Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.801
Filtrar
2.
Phys Chem Chem Phys ; 21(33): 18352-18362, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31402363

RESUMO

Graphene coated gold nanoparticles (GGNPs) have attracted great attention in recent years because of their high thermal stability and unique optical properties. In this paper, we study photothermal properties of GGNPs using the Mie and Gans theories combined with the Pennes bioheat equation. The effect of various sizes and different shapes of GGNPs such as nanosphere, nanorod and nanodisc are taken into account. The extinction efficiency and temperature distribution in tumor tissue show that graphene coated gold nanorods, because of the high temperature rise during laser irradiation, are more suitable candidates for photothermal therapy (PTT) applications. Also, we show that the extinction peak of graphene coated gold nanorods can be adjusted in the biological windows by increasing the graphene shell thickness and/or by changing their aspect ratio. Finally, we investigated the effect of the number of graphene layers upon the temperature rise in the tumor and found that the temperature rise increases with increasing number of graphene layers. Our findings introduce a new class of nanoagents which can be used in PTT applications.


Assuntos
Ouro/química , Grafite/química , Nanopartículas Metálicas/química , Nanotubos/química , Fototerapia/métodos
3.
Chem Commun (Camb) ; 55(71): 10571-10574, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31417999

RESUMO

A portable dual-mode sensing platform based on a self-standing TiO2 nanotube membrane is developed for simultaneously performing both qualitative analysis by the naked eye and quantitative analysis by ionic current. This dual-mode diagnosis strategy exhibits a high performance in telomerase detection in urine specimens from patients with bladder cancer.


Assuntos
Nanotubos/química , Telomerase/urina , Titânio/química , Neoplasias da Bexiga Urinária/diagnóstico , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Cor , Ouro/química , Humanos , Membranas Artificiais , Nanopartículas Metálicas/química , Prata/química , Neoplasias da Bexiga Urinária/urina
4.
Anal Bioanal Chem ; 411(21): 5509-5518, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31280475

RESUMO

The rapid analysis and detection of biomolecules has become increasingly important in biological research. Hence, here we propose a novel suspension array method that is based on gold nanorod (AuNR)-enhanced Raman spectroscopy and uses micro-quartz pieces (MQPs) as microcarriers. AuNRs and Raman reporter molecules are coupled together by Au-S bonds to obtain surface-enhanced Raman scattering labels (SERS labels). The SERS labels are then assembled on the surfaces of the MQPs via electrostatic interactions, yielding encoded MQPs. Experimental results showed that the encoded MQPs could be decoded using a Raman spectrometer. A multiplex immunoassay experiment demonstrated the validity and specificity of these encoded MQPs when they were used for bioanalysis. In concentration gradient experiments, the proposed method was found to give a linear concentration response to the target biomolecule at target concentrations of 0.46875-30 nM, and the detection limit was calculated to be 1.78 nM. The proposed method utilizes MQPs as carriers rather than conventional microbeads, which allows the interference caused by the background fluorescence of microbeads to be eliminated. The fluorescence of the encoded MQPs can be simply, rapidly, and inexpensively quantified using fluorescence microscopy. By dividing the quantitative and qualitative detection of biomolecules into two independent channels, crosstalk between the encoded signal and the labeled signal is averted and high decoding accuracy and detection sensitivity are guaranteed. Graphical abstract.


Assuntos
Ouro/química , Nanotubos/química , Quartzo , Análise Espectral Raman/métodos
5.
J Agric Food Chem ; 67(28): 8035-8044, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31282154

