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1.
J Nanosci Nanotechnol ; 20(2): 802-809, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383075

RESUMO

AgIO3/Ag2O/Ag nanocomposites with enhanced photocatalytic activities were synthesized by a onestep coprecipitation method at room temperature. The optimum hybrid of AgIO3/Ag2O = 1.25:1 with Ag nanoparticles (Ag NPs) loading (denoted as AA125) exhibited superior photocatalytic activity, demonstrating 97.19% tetracycline (TC) degradation within 60 min under simulated solar irradiation. This was approximately 10.44 and 2.63 times higher than that of pure Ag2O and AgIO3, respectively. The advanced photocatalytic activity can be ascribed to the synergetic effects of the heterostructured AgIO3/Ag2O/Ag and the strong surface plasmon resonance (SPR) effect of Ag NPs generated on the surface, which improved the separation and transfer efficiency of photoinduced electron-hole pairs. The results from radical scavenger experiments indicated that the degradation of TC was driven mainly by the participation of superoxide radical (·O-2).

2.
J Nanosci Nanotechnol ; 19(8): 5150-5157, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913829

RESUMO

Constructing heterojunction is an effective way to enhance the catalytic activities of semiconductor photocatalyst owing to its special synergistic effect. In this study, a novel p-n heterostructured CdWO4/BiOCl nanocomposites were synthesized by a facile hydrothermal and subsequently chemistry bath method. The photocatalytic performance of CdWO4/BiOCl heterojunctions was investigated by degrading phenol and RhB under simulated solar light irradiation. Highly improved photocatalytic activities were achieved on all CdWO4/BiOCl heterojunctions compared with both pure CdWO4 and BiOCl. The CdWO4/BiOCl heterojunction with optimal mole ratio of 25% CdWO4 displayed the highest photoactivity with RhB and phenol being completely degraded in 15 min and 6 h, respectively. Mechanism analysis revealed that the interface of p-n heterojunction of CdWO4/BiOCl composites can produce spontaneously electric field which can effectively separate photogenerated electrons and holes. Moreover, the active species research demonstrated that holes and superoxide radicals proved to be the principal active species during the photocatalytic process. This work demonstrated that the CdWO4/BiOCl photocatalyst may be a promising material for purifying the organic contaminant in practical application.

3.
J Nanosci Nanotechnol ; 19(8): 5287-5294, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913846

RESUMO

3D hierarchical structure BiOX(X ═ Cl, Br)-(CMC) assembled from 2D nanosheets with {010} facets exposed have been successfully synthesized by the assistance of biomass solvent CMC-Na. All the nitrogen adsorption isotherms and photoelectrochemical results reflected that BiOX(X Cl, Br)-(CMC) exhibit higher specific surface area, superior optical absorption efficiency and separation efficiency of photoinduced electron-hole than BiOX(X═Cl, Br) 2D nanosheets exposed with {001} facets. Besides, 96.5% and 60.3% of tetracycline hydrochloride (TC) were photodegradated in 60 minutes under the visible light irradiation catalyzed by BiOBr-(CMC) and BiOCl-(CMC), which is much better than BiOBr and BiOCl. The formation and enhanced photocatalytic activity of 3D hierarchical structure BiOX-(CMC) may be ascribe to the bi-functional groups of CMC, which can affect the crystallization process and morphology of BiOX. According to the merit of environmental friendly and improved photocatalytic activity of the 3D hierarchitecture, we believe that this work broadens the possibility of designing efficient BiOX photocatalyst with {010} facets exposed.

4.
Neural Regen Res ; 13(2): 347-352, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29557387

RESUMO

Deep brain stimulation of the subthalamic nucleus is recognized as the most effective treatment for moderate and advanced Parkinson's disease. Programming of the stimulation parameters is important for maintaining the efficacy of deep brain stimulation. Voltage is considered to be the most effective programming parameter. The present study is a retrospective analysis of six patients with Parkinson's disease (four men and two women, aged 37-65 years), who underwent bilateral deep brain stimulation of the subthalamic nucleus at the First Affiliated Hospital of Sun Yat-sen University, China, and who subsequently adjusted only the stimulation voltage. We evaluated motor symptom severity using the Unified Parkinson's Disease Rating Scale Part III, symptom progression using the Hoehn and Yahr scale, and the levodopa equivalent daily dose, before surgery and 1 and 2 years after surgery. The 2-year follow-up results show that rigidity and tremor improved, and clinical symptoms were reduced, while pulse width was maintained at 60 µs and frequency at 130 Hz. Voltage adjustment alone is particularly suitable for patients who cannot tolerate multiparameter program adjustment. Levodopa equivalent daily dose was markedly reduced 1 and 2 years after surgery compared with baseline. Our results confirm that rigidity, tremor and bradykinesia can be best alleviated by voltage adjustment. The trial was registered at ClinicalTrials.gov (identifier: NCT01934881).

