h of incubation. The NPS-CDs were used as fluorescent probes for Cr(VI). The detection limit is 0.23 µM (three times standard deviation versus slope), and the linear response covers the 1 to 500 µM chromate concentration range. The NPS-CDs were applied to the determination of Cr(VI) in real waters and living cells (HeLa and MCF-7) and gave satisfying results. Graphical abstractSchematic representation of hydrothermal synthesis of nitrogen, phosphorus, and sulfur tri-doped carbon dots (NPS-CDs) for Cr(VI) detection via inner filter effect (IFE). NPS-CDs were applied to the determination of Cr(VI) in living cells (HeLa and MCF-7) with satisfying results.


Assuntos
Cromo/análise , Corantes Fluorescentes/química , Pontos Quânticos/química , Poluentes Químicos da Água/análise , Carbono/química , Carbono/toxicidade , Linhagem Celular Tumoral , Água Potável/análise , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Humanos , Lagos/análise , Limite de Detecção , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Nitrogênio/química , Nitrogênio/toxicidade , Fósforo/química , Fósforo/toxicidade , Pontos Quânticos/toxicidade , Chuva/química , Rios/química , Espectrometria de Fluorescência/métodos , Enxofre/química , Enxofre/toxicidade , Águas Residuárias/análise
20.
Chem Commun (Camb) ; 55(100): 15053-15056, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31777878

RESUMO

The present study reports an aqueous synthesis approach towards off-stoichiometric copper indium sulfide quantum dots with emissions in the near-infrared spectral range. The photoluminescence properties of the dots, and in particular the appearance of dual emission at high Cu deficiency, were studied with temperature-dependent steady-state and transient photoluminescence spectroscopy.


Assuntos
Materiais Biocompatíveis/química , Pontos Quânticos/química , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular , Cobre/química , Células HeLa , Humanos , Índio/química , Medições Luminescentes , Pontos Quânticos/toxicidade , Temperatura , Raios Ultravioleta
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