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1.
PLoS One ; 15(8): e0237389, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797116

RESUMO

In the present work, a series of magnetically separable Fe3O4/g-C3N4/MoO3 nanocomposite catalysts were prepared. The as-prepared catalysts were characterized by XRD, EDX, TEM, FT-IR, UV-Vis DRS, TGA, PL, BET and VSM. The photocatalytic activity of photocatalytic materials was evaluated by catalytic degradation of tetracycline solution under visible light irradiation. Furthermore, the influences of weight percent of MoO3 and scavengers of the reactive species on the degradation activity were investigated. The results showed that the Fe3O4/g-C3N4/MoO3 (30%) nanocomposites exhibited highest removal ability for TC, 94% TC was removed during the treatment. Photocatalytic activity of Fe3O4/g-C3N4/MoO3 (30%) was about 6.9, 5, and 19.9-fold higher than those of the MoO3, g-C3N4, and Fe3O4/g-C3N4 samples, respectively. The excellent photocatalytic performance was mainly attributed to the Z-scheme structure formed between MoO3 and g-C3N4, which enhanced the efficient separation of the electron-hole and sufficient utilization charge carriers for generating active radials. The highly improved activity was also partially beneficial from the increase in adsorption of the photocatalysts in visible range due to the combinaion of Fe3O4. Superoxide ions (·O2-) was the primary reactive species for the photocatalytic degradation of TC, as degradation rate were decreased to 6% in solution containing benzoquinone (BQ). Data indicate that the novel Fe3O4/g-C3N4/MoO3 was favorable for the degradation of high concentrations of tetracycline in water.


Assuntos
Óxido Ferroso-Férrico/química , Grafite/química , Molibdênio/química , Nanocompostos/química , Compostos de Nitrogênio/química , Óxidos/química , Processos Fotoquímicos , Tetraciclina/química , Água/química , Catálise , Luz , Imãs/química , Tetraciclina/isolamento & purificação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
2.
Int J Nanomedicine ; 15: 5517-5526, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801703

RESUMO

Introduction: Hypertension is a major health problem worldwide and is typically treated using oral drugs. However, the frequency of oral administration may result in poor patient compliance, and reduced bioavailability owing to the first-pass effect can also prove problematic. Methods: In this study, we developed a new transdermal-drug-delivery system (TDDS) for the treatment of hypertension using atenolol (ATE) based on poly(acrylic acid) (PAA)-decorated three-dimensional (3D) flower-like MoS2 nanoparticles (PAA-MoS2 NPs) that respond to NIR laser irradiation. The PAA-modified MoS2 NPs were synthesized and characterized using attenuated total reflection Fourier-transform infrared spectroscopy, X-ray diffraction measurements, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, and the sedimentation equilibrium method. The drug-loading efficiency and photothermal conversion effect were also explored. Results: The results showed that the colloidally stable PAA-MoS2 NPs exhibited a high drug-loading capacity of 54.99% and high photothermal conversion ability. Further, the capacity of the PAA-MoS2 NPs for controlled release was explored using in vitro drug-release and skin-penetration studies. The drug-release percentage was 44.72 ± 1.04%, and skin penetration was enhanced by a factor of 1.85 in the laser-stimulated group. Sustained and controlled release by the developed TDDS were observed with laser stimulation. Moreover, in vivo erythema index analysis verified that the PAA-MoS2 NPs did not cause skin irritation. Discussion: Our findings demonstrate that PAA-MoS2 NPs can be used as a new carrier for transdermal drug delivery for the first time.


Assuntos
Anti-Hipertensivos/administração & dosagem , Atenolol/administração & dosagem , Dissulfetos/química , Sistemas de Liberação de Medicamentos/métodos , Molibdênio/química , Nanopartículas/administração & dosagem , Resinas Acrílicas/química , Administração Cutânea , Animais , Anti-Hipertensivos/farmacocinética , Atenolol/efeitos adversos , Atenolol/farmacocinética , Sistemas de Liberação de Medicamentos/efeitos adversos , Liberação Controlada de Fármacos , Difusão Dinâmica da Luz , Eritema/induzido quimicamente , Humanos , Lasers , Masculino , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Coelhos , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
3.
Food Chem ; 333: 127515, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683260

RESUMO

The nutritional and commercial value of the sweet cherry provides it a great economic importance in Italy. The aim of this study was to characterize 35 sweet cherry cultivars and one of sour cherry, by analyzing values of different pomological and nutraceutical traits, identifying cultivars with antioxidant activity and total anthocyanins content closest to those present in literature for Ferrovia (largely diffused in Italy). To this goal, a multivariate metric index through the Soft Independent Modeling of Class Analogy analyzing an artificial dataset and testing a real one, two hierarchical clustering and a principal component analysis, were performed. The multivariate analyses result simultaneously investigated all the variables highlighting cvs. Sylvia, Graffione nero Col di Mosso, Ferrovia, Mora della Punta, Bianchetta Nuchis and Sandra to be more similar to literature data of Ferrovia. This matrix index was a useful tool, to select the most commercial promising varieties.


Assuntos
Algoritmos , Prunus avium/classificação , Antocianinas/análise , Antioxidantes/química , Análise por Conglomerados , Frutas/química , Frutas/metabolismo , Concentração de Íons de Hidrogênio , Itália , Molibdênio/química , Fenóis/análise , Extratos Vegetais/química , Análise de Componente Principal , Prunus avium/química , Prunus avium/metabolismo , Compostos de Tungstênio/química
4.
Int J Nanomedicine ; 15: 3291-3302, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32494130

RESUMO

Background: Inhaled nanoparticles can cross pulmonary air-blood barrier into circulation and cause vascular endothelial injury and progression of cardiovascular disease. However, the molecular mechanism underlying the vascular toxicity of copper oxide nanoparticles (CuONPs) remains unclear. We have recently demonstrated that the release of copper ions and the accumulation of superoxide anions contributed to CuONPs-induced cell death in human umbilical vein endothelial cells (HUVECs). Herein, we further demonstrate the mechanism underlying copper ions-induced cell death in HUVECs. Methods and Results: CuONPs were suspended in culture medium and vigorously vortexed for several seconds before exposure. After treatment with CuONPs, HUVECs were collected, and cell function assays were conducted to elucidate cellular processes including cell viability, oxidative stress, DNA damage and cell signaling pathways. We demonstrated that CuONPs uptake induced DNA damage in HUVECs as evidenced by γH2AX foci formation and increased phosphorylation levels of ATR, ATM, p53 and H2AX. Meanwhile, we showed that CuONPs exposure induced oxidative stress, indicated by the increase of cellular levels of superoxide anions, the upregulation of protein levels of heme oxygenase-1 (HO-1) and glutamate-cysteine ligase modifier subunit (GCLM), the elevation of the levels of malondialdehyde (MDA), but the reduction of glutathione to glutathione disulfide ratio. We also found that antioxidant N-acetyl-L-cysteine (NAC) could ameliorate CuONPs-induced oxidative stress and cell death. Interestingly, we demonstrated that p38 mitogen-activated protein kinase (MAPK) signaling pathway was activated in CuONPs-treated HUVECs, while p38α MAPK knockdown by siRNA significantly rescued HUVECs from CuONPs-induced DNA damage and cell death. Importantly, we showed that copper ions chelator tetrathiomolybdate (TTM) could alleviate CuONPs-induced oxidative stress, DNA damage, p38 MAPK pathway activation and cell death in HUVECs. Conclusion: We demonstrated that CuONPs induced oxidative DNA damage and cell death via copper ions-mediated p38 MAPK activation in HUVECs, suggesting that the release of copper ions was the upstream activator for CuONPs-induced vascular endothelial toxicity, and the copper ions chelator TTM can alleviate CuONPs-associated cardiovascular disease.


Assuntos
Cobre/toxicidade , Dano ao DNA , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/patologia , Nanopartículas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Morte Celular/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Modelos Biológicos , Molibdênio/química , Nanopartículas/ultraestrutura
5.
Chemosphere ; 255: 126995, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32416394

RESUMO

In this paper, we present the preparation of MoS2-modified magnetic biochar (MoS2@MBC) as a novel adsorbent by a simple hydrothermal method. MoS2@MBC contains abundant S-containing functional groups that facilitate efficient Cd(II) removal from aqueous systems. We employed various characterization techniques to explore the morphology, surface area, and chemical composition of MoS2@MBC; these included Brunauer-Emmett-Teller analysis scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction,. The results indicated the successful decoration of the surface of MoS2@MBC with iron and MoS2, and a higher surface area of MoS2@MBC than that of unmodified biochar. Moreover, adsorption properties including thermodynamics and kinetics were investigated along with the effects of pH, humic acid, and ionic strength on the Cd(II) adsorption onto MoS2@MBC. The O-, C-, S-, and Fe-containing functional groups on the surface of MoS2@MBC led to an electrostatic attraction of Cd(II) and strong Cd-S complexation. The Langmuir and pseudo second-order models fitted best for the batch adsorption experiments results. The adsorption capacity of MoS2@MBC (139 mg g-1 on the basis of the Langmuir model) was 7.81 times higher than that of pristine biochar. The adsorption process was found to be pH-dependent. The experimental results indicated that MoS2@MBC is an effective adsorbent for removing Cd(II) from water solutions. Further, the adsorption process involved the complexation of Cd(II) with oxygen-based functional groups, ion exchange, electrostatic attraction, Cd(II)-π interactions, metal-sulfur complexation, and inner-surface complexation. This work provides new insights into the Cd(II) ions removal from water via adsorption. It also demonstrates that MoS2@MBC is an efficient and economic adsorbent to treat Cd(II)-contaminated water.


Assuntos
Adsorção , Cádmio/isolamento & purificação , Carvão Vegetal/química , Dissulfetos/química , Molibdênio/química , Purificação da Água/métodos , Cádmio/química , Cinética , Concentração Osmolar , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
6.
Chemosphere ; 256: 127099, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32470733

RESUMO

Membrane fouling is an issue of concern due to the hydrophobic properties of polyethersulfone (PES) membrane when applied in water treatment. In this work, a facile hydrothermal method was utilized to synthesize hierarchical flower-like structured molybdenum disulfide nanosheets (HF-MoS2 NSs) that then incorporated into PES membranes as composite membranes. We characterized their permeability, the separation performance, the antifouling performance, and the antibacterial activity systematically. Results showed that composite membranes exhibited a better pure water flux (286 LMH/bar) at the HF-MoS2 NSs content of 0.4 wt%, which was 1.8 times higher than the control membrane. Also, composite PES membranes achieved 98.2% and 96.9% rejection of BSA and HA in comparison with the control PES membrane (87.3%, and 84.5%, respectively). Compare to the control PES membrane, the flux recovery ratio of the composite membrane increased from 69% to 88% for BSA fouling and increased from 84% to 93% for HA fouling. The retention rate for the organic dyes also improved slightly after HF-MoS2 NSs incorporation into the membrane. Additionally, the composite membranes exhibited a relatively high antibacterial activity against E. coli and B. subtilis with antibacterial rates of 67.8% and 82.5%, respectively. In conclusion, HF-MoS2 NSs incorporated composite membranes were shown to have outstanding filtration performance and could be a promising candidate for practical application in water filtration.


Assuntos
Nanoestruturas/química , Polímeros/química , Sulfonas/química , Purificação da Água/métodos , Dissulfetos/química , Escherichia coli , Filtração , Interações Hidrofóbicas e Hidrofílicas , Membranas Artificiais , Molibdênio/química , Permeabilidade , Água/química
7.
Proc Natl Acad Sci U S A ; 117(24): 13329-13338, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32461372

RESUMO

Two-dimensional (2D) molybdenum disulfide (MoS2) nanomaterials are an emerging class of biomaterials that are photoresponsive at near-infrared wavelengths (NIR). Here, we demonstrate the ability of 2D MoS2 to modulate cellular functions of human stem cells through photothermal mechanisms. The interaction of MoS2 and NIR stimulation of MoS2 with human stem cells is investigated using whole-transcriptome sequencing (RNA-seq). Global gene expression profile of stem cells reveals significant influence of MoS2 and NIR stimulation of MoS2 on integrins, cellular migration, and wound healing. The combination of MoS2 and NIR light may provide new approaches to regulate and direct these cellular functions for the purposes of regenerative medicine as well as cancer therapy.


Assuntos
Dissulfetos/efeitos da radiação , Células-Tronco Mesenquimais/efeitos da radiação , Molibdênio/efeitos da radiação , Nanoestruturas/efeitos da radiação , Adesão Celular/efeitos da radiação , Movimento Celular/efeitos da radiação , Sobrevivência Celular , Dissulfetos/química , Dissulfetos/metabolismo , Perfilação da Expressão Gênica , Humanos , Raios Infravermelhos , Integrinas/genética , Integrinas/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Molibdênio/química , Molibdênio/metabolismo , Nanoestruturas/química , Fármacos Fotossensibilizantes , Transdução de Sinais/efeitos da radiação
8.
Ecotoxicol Environ Saf ; 200: 110772, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32464444

RESUMO

Recently two-dimensional nanomaterials, such as graphene and molybdenum disulfide (MoS2), have received much attention as adsorbent materials for the effective removal of organic contaminants. MoS2 is attracting attention, not only for its chemical-physical properties, but also for its wide availability in nature as a constituent of molybdenite. The aim of this investigation was to assess the effects of different MoS2 concentrations (5 × 10-1, 5 × 10-2 and 5 × 10-3 mg/ml) on the embryonated eggs of Gallus gallus domesticus, according to Beck method. We evaluated the toxic effect of the MoS2 powder purchased at Sigma-Aldrich indicated as "received" and MoS2 powder treated via mechanical milling indicated as "ball mille". Subsequently, the embryos were sacrificed at different times of embryonic development (11th, 15th and 19th day after incubation) in order to evaluate their embryotoxic and teratogenic effects. The alterations of the embryonic development were studied by morphological and immunohistochemical analysis of the tissues. The results obtained have shown the toxicity of both powders of MoS2 with a high percentage of deaths and growth delays. Moreover, the immunohistochemical analysis performed on several tissue sections showed a strong positivity to the anti-metallothionein1 antibody only for the erythrocytes.


Assuntos
Dissulfetos/química , Dissulfetos/toxicidade , Desenvolvimento Embrionário/efeitos dos fármacos , Molibdênio/química , Molibdênio/toxicidade , Nanopartículas/química , Nanopartículas/toxicidade , Animais , Embrião de Galinha , Relação Dose-Resposta a Droga , Grafite/química , Coração/efeitos dos fármacos , Coração/embriologia , Fígado/efeitos dos fármacos , Fígado/embriologia , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/embriologia , Pulmão/patologia , Tamanho da Partícula , Propriedades de Superfície
9.
Anal Chim Acta ; 1113: 43-51, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32340668

RESUMO

This study fabricated a dual-emission probe consisting of monolayer MoS2 quantum dots (M - MoS2 QDs) and L-cystine-linked boron-dipyrromethene (L-Cys-BODIPY) molecules for ratiometric sensing of biothiols, thiol product-related enzyme reactions, and ratiometric imaging of glutathione (GSH)-related reactions in HeLa cells. The formation of L-Cys-BODIPY-adsorbed M - MoS2 QDs (named as BODIPY-M-MoS2 QDs) was demonstrated by comparing them with M - MoS2 QDs using transmission electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. The BODIPY-M-MoS2 QDs exhibited dual-emission bands, excellent biocompatibility, and good resistance to photobleaching. It was found that the adsorbed L-Cys-BODIPY molecules rarely quenched the fluorescence of M - MoS2 QDs, and meanwhile, they were self-quenched by π-π stacking between each BODIPY backbones. The presence of biothiols induced the reduction of weakly fluorescent L-Cys-BODIPY to strongly fluorescent of L-cysteine-conjugated BODIPY. Since having a much higher molar absorption coefficient than L-Cys-BODIPY, the liberated L-cysteine-conjugated BODIPY behaved as an effective inner filter to absorb the excitation light and subsequently quenched the fluorescence of M - MoS2 QDs. The appearance of L-cysteine-conjugated BODIPY could barely affected to the fluorescence lifetime of M - MoS2 QDs, confirming the inner filter effect of L-cysteine-conjugated BODIPY onto the fluorescence of M - MoS2 QDs. The present probe not only provided a linear ratiometric response to 1-10 mM GSH, 1-10 µM cysteine, and 1-10 µM of homocysteine but also remarkably showed the ratiometric detection of thiol products from the reactions of 1-900 units L-1 S-adenosylhomocysteine (SAH) hydrolase and SAH as well as 1-850 units L-1 GSH reductase and disulfide GSH. Additionally, the present probe was well-suited for ratiometric imaging of intracellular GSH levels in non-treated and drug-treated HeLa cells.


Assuntos
Cisteína/análise , Corantes Fluorescentes/química , Glutationa/análise , Homocisteína/análise , Pontos Quânticos/química , Compostos de Boro/química , Cistina/química , Dissulfetos/química , Células HeLa , Humanos , Limite de Detecção , Molibdênio/química , Espectrometria de Fluorescência/métodos
10.
Nat Commun ; 11(1): 1912, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313256

RESUMO

Metal-containing formate dehydrogenases (FDH) catalyse the reversible oxidation of formate to carbon dioxide at their molybdenum or tungsten active site. They display a diverse subunit and cofactor composition, but structural information on these enzymes is limited. Here we report the cryo-electron microscopic structures of the soluble Rhodobacter capsulatus FDH (RcFDH) as isolated and in the presence of reduced nicotinamide adenine dinucleotide (NADH). RcFDH assembles into a 360 kDa dimer of heterotetramers revealing a putative interconnection of electron pathway chains. In the presence of NADH, the RcFDH structure shows charging of cofactors, indicative of an increased electron load.


Assuntos
Microscopia Crioeletrônica/métodos , Formiato Desidrogenases/química , Rhodobacter capsulatus/metabolismo , Dióxido de Carbono/metabolismo , Catálise , Domínio Catalítico , Modelos Moleculares , Molibdênio/química , NAD/química , NAD/metabolismo , Oxirredução , Tungstênio
11.
Inorg Chem ; 59(8): 5243-5246, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32255347

RESUMO

The Anderson-type hexamolybdoaluminate functionalized with lauric acid (LA), (TBA)3[Al(OH)3Mo6O18{(OCH2)3CNHCOC11H23}]·9H2O (TBA-AlMo6-LA, where TBA = tetrabutylammonium), was prepared via two synthetic routes and characterized by thermogravimetric and elemental analyses, mass spectrometry, IR and 1H NMR spectroscopy, and powder and single-crystal X-ray diffraction. The interaction of TBA-AlMo6-LA with human serum albumin (HSA) was investigated via fluorescence and circular dichroism spectroscopy. The results revealed that TBA-AlMo6-LA binds strongly to HSA (63% quenching at an HSA/TBA-AlMo6-LA ratio of 1:1), exhibiting static quenching. In contrast to TBA-AlMo6-LA, the nonfunctionalized polyoxometalate, Na3(H2O)6[Al(OH)6Mo6O18]·2H2O (AlMo6), showed weak binding toward HSA (22% quenching at a HSA/AlMo6 ratio of 1:25). HSA binding was confirmed by X-ray structure analysis of the HSA-Myr-AlMo6-LA complex (Myr = myristate). These results provide a promising lead for the design of novel polyoxometalate-based hybrids that are able to exploit HSA as a delivery vehicle to improve their pharmacokinetics and bioactivity.


Assuntos
Compostos de Alumínio/metabolismo , Ácidos Láuricos/metabolismo , Albumina Sérica Humana/metabolismo , Compostos de Alumínio/síntese química , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Dicroísmo Circular , Cristalografia por Raios X , Humanos , Ácidos Láuricos/síntese química , Molibdênio/química , Ligação Proteica , Albumina Sérica Humana/química , Espectrometria de Fluorescência , Triptofano/química
12.
Food Chem ; 319: 126572, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32163838

RESUMO

In this study, a molybdenum coated T-shaped slotted quartz tube atom trap flame atomic absorption spectrophotometry method (Mo coated-T-SQT-AT-FAAS) was developed for the determination of cadmium with on-line preconcentration. Inner surface of T-SQT was coated with molybdenum to enhance the trapping efficiency. Hydrogen gas was used instead of organic solvents to release trapped atoms. Limit of detection and quantification were found to be 0.057 and 0.082 µg/L, respectively. The developed method has a linear working range between 0.10 and 1.0 µg/L with a low %RSD value (<3.7). About 1202 times enhancement in detection power was recorded over the conventional FAAS system. Recovery experiments were used to determine the applicability of the method developed to real samples (linden, milk powder and mint) and significant results (94.4-100.7%) were obtained for the samples spiked at 0.30, 0.50 and 1.0 µg/L. The method was also applied to Tomato Leaves 1573a SRM to check the accuracy.


Assuntos
Cádmio/análise , Análise de Alimentos , Alimentos , Molibdênio/química , Espectrofotometria Atômica/métodos , Hidrogênio , Limite de Detecção , Quartzo , Solventes/química
13.
Chemosphere ; 248: 126025, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32006838

RESUMO

Novel molybdenum disulfide-montmorillonite (MoS2@2DMMT) hydrogels for Cu(II) removal and inhibition on bacterial growth were successfully prepared. MoS2 was first in-situ growth onto 2DMMT platelet through hydrothermal method and then cross-linked with organic reagents to form hydrogels. The flower-like structure of synthesized MoS2 could be clearly observed in MoS2@2DMMT by SEM. The synthesized hydrogels possessed a three-dimensional macroporous structure, offering a free access for contaminants to get inside and combine with the active sites. Adsorption tests revealed that efficient Cu(II) removal (65.75 mg/g) could be achieved within a short time (30 min) at pH 5. The pseudo-second-order kinetics model and Langmuir isotherm model indicated the existence of chemisorption and monolayer absorption for Cu(II) onto MoS2@2DMMT hydrogels. Characterizations of EDS and XPS indicated that Cu(II) reacted with groups of carboxyl, hydroxyl and amidogen. Bacteriostatic tests revealed that almost a complete bacteriostatic was achieved with just small dosage (0.8 mg/mL) of MoS2@2DMMT hydrogels after the Cu(II) removal under the normal illumination. The mechanism was ascribed to the destructive effect of Cu(II) to the cytomembrane and the damage of reactive oxygen species (ROS) to the DNA. Such hydrogel not only provided insights for treating co-existing contaminates, but also guides for designing novel polymer materials from two-dimensional (2D) nano-materials.


Assuntos
Antibacterianos/farmacologia , Bentonita/química , Cobre/isolamento & purificação , Dissulfetos/química , Hidrogéis/química , Molibdênio/química , Adsorção , Antibacterianos/química , Cobre/química , Cobre/farmacologia , Reagentes para Ligações Cruzadas/química , Escherichia coli/efeitos dos fármacos , Cinética , Microscopia de Força Atômica , Espécies Reativas de Oxigênio/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Difração de Raios X
14.
Appl Microbiol Biotechnol ; 104(7): 3121-3131, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32060693

RESUMO

Antibiotic resistance in pathogenic bacteria is a major health challenge, as Infectious Diseases Society of America (IDSA) has recognized that the past simply drugs susceptible pathogens are now the most dangerous pathogens due to their nonstop growing resistance towards conventional antibiotics. Therefore, due to the emergence of multi-drug resistance, the bacterial infections have become a serious global problem. Acute infections feasibly develop into chronic infections because of many factors; one of them is the failure of effectiveness of antibiotics against superbugs. Modern research of two-dimensional nanoparticles and biopolymers are of great interest to attain the intricate bactericidal activity. In this study, we fabricated an antibacterial nanocomposite consisting of representative two-dimensional molybdenum disulfide (2D MoS2) nanoparticles. Polyhydroxyalkanoate (PHA) and chitosan (Ch) are used to encapsulate MoS2 nanoparticles into their matrix. This study reports the in vitro antibacterial activity and host cytotoxicity of novel PHA-Ch/MoS2 nanocomposites. PHA-Ch/MoS2 nanocomposites were subjected to time-dependent antibacterial assays at various doses to examine their antibacterial activity against multi-drug-resistant Escherichia coli K1 (Malaysian Type Culture Collection 710859) and methicillin-resistant Staphylococcus aureus (MRSA) (Malaysian Type Culture Collection 381123). Furthermore, the cytotoxicity of nanocomposites was examined against spontaneously immortalized human keratinocyte (HaCaT) cell lines. The results indicated significant antibacterial activity (p value < 0.05) against E. coli K1 and MRSA. In addition, PHA-Ch/MoS2 showed significant host cytocompatibility (p < 0.05) against HaCaT cells. The fabricated PHA-Ch/MoS2 nanocomposites have demonstrated effective antibacterial activity against both Gram-positive and -negative bacteria and exhibited better biocompatibility. Finally, PHA-Ch/MoS2 nanocomposites are shown to be suitable for antibacterial applications and also hold potential for further biomedical studies. Graphical Abstract.


Assuntos
Antibacterianos/farmacologia , Biopolímeros/farmacologia , Dissulfetos/farmacologia , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Molibdênio/farmacologia , Poli-Hidroxialcanoatos/farmacologia , Antibacterianos/química , Biopolímeros/química , Linhagem Celular , Quitosana/química , Dissulfetos/química , Farmacorresistência Bacteriana Múltipla/fisiologia , Humanos , Nanopartículas Metálicas/química , Molibdênio/química , Nanocompostos/química , Poli-Hidroxialcanoatos/síntese química , Poli-Hidroxialcanoatos/química
15.
Talanta ; 209: 120507, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892003

RESUMO

To overcome the poor conductivities and promote the application in the biosensors of metal-organic frameworks (MOFs), a simple approach was employed to improve their overall conductivity by adjusting the metal centers of MOFs and coating conductive polypyrrole (PPy) in the work. An unprecedented molybdenum oxide-based three-dimensional MOFs with helical channels (CuTRZMoO4) was synthesized based on MoO4-, Cu2+ ions and 1,2,3-trz for the first time, then combined with PPy to fabricate hybrid composites (CuTRZMoO4@PPy-n) with both advantages. The CuTRZMoO4 modified glassy carbon electrode show high sensitivity for detecting the neurotransmitter dopamine (DA), and the CuTRZMoO4@PPy-2 modified glassy carbon electrode has the highest catalytical activity to DA with the linear detection range from 1 µM to 100 µM and the detection limit of 80 nM (S/N = 3) by differential pulse voltammetry (DPV). Moreover, the developed biosensor has good selectivity, reproducibility and stability. The concept behinds the new architecture to modify electrodes should promote the further development of MOF-based biosensors.


Assuntos
Dopamina/sangue , Estruturas Metalorgânicas/química , Molibdênio/química , Nanocompostos/química , Óxidos/química , Polímeros/química , Pirróis/química , Técnicas Biossensoriais/métodos , Carbono/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Limite de Detecção , Estruturas Metalorgânicas/síntese química
16.
Molecules ; 25(2)2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31936021

RESUMO

The molybdenum (Mo)-catalyzed oxidation of sulfide under neutral conditions yields sulfone. This reaction proceeds more smoothly than olefin epoxidation and primary or secondary alcohol oxidation. In this study, Mo-catalyzed oxidation was used to screen for sulfur compounds (named "MoS-screening") in microbial broths by liquid chromatography-mass spectrometry (LC/MS). To demonstrate proof-of-concept, known sulfur microbial compounds were successfully identified from a mixture of non-sulfur microbial compounds as sulfinyl or sulfonyl products of Mo-catalyzed oxidation. Then our MoS-screening method was used to screen 300 samples of microbial broth for sulfur compounds. One of the identified compounds was a kitasetaline-containing N-acetyl cysteine moiety produced by an actinomycete strain. These results demonstrate the potential of MoS-screening in the search for new sulfur compounds from microbial sources.


Assuntos
Actinobacteria/metabolismo , Molibdênio/química , Sulfonas/química , Compostos de Enxofre/química , Acetilcisteína/química , Actinobacteria/química , Actinobacteria/crescimento & desenvolvimento , Catálise , Cromatografia Líquida , Fermentação , Espectrometria de Massas , Oxirredução , Sulfetos/química , Enxofre/química
17.
Anal Chim Acta ; 1098: 181-189, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31948582

RESUMO

Protein N-glycosylation plays crucial roles in many biological processes and has close association with the occurrence and development of various cancers. Therefore, it is necessary to analyze the abnormal changes of N-glycopeptides in complex biological samples for biomarker discovery. However, due to their low abundance and poor ionization, N-glycopeptides identification in complex samples by mass spectrometry (MS) is still a challenging task. In this work, a novel magnetic hydrophilic material was prepared by serial functionalization of ultra-thin two-dimensional molybdenum disulfide with Fe3O4 nanoparticles, gold nanowire and glutathione (MoS2-Fe3O4-Au/NWs-GSH) for efficient N-glycopeptides enrichment. The advantage of using the new nanocomposite is threefold. First, the introduction of magnetic Fe3O4 nanoparticles efficiently simplifies the enrichment process. Second, the gold nanowire modification enlarges the surface area of the nanocomposites to facilitate interaction with N-glycopeptides. Third, the employment of highly hydrophilic glutathione leads to specific HILIC-based retention of N-glycopeptides. Low femtomolar detection sensitivity and 1:1000 enrichment selectivity can be achieved using MoS2-Fe3O4-Au/NWs-GSH enrichment and bio-mass spectrometry analysis. Successful applications in human urine exosome and serum proteins were demonstrated by the enrichment and identification of 1250 and 489 N-glycopeptides, respectively. This remarkable data set of N-glycoproteome indicates the application potential of the novel nanocomposites for N-glycopeptides enrichment in complex biological samples and for related glycoproteome studies.


Assuntos
Proteínas Sanguíneas/urina , Dissulfetos/química , Exossomos/química , Glutationa/química , Glicopeptídeos/química , Nanopartículas de Magnetita/química , Molibdênio/química , Cromatografia Líquida de Alta Pressão , Humanos , Interações Hidrofóbicas e Hidrofílicas
18.
Molecules ; 25(2)2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31936680

RESUMO

A type of molecular-imprinted polymer with magnetic molybdenum disulfide as a base and deep eutectic solvent as a functional monomer (Fe3O4@MoS2@DES-MIP) was prepared with surface molecular imprinting method. It was applied as the adsorbent for the selective recognition and separation of (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate, and (-)-epigallocatechin gallate in green tea in the process of magnetic solid-phase extraction (MSPE) combined with high-performance liquid chromatography (HPLC). The structure of Fe3O4@MoS2@DES-MIP was characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The adsorption properties and selective recognition ability on (-)-epigallocatechin gallate and the other four structural analogues were examined and compared. The results show that the polymer has excellent selective recognition ability for (-)-epigallocatechin gallate, and its adsorption capacity was much higher than that of structural analogues. The Fe3O4@MoS2@DES-MIP not only has the special recognition ability to template a molecule, but also can be separated by magnets with high separation efficiency and can be used in MSPE.


Assuntos
Catequina/análogos & derivados , Catequina/isolamento & purificação , Impressão Molecular , Chá/química , Catequina/química , Cromatografia Líquida de Alta Pressão , Dissulfetos/química , Molibdênio/química , Polímeros/química
19.
Mikrochim Acta ; 187(2): 148, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980908

RESUMO

Electrochemical assay for analysis of cell surface glycan expression is reported. Mannose on human breast cancer cells (type MCF-7) is selected as the glycan model. Gold nanoparticles are modified with binding aptamer for MCF-7 cells and act as electrochemical probe. The analysis of cell surface glycan expression follows a traditional sandwich protocol. Concanavalin A that can specifically recognize mannose is immobilized onto MnO2 nanosheets modified electrode for the capture of MCF-7 cells. Then, the modified gold nanoparticles are immobilized onto the electrode via the binding between MCF-7 cell and aptamer on the gold nanoparticles. The aptamer on the gold nanoparticles reacts with molybdate. More specifically, the reaction of the phosphate backbone of aptamer with molybdate results in the formation of a redox-active molybdophosphate precipitate and generates an electrochemical current. The current intensity at 0.20 V (vs. Ag/AgCl) is recorded to test the linear range of the assay. The assay shows an obvious response to MCF-7 cells with a wide linear range from 1.0 × 103 to 1.0 × 106 cells mL-1 and a limit of detection down to 300 cells mL-1. The assay can be used to selectively monitor the change of mannose expression on cell surfaces upon the treatment with the N-glycan inhibitor. Graphical abstractSchematic of an electrochemical assay for analysis of cell surface glycan expression of MCF-7 cancer cells.


Assuntos
Membrana Celular/química , DNA/química , Técnicas Eletroquímicas/métodos , Compostos de Manganês , Nanopartículas Metálicas/química , Óxidos , Polissacarídeos/análise , Aptâmeros de Nucleotídeos/química , Carbono , Linhagem Celular Tumoral , Eletrodos , Ouro , Humanos , Limite de Detecção , Células MCF-7 , Molibdênio/química
20.
Ultrason Sonochem ; 62: 104867, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31806551

RESUMO

For the first time, Bi2MoO6 nanofilms were successfully synthesized by simultaneous pulse sonication-pulse electrodeposition (PS-PED) on the stainless steel mesh surface. Bismuth molybdate films were formed under various combinations of electrodeposition and sonication (sono-electrodeposition) in continuous and pulse modes. Porous Bi2MoO6 films synthesized by PS-PED method and showed the highest efficiency in photocatalytic degradation in comparison with other films. Bi2MoO6 film obtained from PS-PED had a thickness of 13.78 nm while, the thickness for the electrodeposition method was 39.52 nm. The high photocatalytic efficiency is attributed to the high surface roughness and low thickness of film synthesized by PS-PED method. Indeed, ultrasound played a key role in the synthesis of films with high surface roughness. On the other hand, shock waves and micro-jets could be dissolved diffusion problems and reduced the dendrite like structures in deposition process. Simultaneous application of pulse modes for both combined methods led to more growth of crystallographic planes. This is due to reaction of ions on the surface in interval relaxation times and produce more nuclei for growth. In order to obtain a high efficiency, response surface methodology was used for optimization of effective variable parameters (ton, toff and sonication amplitude) in film preparation.


Assuntos
Anti-Inflamatórios não Esteroides/química , Bismuto/química , Diclofenaco/química , Galvanoplastia/métodos , Molibdênio/química , Nanoestruturas , Sonicação , Aço Inoxidável/química , Poluentes Químicos da Água/química , Catálise , Processos Fotoquímicos , Propriedades de Superfície
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