5.
J Nanosci Nanotechnol ; 18(7): 4858-4864, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442666

RESUMO

An electrochemical palladium/ferric oxide (Pd/Fe2O3) nanocomposite modified glassy carbon electrode (GCE) was fabricated by hydrothermal method of Fe2O3 and electrochemical deposition of palladium nanoparticles, respectively. As-prepared Pd/Fe2O3 composite modified electrode exhibits enhanced electrocatalytic activity towards the catalytic oxidation of nitrite compared to Fe2O3, PdNPs modified electrodes and bare electrode. The parameters such as the influence of amount of Pd nanoparticles deposition onto the Pd/Fe2O3 modified electrode (ME) and effect of solution pH were investigated and discussed in detail. Under the optimal conditions, the Pd/Fe2O3 modified GCE can be used to detect nitrite concentration in a wide linear range of 10 and 1000 µM with the detection limit of 0.1 µM. The presence of Cu2+, Na+, Cl-, PO3-4 SO2-4, Mg2+ K+, NO-3, and NH+4 showed a trivial effect on the response of nitrite determination, revealing that developed modified electrode has an excellent anti-interference ability to common ions. It also shows good stability and reproducibility.

6.
J Nanosci Nanotechnol ; 18(8): 5575-5581, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29458612

RESUMO

Bi2MoO6-BiOCl nanoplate composites were successfully synthesized by a simple solvothermal process. The morphology, microstructure and optical properties of the as-prepared Bi2MoO6-BiOCl nanocomposites were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Vis diffuse reflection spectroscopy (DRS). A noteworthy enhancement in the visible-light-responsive photocatalytic degradation of RhB was observed over the Bi2MoO6-BiOCl nanocomposites compared to its individual components. The enhanced photocatalytic performance of Bi2MoO6-BiOCl nanocomposites could be attributed to the heterojunction interface in the composite, which can both efficiently separate photogenerated electron-hole pairs and also restrain the recombination of photoinduced charges.

7.
J Nanosci Nanotechnol ; 18(6): 4065-4071, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442744

RESUMO

Herein, a novel visible-light-driven heterojunction AgI/WO3 nanocomposite was successfully prepared using a facile two-step hydrothermal-precipitation process and applied for photodegradation of organic pollutants. The information of phase structures, morphology, optical properties of the asprepared samples was analysed in detail by XRD, TEM, EDS, STEM, DRS measurement and so on. Formation of the heterostructure and intimate interactions between AgI and WO3 can promote highly effective photogenerated electron-hole pairs separation, which enable the heterojuctions to perform excellent photocatalytic activity as greatly enhanced photocatalysts compared to that of pristine AgI and WO3 for decomposing Rhodamine B (RhB) dye under visible light irradiation. In addition, the AgI/WO3 (1:1) nanocomposites exhibit optimal photocatalytic activity. Moreover, the as-prepared samples exhibit good stability, which is favorable for its potential application. Additionally, we have an analysis on a possible photocatalytic mechanism based on trapping experiments together with other experimental results.

8.
J Nanosci Nanotechnol ; 18(5): 3585-3591, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442870

RESUMO

An electrochemical sensor ground on nickel oxide (NiO) nanoparticles and multi-walled carbon nanotubes (MWCNTs) was exploited for the detection of nitrite. Scanning electron microscopy (SEM) ensure the morphology of the nanocomposite consisted of NiO nanoparticle and MWCNTs. High Resolution Transmission electron microscopy (HR-TEM) reveals that the structure of NiO nanoparticles and MWCNTs. Scanning transmission electron microscopy (STEM) persuasively verified presence of the C, Ni and O element. The electrochemical character of the nanocomposite were researched by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the behavior of electrochemical oxidation to nitrite on NiO/MWCNTs/CP was explored by chronoamperometry. In tests, the NiO/MWCNTs/CP shown a sensitive current response toward nitrite, the oxidation peak current are linearly related to nitrite concentration in the range from 10-6 M to 10-4 M (R = 0.997) with a sensitivity of 3.53 µA µM-1 and a detection limit of 0.25 µM (S/N = 3). The validity of utilizing the proposed electrode to determine nitrite in tap water was also demonstrated.

