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2.
Environ Health Prev Med ; 24(1): 36, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101002

RESUMO

BACKGROUND: Melanin is detectable in various sense organs including the skin in animals. It has been reported that melanin adsorbs toxic elements such as mercury, cadmium, and lead. In this study, we investigated the adsorption of molybdenum, which is widely recognized as a toxic element, by melanin. METHODS: Molybdenum level of the mouse skin was measured by inductively coupled plasma mass spectrometry. The pigmentation level of murine skin was digitalized as the L* value by using a reflectance spectrophotometer. An in vitro adsorption assay was performed to confirm the interaction between molybdenum and melanin. RESULTS: Our analysis of hairless mice with different levels of skin pigmentation showed that the level of molybdenum increased with an increase in the level of skin pigmentation (L* value). Moreover, our analysis by Spearman's correlation coefficient test showed a strong correlation (r = - 0.9441, p < 0.0001) between L* value and molybdenum level. Our cell-free experiment using the Langmuir isotherm provided evidence for the adsorption of molybdenum by melanin. The maximum adsorption capacity of 1 mg of synthetic melanin for molybdenum was 131 µg in theory. CONCLUSION: Our in vivo and in vitro results showed a new aspect of melanin as an adsorbent of molybdenum.


Assuntos
Melaninas/química , Molibdênio/química , Poluentes Químicos da Água/química , Adsorção , Animais , Melaninas/metabolismo , Camundongos , Camundongos Pelados , Camundongos Transgênicos , Molibdênio/metabolismo , Molibdênio/farmacologia , Pele/química , Pele/efeitos dos fármacos , Pigmentação da Pele/efeitos dos fármacos , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/farmacologia
3.
Carbohydr Polym ; 215: 226-234, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30981349

RESUMO

Bacterial infections have evolved as a life-threatening problem afflicting people due to the abuse of antibiotics and emergence of drug-resistant bacteria. Thus developing novel antibacterial materials is an urgent need. Herein, chitosan-MoS2 (CS-MoS2) nanocomposite was synthesized through thiol ligand functionalization and chemical modification to achieve more efficient bactericidal activity. CS-MoS2 exhibited synergistic remarkable bactericidal capability against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E.coli), where bacterial viabilities were significantly reduced. After treatment with 10 µg/mL of CS-MoS2, 100% and 98.1% of S. aureus and E.coli cells were killed respectively. A mechanism study revealed that the positively charged CS-MoS2 could interact with cell membrane, then cause damage to the membrane and cellular constituents by generation of reactive oxygen species (ROS) and glutathione (GSH) oxidation, finally inhibit bacterial growth. The CS-MoS2 could be an attractive antibacterial agent with improved efficiency and provide more strategies for application of MoS2.


Assuntos
Antibacterianos/química , Quitosana , Dissulfetos , Escherichia coli/efeitos dos fármacos , Molibdênio , Nanocompostos/química , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Quitosana/química , Quitosana/farmacologia , Dissulfetos/química , Dissulfetos/farmacologia , Molibdênio/química , Molibdênio/farmacologia
4.
Nanoscale ; 11(15): 7209-7220, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30920555

RESUMO

Currently, one of the major hurdles hindering the clinical applications of photothermal therapy (PTT) and photothermal-chemo combination therapy (PCT) is the lack of highly efficient, readily derived, and irradiation-safe photothermal agents in the biologically transparent window. Herein, we report the first design and rational construction of 0D/2D/0D sandwich heterojunctions for greatly enhanced PTT and PCT performances using 0D N-doped carbon dots and 2D MoS2 nanosheets as the assembly units. The well-matching heterojunctions enabled an additional enhancement in NIR absorbance owing to the carrier injection from carbon dots to MoS2 nanosheets, and achieved a much higher photothermal conversion efficiency (78.2%) than that of single NIR-CDs (37.6%) and MoS2 (38.3%) only. In virtue of the heterojunction-based PTT, complete tumor recession without recurrence or pulmonary metastasis was realized at an ultralow and safe laser exposure (0.2 W cm-2) below the skin tolerance irradiation threshold. Furthermore, by taking advantage of the strong X-ray attenuation and effective drug loading capacity of MoS2 nanosheets, the CT imaging-guided PCT was achieved at 0.1 W cm-2, without inducing noticeable toxic side effects. Our findings can substantiate the potential of a novel 0D/2D heterojunction for cancer theranostics.


