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1.
Stomatologiia (Mosk) ; 99(1): 7-11, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32125295

RESUMO

PURPOSE: To determine the effect of whitening toothpastes on the color of a nanocomposite material using a spectrophotometer. MATERIAL AND METHODS: The study involved 50 samples from nanocomposite restoration material which were exposed under laboratory conditions to brushing with one of 4 types of toothpastes (control with no bleaching agents, peroxide paste with carbamide, abrasive and enzyme-based pastes). Using the parameters a, b and L obtained by spectrophotometry, delta E (ΔE) value was calculated. To determine the maximum and minimum A posteriori comparisons by the Scheffe method were used to influence the delta E parameter after exposure to the pastes. Oxygen-containing paste (OZPP) had a maximum effect on the increase of the ΔE parameter, ΔE=1.03 comparing to ΔE=0.20 in control toothpaste. The isolated effect of a toothbrush resulted in a large change in the parameter ΔE, compared to the effect of a controls. However, the ΔE does not indicate the clarification of the material, but only a change in color relative to the initial measurement. As a result of spectrophotometry and statistical data processing, it was found that all pastes had a sufficient effect on the color change for the device to determine, but this change was not noticeable to the human eye.


Assuntos
Nanocompostos , Clareadores Dentários , Clareamento Dental , Humanos , Espectrofotometria , Cremes Dentais
2.
Biomed Khim ; 66(1): 64-70, 2020 Jan.
Artigo em Russo | MEDLINE | ID: mdl-32116227

RESUMO

The electroanalytical characteristics of recombinant cytochrome P450 3A4 (P450 3A4) immobilized on the surface of screen-printed graphite electrodes modified with multi-walled carbon nanotubes have been studied. The role and the influence of graphite working electrode modification with carbon nanotubes on electroanalytical characteristics of cytochrome P450 3A4 have been demonstrated. The conditions for the immobilization of cytochrome P450 3A4 on the obtained screen-printed graphite electrodes modified with carbon multi-walled nanotubes have been optimized. The electrochemical parameters of the oxidation and reduction of the heme iron of the enzyme have been estimated. The midpoint potential E0' was -0.35±0.01 V vs Ag/AgCl; the calculated heterogeneous electron transfer rate constant ks, was 0.57±0.04 s-1; the amount of electroactive cytochrome P450 3A4 on the electrode Г0, was determined as (2.6±0.6)⋅10-10 mol/cm2. The functioning mechanism of P450 3A4-based electrochemical sensor followed the "protein film voltammetry". In order to develop electrochemical analysis of drugs being substrates of that hemoprotein and respective medical biosensors the voltammetric study of catalytic activity of immobilized cytochrome P450 3A4 was carried out. Electrocatalytic properties of cytochrome P450 3A4, immobilized on modified screen-printed graphite electrodes, has been investigated using erythromycin (macrolide antibiotics). It has been shown that the modification of electrodes plays a decisive role for the study of the properties of cytochromes P450 in electrochemical investigations. Smart electrodes can serve as sensors for analytical purposes, as well as electrocatalysts for the study of biotransformation processes and metabolic processes. Electrodes modified with carbon nanomaterials are applicable for analytical purposes in the registration of hemoproteins. Electrodes modified with synthetic membrane-like compounds (e.g. didodecyldimethylammonium bromide) are effective in enzyme-dependent electrocatalysis.


Assuntos
Citocromo P-450 CYP3A/química , Eletrodos , Nanocompostos , Nanotubos de Carbono , Técnicas Eletroquímicas , Oxirredução
3.
Bioresour Technol ; 302: 122842, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32006925

RESUMO

In this work, magnetic wakame biochar nanocomposites for the first time had been synthesized to investigate their adsorption to methylene blue dye. As-prepared magnetic biochar samples were obtained by the impregnation method to load nickel on wakame biochar via one-step carbonization with activation agent KOH at 800 °C. The prepared samples were characterized by BET, XRD, FTIR, Raman, SEM, TEM and so on. The results exhibited that the maximum adsorption capacity of BW(Ni)0.5 to methylene blue could reach 479.49 mg/g at 20 °C. The adsorption behavior was more suitable for Langmuir isotherm equation and the kinetic data were most consistent with the pseudo second-order model. And also, the adsorption reaction was a spontaneous and endothermic process. After five cycles, it was found that BW(Ni)0.5 had a high adsorption capacity for methylene blue (117.58 mg/g). This study demonstrated that wakame biochar could have great potential in dye wastewater treatment.