RESUMO

The simultaneous detection of multiple mycotoxins is important due to the increased toxic effects of combined mycotoxins in grains. In this research, a combination of modified QuEChERS with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for simultaneous detection of 20 mycotoxins in grains. A series of different types of magnetic (Fe3O4) nanoparticles modified with multiwalled carbon nanotubes (Fe3O4-MWCNTs) were designed as modified QuEChERS adsorbents for facile and efficient purification and for target interferences removal in the matrices. When there is an external magnetic field, the proposed modified QuEChERS method uses a shorter pretreatment time compared with the traditional QuEChERS method, which makes it possible to conduct high-throughput analyses. To optimize the QuEChERS process, the extraction solvent and the type and amount of the Fe3O4-MWCNTs were investigated. Under optimal conditions, the method was validated and showed satisfactory linearity (r2 ≥ 0.9965), good recovery (73.5-112.9%), good precision (1.3-12.7%), and excellent sensitivity (ranging from 0.0021 to 5.4457 ng g-1), which indicates that this method can be used for detecting multiple mycotoxins in real samples.


Assuntos
Carbono/química , Cromatografia Líquida de Alta Pressão/métodos , Grão Comestível/química , Micotoxinas/química , Micotoxinas/isolamento & purificação , Nanotubos/química , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Adsorção , Magnetismo , Extração em Fase Sólida/instrumentação
6.
Chemistry ; 25(47): 11058-11065, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31150560

RESUMO

The self-assembly of protein polymers is a promising route to prepare sophisticated functional nanostructures. However, the interplay between protein self-assembly by itself and its co-assembly with a template is not well understood. Silk-based protein polymers that co-assemble with DNA to form rod-like artificial viruses are herein developed and the effects of silk block length, concentration, and temperature in the self-assembly of the proteins alone are characterized by using a combination of bulk dynamic light scattering (DLS) and single-molecule atomic force microscopy (AFM). Protein nanorods were slowly formed (up to hours) through the interaction of the silk-like blocks. The proteins present a silk-length dependent critical elongation concentration, and above it the amount and size of nanorods rapidly increase. Temperature-dependent light scattering data was adequately fitted into a cooperative model of nucleation-elongation. These results are also important to understand the self-assembly of designed viral coat proteins with DNA templates to form artificial virus-like particles and help us to define general guidelines to design proteins with the ability to precisely organize matter at the nanoscale.


Assuntos
Proteínas do Capsídeo/química , Nanotubos/química , Sequência de Aminoácidos , Proteínas do Capsídeo/metabolismo , Difusão Dinâmica da Luz , Cinética , Microscopia de Força Atômica , Temperatura Ambiente
7.
Int J Food Microbiol ; 304: 58-67, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31163357

RESUMO

This paper demonstrates the application of surface-enhanced Raman scattering (SERS) using positive charged gold nanorods (Au NRs) as an enhancement substrate to classify Pseudomonas spp. coupled with multivariate methods. Four species of Pseudomonas as dominant spoilage bacteria of food were isolated from rotten chicken, namely, Pseudomonas gessardii (P9), Pseudomonas psychrophila (P8), Pseudomonas psychrophila (S2) and Pseudomonas fluorescens (T3). Au NRs were synthesized with positive charge by seed-mediated growth method which can be adsorbed onto the surface of the bacteria by electrostatic adsorption. SERS spectra were collected individually for four types of Pseudomonas and pretreated by mean centering (MC), then principal component analysis (PCA) and hierarchical clustering analysis (LDA) were used to achieve data dimensionality reduction and visualize the result of differentiation for the species of Pseudomonas. Particularly, the classification accuracy of LDA was reached to 100%. Following we applied hierarchical clustering analysis (HCA) to cluster each species of Pseudomonas and the results of HCA consistent with the results of 16S rRNA. This study has shown that SERS combined with LDA and HCA can be used as a reliable method to classify Pseudomonas.