Assuntos
Carbono , Dissulfetos , Hipertermia Induzida , Molibdênio , Técnicas Fotoacústicas , Fotoquimioterapia , Pontos Quânticos , Tomografia Computadorizada por Raios X , Animais , Carbono/química , Carbono/farmacologia , Linhagem Celular Tumoral , Terapia Combinada , Dissulfetos/química , Dissulfetos/farmacologia , Humanos , Camundongos , Molibdênio/química , Molibdênio/farmacologia , Metástase Neoplásica , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia , Pontos Quânticos/química , Pontos Quânticos/uso terapêutico , Pontos Quânticos/ultraestrutura , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Mater Sci Eng C Mater Biol Appl ; 99: 552-562, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889729

RESUMO

In this work, two new α +â€¯ß titanium alloys with low contents of ubiquitous and low-cost alloying elements (i.e., Mo and Fe) were designed on the basis of the electronic parameters and molybdenum equivalent approaches. The designed Ti - 2Mo - 0.5Fe at. % (TMF6) and Ti - 3Mo - 0.5Fe at. % (TMF8) alloys were produced using arc melting process for studying their mechanical, electrochemical and cytotoxicity compatibilities and comparing these compatibilities to those of Ti-6Al-4V ELI alloy. The cost of the used raw materials for producing the TMF6 and TMF8 alloys are almost 1/6 of those for producing the Ti-6Al-4V ELI alloy. The hardness of the two alloys are higher than that of the Ti-6Al-4V ELI alloy, while their Young's moduli (in the range of 85-82 GPa) are lower than that of the Ti-6Al-4V ELI alloy (110 GPa). Increasing the Mo equivalent from 6 (in TMF6 alloy) to 8 (in TMF8 alloy) led to an increase in the plastic strain percent from 4% to 17%, respectively, and a decrease in the ultimate tensile strength from 949 MPa to 800 MPa, respectively. The microstructure of TMF6 alloy consists of α'/α″ phases, while TMF8 alloy substantially consists of α″ phase. The corrosion current densities and the film resistances of the new alloys are in the range of 0.70-1.07 nA/cm2 and on the order of 105â€¯Ω·cm2, respectively. These values are more compatible with biomedical applications than those measured for the Ti-6Al-4V ELI alloy. Furthermore, the cell viabilities of the TMF6 and TMF8 alloys indicate their improved compatibility compared to that of the Ti-6Al-4V ELI alloy. The CCK-8 (Cell Counting Kit-8) assay was conducted to investigate the cytotoxicity, proliferation, and shape index of the cells of the candidate alloys. Overall, the measured compatibility of the new V-free low-cost alloys, particularly TMF8, makes them promising candidates for replacing the Ti-6Al-4V ELI alloy in biomedical applications.


Assuntos
Ligas/farmacologia , Materiais Biocompatíveis/economia , Materiais Biocompatíveis/farmacologia , Custos e Análise de Custo , Ferro/farmacologia , Molibdênio/farmacologia , Implantação de Prótese , Titânio/farmacologia , Ligas/economia , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Forma Celular/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Corrosão , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Espectroscopia Dielétrica , Módulo de Elasticidade , Técnicas Eletroquímicas , Dureza , Camundongos , Estresse Mecânico , Resistência à Tração , Difração de Raios X
6.
Int J Biol Macromol ; 128: 870-876, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30716371

RESUMO

In this study, cysteamine-functionalized molybdenum disulfide quantum dots (MoS2 QDs) were synthesized by a one-pot hydrothermal method. A range of techniques including of Thioflavin T and 8-Anilino-1-naphthalenesulfonic acid fluorescence assays, circular dichroism, and transmission electron microscope have been employed to determination the efficacy of MoS2 QDs on the inhibition/reversion of fibrillation and hindering cytotoxicity induced by protofibrils and amyloid fibrils of bovine serum albumin (BSA). Results demonstrated that MoS2 QDs could effectively inhibit the fibrillogenesis and destabilize preformed fibrils of BSA in a concentration-dependent manner. Cytotoxicity protection and imagine on Hela cells was investigated using the methyl thiazolyl tetrazolium (MTT) assay. It was found that MoS2 QDs not only has good biocompatibility, low toxicity and good cell penetration, but also could effectively decrease the cytotoxicity caused by the formed fibrils of BSA. The results obtained in this work suggested the potential biological application of MoS2 QDs in therapeutics and provided new insight into the design of multifunctional nanomaterials for amyloid-related diseases.