Assuntos
Nanocompostos , Undaria , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Concentração de Íons de Hidrogênio , Cinética , Fenômenos Magnéticos , Azul de Metileno , Termodinâmica
4.
Bioresour Technol ; 302: 122812, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32007848

RESUMO

In this work, two plant wastes were reused to fabricate the homogeneous 3D micro-nano porous structured humic acid/cellulose nanocomposite beads (IHA@CB) embedded with insoluble humic acid (IHA) particles. The subtle synthesis method attributed to the homogenous distribution of IHA particles in the cellulose matrix and improved the adsorption performance of IHA@CB for low concentration ciprofloxacin in water. Physical and chemical properties of the beads were characterized by SEM, EDX, XRD, FTIR, and the adsorption process of ciprofloxacin was studied by isotherm, kinetic and dynamic adsorption experiments. The maximum adsorption capacity of IHA@CB on CPX reached 10.87 mg g-1 under 318 K. The dynamic experiments were conducted by adjusting bed height, flow rate, initial concentration and pH values, and the regeneration experiments proved the adsorbent exhibited good repeatability. The adsorption mechanism was revealed that CPX was adsorbed by IHA@CB mainly through cation exchange.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Adsorção , Celulose , Ciprofloxacino , Concentração de Íons de Hidrogênio , Cinética , Água
5.
Chemosphere ; 244: 125577, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050350

RESUMO

Persulfate based advanced oxidation process is a promising technology for refractory contaminants removal. Cobalt is considered as the most efficient metal in catalyzing peroxymonosulfate decomposition. Although different cobalt based nanomaterials have been developed, easy aggregation and metal ion leaching during catalytic reaction would result in its deficiency. To address the above issue, in this work, carbon supported Co/CoO core-shell nanocomposite was in-situ fabricated by using polyphenol-metal coordinate as precursor. Results indicated that cobalt nanoparticle with size of 10 nm was successfully prepared and well dispersed within the carbon matrix. By using as-prepared material as catalyst, 50 mg/L orange II was completely removed under the condition of 0.2 g/L peroxymonosulfate, 0.05 g/L catalyst, pH = 4.0-10.0. Both sulfate and hydroxyl radicals were formed during peroxymonosulfate decomposition, while sulfate radical dominated the pollutant removal. Mechanism study revealed that the cobalt was the key site for catalyzing peroxymonosulfate decomposition. This work might provide valuable information in designing and fabricating metal anchored carbon composite catalyst for efficiently and cost-effectively activate peroxymonosulfate.


Assuntos
Corantes/química , Nanocompostos/química , Peróxidos/química , Compostos Azo , Benzenossulfonatos , Carbono/química , Catálise , Cobalto/química , Modelos Químicos , Oxirredução , Sulfatos
6.
J Photochem Photobiol B ; 204: 111767, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32006893