Assuntos
Contaminação de Alimentos/análise , Pseudomonas/classificação , Pseudomonas/genética , Análise Espectral Raman/métodos , Análise por Conglomerados , Microbiologia de Alimentos/métodos , Ouro/química , Nanotubos/química , Análise de Componente Principal , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética
8.
Int J Nanomedicine ; 14: 3297-3309, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190794

RESUMO

Background: Cardiovascular disease (CVD) is the leading cause of mortality all over the world. Vascular stents are used to ameliorate vascular stenosis and recover vascular function. The application of nanotubular coatings has been confirmed to promote endothelial cell (EC) proliferation and function. However, the regulatory mechanisms involved in cellular responses to the nanotubular topography have not been defined. In the present study, a microarray analysis was performed to explore the expression patterns of long noncoding RNAs (lncRNAs) in human coronary artery endothelial cells (HCAECs) that were differentially expressed in response to nitinol-based nanotubular coatings. Materials and methods: First, anodization was performed to synthesize nitinol-based nanotubular coatings. Then, HCAECs were cultured on the samples for 24 h to evaluate cell cytoskeleton organization. Next, total RNA was extracted and synthesized into cRNA, which was hybridized onto the microarray. GO analysis and KEGG pathway analysis were performed to investigate the roles of differentially expressed messenger RNAs (mRNAs). Quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) was performed to validate the expression of randomly selected lncRNAs. Coexpression networks were created to identify the interactions among lncRNAs and the protein-coding genes involved in nanotubular topography-induced biological and molecular pathways. Independent Student's t-test was applied for comparisons between two groups with statistical significance set at p<0.05. Results: 1085 lncRNAs and 227 mRNAs were significantly differentially expressed in the nitinol-based nanotubular coating group. Bioinformatics analysis revealed that extracellular matrix receptor interactions and cell adhesion molecules play critical roles in the sensing of nitinol-based nanotubular coatings by HCAECs. The TATA-binding protein (TBP) and TBP-associated transfactor 1 (TAF1) are important molecules in EC responses to substrate topography. Conclusion: This study suggests that nanotubular substrate topography regulates ECs by differentially expressed lncRNAs involved extracellular matrix receptor interactions and cell adhesion molecules.


Assuntos
Ligas/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Vasos Coronários/citologia , Células Endoteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Nanotubos/química , RNA Longo não Codificante/genética , Proliferação de Células/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Células Endoteliais/efeitos dos fármacos , Perfilação da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes/efeitos dos fármacos , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Análise em Microsséries , Nanotubos/ultraestrutura , Fenótipo , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/metabolismo
9.
Int J Nanomedicine ; 14: 3583-3600, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190813

RESUMO

Purpose: This study aimed to decorate the surface of TiO2 nanotubes (TiO2 NTs) grown on medical grade Ti-6Al-4V alloy with an antimicrobial layer of nano zinc oxide particles (nZnO) and then determine if the antimicrobial properties were maintained with a final layer of nano-hydroxyapatite (HA) on the composite. Methods: The additions of nZnO were attempted at three different annealing temperatures: 350, 450 and 550 °C. Of these temperatures, 350°C provided the most uniform and nanoporous coating and was selected for antimicrobial testing. Results: The LIVE/DEAD assay showed that ZnCl2 and nZnO alone were >90% biocidal to the attached bacteria, and nZnO as a coating on the nanotubes resulted in around 70% biocidal activity. The lactate production assay agreed with the LIVE/DEAD assay. The concentrations of lactate produced by the attached bacteria on the surface of nZnO-coated TiO2 NTs and ZnO/HA-coated TiO2 NTs were 0.13±0.03 mM and 0.37±0.1 mM, respectively, which was significantly lower than that produced by the bacteria on TiO2 NTs alone, 1.09±0.30 mM (Kruskal-Wallis, P<0.05, n=6). These biochemical measurements were correlated with electron micrographs of cell morphology and cell coverage on the coatings. Conclusion: nZnO on TiO2 NTs was a stable and antimicrobial coating, and most of the biocidal properties remained in the presence of nano-HA on the coating.