Assuntos
Amiloide/química , Cisteamina/química , Dissulfetos/química , Dissulfetos/farmacologia , Molibdênio/química , Molibdênio/farmacologia , Agregados Proteicos/efeitos dos fármacos , Pontos Quânticos/química , Soroalbumina Bovina/química , Animais , Transporte Biológico , Bovinos , Dissulfetos/metabolismo , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Molibdênio/metabolismo , Estrutura Secundária de Proteína
7.
Talanta ; 197: 567-577, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771977

RESUMO

With the development of deep eutectic solvents (DESs), more DES-based functional materials have been explored and applied in various areas. In this work, a novel choline chloride-acrylic acid (ChCl-AA) DES polymer, on a 2D magnetic base, was prepared for the recognition of ß-lactoglobulin (ß-LG) biomacromolecules in milk and for the inhibition of common bacteria such as Escherichia coli (E. coli), Pseudomonas fluorescens (P. fluorescens), Staphylococcus aureus (S. aureus), and Bacillus subtilis (B. subtilis). The ChCl-AA DESs were polymerized on the surface of 2D MoS2 sheets doped with nano Fe3O4 particles, and the resulting polymer was abbreviated poly(ChCl-AA DES)@Fe3O4@MoS2. The free energy (ΔG=-92) of ChCl-AA DES was calculated using the Gaussian software, the composition and structure of poly(ChCl-AA DES)@Fe3O4@MoS2 were characterized by field emission scanning electron microscopy, transmission electron microscopy, etc., the qualitative and quantitative analyses of ß-LG were done by fluorescence spectra, sodium dodecyl sulfate polyacrylamide gel electrophoresis and high performance liquid chromatography, and the bioactivity of bacteria was analyzed by flat colony counting. Based on the present analysis, poly(ChCl-AA DES)@Fe3O4@MoS2 specifically recognized ß-LG in a good fitting Langmuir isotherm (R2 = 0.9909) and second-order kinetic model (R2 = 0.9989) by affinity, and evidently inhibited three bacteria, namely, E. coil (65%), S. aureus (50%), and B. subtilis (54%), effectively reducing the relative colony number. As the poly(ChCl-AA DES)@Fe3O4@MoS2 material did not only exhibit specific recognition of biomacromolecules, but also had an antimicrobial effect against common bacteria, it could be an ideal separation media or carrier for biomacromolecules in real samples.


Assuntos
Acrilatos/química , Antibacterianos/análise , Colina/química , Lactoglobulinas/análise , Leite/química , Polímeros/química , Acrilatos/farmacologia , Animais , Antibacterianos/farmacologia , Colina/farmacologia , Dissulfetos/química , Dissulfetos/farmacologia , Compostos Férricos/química , Compostos Férricos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Leite/microbiologia , Molibdênio/química , Molibdênio/farmacologia , Tamanho da Partícula , Polímeros/farmacologia , Solventes/química , Propriedades de Superfície
8.
ACS Appl Mater Interfaces ; 11(7): 6829-6839, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30694645

RESUMO

The ability of nanoparticles to induce adverse consequences in human cells relies on their physical shapes. In this aspect, how two-dimensional nanoparticles differ from three-dimensional nanoparticles is not well-known. To elucidate this difference, combined experimental and theoretical approaches are employed to compare MoS2 nanosheets with 5-layer and 40-layer thicknesses for their cellular effects and the associated molecular events. At a concentration as defined by the nanosheet surface areas (10 cm2/mL), 40-layer nanosheets are internalized by cells, whereas 5-layer nanosheets mostly bind to the cell surface without internalization. Although they alter different autophagy-related genes, a common mechanism is that they both perturb cell surface protein amyloid precursor proteins and activate the mTOR signaling pathway. Our findings prove that the perturbation of cellular function without nanoparticle internalization has significant nanomedicinal and nanotoxicological significances.