RESUMO

Colon carcinoma is a recurring type of cancer that affects the intestine epithelial with a poor survival rate. It was already proven the anticancer property of hesperidin in various cancers but the bioavailability hesperidin is poor, which hinders the hesperidin usage. In this investigation we synthesized hesperidin loaded Zn2+@ SA/PCT nanocomposites and assessed its anticancer potential against colon cancer (HCT116) cells. Hesperidin loaded Zn2+@ SA/PCT nanocomposites were characterized using Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis. The drug releasing capacity and cytotoxic property was assessed via drug releasing assay, MTT assay with HCT116 cells. The anticancer potency of hesperidin nanocomposites were evaluated with TUNEL, DAPI staining, reactive oxygen species (ROS) generation assay and it is confirmed with flow cytometry analysis of MMP disruption in colon cancer (HCT116) cell line. Further the immunoblotting analysis of cysteine proteases Caspases 3, 9, PARP, proapoptotic protein Bax and antiapoptotic protein Bcl2 were performed. The results of FTIR, XRD and electroscopic analyses confirmed the synthesized hesperidin nanocomposites accomplish the properties of potent nanodrug and the MTT assay authentically confirmed that the synthesized hesperidin nanocomposite inhibited the HCT116 cell growth, and the results of fluorescent staining proved that the hesperidin nanocomposite induced the apoptotic mediated cell necrosis via promoting the expression of apoptotic proteins thereby induced the apoptosis in colon cancer (HCT116) cells. Hence, it was concluded that the, hesperidin loaded nanocomposites persuasively inhibited proliferation of colon carcinoma cell and induced apoptosis in in vitro condition.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Hesperidina/química , Nanocompostos/química , Alginatos/química , Antineoplásicos Fitogênicos/química , Caspase 3/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Composição de Medicamentos , Liberação Controlada de Fármacos , Células HCT116 , Hesperidina/farmacologia , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Pectinas/química , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Zinco/química
7.
J Environ Manage ; 260: 110175, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32090853

RESUMO

Although Cu2O is a commonly used narrow band gap semiconductor to fabricate visible response photocatalysts, up to date there are only a few reports on Ag co-catalysed TiO2-Cu2O nanocomposites. Herein we report a facile wet chemical synthesis approach to prepare TiO2-Ag-Cu2O ternary hybrid nanomaterials. Uniquely, both the effect of Ag content and the synthesis sequence of Ag deposition step was investigated on the visible decoloration rate. The crystal structure, morphology, optical and dark adsorption properties of the nanostructures were characterized by XRD, SEM, TEM and diffuse reflectance, respectively. Due to the mixed indirect and direct nature of the nanocomposites, the band gap estimation was performed by using both Tauc plot and differential reflectance model. The dark adsorption properties of catalysts could be typically well-approximated by pseudo-second order kinetics, while TiO2-Ag(5%)-Cu2O catalyst cannot be described by standard models due to a delayed adsorption behaviour observed in the first 50 min. The apparent visible activities followed pseudo-zero order kinetics. It was found that TiO2-Ag(3%)-Cu2O catalyst exhibited the highest rate constant which was ca. two times as high as that of the binary TiO2-Cu2O catalyst. The synthesis sequence of the Ag deposition step significantly altered the material properties which resulted in different dark adsorption and apparent visible activities.


Assuntos
Nanocompostos , Prata , Adsorção , Catálise , Titânio
8.
J Photochem Photobiol B ; 204: 111783, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954265

RESUMO

Cadmium sulfide-graphitic carbon nitride nanocomposite was synthesized by pulsed laser ablation in liquid, and it was found from the results of optical and morphological characterizations that the proper anchoring of nanostructured cadmium sulfide on the nano-sheets of graphitic carbon nitride took place, which brought about the positive attributes such as enhanced visible light absorption and reduced photo-generated charge recombination, the key features required for an efficient photo-catalyst by solar light harvesting. The pulsed laser ablation in liquid method adopted for the synthesis of cadmium sulfide-graphitic carbon nitride has the following advantages: the shape and size of the synthesized particles can be controlled by altering the experimental parameters such as laser wavelength, pulse laser duration, the pH of the solution, the surfactants and the temperature of the solution, pulsed laser ablation in liquid method neither requires cumbersome equipment nor does it require intermediate chemicals and catalysts nor does it necessitate the post synthesis purification. The enhancement of photo-catalytic activity of cadmium sulfide-graphitic carbon nitride nanocomposite was tested for the photo-catalytic deactivation of Escherichia coli bacteria in water under visible light radiation. As anticipated, a significant improvement of photo-catalytic deactivation was observed, which is attributed to the enhanced and extended light absorption in the visible spectral region, and the formation of herterojunction between the semiconductors, which is instrumental in inhibiting the undesired recombination of photo-generated charge carriers. Quantitatively, the presence of cadmium sulfide on the graphitic carbon nitride surface contributed to a remarkable 129% increase of photo-catalytic degradation constant compared to pure graphitic carbon nitride, which resulted in the decrease of total depletion time of Escherichia coli from 156 min to 67 min with the cadmium sulfide-graphitic carbon nitride nanocomposite synthesized by pulsed laser ablation in liquid method. Our results on the efficient photo-catalytic deactivation of Escherichia coli under visible light assures that cadmium sulfide-graphitic carbon nitride nanocomposite can very well be used for photo-catalytic water purification by harvesting the abundant solar light.


Assuntos
Compostos de Cádmio/química , Grafite/química , Luz , Nanocompostos/química , Compostos de Nitrogênio/química , Sulfetos/química , Purificação da Água/métodos , Catálise , Escherichia coli/efeitos dos fármacos , Nanocompostos/toxicidade , Estudos Prospectivos
9.
J Nanobiotechnology ; 18(1): 17, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31964393

RESUMO

This study aimed to develop a new colon-targeted drug delivery system via the preparation of ternary nanocomposite carriers based on organic polymer, aminoclay and lipid vesicles. Budesonide (Bud), an anti-inflammatory drug was chosen as a model drug and encapsulated into three different formulations: liposome (Bud-Lip), aminoclay-coated liposome (AC-Bud-Lip), and Eudragit® S100-aminoclay double coated liposome (EAC-Bud-Lip). The formation of the aminoclay-lipid vesicle nanocomposite was confirmed by energy dispersive X-ray spectrum, transmission electron microscopy, and Fourier-transform infrared spectroscopy. All formulations were produced with a high encapsulation efficiency in a narrow size distribution. Drug release from EAC-Bud-Lip was approximately 10% for 2-h incubation at pH 1.2, implying the minimal drug release in acidic gastric condition. At pH 7.4, EAC-Bud-Lip underwent significant size reduction and exhibited drug release profiles similar to that from AC-Bud-Lip, implying the pH-dependent removal of the outer coating layer. Compared to free Bud solution, EAC-Bud-Lip achieved a higher drug uptake in Caco-2 cells and exhibited a stronger inhibition of TNF-α and IL-6 secretion in LPS-stimulated Raw264.7 cells. Furthermore, a bio-distribution study in mice demonstrated that Eudragit® S100-aminoclay dual coating led to a higher colonic distribution with a longer residence time, which correlated well with the delayed systemic drug exposure in rats. Taken together, the present study suggests that the ternary nanocomposite carrier consisting of Eudragit® S100, aminoclay, and lipid vesicle might be useful as an effective colon-targeted drug delivery system.


Assuntos
Anti-Inflamatórios/química , Budesonida/química , Argila/química , Colo/metabolismo , Lipídeos/química , Lipossomos/química , Nanocompostos/química , Animais , Anti-Inflamatórios/farmacocinética , Budesonida/farmacocinética , Células CACO-2 , Liberação Controlada de Fármacos , Humanos , Concentração de Íons de Hidrogênio , Interleucina-6/metabolismo , Masculino , Camundongos , Ácidos Polimetacrílicos/química , Células RAW 264.7 , Ratos Sprague-Dawley , Solubilidade , Propriedades de Superfície , Distribuição Tecidual , Fator de Necrose Tumoral alfa/metabolismo
10.
J Photochem Photobiol B ; 203: 111774, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31931386

RESUMO

Zeolitic imidazole framework (ZIF) is an emerging class of metal organic frameworks exhibiting unique features such as crystalline nature with tunable pore size, large surface area and biocompatible nature. Exceptional thermal and chemical stabilities of ZIF-L make it a suitable candidate for biomedical applications. The present study has focused on the single step fabrication of catechin encapsulated ZIF-L and evaluation of its antibiofilm efficiency, larvicidal activity and dye degradation ability. The as- prepared CA@ZIF-L nanocomposite was characterized by spectroscopic and microscopic techniques. The results revealed that the CA@ZIF-L showed significant toxicity against mosquito larvae in a dose dependent manner with the IC50 63.43±1.25 µg/mL. CA@ZIF-L showed dose dependent reduction of biofilm formation in both ATCC and clinical MRSA strains. In addition, CA@ZIF-L exhibited excellent photocatalytic activity with around 92% degradation of methylene blue under direct sunlight. Overall, the present work highlights the possibility of employing the multifunctional CA@ZIF-L nanocomposite as a suitable material for biomedical and photocatalytic applications.


Assuntos
Biofilmes/efeitos dos fármacos , Catequina/química , Estruturas Metalorgânicas/química , Nanocompostos/toxicidade , Zeolitas/química , Animais , Catálise , Culicidae/efeitos dos fármacos , Culicidae/crescimento & desenvolvimento , Imidazóis/química , Larva/efeitos dos fármacos , Luz , Staphylococcus aureus Resistente à Meticilina/fisiologia , Azul de Metileno/química , Nanocompostos/química , Tamanho da Partícula , Fotólise/efeitos da radiação
11.
Chem Commun (Camb) ; 56(11): 1717-1720, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31942593

RESUMO

A novel sensor array based on a (+)AuNP/AuNC nanocomposite was constructed for the selective discrimination of 10 types of Gram-negative bacteria (including 3 types of antibiotic-resistant strains) at a low concentration level of OD600 = 0.015. By recognizing the triple optical patterns of Gram-negative bacteria with the assistance of LDA, the sensor array is able to group the bacteria with respect to their species to each other.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Bactérias Gram-Negativas/isolamento & purificação , Nanopartículas Metálicas/química , Análise por Conglomerados , Análise Discriminante , Ouro/química , Bactérias Gram-Negativas/classificação , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Nanocompostos/química , Espalhamento de Radiação , Espectrometria de Fluorescência , Urina/microbiologia , Vancomicina/química
12.
Ecotoxicol Environ Saf ; 190: 110098, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31901811

RESUMO

Prostate cancer is one of the primary causes of death around the world. As an important drug, flutamide has been used in the clinical diagnosis of prostate cancer. However, the over dosage and improper discharge of flutamide could affect the living organism. Thus, it necessary to develop the sensor for detection of flutamide with highly sensitivity. In this paper, we report the synthesis of lanthanum cobaltite decorated halloysite nanotube (LCO/HNT) nanocomposite prepared by a facile method and evaluated for selective reduction of flutamide. The as-prepared LCO/HNT nanocomposite shows the best catalytic performance towards detection of flutamide, when compared to other bare and modified electrodes. The good electrochemical performance of the LCO/HNT nanocomposite modified electrode is ascribed to abundant active sites, large specific surface area and their synergetic effects. Furthermore, the LCO/HNT modified electrode exhibits low detection limit (0.002 µM), wide working range (0.009-145 µM) and excellent selectivity with remarkable stability. Meaningfully, the developed electrochemical sensor was applied in real environmental samples with an acceptable recovery range.


Assuntos
Poluentes Ambientais/análise , Flutamida/análise , Lantânio/química , Nanocompostos/química , Catálise , Argila , Técnicas Eletroquímicas/métodos , Eletrodos , Grafite/química , Humanos , Limite de Detecção , Minerais , Nanotubos/química
13.
Anal Bioanal Chem ; 412(1): 193-201, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760449

RESUMO

A highly sensitive approach to detect trace amount of clenbuterol (CB) based on graphene oxide/gold nanoparticles (GO/Au NPs) by surface-enhanced Raman spectroscopy (SERS) was presented. To be specific, the GO/Au nanocomposites were formed by depositing Au NPs onto the surface of GO through an in situ reduction process, where a high density of inherent hot spots was created between Au NPs. By optimizing the depositing density of Au NPs, the strongest electromagnetic coupling effect originating from highly dense hot spots was obtained. The optimized GO/Au was demonstrated to enhance the Raman signals of CB by 4.8 times more than that of CB enhanced by Au NPs. Moreover, GO/Au nanocomposites exhibit good biocompatibility and accessible surface for high adsorption of target molecules through the pi-pi stacking with graphene oxide. Hence, the proposed GO/Au nanocomposites were utilized to capture aromatic molecules like CB and served as excellent sensitive SERS-active substrates for sensing of it, which exhibited an excellent linear performance in the range of 5 × 10-8 to 1 × 10-6 mol/L with a limit of detection (LOD) of 3.34 × 10-8 mol/L (S/N = 3). Due to high-density hot spots with easy operation, this proposed GO/Au nanocomposite-based SERS technique holds great potential in the application of food safety analysis and biomedical science.


Assuntos
Agonistas Adrenérgicos beta/análise , Clembuterol/análise , Ouro/química , Grafite/química , Nanocompostos/química , Análise Espectral Raman/métodos , Limite de Detecção
14.
Bioresour Technol ; 297: 122472, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31791917

RESUMO

The present study enlightens facile synthesis and characterization of magnetic biochar derived from waste banana pseudostem biomass for the removal of nitrofuran antibiotic 'furazolidone' (FZD). Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), magnetic hysteresis, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) revealed successful hybridization of magnetic nanocomposites with biochar (BPB600). The maximum adsorption capacity of magnetic BPB600 was 96.81% (37.86 mg g-1), which was significantly higher than the non-coated BPB600 (77.25%; 31.45 mg g-1). Adsorption kinetics data fitted well with pseudo-second order, and Elovich model demonstrating dominance of the chemisorption mechanism. Furthermore, the response surface methodology (RSM) was applied to evaluate the interactive effect of pH, temperature, and FZD concentration on adsorption. Therefore, the results of present study would provide an effective strategy to tackle antibiotic contaminants responsible for the antibiotic resistance genes or bacteria that decreases the therapeutic value of antibiotics.


Assuntos
Musa , Nanocompostos , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Furazolidona , Cinética , Fenômenos Magnéticos , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Chemosphere ; 241: 124981, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31606579

RESUMO

Photocatalytic degradation of toxic pollutants is an efficient technique to completely remove the toxic pollutants from water bodies. In the present investigation, photocatalytic degradation of pollutants was studied over porous g-C3N4/H-ZSM-5 nanocomposite under visible light irradiation. The composite g-C3N4/H-ZSM-5 was synthesized by mixing an aqueous solution of H-ZSM-5 zeolite (increases surface area and provides active sites for degradation) with melamine (precursor of g-C3N4) for 10-12 h followed by calcinations at 550 °C. The photocatalyst was characterized by XRD, BET, HRTEM, FESEM, EDS and elemental mapping analysis. These techniques confirmed that, g-C3N4/H-ZSM-5 composite have layered and porous structure with uniform distribution of g-C3N4 on H-ZSM-5 surface. The BET N2 adsorption-desorption analysis verified that the catalyst has high surface area (∼175 m2/g) having mesopores and micropores. The prepared catalyst was then used for the photodegradation of a model dye, Methylene Blue (MB) and an endocrine disrupting compound, Fipronil (FIP). Effects of various parameters such as pH, catalyst dose and scavengers were also studied. The % photocatalytic degradation of MB and FIP were around ∼92% and ∼84% with a high rate constants of 0.00997 and 0.00875 min-1, respectively. From the scavenger study, OH (hydroxyl radical) and radical was found to be the major reactive species for MB and FIP degradation. From these studies it is revealed that, the catalyst is visible active, easy to prepare and an efficient photocatalyst for toxic pollutant degradation.


Assuntos
Disruptores Endócrinos/química , Luz , Nanocompostos/química , Fotólise , Zeolitas/química , Adsorção , Catálise , Disruptores Endócrinos/efeitos da radiação , Azul de Metileno/química , Microscopia Eletrônica de Transmissão , Porosidade
16.
Chemosphere ; 241: 125068, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31629244

RESUMO

This paper reports a novel nanocomposite additive for a polyvinylidene fluoride (PVDF) membrane with high hydrophilicity through the association of graphene oxide (GO) and ZnO. The influence of the hydrophilicity of GO-ZnO on the PVDF membrane was examined on different GO-ZnO loadings. The porosity and wettability (or hydrophilicity) of the membrane were improved significantly by blending GO-ZnO nanocomposite. In addition, the water flux of the GO-ZnO/PVDF membrane was 48% higher than that of bare PVDF, and the anti-fouling properties of this modified membrane were also improved. The irreversible fouling ratio (Rir) of bovine serum albumin (BSA) was reduced substantially with increasing the loading of GO-ZnO nanocomposite. The lowest irreversible fouling ratio (7.21%) was obtained for the membrane containing 0.2 wt % GO-ZnO of the nanocomposite (M6). GO-ZnO modification PVDF membranes were assumed to reduce the affinity between membrane and BSA foulant, which improved the anti-fouling properties PVDF membrane. In the activated sludge flux test, the membrane containing GO-ZnO in the polymer matrix had a higher flux than that of the bare PVDF membrane. The effluent quality after the composite membrane (0.6 NTU) was stable, indicating that the composite membrane can be used for practical applications Overall, the properties of the PVDF membrane were improved after modification due to hydrogen bonding or the hydrophilicity of the GO-ZnO nanocomposite.


Assuntos
Grafite/química , Polivinil/química , Ultrafiltração , Eliminação de Resíduos Líquidos/métodos , Interações Hidrofóbicas e Hidrofílicas , Membranas Artificiais , Nanocompostos , Nanopartículas/química , Polímeros , Porosidade , Soroalbumina Bovina , Óxido de Zinco/química
17.
Chemosphere ; 241: 125020, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31614314

RESUMO

A nanocomposite of graphene and titanium dioxide (G/TiO2) was prepared using the sol-gel method for use in an electrochemical adsorption/regeneration process. The effect of annealing temperature on electrochemical characteristics of the nanocomposites was investigated by cyclic voltammetry and constant current electrochemical regeneration, using methylene blue (MB) as the adsorbate. The G/TiO2 could be regenerated more rapidly and with less corrosion than the bare graphene. The G/TiO2 annealed at 400 °C had a higher proportion of anatase phase TiO2 (ca. 7% rutile TiO2) compared to that annealed at 500 °C (ca. 40% rutile TiO2). Cyclic voltammetry indicated that the G/TiO2 annealed at 400 °C had a higher activity for MB oxidation than the nanocomposite annealed at 500 °C. Similarly, the regeneration of MB loaded G/TiO2 annealed at 400 °C was much faster than for the nanocomposite annealed at 500 °C. Complete regeneration of the G/TiO2 annealed at 400 °C was obtained after an electrochemical charge of 21 C per mg of adsorbate. The G/TiO2 annealed at 400 °C was regenerated in half the time required for the bare graphene. TEM studies showed that the bare graphene was rapidly corroded, while corrosion was not observed for the G/TiO2 nanocomposites.


Assuntos
Corantes/química , Técnicas Eletroquímicas/métodos , Grafite , Nanocompostos/química , Reciclagem/métodos , Titânio , Adsorção , Corrosão , Eletrodos , Azul de Metileno/química
18.
J Photochem Photobiol B ; 202: 111685, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31810035

RESUMO

Surface tailored GaAu loaded mesoporous silica nanoparticles are considered as an important nanomaterial for biomedical applications such as diagnosis and cancer treatment. In this study, we used GaAu loaded mesoporous silica nanoparticles (Ga-Au@mSiO2) for the photothermal treatment of two prostate cancer cell lines. We systematically examined the nanocomposite form by various spectroscopic (UV-Vis, TGA and DTA) and electroscopic techniques (TEM and SEM including the elemental mapping analysis). After careful evaluation of the nanocomposite form, we performed cancer cell growth inhibition properties of the prostate cancer cell lines (DU145 and LNCaP). Also, we performed the photothermal effects of these nanocomposites on cell proliferation and apoptosis using different biochemical staining and flow cytometry. Our in vitro investigational datas are established Ga-Au@mSiO2 effectively exhibited and also with Ga-Au@mSiO2 + NIR the photothermal conversion therapy improved prostate cancer cells abolishing the prostate cancer cells. Interestingly, Ga-Au@mSiO2 + NIR was found to surpass the activity of Ga-Au@mSiO2 in all the cancer cells tested a topnotches. Hence, our current results demonstrated that surface tailored GaAu loaded mesoporous silica nanoparticles significantly inhibited the growth of prostate cancer cell lines and shown prominent antitumor effect in vitro. Thus, our study suggests that Ga-Au@mSiO2 + NIR could be used as impending anticancer candidate for photothermal ablation of prostate cancer cells. Further examinations of the mechanism indicated that anticancer activity was accomplished by inducing apoptosis in cancer cells, which is suggesting that these Ga-Au@mSiO2 + NIR nanocomposite can be used as promising candidates for nursing care cancer therapy.


Assuntos
Gálio/química , Ouro/química , Raios Infravermelhos , Nanocompostos/química , Neoplasias da Próstata/terapia , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Humanos , Masculino , Nanocompostos/uso terapêutico , Nanocompostos/toxicidade , Cuidados de Enfermagem , Fototerapia , Porosidade , Neoplasias da Próstata/patologia , Dióxido de Silício/química
19.
J Photochem Photobiol B ; 202: 111666, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31837585

RESUMO

In this study, the effect of Polyp-Au-GO nanocomposite on VSMC proliferation, cell cycle proteins, down-regulation of mRNA in the rat was tested. Briefly, Polyp-Au-GO composite material was synthesized and characterized by UV-Vis spectra, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Polyp-Au-GO composite exhibited the absorbance peak at 530 nm. XRD analysis confirmed the crystalline particle with size ranging between 16.5 and 32.6 nm. The crystallinity differences of the nanocomposite were examined by Raman spectroscopy analysis. The presence of a strong band (1500 cm-1) and the absence of other lower frequency bands confirmed that the absence of crystallinity of Polyp-Au-GO nanocomposite. The thermal properties of Polyp-Au-GO nanocomposite were determined by TGA analysis. The results revealed that 15% of its weight loss has occurred at 300 °C. Further, the growth of VSMCs was inhibited by the treatment of Polyp-Au-GO composite at 72 h. The IC50 value was registered at 0.57 µg/mL. Additionally, the Polyp-Au-GO composite arrest G1 cell cycle and down-regulated cell cycle proteins. These Polyp-Au-GO composite also reduced the extracellular ERK1/2 phosphorylation. Furthermore, Polyp-Au-GO composite inhibited TNF-R-evoked inflammatory responses. Moreover, Polyp-Au-GO composite inhibited of CEC proliferation. These results suggest that Polyp-Au-GO composite inhibits VSMC proliferation and TNF-R-mediated inflammatory responses. This study suggested the therapeutic role of Polyp-Au-GO composite in cardiovascular disease.


Assuntos
Grafite/química , Nanocompostos/química , Polifenóis/química , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Nanocompostos/toxicidade , Tamanho da Partícula , Fosforilação/efeitos dos fármacos , Polifenóis/farmacologia , Ratos
20.
Chem Biodivers ; 17(1): e1900436, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31705573

RESUMO

A facile method was developed for synthesis of boronic acid-functionalized silica nanocomposites (SiO2 -BA) by 'thiol-ene' click reaction, where silica nanoparticles were synthesized by using tetraethoxysilane (TEOS) and γ-mercaptopropyl trimethoxysilane (γ-MPTS) as precursors. The morphology and structure properties of the resultant SiO2 -BA were characterized by transmission electronic microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and Brunner-Emmet-Teller measurements (BET). The adsorption behavior of the SiO2 -BA for glycoproteins was evaluated. Under the optimized conditions, the SiO2 -BA exhibited higher adsorption capacity towards glycoproteins (ovalbumin, OVA, 7.64 µmol/g) than non-glycoproteins (bovine serum albumin, BSA, 0.83 µmol/g). In addition, the practicality of the SiO2 -BA was further assessed by selective enrichment of glycoproteins from egg white samples.


Assuntos
Ácidos Borônicos/química , Glicoproteínas/química , Nanocompostos/química , Dióxido de Silício/química , Adsorção , Clara de Ovo/química , Estrutura Molecular , Tamanho da Partícula , Dióxido de Silício/síntese química , Propriedades de Superfície
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