Assuntos
Anti-Infecciosos/farmacologia , Materiais Revestidos Biocompatíveis/química , Durapatita/química , Nanotubos/química , Staphylococcus aureus/efeitos dos fármacos , Titânio/química , Óxido de Zinco/química , Zinco/farmacologia , Anti-Infecciosos/química , Preparações de Ação Retardada/química , Diálise , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Nanopartículas/química , Nanopartículas/ultraestrutura , Nanotubos/ultraestrutura , Propriedades de Superfície
10.
Int J Nanomedicine ; 14: 4133-4144, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239672

RESUMO

Background: Although titanium dioxide nanotubes (TNTs) had great potential to promote osteogenesis, their weak bonding strength with titanium substrates greatly limited their clinical application. Purpose: The objective of this study was to maintain porosity and improve the stability of TNT coatings by preparing some micro-patterned mesoporous/nanotube (MP/TNT) structures via a photolithography-assisted anodization technology. Methods: The adhesion strength of different coatings was studied by ultrasonic cleaning machine and scratch tester. The early adhesion, spreading, proliferation and differentiation of MC3T3-E1 cells on different substrates were investigated in vitro by fluorescent staining, CCK8, alkaline phosphatase activity, mineralization and polymerase chain reaction assays, respectively. Results: Results of ultrasonic and scratch assays showed that the stability of TNTs (especially 125 nm) was significantly improved after being patterned with MP structures. In vitro cell assays further demonstrated that the insertion of MP structure into 125 nm TNT coating, which was denoted as MP125, could effectively improve the early adhesion, spreading and proliferation of surface MC3T3-E1 cells without damaging their osteogenic differentiation. Conclusion: We determined that the MP/TNT patterned samples (especially MP125) have excellent stability and osteogenesis properties, and may have better clinical application prospects.


Assuntos
Nanotubos/química , Osteogênese , Titânio/química , Adsorção , Fosfatase Alcalina/metabolismo , Animais , Adesão Celular/genética , Diferenciação Celular/genética , Linhagem Celular , Proliferação de Células/genética , Forma Celular/genética , Sobrevivência Celular/genética , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Fluorescência , Regulação da Expressão Gênica , Humanos , Camundongos , Minerais/metabolismo , Osteocalcina/genética , Osteocalcina/metabolismo , Osteogênese/genética , Osteopontina/genética , Osteopontina/metabolismo , Porosidade , Água/química
11.
Environ Sci Pollut Res Int ; 26(21): 22082-22096, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31147996

RESUMO

In this study, TiO2 nanotubes (TNTs) and AgCl-modified TNTs nanocomposites with multiple crystal phases were synthesized through a hydrothermal method without calcination. The resultant samples had a large Brunauer-Emmett-Teller surface area. Additionally, the Ag modification process reduced the recombination rate of electron-hole pairs in the synthesized sample and possessed more oxygen vacancy sites. The surface area of the AgCl-modified TNTs was smaller than that of non-modified TNTs sample; however, the nanocomposites exhibited outstanding photocatalytic performance and adsorption properties. AgCl compounds present on the TNTs surface effectively interacted with Hg0, improving the dye photodegradation efficiency. The Hg0 removal efficiencies of the TNTs and AgCl-modified TNTs samples were about 63% and 86%, respectively. The crystal violet (CV) and malachite green (MG) removal efficiencies of the AgCl-modified TNTs sample were around 57% and 72%, respectively. Both dyes photodecomposition efficiencies for AgCl-modified TNTs sample are higher than those of TNTs sample. The oxygen vacancy on the AgCl-modified TNTs surface was determined to be advantageous for OH- and arsenate adsorption through ligand exchange. The maximum adsorption quantity of As5+ calculated by Langmuir equation was 15.38 mg g-1 (TNTs) and 21.10 mg g-1 (AgCl-modified TNTs).