9.
J Nanosci Nanotechnol ; 17(2): 1407-412, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-29687974

RESUMO

A new magnetic Fe3O4@C@Ag3PO4 nanocomposites photocatalyst with visible light response has been prepared by solvothermal, hydrothermal and precipitation process. The photocatalyst exhibited high photocatalytic activity and stability for the degradation of rhodamine B (RhB). Almost 100% of RhB was photodegraded with the assistance of magnetic Fe3O4@C@Ag3PO4 nanocomposites after 40 min, and the photocatalyst showed no obvious loss of photocatalytic activity after four times of cyclic utilization. Furthermore, the magnetic Fe3O4@C@Ag3PO4 nanocomposites can be separated by external magnetic field. Further study proved that the photogenerated holes were the main active species in the degradation process.

10.
Biomed Res Int ; 2016: 5013409, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27830147

RESUMO

Previously we have shown that (-)-epigallocatechin gallate (EGCG) can induce nonapoptotic cell death in human hepatoma HepG2 cells only under serum-free condition. However, the underlying mechanism for serum in determining the cell fate remains to be answered. The effects of fetal bovine serum (FBS) and its major component bovine serum albumin (BSA) on EGCG-induced cell death were investigated in this study. It was found that BSA, just like FBS, can protect cells from EGCG-induced cell death in a dose-dependent manner. Detailed analysis revealed that both FBS and BSA inhibited generation of ROS to protect against toxicity of EGCG. Furthermore, EGCG was shown to bind to certain cellular proteins including caspase-3, PARP, and α-tubulin, but not LC3 nor ß-actin, which formed EGCG-protein complexes that were inseparable by SDS-gel. On the other hand, addition of FBS or BSA to culture medium can block the binding of EGCG to these proteins. In silico docking analysis results suggested that BSA had a stronger affinity to EGCG than the other proteins. Taken together, these data indicated that the protective effect of FBS and BSA against EGCG-induced cell death could be due to (1) the decreased generation of ROS and (2) the competitive binding of BSA to EGCG.


Assuntos
Catequina/análogos & derivados , Espaço Intracelular/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Soroalbumina Bovina/farmacologia , Soro/metabolismo , Animais , Catequina/farmacologia , Bovinos , Morte Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica/efeitos dos fármacos
11.
Int J Toxicol ; 35(6): 634-643, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27306319

RESUMO

Multiwalled carbon nanotubes (MWCNTs) have been explored in pharmaceutical applications such as tumor targeting and delivery of drugs, in which MWCNTs are given through intravenous injection. However, the biosafety of MWCNTs is of concern for such application. Therefore, in the current study, we used a fatty liver model to investigate the possible toxicity of MWCNTs to the liver, as MWCNTs were retained mainly in the liver of mice after intravenous injection. Male Sprague Dawley rats were used to generate the fatty liver model, and the effects of intravenous administration of MWCNTs on fatty liver were studied. Hematoxylin and eosin staining for hepatocellular anatomy and Masson trichrome staining for hepatic fibrosis were conducted. Histologically, MWCNTs aggravated steatohepatitis with higher nonalcoholic fatty liver disease scores. Analysis of liver injury markers indicated that MWCNTs administration resulted in chronic hepatitis, along with increased liver fat and altered liver oxidation, including the increase of P6 protein and the depletion of glutathione. In conclusion, our results suggest that MWCNTs can aggravate nonalcoholic steatohepatitis in Sprague Dawley rats, and oxidative injury may be involved in this process.


Assuntos
Fígado/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Hepatopatia Gordurosa não Alcoólica , Animais , Aspartato Aminotransferases/sangue , Dieta Hiperlipídica , Ácidos Graxos não Esterificados/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/sangue , Injeções Intravenosas , Fígado/metabolismo , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo , Triglicerídeos/metabolismo , gama-Glutamiltransferase/sangue
12.
Phys Chem Chem Phys ; 17(43): 29354-62, 2015 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-26473944

RESUMO

In this study, C3N4/Zn(1-x)Cd(x)S (0 ≤ x ≤ 1) heterostructures with adjustment of the band gap were successfully prepared by calcination and a hydrothermal synthesis method. The photocatalytic properties of C3N4/Zn(1-x)Cd(x)S composite photocatalysts were evaluated by the photocatalytic degradation of RhB under visible light irradiation. The results showed that the combination of the two semiconductor photocatalysts (C3N4 and Zn(1-x)Cd(x)S) greatly enhanced the photocatalytic degradation efficiency of RhB compared to the pure C3N4 and Zn(1-x)Cd(x)S under visible light irradiation. Among them, the 0.1C3N4/Zn0.8Cd0.2S composite photocatalyst exhibited the highest photocatalytic activities with the degradation efficiency of RhB arriving to 97.9% within 90 min. The remarkable photocatalytic activity of the 0.1C3N4/Zn0.8Cd0.2S composite photocatalyst was mainly attributed to the appropriate band structure and the effective separation of photogenerated electron-hole pairs. Additionally, a possible basic mechanism of the composite semiconductor photocatalytic process was also discussed. Moreover, it was also investigated that O2(˙⁻) and h(+) were the main reactive oxidative species in this photocatalytic process of the degradation of RhB on the 0.1C3N4/Zn0.8Cd0.2S heterostructure photocatalyst.

13.
In Vivo ; 28(4): 495-503, 2014 Jul-Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24982215

RESUMO

BACKGROUND: The purpose of the present study was to compare the antioxidant potential of lipophilic tea polyphenols (LTP) against the one of naturally-occurring water-soluble green tea polyphenols (GTP) in a two-stage model of diethylnitrosamine (DEN)/phenobarbital (PB)-induced hepatocarcinogenesis in Sprague-Dawley rats. MATERIALS AND METHODS: GTP/LTP was given 5-times weekly by oral gavage with tea polyphenols equivalent to 0-, 40- and 400-mg/kg of body weight/day. GTP/LTP treatment was started 2 weeks prior to the initiation of DEN and continued for 30 weeks. RESULTS: Histopathological and electron microscopic examination of liver tissue confirmed the protective effect of LTP on DEN/PB-induced liver damage and pre-carcinogenesis. LTP treatment significantly increased total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) activity in liver tissues. Immunohistochemical detection of cellular nuclear factor erythroid-2-related factor-2 (Nrf2) and peroxiredoxin-6 (P6) indicated a down-regulation in Nrf2 and up-regulation of P6 expression in the liver of LTP-supplemented rats. CONCLUSION: The present study provides evidence for the first time, that LTP exerts significant antioxidant effects on DEN/PB-induced liver damage and hepatocarcinogenesis through elevating T-AOC levels, enhancing GSH-Px activity and inducing P6 expression in rat liver tissues.


Assuntos
Antioxidantes/farmacologia , Carcinógenos , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/efeitos dos fármacos , Dietilnitrosamina/efeitos adversos , Fenobarbital/efeitos adversos , Polifenóis/farmacologia , Chá/química , Animais , Antioxidantes/administração & dosagem , Peso Corporal/efeitos dos fármacos , Imuno-Histoquímica , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas Experimentais , Masculino , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Peroxirredoxina VI/genética , Peroxirredoxina VI/metabolismo , Polifenóis/administração & dosagem , Ratos
14.
Anticancer Res ; 34(2): 683-93, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24511000

RESUMO

BACKGROUND: Green tea polyphenols (GTPs) have been proposed as promising candidates for chemoprevention. However, GTPs levels are maintained relatively low in the blood and are chemically-unstable. Lipid-soluble tea polyphenols (LTPs) are products of modified GTPs with ester linkage with fatty acids. LTPs are lipophilic and expected to provide improved absorption and utilization in the body compared with water-soluble polyphenols. The current study was designed to investigate the chemo-preventive property and the possible mechanisms of LTP action against diethylnitrosamine (DEN)-induced liver cancer in rats. MATERIALS AND METHODS: Oral administration of LTPs at doses of 0, 40, and 400 mg/kg/day was initiated 2 weeks prior to DEN injection and was continued for 30 weeks. At that time point samples were collected and liver histopathological analyses were performed. RESULTS: LTPs decreased the area and number of placental glutathione S-transferase-positive foci in liver samples of DEN-treated rats. Furthermore, LTPs counteracted DEN-induced fibrosis formation in liver. Immunohistochemical staining of rat liver showed that LTPs inhibited DEN-mediated elevations in numbers of cells positive for PCNA and 8-OHdG. CONCLUSION: For the first time, the present study demonstrated, that LTPs exert a chemo-preventive effect against precancerous lesions through inhibition of cellular proliferation and DNA damage in a rat liver model.


Assuntos
Neoplasias Hepáticas Experimentais/prevenção & controle , Polifenóis/farmacologia , Lesões Pré-Cancerosas/tratamento farmacológico , Chá/química , Animais , Processos de Crescimento Celular/efeitos dos fármacos , Dano ao DNA , Dietilnitrosamina , Imuno-Histoquímica , Lipídeos/química , Fígado/efeitos dos fármacos , Fígado/patologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/patologia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Fenobarbital , Polifenóis/química , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/patologia , Ratos , Ratos Sprague-Dawley , Solubilidade
15.
Artigo em Chinês | MEDLINE | ID: mdl-24053910

RESUMO

OBJECTIVE: To investigate the pulmonary toxicity of different concentrations of nano-silica (nano-SiO2) under continuous dynamic inhalation conditions in the rat. METHODS: 48 male Sprague-Dawley rats were randomly divided into four groups, including the dispersant control group (saline) and nano-SiO2 low-dose group (0.3%, w/v), the middle-dose group (1%) and the high-dose group (3%). Animals were sacrificed at 28 d after exposure under continuous dynamic inhalation conditions, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected. And following items were observed: body coefficient, BALF related items (leukocytes and classification, total protein content, LDH activity), lung tissue pathological changes (HE staining), and pulmonary fibrosis forming (collagen fiber VG staining). RESULTS: Compared to the dispersant control group, there was no significant change on lung organ coefficient in Nano-SiO2 group (P < 0.05). The BALF total WBC count in 1% and 3% in nano-SiO2 groups showed higher value than the dispersant control group (P < 0.05). No obvious changes were found on total protein content and LDH activity in nano-SiO2 groups compared to the dispersant control group (P > 0.05). For differential WBC counts, lymphocyte count in BALF in nano-SiO2 groups was significantly decreased (P < 0.05), monocyte and macrophage counts were significantly increased (P < 0.05), but there was no difference on the proportion of neutrophils (P > 0.05). HE staining results showed that the obvious thickening of alveolar wall in nano-SiO2 groups, inflammatory cell infiltration also increased around the bronchial and vascular wall. Lung fibrosis VG staining showed no significant change of collagen fiber distribution. CONCLUSION: Under our experimental conditions, the continuous dynamic inhalation of nano-SiO2 only caused the significant inflammation in rat lungs, pulmonary fibrosis phenomenon could not be observed significantly.


Assuntos
Exposição por Inalação , Fibrose Pulmonar/induzido quimicamente , Dióxido de Silício/toxicidade , Animais , Líquido da Lavagem Broncoalveolar/química , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Ratos , Ratos Sprague-Dawley , Dióxido de Silício/administração & dosagem
16.
Environ Toxicol ; 28(8): 442-50, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21656646

RESUMO

Growing evidence has indicated the potential adverse effects on cardiovascular system of some nanomaterials, including fullerenes. In this study, we have evaluated the biological effects of multiwall carbon nano-onions (MWCNOs) (average size of 31.2 nm, ζ potential of 1.6 mV) on human umbilical vein endothelial cells (HUVECs). It was found that MWCNOs exhibited a dose-dependent inhibitory effect on cell growth; EC50 was 44.12 µg/mL. Thus, three concentrations were chosen (0.2, 1, and 5 µg/mL) for further experiments. Flow cytometry analysis revealed that 1 and 5 µg/mL MWCNOs could induce apoptosis in HUVECs, the apoptotic rates were 12% and 24% at 24 h after exposure. On the other hand, MWCNOs did not affect the cell cycle distribution during 24 h period. Using γH2AX foci formation as an indicator for DNA damage, it was shown that 5 µg/mL MWCNOs can induce γH2AX foci formation in HUVECs at 6, 12, and 24 h after treatment, whereas 0.2 µg/mL MWCNOs induced γH2AX foci formation only at 6 h after treatment. In addition, all three concentrations of MWCNOs induced the generation of reactive oxygen species (ROS), and inhibition of ROS generation can partially decrease the γH2AX foci formation induced by MWCNOs. Taken together, these data first suggested that MWCNOs can induce DNA damage and apoptosis in HUVECs, and that ROS might be involved in this process.


Assuntos
Apoptose/efeitos dos fármacos , Dano ao DNA , Fulerenos/toxicidade , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citometria de Fluxo , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Espécies Reativas de Oxigênio/metabolismo
17.
Artigo em Chinês | MEDLINE | ID: mdl-23256996

RESUMO

OBJECTIVE: To observe the effects of multi-walled carbon nano-onions (MWCNOs) on platelet adhesion and experimental thrombosis in rats. METHODS: Experimental rats were randomly divided into sham operation group, solvent group, and MWCNO group, each including 6 ∼ 9 rats. An inverted fluorescence microscope and a flow chamber were used to observe the effects of 20 g/ml MWCNOs on platelet adhesion at shear rates of 500 s(-1) and 1000 s(-1); the experiment was repeated at least three times in each group. A rat model of carotid artery thrombosis was induced by 25% FeCl3, and the effects of 2 mg/kg MWCNOs on the blood flow and wet weight of thrombus per millimeter in the model were observed. RESULTS: When the shear rate was 500 s(-1), the MWCNO group showed a significantly smaller number of adhering platelets than the solvent group (58.3 ± 16.1 platelets/0.01 mm(2) vs 190.1 ± 36.0 platelets/0.01 mm(2)), but the inhibitory effect of MWCNOs on platelet adhesion disappeared as the shear rate increased to 1000 s(-1). The wet weights of thrombus per millimeter at 0 h after injection of a solvent or MWCNOs via the caudal vein were 0.83 ± 0.12 mg/mm in the solvent group and 0.97 ± 0.11 mg/mm in the MWCNO group, and the wet weights of thrombus per millimeter at 12 h after injection were 0.89 ± 0.12 mg/mm in the solvent group and 1.01 ± 0.15 mg/mm in the MWCNO group, exhibiting no significant differences between the two groups (P > 0.05). There were also no significant differences between the two groups in terms of blood flow at 0 h and 12 h after injection (P > 0.05). CONCLUSION: MWCNOs have inhibitory effect on platelet adhesion in vitro, but the injection of MWCNOs via the caudal vein has no effects on the blood flow and wet weight of thrombus per millimeter in experimental thrombosis in rats.


Assuntos
Plaquetas/efeitos dos fármacos , Nanotubos de Carbono/efeitos adversos , Adesividade Plaquetária/efeitos dos fármacos , Trombose/patologia , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Trombose/induzido quimicamente
18.
J Occup Health ; 54(5): 361-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22972483

RESUMO

BACKGROUND: Carbon nanotubes (CNTs) have many potential applications, including as delivery systems for a variety of diagnostic or therapeutic agents. However, it has been suggested that exposure to carbon nano-materials may be a risk for the development of vascular diseases due to its impact on the vascular endothelium. MATERIALS AND METHODS: Male Sprague-Dawley rats (180-200 g) were used to generate an atherosclerosis (AS) model, and the effect of intravenous administration of multi-walled carbon nanotubes (MWCNTs) on AS was studied. To further understand the underlying mechanisms, the effects of exposure of human umbilical vascular endothelial cells (HUVECs) to MWCNTs were examined. RESULTS: Exposure to 200 µg/kg MWCNTs aggravated AS in this model. In addition, exposure to 50, 100 and 200 µg/kg MWCNTs increased the calcification of the aorta in the model. Short-term exposure also revealed that 200 µg/kg MWCNTs injured the endothelium in the aorta. MWCNTs disrupted the endothelial tight junction and induced endothelial cell death. CONCLUSION: The results demonstrated that MWCNTs could induce structural and functional changes in the endothelium, probably through vascular endotheliocyte injury, which eventually affected the development of AS in SD rats.


Assuntos
Aterosclerose/induzido quimicamente , Endotélio Vascular/efeitos dos fármacos , Nanotubos de Carbono/efeitos adversos , Animais , Infusões Intravenosas , Masculino , Modelos Animais , Ratos , Ratos Sprague-Dawley
19.
Artigo em Chinês | MEDLINE | ID: mdl-22931766

RESUMO

OBJECTIVE: To observe the pulmonary toxicity of multi-walled carbon nanotubes (MWCNTs) in high-fat diet SD rats. METHODS: One hundred forty male SD rats were randomly divided into 6 groups. The normal control group, high-fat diet model group, vehicle group, and group treated with low dose of MWCNTs consisted of 30 rats, respectively, which were divided in 3 subgroups (10 rats each subgroup), respectively. The groups treated with medium and high loses of MWCNTs consisted of 10 rats, respectively. All the animals were exposed to high-fat-diet except for the control group which was given with normal diet. Before intravenous exposure, the high-fat diet model group, vehicle group, and three MWCNTs treated groups were gavaged with 700 thousand U/kg Vit D3 for three days, then given with high-fat-diet. The vehicle group was exposed to normal saline containing 1% Tween 80 and the low exposure group was exposed to MWCNTs at the dose of 50 µg/kg by tail vein injection twice a week for 8, 12 or 16 weeks. Other tow exposure groups were exposed to MWCNTs at the doses of 100, and 200 µg/kg by tail vein injection twice a week, respectively for 16 weeks. The lungs were from the executed rats, the lung indexes were calculated, the pathological changes of lungs were examined under light microscope after HE staining. qRT-PCR assay was utilized to detect the expression levels of pro-inflammation cytokines IL-1ß (IL-1ß) and TNF-α mRNA in the lungs. RESULTS: As compared with the vehicle group, the lung indexes in groups exposed to 100 and 200 µg/kg MWCNTs increased significantly (P < 0.05). It was found under light microscope that the MWCNTs were accumulated in lungs of three exposure groups in 16 weeks after exposure, including pneumorrhagia, alveolar walls thicken, fibrosis, and granulomas. As compared with the vehicle group, the levels of IL-1ß mRNA in group exposed to 50 µg/kg MWCNTs for 12 weeks and the groups exposed to 50, 100 and 200 µg/kg MWCNTs for 16 weeks decreased significantly (P < 0.05). As compared with the vehicle group, the levels of TNF-α mRNA in the groups exposed to 50 µg/kg MWCNTs for 8 and 16 weeks increased significantly (P < 0.05), the level of TNF-α mRNA in the groups exposed to 50 µg/kg MWCNTs for 12 weeks decreased significantly (P < 0.05). As compared with the vehicle group, the level of TNF-α mRNA in the groups exposed to 200 µg/kg MWCNTs for 16 weeks reduced significantly (P < 0.05). CONCLUSION: The MWCNTs accumulation and chronic inflammatory changes were found in the lungs of rats exposed to MWCNTs by tail vein injection.


Assuntos
Dieta Hiperlipídica , Pulmão/patologia , Nanotubos de Carbono/toxicidade , Animais , Citocinas/análise , Injeções Intravenosas , Pulmão/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley
20.
Artigo em Chinês | MEDLINE | ID: mdl-21972523

RESUMO

OBJECTIVE: To observe the effects of multiwall carbon nano-onions (MWCNOs) on platelet aggregation and hemostatic function. METHODS: The platelet aggregation was determined with Born's method at different concentration of MWCNOs (0, 0.2, 2.0, 20.0 microg/ml) in vitro. Twenty male SD rats were randomly divided into 4 groups which were exposed to 0, 2, 4 and 8 mg/kg MWCNOs, respectively. Then platelet count, platelet aggregation, activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), bleeding time (BT) and platelet count (PC) were measured at 12 h after receiving tail intravenous injection of MWCNOs. The effects of MWCNOs (4 mg/kg) on platelet aggregation and platelet count at different time points were observed. RESULTS: In vitro, MWCNOs exhibited the potent inhibitory effects on rat platelet aggregation caused by ADP in a concentration-dependent manner. The platelet aggregation in the highest dosage of 20.0 microg/ml group was 50.0% +/- 6.9% which was significantly lower than that (73.2% +/- 4.3%) in control group (P<0.01). In vivo, the highest inhibitory was up to 20.4%, but there was no significant difference, as compared with control group. MWCNOs did not affect the APTT, PT, TT, BT and PC. CONCLUSION: Under this experimental condition, MWCNOs might inhibit platelet aggregation but not affect hemostatic function.


Assuntos
Carbono/farmacologia , Hemostasia/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Animais , Tempo de Sangramento , Coagulação Sanguínea/efeitos dos fármacos , Carbono/administração & dosagem , Masculino , Nanoestruturas , Tempo de Tromboplastina Parcial , Contagem de Plaquetas , Tempo de Protrombina , Ratos , Ratos Sprague-Dawley , Tempo de Trombina
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