Assuntos
Autofagia/efeitos dos fármacos , Dissulfetos , Molibdênio , Nanopartículas , Proteínas de Neoplasias/metabolismo , Neoplasias , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Linhagem Celular Tumoral , Dissulfetos/química , Dissulfetos/farmacologia , Humanos , Molibdênio/química , Molibdênio/farmacologia , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Receptores de Superfície Celular/metabolismo
9.
Biomater Sci ; 7(4): 1386-1392, 2019 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-30656318

RESUMO

Octahedral molybdenum cluster complexes have recently come forth as pertinent singlet oxygen photosensitizers towards biological applications. Still, their phototoxic efficiency in the absence of nanocarriers remains limited due to their poor cellular uptake. Here, two cationic octahedral molybdenum cluster complexes, bearing carboxylate ligands with triphenylphosphonium (1) or N-methyl pyridinium (2) mitochondria-targeting terminal functions, have been designed and synthesized. Their photophysical properties in water and in vitro biological activity were investigated in the context of blue-light photodynamic therapy of cancer and photoinactivation of bacteria. Upon blue light irradiation, complex 1 displays red luminescence with a quantum yield of 0.24 in water, whereas complex 2 is much less emissive (ΦL < 0.01). Nevertheless, both complexes efficiently produce singlet oxygen, O2(1Δg). Complex 1 is rapidly internalized into HeLa cells and accumulated in mitochondria, followed by relocation to lysosomes and clearance at longer times. In contrast, the more hydrophilic 2 is not internalized into HeLa cells, highlighting the effect of the apical ligands on the uptake properties. The treatment with 1 results in an intensive phototoxic effect under 460 nm irradiation (IC50 = 0.10 ± 0.02 µM), which exceeds by far those previously reported for octahedral cluster-based molecular photosensitizers. The ratio between phototoxicity and dark toxicity is approximately 50 and evidences a therapeutic window for the application of 1 in blue-light photodynamic therapy. Complex 1 also enters and efficiently photoinactivates Gram-positive bacteria Enterococcus faecalis and Staphylococcus aureus, documenting its suitability as a blue-light photosensitizer for antimicrobial applications.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Mitocôndrias/efeitos dos fármacos , Molibdênio/farmacologia , Compostos Organometálicos/farmacologia , Fotoquimioterapia , Antibacterianos/síntese química , Antibacterianos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Cátions/síntese química , Cátions/química , Cátions/farmacologia , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Células HeLa , Humanos , Ligantes , Testes de Sensibilidade Microbiana , Estrutura Molecular , Molibdênio/química , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo , Relação Estrutura-Atividade
10.
Biomater Sci ; 7(4): 1437-1447, 2019 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-30666993

RESUMO

Implant materials are prone to bacterial infections and cause serious consequences, while traditional antibiotic therapy has a long treatment cycle and even causes bacterial resistance. In this work, a photothermal therapy (PTT) assisted drug release system has been developed on the implant surface for in situ rapid disinfection under 808 nm light irradiation within a short time, in which gentamicin (Gent) is loaded by polyethylene glycol (PEG) modified molybdenum disulfide (MoS2) on Ti surface, and then encapsulated with chitosan (CS) (CS/Gent/PEG/MoS2-Ti). The hyperthermia produced by the coatings irradiated by 808 nm near-infrared (NIR) light can not only accelerate the local release of Gent, but also reduce the activity of bacteria, which makes it easy for these locally released drugs to enter the interior of the bacteria to inhibit the protein synthesis and destroy the cell membrane. When maintained at 50 °C for 5 min under NIR irradiation, this system can achieve an antibacterial efficacy of 99.93% and 99.19% against Escherichia coli and Staphylococcus aureus, respectively. By contrast, even after treatment for 120 min, only a 93.79% antibacterial ratio can be obtained for Gent alone. This is because hyperthermia produced from the coatings during irradiation can assist antibiotics in killing bacteria in a short time. Even under a low dose of 2 µg mL-1, the photothermal effect assisted gentamicin can achieve an antibacterial efficacy of 96.86% within 5 min. In vitro cell culture shows that the modified surface can facilitate cell adhesion, spreading and proliferation. The 7 day subcutaneous infection model confirms that the prepared surface system can exhibit a much faster sterilization and tissue reconstruction than the control group with light assistance. Compared with the traditional drug release system, this photothermy controlled drug-loaded implant surface system can not only provide rapid and high-efficiency in situ sterilization, but also offer long-term prevention of local bacterial infection.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Gentamicinas/farmacologia , Fototerapia , Staphylococcus aureus/efeitos dos fármacos , Temperatura Ambiente , Animais , Antibacterianos/síntese química , Antibacterianos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Dissulfetos/química , Dissulfetos/farmacologia , Gentamicinas/síntese química , Gentamicinas/química , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Molibdênio/química , Molibdênio/farmacologia , Células NIH 3T3 , Tamanho da Partícula , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Ratos , Ratos Sprague-Dawley , Infecções Estafilocócicas/tratamento farmacológico , Propriedades de Superfície , Titânio/química , Titânio/farmacologia
11.
Nat Commun ; 10(1): 186, 2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-30643139

RESUMO

Tetrathiomolybdate (TM) is used in the clinic for the treatment of Wilson's disease by targeting the cellular copper efflux protein ATP7B (WLN). Interestingly, both TM and WLN are associated with the efficacy of cisplatin, a widely used anticancer drug. Herein, we show that TM induces dimerization of the metal-binding domain of ATP7B (WLN4) through a unique sulfur-bridged Mo2S6O2 cluster. TM expels copper ions from Cu-WLN4 and forms a copper-free dimer. The binding of Mo to cysteine residues of WLN4 inhibits platination of the protein. Reaction with multi-domain proteins indicates that TM can also connect two domains in the same molecule, forming Mo-bridged intramolecular crosslinks. These results provide structural and chemical insight into the mechanism of action of TM against ATPase, and reveal the molecular mechanism by which TM attenuates the cisplatin resistance mediated by copper efflux proteins.


Assuntos
Antineoplásicos/farmacologia , Quelantes/farmacologia , Cisplatino/farmacologia , ATPases Transportadoras de Cobre/metabolismo , Molibdênio/farmacologia , Antineoplásicos/uso terapêutico , Quelantes/uso terapêutico , Cisplatino/uso terapêutico , Cobre/metabolismo , ATPases Transportadoras de Cobre/antagonistas & inibidores , ATPases Transportadoras de Cobre/química , Reagentes para Ligações Cruzadas/química , Reagentes para Ligações Cruzadas/farmacologia , Reagentes para Ligações Cruzadas/uso terapêutico , Cristalografia por Raios X , Cisteína/química , Cisteína/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Humanos , Molibdênio/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Platina/metabolismo , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína
12.
J Colloid Interface Sci ; 539: 575-584, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30611053

RESUMO

Development of effective inhibitors toward Aß aggregation and reactive oxygen species (ROS) scavengers are of crucial therapeutic implications for Alzheimer's disease (AD). Herein, a novel agent with dual enzyme mimic activities has been fabricated as a multifunctional Aß fibrillation modulator. MoO3-x nanodots were synthesized by pulsed laser ablation (PLA) method in MoS2 nanosheets solutions, which may act directly as numerous fine targets. MoO3-x nanodots showed a uniform and monodispersed morphology, and the tiny dots were around 3-5 nm with a narrow size distribution. Due to the efficient charge transition between Mo5+/Mo6+ on the dots surface, MoO3-x nanodots exhibited excellent catalase and SOD mimic activities, which were adopted to alleviate Aß-mediated oxidative stress. Moreover, MoO3-x nanodots can efficiently inhibit Aß aggregation and destabilize the preformed fibrils, and eventually protect neuronal cells from apoptosis induced by Aß. Taken together, MoO3-x nanodots with multifunctional roles can act as a potential therapeutic strategy for treatment of amyloid induced neurotoxicity.


Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/toxicidade , Molibdênio/química , Molibdênio/farmacologia , Nanopartículas/química , Neurônios/efeitos dos fármacos , Neurônios/patologia , Óxidos/química , Óxidos/farmacologia , Apoptose/efeitos dos fármacos , Catalase/química , Sobrevivência Celular/efeitos dos fármacos , Humanos , Molibdênio/metabolismo , Neurônios/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Óxidos/metabolismo , Tamanho da Partícula , Agregados Proteicos/efeitos dos fármacos , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/química , Propriedades de Superfície , Células Tumorais Cultivadas
13.
ACS Appl Mater Interfaces ; 11(5): 4858-4866, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30628779

RESUMO

Molybdenum disulfide (MoS2) nanosheets have received considerable interest due to their superior physicochemical performances to graphene nanosheets. As the lateral size and layer thickness decrease, the formed MoS2 quantum dots (QDs) show more promise as photocatalysts, endowing them with potential antimicrobial properties under environmental conditions. However, studies on the antibacterial photodynamic therapy of MoS2 QDs have rarely been reported. Here, we show that MoS2 QDs more effectively promote the creation and separation of electron-hole pair than MoS2 nanosheets, resulting in the formation of multiple reactive oxygen species (ROS) under simulated solar light irradiation. As a result, photoexcited MoS2 QDs show remarkably enhanced antibacterial activity, and the ROS-mediated oxidative stress plays a dominant role in the antibacterial mechanism. The in vivo experiments showed that MoS2 QDs are efficacious in wound healing under simulated solar light irradiation and exert protective effects on normal tissues, suggesting good biocompatibility properties. Our findings provide a full description of the photochemical behavior of MoS2 QDs and the resulting antibacterial activity, which might advance the development of MoS2-based nanomaterials as photodynamic antibacterial agents under environmental conditions.


Assuntos
Antibacterianos , Dissulfetos , Molibdênio , Pontos Quânticos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Bactérias/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dissulfetos/química , Dissulfetos/farmacologia , Dissulfetos/toxicidade , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Molibdênio/química , Molibdênio/farmacologia , Molibdênio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Processos Fotoquímicos , Pontos Quânticos/química , Pontos Quânticos/efeitos da radiação , Pontos Quânticos/toxicidade , Espécies Reativas de Oxigênio , Infecção dos Ferimentos
14.
Theriogenology ; 126: 49-54, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30530157

RESUMO

Infertility is a serious public health problem worldwide. Molybdenum (Mo) plays an important role in maintaining normal metabolism. To explore the therapeutic efficacy of molybdenum (Mo) on male infertility, 90 mice were randomly divided into control, busulfan and busulfan + Mo groups. The male mice in the busulfan and busulfan + Mo groups were exposed to busulfan (20 mg/kg body weight) with a single intraperitoneal injection to establish the infertility model. The sterile mice were successfully obtained 30 days after busulfan exposure. Then, the male mice in the busulfan + Mo group were given drinking water containing 20 mg/L Mo continuously for 42 days. At 72 Day after treatment, 30 mice in the three groups were tested for various indices, and 60 mice were mated with females in spontaneous estrus. Mo significantly reversed the thinner seminiferous tubules and disappeared tubule and germ cells. Mo also normalized previously abnormal levels of testosterone, estradiol, luteinizing hormone, superoxide dismutase, lactate dehydrogenase, malondialdehyde. Furthermore, expression levels expression of Bax, Bcl-2, caspase-3 and caspase-9 returned to control levels; and finally, Mo-treated sterile mice obtained offspring with normal number and gender ratio. These results suggested that Mo at 20 mg/L had a significant therapeutic effect on reproductive dysfunction in sterile mice. Its mechanism could via repair of damaged testicular structures, regulation of abnormal reproductive hormone levels, decreased oxidative stress or and resistance to cell apoptosis. Mo may be a new candidate medicine for treatment of male infertility.


Assuntos
Infertilidade Masculina/tratamento farmacológico , Molibdênio/uso terapêutico , Oligoelementos/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Bussulfano , Hormônios Esteroides Gonadais/sangue , Infertilidade Masculina/induzido quimicamente , Masculino , Camundongos , Molibdênio/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Distribuição Aleatória , Túbulos Seminíferos/efeitos dos fármacos , Oligoelementos/farmacologia
15.
Biol Pharm Bull ; 41(8): 1203-1210, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30068869

RESUMO

Both lipid accumulation and oxidative stress are major pathologic contributors to the development of hepatic steatosis. Treatment with molybdate reduces hepatic levels of lipids in diabetic rats. Potential activities of molybdate as an antioxidant have also been demonstrated in various animal models. In the present study, we evaluated the effects of sodium molybdate dihydrate (SM) on hepatic steatosis and associated disturbances in a widely used mouse model of the metabolic disease. Male C57Bl/6 mice at 10 weeks of age were fed a diet deficient in methionine and choline (MCD) and bottled water containing SM for four weeks. The SM treatment markedly attenuated MCD-induced accumulation of lipids, mainly triglycerides, in the liver. Lipid catabolic autophagic pathways were activated by SM in the MCD-fed mouse livers, as evidenced by a decreased level of p62 expression. MCD-induced oxidative damage, such as lipid and protein oxidation, was also alleviated by SM in the liver. However, the level of MCD-induced hepatocellular damage was not affected by SM. Taken together, these findings suggest that molybdate can be used in the treatment and prevention of hepatic steatosis without inducing adverse effects in the liver. To the best of our knowledge, this is the first experimental study to investigate the effects of molybdate in non-alcoholic fatty liver disease, and also the first that demonstrates molybdate-induced autophagy.


Assuntos
Fígado/efeitos dos fármacos , Molibdênio/farmacologia , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Deficiência de Colina , Dieta , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Metionina/deficiência , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo
16.
Int J Mol Sci ; 19(8)2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-30042365

RESUMO

Cadmium (Cd) is highly toxic, even at very low concentrations, to both animals and plants. Pollen is extremely sensitive to heavy metal pollutants; however, less attention has been paid to the protection of this vital part under heavy metal stress. A pot experiment was designed to investigate the effect of foliar application of Se (1 mg/L) and Mo (0.3 mg/L) either alone or in combination on their absorption, translocation, and their impact on Cd uptake and its further distribution in Brassica napus, as well as the impact of these fertilizers on the pollen grains morphology, viability, and germination rate in B. napus under Cd stress. Foliar application of either Se or Mo could counteract Cd toxicity and increase the plant biomass, while combined application of Se and Mo solutions on B. napus has no significant promotional effect on plant root and stem, but reduces the seeds' weight by 10⁻11%. Se and Mo have decreased the accumulated Cd in seeds by 6.8% and 9.7%, respectively. Microscopic studies, SEM, and pollen viability tests demonstrated that pollen grains could be negatively affected by Cd, thus disturbing the plant fertility. Se and Mo foliar application could reduce the toxic symptoms in pollen grains when the one or the other was sprayed alone on plants. In an in vitro pollen germination test, 500 µM Cd stress could strongly inhibit the pollen germination rate to less than 2.5%, however, when Se (10 µM) or Mo (1.0 µM) was added to the germination medium, the rate increased, reaching 66.2% and 39.4%, respectively. At the molecular level, Se and Mo could greatly affect the expression levels of some genes related to Cd uptake by roots (IRT1), Cd transport (HMA2 and HMA4), Cd sequestration in plant vacuoles (HMA3), and the final Cd distribution in plant tissue at the physiological level (PCS1).


Assuntos
Brassica napus/efeitos dos fármacos , Cádmio/toxicidade , Molibdênio/farmacologia , Pólen/efeitos dos fármacos , Selênio/farmacologia , Fertilizantes/efeitos adversos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Caules de Planta/efeitos dos fármacos , Sementes/efeitos dos fármacos
17.
J Plant Physiol ; 228: 189-196, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29960143

RESUMO

The influence of molybdenum, tungsten on germination and growth of barley Hordeum vulgare L. was studied. Results of this study revealed the differential effect of heavy metals on seedlings growth. Exogenous molybdenum treatment stimulated the growth of seedlings. The addition of the metal significantly stimulated root elongation. Contrastingly, the addition of tungsten resulted in increased seed germination and inhibits the growth of seedlings. The negative effect of tungsten on the growth of barley was more profound for roots of plants. In addition, the influence of metals on the growth of plants was also tested in saline conditions. It is shown that under salinity stress plant growth drastically decreased in presence of tungsten. Results of this study showed that activity of molybdenum-containing aldehyde oxidase (AO; EC 1.2.3.1) was also significantly affected by metals. The activity of AO in leaves and roots enhanced with increasing concentrations of molybdate, while tungstate treatment inhibited the enzyme activity. Perhaps, the differential influence of molybdenum and tungsten on the growth of barley is a direct effect of metals on aldehyde oxidase activity in plants. Moreover, the intense negative effect of tungsten treatment on barley growth under salinity conditions emphasizes an important role of aldehyde oxidase in plant resistance to stress factors.


Assuntos
Hordeum/efeitos dos fármacos , Hordeum/metabolismo , Molibdênio/farmacologia , Plântula/efeitos dos fármacos , Plântula/metabolismo , Tungstênio/farmacologia , Aldeído Oxidase/metabolismo , Germinação/efeitos dos fármacos , Cloreto de Sódio/farmacologia
18.
Colloids Surf B Biointerfaces ; 170: 233-241, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29933232

RESUMO

Tailored colloids of uniformly sized and engineered molybdenum oxide nanoparticles were produced, for the first time, by pulsed laser ablation in water. This green technique ensures the formation of contaminant-free nanostructures and the absence of by-products, very useful issues in biological applications. A selective tuning of MoO chemical bonding configurations and a suitable control of nanoparticles size distributions were achieved during the ablation processes by varying the water temperature and by applying an external electric field. The metal redox properties are fundamental factors governing both cell uptake and interaction mode with Mo oxide nanoparticles. Micro-Raman spectroscopy was used to investigate the existence of cellular changes induced by Mo oxide colloids on the fibroblast cell line NIH/3T3 in relation to the molecular vibrations due to proteins, lipids and nucleic acids. The label-free micro-Raman spectroscopy provides an easy and noninvasive method to monitor the harmful effect of toxic agents on cells through ROS production or redox-dependent mechanisms. In view of potential biological applications, molybdenum oxide nanoparticles cytotoxicity towards NIH/3T3 cells was also investigated. A statistical analysis shows that, in the 10-100 µg/mL Mo concentration range, all the colloids are cytotoxic, progressively reducing the cell viability down to 75% upon increasing the concentration. The effect is less pronounced for the oxygen deficient MoO3 samples where cell viability does not fall below 85%. These results open the way to identify potential bioactive products affecting cellular redox status, by using only the Raman spectral data, even before performing lengthy and expensive specific clinical analyses.


Assuntos
Fibroblastos/efeitos dos fármacos , Molibdênio/farmacologia , Nanopartículas/química , Óxidos/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Coloides/química , Coloides/farmacologia , Relação Dose-Resposta a Droga , Fibroblastos/citologia , Camundongos , Molibdênio/química , Células NIH 3T3 , Óxidos/química , Tamanho da Partícula , Análise Espectral Raman , Relação Estrutura-Atividade , Propriedades de Superfície
19.
J Med Microbiol ; 67(8): 1042-1046, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29939129

RESUMO

Multidrug-resistant bacteria pose a major threat to effective antibiotics and alternatives to fight multidrug-resistant pathogens are needed. We synthetized molybdenum oxide (MoO3) nanoparticles (NP) and determined their antibacterial activity against 39 isolates: (i) eight Staphylococcus aureus, including representatives of methicillin-resistant S. aureus epidemic clones; (ii) six enterococci, including vancomycin-resistant isolates; and (iii) 25 Gram-negative isolates (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae), including extended spectrum beta-lactamases and carbapenemases producers. All isolates showed a MoO3 NP MIC of 700-800 mg l-1. MoO3 NP produced a clear inhibition zone for S. aureus and all Gram-negative isolates at concentrations ≥25 mg ml-1 and ≥50 mg ml-1 for enterococci. When the NP solutions were adjusted to pH ~7, the biocidal activity was completely abolished. MoO3 NP create an acidic pH and show a universal antimicrobial activity against susceptible and resistant isolates belonging to the most relevant bacterial species responsible for hospital-acquired infections.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Molibdênio/farmacologia , Nanopartículas , Óxidos/farmacologia , Antibacterianos/química , Infecções Bacterianas/microbiologia , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Molibdênio/química , Óxidos/química
20.
Chemosphere ; 208: 425-432, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29885509

RESUMO

The C-repeat binding factor/dehydration responsive element binding proteins (CBF/DREB) constitute a large group of transcriptional factors. Their role in abiotic stresses such as drought, salinity and low temperature tolerance in plants have been well established, while little information about their role in metals stress tolerance is available. Transcriptomic analyses of four genes (DREB-1A, DREB-1B, DREB-1F and CBF) were carried out in industrially important plant Ricinus communis under cadmium (Cd) and molybdenum (Mo) treatments. Cadmium (in soil) and Mo (as foliar spray) were used separate as well as in combinations. All the genes (except DREB 1A) expressed under Cd stress, while Mo further enhanced their expression. The proline (55.68 ±â€¯5.51 ppm) and phenolic (120.00 ±â€¯14.40 ppm) contents were significant increase in combination treatments of Cd and Mo. Positive and significant correlations of DREB 1B, DREB 1F and CBF genes expressions with free proline (0.92, 0.93 and 0.88 respectively), phenolic (075, 0.77 and 0.62 respectively) contents and Cd accumulation were demonstrated. Nucleotide sequence of R. comunis DREB1F and CBF genes showed more than 80% homology with related genes of other flowering plants. Predicted amino acids sequence of R. communis DREB 1F and CBF protein fragment demonstrated more than 75% homology with related proteins from other flowering plants.


Assuntos
Cádmio/farmacologia , Molibdênio/farmacologia , Proteínas de Plantas/fisiologia , Ricinus/genética , Fatores de Transcrição/genética , Cádmio/metabolismo , Tolerância a Medicamentos , Regulação da Expressão Gênica de Plantas , Molibdênio/metabolismo , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Estresse Fisiológico
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