Assuntos
Metais Pesados/química , Nanocompostos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Arseniatos , Corantes/química , Nanotubos/química , Fotólise , Trinitrotolueno
12.
Talanta ; 200: 212-217, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036175

RESUMO

A surface-enhanced Raman scattering (SERS) imaging probe and drug carrier based on zeolitic imidazolate framework (ZIF-8)-coated Au@Ag core-shell nanorod has been developed. Strong Raman signal is generated by a reporter molecule of 4-aminothiophenol (4-ATP) adsorbed on Au@Ag core-shell nanorod, endowing the probe with function of SERS imaging. Further coating of ZIF-8 on Au@Ag core-shell nanorod offered high loading capacity for anti-cancer drugs, doxorubicin (DOX), as well as improved the stability and biocompatibility of the SERS tag due to the protection of ZIF-8 shell. After immobilization of folic acid onto the Au@Ag NRs4-ATP@ZIF-8, the SERS probes were successfully applied to the targeted SERS imaging of HeLa, MCF-7, LNCaP, QGY-7703, HCT116 and MDA-MB-231 cells with low cytotoxicity, and further applied to the image of tumor tissue of human colon cancer. In vitro cell cytotoxicity confirmed that DOX-loaded SERS probes had potential therapeutic effect compared with the free drug. All of these original results contribute to develop potential biocompatible nanosystem integrating diagnosis and therapy.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Materiais Biocompatíveis/farmacologia , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Nanotubos/química , Zeolitas/farmacologia , Antibióticos Antineoplásicos/química , Materiais Biocompatíveis/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Doxorrubicina/química , Ensaios de Seleção de Medicamentos Antitumorais , Ouro/química , Ouro/farmacologia , Células HeLa , Humanos , Células MCF-7 , Imagem Óptica , Prata/química , Prata/farmacologia , Análise Espectral Raman , Relação Estrutura-Atividade , Propriedades de Superfície , Zeolitas/química
13.
Talanta ; 200: 84-90, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036229

RESUMO

An effective, simple and portable gold nanorod (Au NR) based casting-and-sensing surface enhanced Raman scattering (SERS) platform was developed for rapid and fingerprinted detection of pesticide methyl parathion. Monodispersed Au NRs with an average length of 60 nm and an aspect ratio of ca. 3 were synthesized through a seed mediated method and then systematically characterized. After a proof-of-concept detection for methyl parathion in DI water and on solid surface, the sensing platform was further applied to real samples (lake water, orange, apple and plant leave) contaminated with methyl parathion. The results show that the sensitivity of the SERS sensor for methyl parathion was satisfactory for real application, with detection limits of 1 µM in spiked lake water and 110-440 ng/cm2 on the surface of various fruits and plant leaves. This study indicates that the developed casting-and-sensing SERS sensor shows great promise to secure agricultural, food and environmental safety.


Assuntos
Contaminação de Alimentos/análise , Frutas/química , Metil Paration/análise , Praguicidas/análise , Folhas de Planta/química , Poluentes Químicos da Água/química , Ouro/química , Nanotubos/química , Análise Espectral Raman , Propriedades de Superfície
14.
Anal Chim Acta ; 1068: 52-59, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31072477

RESUMO

Early detection of carcinoembryonic antigen (CEA) is of great significance for the screening, diagnosis, monitoring and prognosis analysis of lung cancer. Herein, a novel fluorescence aptasensor with high signal-noise ratio (SNR) was constructed to achieve highly-sensitive detection of CEA relied upon the fluorescence resonance energy transfer (FRET) between near-infrared carbon dots (NIR-CDs) and gold nanorods (AuNRs). Initially, AuNRs@SiO2-Aptamer and NIR-CDs-DNA probe were prepared via the covalent bonding reaction between their corresponding carboxyl and amino groups, respectively. After DNA hybridization, the aptasensor was formed, meanwhile, the fluorescence of NIR-CDs was quenched by AuNRs@SiO2. Once CEA encountered the aptasensor, it would selectively combine with CEA aptamer to unwind the preformed DNA double-strand architecture thereby resulting in the NIR-CDs-DNA detach from the surface of AuNRs@SiO2. The attendant fluorescence recovery of NIR-CDs was linearly correlated with the concentration of CEA. According to this relationship, the NIR-CDs based "turn on" sensing system was constructed and exhibited prominent responses toward CEA in the concentration range of 0.1-5000 pg/mL and a relatively low detection limit (0.02 pg/mL). Moreover, it displayed high specificity against other biomarkers or proteins, good reproducibility and acceptable accuracy regarding human pleural effusion samples.


