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1.
Aquat Toxicol ; 233: 105795, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33677260

RESUMO

Although carbon nanotubes' (CNTs) toxicity in different experimental systems (in vivo and in vitro) is known, little is known about the toxic effects of carbon nanofibers (CNFs) on aquatic vertebrates. We herein investigated the potential impact of CNFs (1 and 10 mg/L) by using Physalaemus cuvieri tadpoles as experimental model. CNFs were able to induce nutritional deficit in animals after 48-h exposure to them, and this finding was inferred by reductions observed in body concentrations of total soluble carbohydrates, total proteins, and triglycerides. The increased production of hydrogen peroxide, reactive oxygen species and thiobarbituric acid reactive substances in tadpoles exposed to CNFs has suggested REDOX homeostasis change into oxidative stress. This process was correlated to the largest number of apoptotic and necrotic cells in the blood of these animals. On the other hand, the increased superoxide dismutase and catalase activity has suggested that the antioxidant system of animals exposed to CNFs was not enough to maintain REDOX balance. In addition, CNFs induced increase in acetylcholinesterase and butyrylcholinesterase activity, as well as changes in the number of neuromasts evaluated on body surface (which is indicative of the neurotoxic effect of nanomaterials on the assessed model system). To the best of our knowledge, this is the first report on the impact of CNFs on amphibians; therefore, it broadened our understanding about ecotoxicological risks associated with their dispersion in freshwater ecosystems and possible contribution to the decline in the populations of anurofauna species.


Assuntos
Carbono/toxicidade , Larva/efeitos dos fármacos , Larva/metabolismo , Nanofibras/toxicidade , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase/metabolismo , Animais , Antioxidantes/metabolismo , Anuros , Ecossistema , Modelos Teóricos , Estresse Oxidativo/efeitos dos fármacos , Projetos de Pesquisa
2.
Nat Commun ; 12(1): 812, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33547279

RESUMO

Carbon dots (CDs) are photoluminescent nanomaterials with wide-ranging applications. Despite their photoactivity, it remains unknown whether CDs degrade under illumination and whether such photodegradation poses any cytotoxic effects. Here, we show laboratory-synthesized CDs irradiated with light degrade into molecules that are toxic to both normal (HEK-293) and cancerous (HeLa and HepG2) human cells. Eight days of irradiation photolyzes 28.6-59.8% of the CDs to <3 kilo Dalton molecules, 1431 of which are detected by high-throughput, non-target high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Molecular network and community analysis further reveal 499 cytotoxicity-related molecules, 212 of which contain polyethylene glycol, glucose, or benzene-related structures. Photo-induced production of hydroxyl and alkyl radicals play important roles in CD degradation as affected by temperature, pH, light intensity and wavelength. Commercial CDs show similar photodegraded products and cytotoxicity profiles, demonstrating that photodegradation-induced cytotoxicity is likely common to CDs regardless of their chemical composition. Our results highlight the importance of light in cytocompatibility studies of CDs.


Assuntos
Carbono/toxicidade , Citotoxinas/toxicidade , Pontos Quânticos/toxicidade , Derivados de Benzeno/química , Derivados de Benzeno/toxicidade , Carbono/química , Carbono/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Citotoxinas/química , Glucose/química , Glucose/toxicidade , Células HEK293 , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Radical Hidroxila/química , Radical Hidroxila/toxicidade , Cinética , Luz , Fotólise , Polietilenoglicóis/química , Polietilenoglicóis/toxicidade , Pontos Quânticos/química , Pontos Quânticos/efeitos da radiação , Temperatura
3.
ACS Appl Mater Interfaces ; 13(1): 1277-1287, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33393300

RESUMO

Selective discrimination and lasting tracking of live bacteria are primary steps for microbiology research and treatment of bacterial infection. However, conventional detection methods, such as the gold standard of Gram staining, are being challenged under actual test conditions. Herein, we provided a novel method, namely, three excitation peaks and single-color emission carbon quantum dots (T-SCQDs) for the rapid (5 min) peptidoglycan-targeting discrimination of Gram-positive bacteria and lasting tracking (24 h) through one-step staining. Bacterial viability testing indicates that T-SCQDs can achieve nondestructive identification of Gram-positive bacteria within 50-500 µg mL-1. Interestingly, the fluorescence imaging system suggests that T-SCQDs can also selectively distinguish the type of colonies based on fluorescence intensity. Furthermore, T-SCQDs were successfully used to visually distinguish Gram-positive bacteria from the microbial environment of A549 cells by confocal fluorescence microscopy. These properties endow T-SCQDs with excellent functions for the diagnosis of infection and other biological applications.


Assuntos
Corantes Fluorescentes/química , Peptidoglicano/metabolismo , Pontos Quânticos/química , Staphylococcus aureus/isolamento & purificação , Células A549 , Carbono/química , Carbono/metabolismo , Carbono/toxicidade , Corantes Fluorescentes/metabolismo , Corantes Fluorescentes/toxicidade , Humanos , Microscopia Confocal , Microscopia de Fluorescência , Pontos Quânticos/metabolismo , Pontos Quânticos/toxicidade
4.
ACS Appl Mater Interfaces ; 13(1): 277-286, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33355448

RESUMO

This work demonstrates the application of hyaluronan-conjugated nitrogen-doped carbon quantum dots (HA-nCQDs) for bioimaging of tumor cells and illustrates their potential use as carriers in targeted drug delivery. Quantum dots are challenging to deliver with specificity, which hinders their application. To facilitate targeted internalization by cancer cells, hyaluronic acid, a natural ligand of CD44 receptors, was covalently grafted on nCQDs. The HA-nCQD conjugate was synthesized by carbodiimide coupling of the amine moieties on nCQDs and the carboxylic acids on HA chains. Conjugated HA-nCQD retained sufficient fluorescence, although with 30% lower quantum efficiency than the original nCQDs. Confocal microscopy showed enhanced internalization of HA-nCQDs, facilitated by CD44 receptors. To demonstrate the specificity of HA-nCQDs toward human tumor cells, patient-derived breast cancer tissue with high-CD44 expression was implanted in adult mice. The tumors were allowed to grow up to 200-250 mm3 prior to the injection of HA-nCQDs. With either local or systemic injection, we achieved a high level of tumor specificity judged by a strong signal-to-noise ratio between the tumor and the surrounding tissue in vivo. Overall, the results show that HA-nCQDs can be used for imaging of CD44-specific tumors in preclinical models of human cancer and potentially used as carriers for targeted drug delivery into CD44-rich cells.


Assuntos
Meios de Contraste/química , Corantes Fluorescentes/química , Ácido Hialurônico/química , Neoplasias/diagnóstico por imagem , Pontos Quânticos/química , Animais , Células CHO , Carbono/química , Carbono/toxicidade , Linhagem Celular Tumoral , Meios de Contraste/metabolismo , Meios de Contraste/toxicidade , Cricetulus , Feminino , Corantes Fluorescentes/metabolismo , Corantes Fluorescentes/toxicidade , Humanos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/metabolismo , Ácido Hialurônico/toxicidade , Camundongos , Microscopia Confocal , Microscopia de Fluorescência , Células NIH 3T3 , Imagem Óptica , Pontos Quânticos/metabolismo , Pontos Quânticos/toxicidade
5.
Food Chem ; 338: 127832, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32818868

RESUMO

Food-borne carbon dots (CDs) may cause health risks due to their unique properties. However, previous efforts were mainly focused on the characterization of their physicochemical properties, their effects on cellular metabolism are not entirely revealed. Herein, the features and potential toxicity of CDs from lamb baked for 15, 30, and 45 min were evaluated, their cytotoxicity increased with the extension of baking time. Furthermore, the metabolic responses of PC12 cells after exposure to CDs from lamb baked for 45 min were investigated. The CDs perturbed purine metabolism, causing reactive oxygen species accumulation. Meanwhile, the CDs down-regulated glycolysis and TCA cycle, led to a significant decrease in ATP. Additionally, the CDs induced triglyceride accumulation, mainly through enhanced fatty acid biosynthesis. The adverse effects of CDs from baked lamb involved the perturbation of energy production, purine metabolism, and triglyceride biosynthesis, which provided additional information about the risks of CDs from food items.


Assuntos
Carbono/química , Metabolismo Energético/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Carne Vermelha/efeitos adversos , Trifosfato de Adenosina/metabolismo , Animais , Carbono/toxicidade , Culinária , Regulação da Expressão Gênica/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Células PC12 , Purinas/metabolismo , Pontos Quânticos/química , Ratos , Espécies Reativas de Oxigênio/metabolismo , Carneiro Doméstico , Triglicerídeos/metabolismo
6.
Ecotoxicol Environ Saf ; 189: 109982, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31830603

RESUMO

The increasing application of nanomaterials in various fields such as drug delivery, cosmetics, disease detection, cancer treatment, food preservation etc. has resulted in high levels of engineered nanoparticles in the environment, thus leading to higher possibility of direct or indirect interactions between these particles and biological systems. In this study, the toxic effects of three commercially available nanomaterials; copper oxide nanoparticles, copper-iron oxide nanopowders and carbon nanopowders were determined in the human hepatoma HepG2 cells using various toxicological assays which are indicative of cytotoxicity (MTT and neutral red assays), mutagenicity (cytokinesis-block micronucleus assay), oxidative stress (total reactive oxygen species and superoxide anion production) and mitochondrial impairment (cellular oxygen consumption). There was increased cytotoxicity, mutagenicity, and mitochondrial impairment in the cells treated with higher concentrations of the nanomaterials, especially the copper oxide nanoparticles. The fold production of reactive oxygen species was similar at the concentrations tested in this study but longer exposure duration resulted in production of more superoxide anions. The results of this study showed that copper oxide nanoparticles are highly toxic to the human HepG2 cells, thus implying that the liver is a target organ in human for copper oxide nanoparticles toxicity.


Assuntos
Carbono/toxicidade , Cobre/toxicidade , Poluentes Ambientais/toxicidade , Compostos Ferrosos/toxicidade , Nanopartículas/toxicidade , Carbono/química , Cobre/química , Dano ao DNA/efeitos dos fármacos , Poluentes Ambientais/química , Compostos Ferrosos/química , Células Hep G2 , Humanos , Mitocôndrias/efeitos dos fármacos , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos
7.
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
8.
Artigo em Inglês | MEDLINE | ID: mdl-31771182

RESUMO

As a non-invasive method, heart rate variability (HRV) has been widely used to study cardiovascular autonomous control. Environmental epidemiological studies indicated that the increase in an average concentration of particulate matter (PM) would result in a decrease in HRV, which was related to the increase of cardiovascular mortality in patients with myocardial infarction and the general population. With rapid economic and social development in Asia, how air pollutants, such as PM of different sizes and their components, affect the cardiovascular health of older people, still need to be further explored. The current study includes a 72 h personal exposure monitoring of seven healthy older people who lived in the Taipei metropolitan area. Mobile equipment, a portable electrocardiogram recorder, and the generalized additive mixed model (GAMM) were adopted to evaluate how HRV indices were affected by size-fractionated PM, particle-bound polycyclic aromatic hydrocarbons (p-PAHs), black carbon (BC), and carbon monoxide (CO). Other related confounding factors, such as age, sex, body mass index (BMI), temperature, relative humidity (RH), time, and monitoring week were controlled by fixed effects of the GAMM. Statistical analyses of multi-pollutant models showed that PM2.5-10, PM1, and nanoparticle (NP) could cause heart rate (HR), time-domain indices, and frequency-domain indices to rise; PM1-2.5 and BC would cause the frequency-domain index to rise; p-PAHs would cause HR to rise, and CO would cause time-domain index and frequency-domain index to decline. In addition, the moving average time all fell after one hour and might appear at 8 h in HRVs' largest percentage change caused by each pollutant, results of which suggested that size-fractionated PM, p-PAHs, BC, and CO exposures have delayed effects on HRVs. In conclusion, the results of the study showed that the increase in personal pollutant exposure would affect cardiac autonomic control function of healthy older residents in metropolitan areas, and the susceptibility of cardiovascular effects was higher than that of healthy young people. Since the small sample size would limit the generalizability of this study, more studies with larger scale are warranted to better understand the HRV effects of simultaneous PM and other pollution exposures for subpopulation groups.


Assuntos
Carbono/toxicidade , Frequência Cardíaca/efeitos dos fármacos , Nanopartículas/toxicidade , Material Particulado/toxicidade , Adolescente , Idoso , Idoso de 80 Anos ou mais , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Carbono/química , Monóxido de Carbono/análise , Poluentes Ambientais/análise , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Tamanho da Partícula , Hidrocarbonetos Policíclicos Aromáticos/análise , Taiwan
9.
Analyst ; 145(1): 177-183, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31729506

RESUMO

Carbon dots (CDs) have broad prospective applications in various fields, and expanding the applications of fluorescent CDs, especially for CDs derived from bacteria, is a major research goal. In this study, novel CDs derived from Escherichia coli BW25113 (WT) were successfully synthesized via a one-step hydrothermal method. Unlike previously developed CDs-E. coli, CDs-WT can be used for microbial imaging of both live and dead cells. We demonstrated the biocompatibility, excellent penetrability, and nontoxic characteristics of CDs-WT for use as fluorescent probes for bioimaging both in vitro and in vivo. Importantly, we provide the first demonstration of CDs-WT distribution in various organs of mice, including the ability to cross the blood-brain barrier and the potential for rapid excretion through the intestines. Additionally, CDs-WT can be instantly utilized as a fluorescent probe for the highly selective and rapid detection of p-nitrophenol (p-NP) by the inner filter effect, with a limit of detection for p-NP of 11 nM, the lowest value reported to date. Hence, our results demonstrate the feasibility of p-NP detection and extend the bio-imaging applications of CDs prepared from bacteria.


Assuntos
Corantes Fluorescentes/química , Nitrofenóis/análise , Pontos Quânticos/química , Animais , Bacillus cereus/metabolismo , Carbono/química , Carbono/toxicidade , Linhagem Celular Tumoral , Escherichia coli/química , Corantes Fluorescentes/toxicidade , Humanos , Limite de Detecção , Masculino , Camundongos Endogâmicos BALB C , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Nitrofenóis/metabolismo , Pontos Quânticos/toxicidade , Saccharomyces cerevisiae/metabolismo , Distribuição Tecidual
10.
Anal Chim Acta ; 1091: 76-87, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31679577

RESUMO

To understand the effect of Cl doping in carbon dots, nitrogen-doped carbon dots (N-Cdots) and nitrogen and chlorine dual-doped carbon dots (Cl,N-Cdots) were fabricated by high-temperature carbonization and low-temperature concentrated acid (HCl) acidification of dried shaddock peel, respectively. The quantum yield of Cl,N-Cdots is about four times of that of N-Cdots and the size of Cl,N-Cdots is smaller than that of N-Cdots. Furthermore, since trinitrophenol (PA) and ClO- could effectively quench the fluorescence of Cl,N-Cdots, the fluorescence sensors for determining PA and ClO- was constructed, respectively. The linear range of PA and ClO- are 0.9-90 µM and 3.24-216 µM with the limit of detection of 37.1 nM and 2.88 µM, respectively. The proposed sensor was used to detect PA in Taiyuan tap water, Wutai tap water, Wutai rain water and Wutai river water samples with encouraging results. The as-constructed sensor was also used to detect ClO- in Taiyuan tap water and commercial disinfectants. Last but not least, Cl,N-Cdots was employed as an agent for A549 and HeLa cell-imaging, possessing optimal imaging effect and ultra-low cytotoxicity. Our results suggested that Cl,N-Cdots has promising applications in sensing, water monitoring, commodity supervision and cell-imaging.


Assuntos
Ácido Hipocloroso/análise , Nitrofenóis/análise , Picratos/análise , Pontos Quânticos/química , Poluentes Químicos da Água/análise , Carbono/química , Carbono/toxicidade , Linhagem Celular Tumoral , Cloro/química , Cloro/toxicidade , Citrus/química , Desinfetantes/análise , Água Potável/análise , Humanos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Nitrogênio/química , Nitrogênio/toxicidade , Pontos Quânticos/toxicidade , Rios/química , Espectrometria de Fluorescência/métodos
11.
Anal Chim Acta ; 1089: 131-143, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31627810

RESUMO

In this work, the as-prepared V2O5 nanobelts can sensitively quench the fluorescence of nitrogen-doped carbon dots (N-CDs) based on the inner filter effect (IFE). In the presence of ascorbic acid (AA), the fluorescence of N-CDs can recover through the redox reaction between V2O5 nanobelts and AA. Meanwhile, in the presence of both alkaline phosphatase (ALP) and ascorbyl-2-phosphate (AAP), the fluorescence of N-CDs can also restore since AAP can be hydrolyzed into AA by ALP. Under optimum conditions, the linear range for AA is from 0.01 to 2.5 µM with a detection limit of 3 nM and that for ALP is from 0.1 to 30 U/L with a detection limit of 0.04 U/L (S/N = 3). Particularly, the proposed probe could be successfully used to detect AA and ALP in human serum samples. Furthermore, N-CDs can be applied in fluorescence imaging of Human breast cancer cells with satisfactory results.


Assuntos
Fosfatase Alcalina/sangue , Ácido Ascórbico/sangue , Corantes Fluorescentes/química , Pontos Quânticos/química , Compostos de Vanádio/química , Técnicas Biossensoriais/métodos , Carbono/química , Carbono/toxicidade , Linhagem Celular Tumoral , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Humanos , Limite de Detecção , Microscopia de Fluorescência/métodos , Nitrogênio/química , Nitrogênio/toxicidade , Pontos Quânticos/toxicidade , Espectrometria de Fluorescência/métodos , Compostos de Vanádio/toxicidade
12.
Anal Chem ; 91(22): 14681-14690, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31617347

RESUMO

Rapid, accurate, and safe screening of foodborne pathogenic bacteria is essential to effectively control and prevent outbreaks of foodborne illness. Fluorescent sensors constructed from carbon dots (CDs) and nanomaterial-based quenchers have provided an innovative method for screening of pathogenic bacteria. Herein, an ultrasensitive magnetic fluorescence aptasensor was designed for separation and detection of Staphylococcus aureus (S. aureus). Multicolor fluorescent CDs with a long fluorescent lifetime (6.73 ns) and high fluorescence stability were synthesized using a facile hydrothermal approach and modified cDNA as a highly sensitive fluorescent probe. CD fluorescence was quenched by Fe3O4 + aptamer via fluorescence resonance energy transfer (FRET). Under optimal conditions, the FRET-based aptasensor can detect S. aureus accompanied by a wide linear range of 50-107 CFU·mL-1 and a detection limit of 8 CFU·mL-1. Compared with other standard methods, this method was faster and more convenient, and the entire test was finished within 30 min. The capability of the aptasensor was simultaneously investigated on food samples. Additionally, the developed CDs exhibited excellent biocompatibility and were thus applied as fluorescent probes for bioimaging both in vitro and in vivo. This new platform provided an excellent application of the CDs for detecting and bioimaging pathogenic bacteria.


Assuntos
Técnicas Biossensoriais/métodos , Corantes Fluorescentes/química , Pontos Quânticos/química , Staphylococcus aureus/isolamento & purificação , Animais , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/toxicidade , Carbono/química , Carbono/toxicidade , DNA/química , DNA/toxicidade , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/toxicidade , Contaminação de Alimentos/análise , Sucos de Frutas e Vegetais/microbiologia , Células Hep G2 , Humanos , Limite de Detecção , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/toxicidade , Camundongos Nus , Leite/microbiologia , Neoplasias/diagnóstico por imagem , Imagem Óptica/métodos , Fenilenodiaminas/química , Fenilenodiaminas/toxicidade , Pontos Quânticos/toxicidade , Staphylococcus aureus/química
13.
Mikrochim Acta ; 186(11): 708, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31641864

RESUMO

Red emissive B,N co-doped carbon dots (BN-CDs) were hydrothermally synthesized from cresyl violet and boric acid. The BN-CDs exhibited excellent photostability, low cytotoxicity, excitation/emission maxima at 520/616 nm, and a relatively high quantum yield of 18%. The BN-CDs can binded to mercury(II), and this results in quenching of the red-colored fluorescence. However, on subsequent addition of the biothiol (such as cysteine, homocysteine or glutathione), fluorescence recovers. Therefore, the BN-CDs can be used as a multifunctional probe based on "on-off-on" fluorescence response for the detection of Hg(II) and biothiols. The following detection limits were accomplished: (a) Hg(II): 2.8 µM; (b) glutathione: 1.7 µM; (c) cysteine: 2.3 µM; (d) homocysteine: 3.0 µM. The BN-CDs also have been successfully applied for the imaging of Hg(II) and biothiols in HepG2 cells with excellent bio-compatibility. Graphical abstract Red emissive B,N co-doped carbon dots (BN-CDs) were synthesized through hydrothermal treatment of cresyl violet and boric acid. The BN-CDs can be used as a multifunctional probe based on "on-off-on" fluorescence response for detecting mercury(II) and biothiols in aqueous solution and living cells.


Assuntos
Cisteína/análise , Corantes Fluorescentes/química , Glutationa/análise , Homocisteína/análise , Mercúrio/análise , Pontos Quânticos/química , Boro/química , Boro/toxicidade , Carbono/química , Carbono/toxicidade , Cor , Água Potável/análise , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Células Hep G2 , Humanos , Lagos/análise , Limite de Detecção , Microscopia Confocal , Microscopia de Fluorescência , Nitrogênio/química , Nitrogênio/toxicidade , Pontos Quânticos/toxicidade , Espectrometria de Fluorescência , Poluentes Químicos da Água/análise
14.
Anal Chim Acta ; 1090: 133-142, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31655638

RESUMO

A fluorescent probe for the determination of nitrite (NO2-) was fabricated by using green fluorescent nitrogen doped carbon dots (NCDs). The NCDs were synthesized via a one-pot hydrothermal carbonization of citric acid in the presence of p-phenylenediamine as the nitrogen source. The N content of the NCDs was high to 17.09% and consisted of a variety of functional groups on the NCDs surface, including sp2-hybridized CN, porphyrin C-N-C and amino N in N-(C) 3 or H-N-(C) 2 et al. N atoms were also doped within the framework of the NCDs. The almost monodisperse NCDs (average particle diameter = 3.67 nm) exhibited green photoluminescence (PL) with excitation/emission maxima of 360/505 nm. The PL of the NCDs was dependent on both excitation wavelength and solution pH. The NCDs showed a strong PL quenching response to NO2- under acidic conditions (pH = 2.5). The PL intensity of the NCDs was inversely proportional to the concentration of NO2- between 0.02 and 40 µM (R2 = 0.992), with a detection limit of 21.2 nM. The practical use of the nanoprobe for NO2- determination in food samples was also demonstrated, successfully. NCD-nitroso compounds formed because of reaction between the abundant amide groups on the surface of NCDs with the NO2-, which caused an inner filter effect and static PL quenching. Importantly, the NCDs had low cellular toxicity and were successfully used as a multicolor cellular imaging agent for Hepg2 cells.


Assuntos
Carbono/química , Corantes Fluorescentes/química , Nitritos/análise , Nitrogênio/química , Pontos Quânticos/química , Brassica/química , Carbono/toxicidade , Ácido Cítrico/química , Corantes Fluorescentes/toxicidade , Contaminação de Alimentos/análise , Células Hep G2 , Temperatura Alta , Humanos , Limite de Detecção , Microscopia de Fluorescência/métodos , Nitrogênio/toxicidade , Fenilenodiaminas/química , Pontos Quânticos/toxicidade , Carne Vermelha/análise , Espectrometria de Fluorescência/métodos , Verduras/química
15.
Analyst ; 144(22): 6729-6735, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31612877

RESUMO

The conjugation of ligands to nanoparticles as drug delivery systems that target specific cells is a promising approach for the delivery of therapeutic agents to tumor cells. Herein, we prepared green-emission fluorescent carbon nanodots (CNDs) by a facile hydrothermal method with d-(+)-glucosamine hydrochloride and l-aspartic acid as the precursors, then covalently conjugated with folate (FA), polyethyleneimine (PEI) and hyaluronic acid (HA) to develop dual ligand-decorated nanocarriers (FA-PEI-HA-CNDs) for the targeted imaging of cancer cells. FA-PEI-HA-CNDs integrated the excellent fluorescence property of CNDs, and can be used for the real-time and noninvasive location tracking of cancer cells. The cellular uptake study demonstrated that FA-PEI-HA-CNDs markedly improved the internalization efficiency in A-549 cells via folate/CD44 receptor-mediated endocytosis in comparison with that of the A549 cells pretreated with excess FA, HA, and FA and HA. Therefore, these dual folate/CD44 receptor-targeted CNDs (FA-PEI-HA-CNDs) show promising potential for cancer detection, drug delivery, and individualized treatment as performance platforms.


Assuntos
Corantes Fluorescentes/química , Pontos Quânticos/química , Células A549 , Carbono/química , Carbono/toxicidade , Endocitose/efeitos dos fármacos , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Receptores de Folato com Âncoras de GPI/metabolismo , Ácido Fólico/análogos & derivados , Ácido Fólico/síntese química , Ácido Fólico/toxicidade , Humanos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/análogos & derivados , Ácido Hialurônico/síntese química , Ácido Hialurônico/toxicidade , Ligantes , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Polietilenoimina/análogos & derivados , Polietilenoimina/síntese química , Polietilenoimina/toxicidade , Pontos Quânticos/toxicidade
16.
Thorax ; 74(11): 1063-1069, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31391318

RESUMO

BACKGROUND: Ambient air pollution accelerates lung function decline among adults, however, there are limited data about its role in the development and progression of early stages of interstitial lung disease. AIMS: To evaluate associations of long-term exposure to traffic and ambient pollutants with odds of interstitial lung abnormalities (ILA) and progression of ILA on repeated imaging. METHODS: We ascertained ILA on chest CT obtained from 2618 Framingham participants from 2008 to 2011. Among 1846 participants who also completed a cardiac CT from 2002 to 2005, we determined interval ILA progression. We assigned distance from home address to major roadway, and the 5-year average of fine particulate matter (PM2.5), elemental carbon (EC, a traffic-related PM2.5 constituent) and ozone using spatio-temporal prediction models. Logistic regression models were adjusted for age, sex, body mass index, smoking status, packyears of smoking, household tobacco exposure, neighbourhood household value, primary occupation, cohort and date. RESULTS: Among 2618 participants with a chest CT, 176 (6.7%) had ILA, 1361 (52.0%) had no ILA, and the remainder were indeterminate. Among 1846 with a preceding cardiac CT, 118 (6.4%) had ILA with interval progression. In adjusted logistic regression models, an IQR difference in 5-year EC exposure of 0.14 µg/m3 was associated with a 1.27 (95% CI 1.04 to 1.55) times greater odds of ILA, and a 1.33 (95% CI 1.00 to 1.76) times greater odds of ILA progression. PM2.5 and O3 were not associated with ILA or ILA progression. CONCLUSIONS: Exposure to EC may increase risk of progressive ILA, however, associations with other measures of ambient pollution were inconclusive.


Assuntos
Poluição do Ar/efeitos adversos , Progressão da Doença , Exposição Ambiental/efeitos adversos , Doenças Pulmonares Intersticiais/etiologia , Poluição Relacionada com o Tráfego/efeitos adversos , Idoso , Poluição do Ar/análise , Carbono/análise , Carbono/toxicidade , Exposição Ambiental/análise , Feminino , Inquéritos Epidemiológicos , Humanos , Estudos Longitudinais , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Ozônio/análise , Ozônio/toxicidade , Material Particulado/análise , Material Particulado/toxicidade , Características de Residência , Fatores de Risco , Fatores de Tempo , Tomografia Computadorizada por Raios X , Poluição Relacionada com o Tráfego/análise
17.
Artigo em Japonês | MEDLINE | ID: mdl-31434811

RESUMO

Recently, the main air pollutant has been fine particulate matter (PM2.5), which is taken up by the whole body with severe adverse health effects. The main chemical components of PM2.5 are salts of sulfate (and nitrate) and carbons. However, it remains unknown which components are toxic. Here, the author reviewed the literatures to determine which components are toxic and the main mechanisms underlying their toxicity. Many epidemiological studies have shown that sulfate concentration is strongly related to mortality. However, there is no experimental evidence showing that sulfate at environmental concentrations of PM2.5 causes cardiovascular disease or other disease. On the other hand, carbon components such as elementary carbon (EC) produces high concentrations of reactive oxygen species (ROS) via its phagocytosis by macrophages, and organic carbon (OC) also produces high concentrations of ROS during its metabolic processes, and the ROS cause acute and chronic inflammation. They cause many diseases including cardiovascular disease, asthma and cancer. Furthermore, there are many lines of evidence showing that epigenetic changes such as DNA methylation or microRNA expression induced by particulate matters also induce the development of many diseases such as those mentioned above. It has been reported that carbon components are incorporated into the brain and produce ROS, and that the ROS cause damage to brain cells and Alzheimer's disease and cognitive disorders in the elderly.From these lines of evidence, the author would like to emphasize that the main toxicity of PM2.5 is due to carbon components, and it is important to take countermeasures to decrease the concentration of carbon components in ambient air.


Assuntos
Poluentes Atmosféricos/toxicidade , Carbono/toxicidade , Material Particulado/toxicidade , Sulfatos/toxicidade , Doença de Alzheimer/etiologia , Animais , Asma/etiologia , Doenças Cardiovasculares/etiologia , Epigênese Genética , Cobaias , Humanos , Camundongos , Neoplasias/etiologia , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo
18.
Int J Pharm ; 569: 118521, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31323371

RESUMO

Carbon dots (CDs) are emerging nanomaterial in medicine and pharmacy. To explore the impact of physicochemical characteristics on their safety, we synthesized a library of 35 CDs exhibiting different size, charge, chemical composition and surface coating, using various starting materials (carbon source and passivation reagent) and carbonization procedures. The 35 CDs triggered different levels of viability loss when incubated with human macrophages at 3-200 µg/mL for 24 h. The smaller NPs (10-20 nm) were more toxic that larger ones (40-100 nm), whereas NPs that aggregated in culture medium were more toxic than dispersed ones. A positive correlation was found between CD charge or nitrogen content and toxicity. Furthermore, a greater toxicity was observed for CDs prepared from high molecular weight polyamines, suggesting a role of the CD global density of positive charges, rather than the charge at the CD surface, in the CD toxicity. At last, PEG decoration decreased the toxicity of cationic NPs. In conclusion, the size, aggregation in culture medium, charge, nitrogen content, nature of the passivation agent and synthesis procedure were found to influence CD toxicity, making it difficult to predict CD safety from a single characteristic.


Assuntos
Carbono/toxicidade , Nanopartículas/toxicidade , Carbono/química , Sobrevivência Celular/efeitos dos fármacos , Humanos , Nanopartículas/química , Tamanho da Partícula , Bibliotecas de Moléculas Pequenas , Células THP-1
19.
Mutat Res ; 842: 22-34, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31255223

RESUMO

Even though the outdoor air pollution and its major component Particulate Matter (PM) are recently classified as human carcinogen, attempts to elucidate the underlying mechanisms of PM toxicity are still crucial and continuing with in vitro approaches in various environmental circumstances. Present study investigated the genotoxicity (Comet assay) and the cytotoxicity (lactate dehydrogenase (LDH) leakage and the water-soluble tetrazolium (WST-1) assays) of 30 daily PM2.5 samples collected in the Kütahya province, to address their daily variability in effects with season (i.e. winter versus summer) and location (i.e. rural versus urban) using A549 human lung cancer epithelial cell line, as well as in relation to their chemical composition, specifically trace elements, organic carbon (OC) and elemental carbon (EC). The genotoxicity, measured by the percentage tail intensity (TI), of the daily PM2.5 samples at the traffic dense urban station was higher than that of the rural site for 80% of the parallel days. The genotoxicity was significant in the winter at the urban and in the summer at the rural site. Cytotoxicity was the highest for the winter urban samples. The PM2.5 mass, OC, and EC concentrations were not correlated to DNA damage, while there were correlations with Mn, Fe, Cu and Ba at the rural PM2.5 samples, and Mn, Co and Ni at the urban samples, respectively. The present study is confirming that the complex composition of PM2.5 originating from spatial and temporal changes can cause differences in the health effects.


Assuntos
Poluentes Atmosféricos/toxicidade , Citotoxinas/toxicidade , Material Particulado/toxicidade , Células A549 , Poluição do Ar/efeitos adversos , Carbono/toxicidade , Linhagem Celular Tumoral , Ensaio Cometa/métodos , Dano ao DNA/efeitos dos fármacos , Monitoramento Ambiental/métodos , Humanos , Tamanho da Partícula , Estações do Ano
20.
Talanta ; 204: 74-81, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357360

RESUMO

The abnormal expression level of alkaline phosphatase (ALP) will lead to serious diseases. Therefore, a sensitive and rapid assay for ALP activity monitoring is of vital importance. In this work, a fluorescence turn-off approach for the detection of ALP is designed on the basis of nitrogen doped carbon dots (N-CDs), which were synthesized by one-step hydrothermal method and applied as signal readout. p-Nitrophenylphosphate (PNPP) can be hydrolyzed into p-nitrophenol (PNP) by ALP and their absorption peaks are different under alkaline conditions, so it was chosen as the ALP substrate. The absorption spectrum of PNP has good overlap with the excitation and emission spectra of N-CDs, thus the fluorescence of N-CDs can be effectively quenched by PNP via the inner filter effect (IFE). Consequently, quantitative detection of ALP is realized because the relative fluorescence intensity is linearly with the ALP activity in a wide range from 0.05 to 40 U L-1. The detection limit is 0.02 U L-1 (S/N = 3), which is much lower than the normal level of serum ALP in adults (about 40-190 U L-1). Moreover, the assay was successfully applied to evaluate ALP inhibitor efficiency and screen ALP inhibitors in drug discovery. It is also demonstrated that N-CDs possesses low cytotoxicity, excellent biocompatibility and photostability, and can be successfully applied in vivo fluorescence imaging, showing great potential in clinical applications.


Assuntos
Fosfatase Alcalina/sangue , Pontos Quânticos/química , Carbono/química , Carbono/toxicidade , Fluorescência , Células HeLa , Humanos , Limite de Detecção , Nitrogênio/química , Nitrogênio/toxicidade , Pontos Quânticos/toxicidade , Espectrometria de Fluorescência/métodos
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