Assuntos
Aptâmeros de Nucleotídeos/química , Carbono/química , Antígeno Carcinoembrionário/análise , Fluorescência , Derrame Pleural/diagnóstico por imagem , Pontos Quânticos/química , Transferência Ressonante de Energia de Fluorescência , Ouro/química , Humanos , Nanotubos/química , Tamanho da Partícula , Propriedades de Superfície
15.
Ultrason Sonochem ; 56: 430-436, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31101281

RESUMO

We report a facile and ultrasound assisted sonochemical synthesis of a Tungsten disulfide nanorods decorated nitrogen-doped reduced graphene oxide based nanocomposite. The WS2 NRs/N-rGOs nanocomposite was characterized by FESEM, HRTEM, XRD, XPS and electrochemical methods and its application towards the electrochemical detection of organo-arsenic drug (coccidiostat). The WS2 NRs/N-rGOs modified SPCE was used for the electrochemical reduction of roxarsone (ROX) and it showed superior electrocatalytic performance in terms of reduction peak current and shift in overpotential when compared to those of WS2 NRs/SPCE, N-rGOs/SPCE and based SPCE. The WS2 NRs/N-rGOs modified SPCE showed an excellent sensing ability towards ROX in nitrogen saturated phosphate buffer (PB) then the other controlled modified and unmodified electrodes. The WS2 NRs/N-rGOs/SPCE displays high sensitive response towards ROX and gives wide linearity in the range of 0.1-442.6 µM ROX in neutral phosphate buffer (pH 7.0) and the sensitivity of the sensor is calculated as 14.733 µA µM-1 cm-2. The WS2 NRs/N-rGOs nanocomposite modified sensor also exhibits valuable ability of anti-interference to electroactive analytes. Furthermore, the as-prepared WS2 NRs/N-rGOs/SPCE has been applied to the determination of ROX in biological and pharmaceutical samples.


Assuntos
Antibacterianos/análise , Eletroquímica/instrumentação , Grafite/química , Limite de Detecção , Nanotubos/química , Nitrogênio/química , Roxarsona/análise , Antibacterianos/química , Catálise , Técnicas de Química Sintética , Eletrodos , Concentração de Íons de Hidrogênio , Cinética , Porosidade , Roxarsona/química
16.
Int J Nanomedicine ; 14: 2903-2914, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31114199

RESUMO

Background: Titanium (Ti) implant-associated infection, which is mostly caused by bacterial adhesion and biofilm formation, may result in implant failure and secondary surgery. Thus it is an urgent issue to prevent bacterial infections at the earliest step. Purpose: To develop a novel surface strategy of polydopamine (PDA) and silver (Ag) nanoparticle-loaded TiO2 nanorods (NRDs) coatings on Ti alloy. Materials and methods: Ag-TiO2@PDA NRDs was fabricated on Ti alloy by hydrothermal synthesis. The antibacterial activity of Ag-TiO2@PDA NRDs against Escherichia coli and methicillin-resistant Staphylococcus aureus were tested by FE-SEM, Live/Dead staining, zone of inhibition, bacteria counting method and protein leakage analysis in vitro. In addition, an implant infection model was conducted and the samples were tested by X-ray, Micro-CT and histological analysis in vivo. Besides, cell morphology and cytotoxicity of Mouse calvarial cells (MC3T3-E1) were characterized by FE-SEM, immunofluorescence and CCK-8 test in vitro. Results: Our study successfully developed a new surface coating of Ag-TiO2@PDA NRDs. The selective physical puncture of bacteria and controlled release of Ag+ ions of Ag-TiO2@PDA NRDs achieved a long-lasting bactericidal ability and anti-biofilm activity with satisfied biocompatibility. Conclusion: This strategy may be promising for clinical applications to reduce the occurrence of infection in the implant surgeries.


Assuntos
Antibacterianos/farmacologia , Indóis/química , Nanopartículas Metálicas/química , Nanotubos/química , Polímeros/química , Prata/farmacologia , Titânio/química , Animais , Aderência Bacteriana/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular , Forma Celular/efeitos dos fármacos , Preparações de Ação Retardada/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/ultraestrutura , Íons , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/ultraestrutura , Camundongos , Testes de Sensibilidade Microbiana , Nanotubos/ultraestrutura , Infecções Relacionadas à Prótese/microbiologia , Infecções Relacionadas à Prótese/patologia , Propriedades de Superfície
17.
Chemosphere ; 228: 611-618, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31059959

RESUMO

The purpose of this research is to investigate the possibility of using a Ti plate with TiO2 nanotube arrays as a novel cathode for nitrate reduction. TiO2 nanotube arrays were grown on a Ti plate by anodization in a glycerol based electrolyte and annealed to change their crystallographic structure. Morphological and crystallographic structures of Ti plates with a TiO2 nanotubular layer were analysed before and after anodization or annealing by using energy-dispersive spectroscopy, Brunauer-Emmett-Teller analysis and X-ray diffraction. Cyclic voltammetry and electrochemical impedance spectroscopy were also performed to test the electrochemical reactivity towards nitrate reduction. A lab-scale electrochemical reactor with a RuO2/Ti anode and a Ti plate with a TiO2 nanotubular layer as a cathode was operated to treat synthetic wastewater containing up to 600 mg L-1 of NO3-N. The Ti plate with a TiO2 nanotubular layer was compared with other cathodes such as Ti, Cu, Ni, and Stainless Steel. The Ti plate with an anatase TiO2 nanotubular layer with a layer thicknesses greater than 45 µm was able to show the most efficient nitrate reduction.


Assuntos
Nanotubos/química , Nitratos/química , Titânio/química , Purificação da Água/métodos , Técnicas Eletroquímicas , Eletrodos , Oxirredução , Águas Residuárias/química
18.
Nanoscale ; 11(18): 9185-9193, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31038146

RESUMO

Recent advances in nanotechnology have developed a lot of opportunities for biological applications. In this work, multifunctional MoS2/AuNR nanocomposites with unique high NIR absorption were designed via combining MoS2 nanosheets and gold nanorods (AuNRs). The nanocomposites were synthesized through electrostatic self-assembly and showed high stability and good biocompatibility. Then they were used to modulate the aggregation of amyloid-ß peptides, destabilize mature fibrils under NIR irradiation, and eliminate Aß-induced ROS against neurotoxicity. The inhibition and destabilization effects were confirmed by Thioflavin T (ThT) fluorescence assay and transmission electron microscopy (TEM). Cell viability assay and ROS assay revealed that MoS2/AuNR nanocomposites could alleviate Aß-induced oxidative stress and cell toxicity. More importantly, both MoS2 nanosheets and AuNRs can be used as NIR photothermal agents, MoS2/AuNR nanocomposites have enhanced ability of disrupting Aß fibrils and improved cell viability by generating local heat under low power NIR irradiation. Our results provide new insights into the design of new multifunctional systems for the treatment of amyloid-related diseases.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Raios Infravermelhos , Nanocompostos/química , Fragmentos de Peptídeos/metabolismo , Amiloide/química , Amiloide/toxicidade , Peptídeos beta-Amiloides/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Dissulfetos/química , Ouro/química , Humanos , Molibdênio/química , Nanocompostos/toxicidade , Nanotubos/química , Fragmentos de Peptídeos/química , Espécies Reativas de Oxigênio/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Int J Nanomedicine ; 14: 3043-3054, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31118621

RESUMO

Background: Many studies have shown that the size of nanotube (NT) can significantly affect the behavior of osteoblasts on titanium-based materials. But the weak bonding strength between NT and substrate greatly limits their application. Purpose: The objective of this study was to compare the stability of NT and nanopore (NP) coatings, and further prepare antibacterial titanium-based materials by loading LL37 peptide in NP structures. Methods: The adhesion strength of NT and NP layers was investigated using a scratch tester. The proliferation and differentiation of MC3T3-E1 cells on different substrates were evaluated in vitro by CCK8, alkaline phosphatase activity, mineralization and polymerase chain reaction assays. The antibacterial rates of NP and NP/LL37 were also measured by spread plate method. Moreover, the osteogenesis around NP and NP/LL373 in vivo was further evaluated using uninfected and infected models. Results: Scratch test proved that the NP layers had stronger bonding strength with the substrates due to their continuous pore structures and thicker pipe walls than the independent NT structures. In vitro, cell results showed that MC3T3-E1 cells on NP substrates had better early adhesion, spreading and osteogenic differentiation than those of NT group. In addition, based on the drug reservoir characteristics of porous materials, the NP substrates were also used to load antibacterial LL37 peptide. After loading LL37, the antibacterial and osteogenic induction abilities of NP were further improved, thus significantly promoting osteogenesis in both uninfected and infected models. Conclusion: We determined that the NP layers had stronger bonding strength than NT structures, and the corresponding NP materials might be more suitable than NT for preparing drug-device combined titanium implants for bone injury treatment.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Nanoporos , Osteogênese/efeitos dos fármacos , Titânio/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Imagem Tridimensional , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Nanoporos/ultraestrutura , Nanotubos/química , Nanotubos/ultraestrutura , Osteoblastos/citologia , Próteses e Implantes , Ratos , Propriedades de Superfície
20.
Talanta ; 200: 378-386, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036199

RESUMO

Zinc oxide (ZnO) based nanostructures owing unique physical properties - high photoluminescence, biocompatibility and other characteristics, therefore, they attract attention as building blocks suitable for biosensor development. In this research as a target we have used human leukemic cell line IM9 (IM9). IM9 was derived from the patient with a multiple myeloma and expressed cluster of differentiation proteins СD19 on the surface of 85-95% here investigated cancer cells. As a control sample healthy human's peripheral blood mononuclear cells (PBMC) were used and the expression of CD19 protein was found only in 5-9% of these cells. Two types of antibodies labeled by fluorescein isothiocyanate (FITC) were used for the labeling of human leukemic cells: FITC-conjugated mouse antibodies against Human CD19 protein (anti-CD19-FITC*) and FITC-conjugated mouse antibodies against Human IgG1 protein (anti-IgG1-FITC*). In order to demonstrate the applicability of zinc oxide nanorods (ZnO-NRs) based platforms three types of ZnO-NRs-based structures were investigated: (i) ZnO-NRs modified by anti-CD19-FITC*; (ii) ZnO-NRs modified by IM9 cells, which were pre-incubated with anti-CD19-FITC*; (iii) ZnO-NRs modified by PBMC cells, which were pre-incubated with anti-CD19-FITC*. It was demonstrated that IM9 cells after specific interaction with anti-CD19-FITC* bind to ZnO-NRs (ZnO-NRs/IM9 +anti-CD19-FITC*) and photoluminescence based signal significantly increase in comparison with that observed in control samples, which contained PBMC cells incubated with anti-CD19-FITC* (ZnO-NRs/PBMC+anti-CD19-FITC*). The photoluminescence results are in good correlation with the data obtained by flow cytometry. This study illustrate that ZnO-NRs exhibit a photoluminescence signal suitable for the determination of anti-CD19-FITC* labeled IM9 cell line at concentrations - from 10 till 500 cells adsorbed per 1 mm2 of ZnO-NRs platform.


Assuntos
Linfócitos B/patologia , Separação Celular , Imunoensaio/métodos , Leucemia/patologia , Nanotubos/química , Óxido de Zinco/química , Biomarcadores/sangue , Células Cultivadas , Citometria de Fluxo , Humanos , Óxido de Zinco/síntese química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA