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1.
Anal Bioanal Chem ; 412(4): 841-848, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31897553

RESUMO

A sensitive photoelectrochemical (PEC) aptasensor was constructed for prostate-specific antigen (PSA) detection using an enhanced photocurrent response strategy. The p-n heterostructure CdS-Cu2O nanorod arrays were prepared on Ti mesh (CdS-Cu2O NAs/TM) by a simple hydrothermal method and successive ionic-layer adsorption reactions. Compared with the original CdS/TM, the synergistic effect of p-n type CdS-Cu2O NAs/TM and the internal electric field realizes the effective separation of photoinduced electron-hole pairs and improves the PEC performance. In order to construct the aptasensor, an amino-modified aptamer was immobilized on CdS-Cu2O NAs/TM to serve as a recognition unit for PSA. After the introduction of PSA, PSA was specifically captured by the aptamer on the PEC aptasensor, which can be oxidized by photogenerated holes to prevent electron-hole recombination and increase photocurrent. Under optimal conditions, the constructed PEC aptasensor has a linear range of 0.1-100 ng·mL-1 and a detection limit as low as 0.026 ng·mL-1. The results of aptasensor detection of human serum indicate that it has broad application prospects in biosensors and photoelectrochemical analysis.


Assuntos
Aptâmeros de Nucleotídeos/química , Compostos de Cádmio/química , Cobre/química , Nanotubos/química , Antígeno Prostático Específico/sangue , Sulfetos/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Humanos , Limite de Detecção , Nanotubos/ultraestrutura
2.
Int J Nanomedicine ; 14: 7281-7289, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31686808

RESUMO

Purpose: This work presents the preparation of a nanocomposite of ampicillin-conjugated gold nanoparticles (AuNPs) and self-assembled rosette nanotubes (RNTs), and evaluates its antibacterial properties against two strains of drug-resistant bacteria (Staphylococcus aureus [S. aureus], methicillin-resistant S. aureus [MRSA]). Materials and methods: Small, nearly monodisperse AuNPs (1.43±0.5 nm in diameter) nucleated on the surface of polyethylene glycol-functionalized RNTs in a one-pot reaction. Upon conjugation with ampicillin, their diameter increased to 1.86±0.32 nm. The antibacterial activity of the nanocomposite against S. aureus and MRSA was tested using different concentrations of ampicillin. The cytocompatibility of the nanocomposite was also tested against human dermal fibroblasts. Results: Based on bacterial inhibition studies, the nanocomposite demonstrated enhanced antibiotic activity against both bacterial strains. The minimum inhibitory concentration (MIC) of the nanocomposite against S. aureus was found to be 0.58 µg/mL, which was 18% lower than ampicillin alone. The nanocomposite also exhibited a 20 hrs MIC of 4 µg/mL against MRSA, approximately 10-20 times lower than previously reported values for ampicillin alone. In addition, at concentrations of 4 µg/mL of ampicillin (70 µg/mL of AuNPs), the nanocomposite showed negligible cytotoxic effects. Conclusion: Our findings offer a new approach for the treatment of drug-resistant bacteria by potentiating inhibitory effects of existing antibiotics, and delivering them using a non-toxic formulation.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Ouro/química , Nanopartículas Metálicas/química , Nanotubos/química , Polietilenoglicóis/química , Sobrevivência Celular/efeitos dos fármacos , Derme/citologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Nanopartículas Metálicas/ultraestrutura , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanotubos/ultraestrutura
3.
Nanoscale ; 11(39): 18099-18108, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31566198

RESUMO

Multi-branched metal nanomaterials can exhibit precisely controllable plasmonic properties with the precise control of their sizes and morphologies. In this study, trepang-like gold nanocrystals (AuNCs) with tunable plasmonic properties were synthesized via DNA-directed self-assembly technology. The gold precursor was precisely controlled to be reduced and grow along the DNA skeleton of DNA-conjugated gold nanorods to form multi-branched trepang-like nanocrystals. It was investigated in detail and proven that several key factors greatly influenced the precise control of the morphology and plasmonic property of the proposed AuNCs during their synthesis, including the gold precursor, reducing agent, surfactant, loading amount of DNA and DNA structure. The relative finite-difference time-domain calculation results suggested that the change in the plasmonic resonance peak is consistent with the precise change in the size and morphology of the as-synthesized AuNCs. The trepang-like AuNCs exhibited broad absorption bands in the wavelength range of 700-1100 nm with a high photothermal conversion efficiency of 36.2%. Finally, the trepang-like AuNCs with good biocompatibility were applied in photothermal therapy and imaging analysis.


Assuntos
DNA/química , Ouro/química , Nanopartículas Metálicas/química , Nanotubos/química , Células HeLa , Humanos , Hipertermia Induzida , Teste de Materiais , Nanopartículas Metálicas/ultraestrutura , Nanotubos/ultraestrutura , Fototerapia
4.
Int J Nanomedicine ; 14: 8047-8058, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632017

RESUMO

Purpose: Treatment strategies to eliminate bacterial infections have long emphasized bacterial killing as a goal. However, bacteria secrete toxins that sustain chronic disease and dead cells release DNA that can promote the spread of antibiotic resistance even when viable cells are eradicated. Meanwhile, biofilms regulated by quorum-sensing system, protect bacteria and promote the development of antibiotic resistance. Thus, all of these factors underscore the need for novel antimicrobial therapeutic treatments as alternatives to traditional antibiotics. Here, a smart material was developed that incorporated gold nanorods and an adsorbed protease (protease-conjugated gold nanorods, PGs). When illuminated with near-infrared (NIR) light, PGs functioned to physically damage bacteria, prevent biofilm and exotoxin production, eliminate pre-existing biofilm and exotoxin, and inhibit bacterial quorum-sensing systems. Methods: PGs were incubated with suspensions of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria followed by exposure to 808-nm NIR laser irradiation. Bacterial viability was determined using a colony-forming unit assay followed by an exploration of cell-damage mechanisms using transmission electron microscopy, scanning electron microscopy, agarose gel electrophoresis, and SDS-PAGE. Quantification of biofilm mass was performed using crystal violet staining. A commercial enterotoxin ELISA kit was used to test inhibitory and degradative effects of PGs on secreted exotoxin. Results: Use of the remote-controlled antibacterial system reduced surviving bacterial populations to 3.2% and 2.1% of untreated control numbers for E. coli and S. aureus, respectively, and inhibited biofilm formation and exotoxin secretion even in the absence of NIR radiation. However, enhanced degradation of existing biofilm and exotoxin was observed when PGs were used with NIR laser irradiation. Conclusion: This promising new strategy achieved both the reduction of viable microorganisms and elimination of biofilm and exotoxin. Thus, this strategy addresses the long-ignored issue of persistence of bacterial residues that perpetuate chronic illness in patients even after viable bacteria have been eradicated.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Endopeptidases/metabolismo , Exotoxinas/metabolismo , Ouro/química , Raios Infravermelhos , Nanotubos/química , Temperatura Ambiente , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/ultraestrutura , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Nanotubos/ultraestrutura , Ácidos Nucleicos/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura
5.
ACS Appl Mater Interfaces ; 11(40): 36420-36427, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31509376

RESUMO

Photothermal conversion effect of plasmonic nanostructures is considered as a promising technique for cellular and molecular manipulations owing to controllability of local temperature. Therefore, this technique has been extensively applied to biological studies such as controlling cellular behavior, delivery of biologics, and biomolecular detection. Herein, we propose a novel method for directed cell positioning and photothermally modulated molecular delivery to the cells using patterned plasmonic interfaces. Plasmonic substrates with gold nanorods (GNRs) and cell adhesion molecules fabricated by microcontact printing are optimized for cellular positioning on designated patterns. Through the photothermal conversion effect of GNRs on the pattern, we further demonstrate on-demand, light-induced delivery of drug molecules to the target cells. We expect that this approach will provide a new way to study single cellular behaviors and enhance molecular delivery to the target cells.


Assuntos
Sistemas de Liberação de Medicamentos , Hipertermia Induzida , Fototerapia , Linhagem Celular Tumoral , Ouro/química , Humanos , Nanotubos/química , Nanotubos/ultraestrutura , Impressão
6.
ACS Appl Mater Interfaces ; 11(40): 36939-36948, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31513367

RESUMO

Stimuli-responsive biomaterials supply a promising solution to adapt to the complex physiological environment for different biomedical applications. In this study, a dynamic UV-triggered pH-responsive biosurface was constructed on titania nanotubes (TNTs) by loading photoacid generators, diphenyliodonium chloride, into the nanotubes, and grafting 2,3-dimethyl maleic anhydride (DMMA)-modified hyperbranched poly(l-lysine) (HBPLL) onto the surface. The local acidity was dramatically enhanced by UV irradiation for only 30 s, leading to the dissociation of DMMA and thereby the transformation of surface chemistry from negatively charged caboxyl groups to positively charged amino groups. The TNTs-HBPLL-DMMA substrate could better promote proliferation and spreading of rat bone mesenchymal stem cells (rBMSCs) after UV irradiation. The osteogenic differentiation of rBMSCs was enhanced because of the charge reversal in combination with the titania-based substrates.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos da radiação , Nanotubos/química , Titânio/farmacologia , Raios Ultravioleta , Fosfatase Alcalina/metabolismo , Animais , Compostos de Bifenilo/química , Adesão Celular/efeitos dos fármacos , Adesão Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Masculino , Anidridos Maleicos/síntese química , Anidridos Maleicos/química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos da radiação , Nanotubos/ultraestrutura , Oniocompostos/química , Polilisina/síntese química , Polilisina/química , Ratos Sprague-Dawley , Propriedades de Superfície
7.
Mater Sci Eng C Mater Biol Appl ; 105: 109982, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546427

RESUMO

Titanium and its alloys especially Ti6Al4V have long been used in biomedical implants. Although, Ti6Al4V is biocompatible, yet there has been consistent effort to improve its osteoconductive and osteogenic property to enhance the implant performance. In this regard, surface modification of Ti6Al4V implants with TiO2 nanotubes and subsequent application of biopolymeric coating has started emerging as a promising approach. Keeping this perspective in mind, here we have coated nano TiO2 modified Ti6Al4V surface with silk fibroin isolated from B. mori cocoons. The coating of silk fibroin was done on the implant using electrophoretic deposition technique at three different voltages. Topography analysis by AFM confirms the uniform coating of silk fibroin. A variation in contact angle from 89.7 ±â€¯2° to 83.6 ±â€¯2° was observed when tested for wettability using drop shape analyzer. The biocompatibility studies showed SF coated substrates support the adhesion of both MG63 bone cells and human mesenchymal stem cells (hMSCs). The formation of peripheral vinculin complexes on SF surface confirmed the adhesion through focal adhesion points. Consequently, SF coating improved the cellular expression of alkaline phosphatase by 1.1 times compared to the polished Ti6Al4V surface (PTi64). Increased expression of late osteogenic markers osterix and osteocalcin was also observed in hMSCs cultured on SF coated nanotubular surface compared to PTi64. These results together implied that coating of silk fibroin on TiO2 modified Ti6Al4V surface improve the osteogenic potential of the implant.


Assuntos
Osso e Ossos/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , Fibroínas/farmacologia , Nanotubos/química , Osteogênese/efeitos dos fármacos , Próteses e Implantes , Titânio/farmacologia , Actinas/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Bombyx , Calcificação Fisiológica/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Nanotubos/ultraestrutura , Osteocalcina/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Vinculina/metabolismo , Molhabilidade
8.
Int J Nanomedicine ; 14: 6313-6324, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31496688

RESUMO

Background: Craniosynostosis is a developmental disorder characterized by the premature fusion of skull sutures, necessitating repetitive, high-risk neurosurgical interventions throughout infancy. This study used protein-releasing Titania nanotubular implant (TNT/Ti) loaded with glypican 3 (GPC3) in the cranial critical-sized defects (CSDs) in Crouzon murine model (Fgfr2c342y/+ knock-in mutation) to address a key challenge of delaying post-operative bone regeneration in craniosynostosis. Materials and methods: A 3 mm wide circular CSD was created in two murine models of Crouzon syndrome: (i) surgical control (CSDs without TNT/Ti or any protein, n=6) and (ii) experimental groups with TNT/Ti loaded with GPC3, further subdivided into the presence or absence of chitosan coating (on nanotubes) (n=12 in each group). The bone volume percentage in CSDs was assessed 90 days post-implantation using micro-computed tomography (micro-CT) and histological analysis. Results: Nano-implants retrieved after 90 days post-operatively depicted well-adhered, hexagonally arranged, and densely packed nanotubes with average diameter of 120±10 nm. The nanotubular architecture was generally well-preserved. Compared with the control bone volume percentage data (without GPC3), GPC3-loaded TNT/Ti without chitosan coating displayed a significantly lower volume percent in cranial CSDs (P<0.001). Histological assessment showed relatively less bone regeneration (healing) in GPC3-loaded CSDs than control CSDs. Conclusion: The finding of inhibition of cranial bone regeneration by GPC3-loaded TNT/Ti in vivo is an important advance in the novel field of minimally-invasive craniosynostosis therapy and holds the prospect of altering the whole paradigm of treatment for affected children. Future animal studies on a larger sample are indicated to refine the dosage and duration of drug delivery across different ages and both sexes with the view to undertake human clinical trials.


Assuntos
Regeneração Óssea , Disostose Craniofacial/terapia , Sistemas de Liberação de Medicamentos , Glipicanas/administração & dosagem , Glipicanas/uso terapêutico , Nanotubos/química , Crânio/patologia , Titânio/química , Animais , Disostose Craniofacial/diagnóstico por imagem , Modelos Animais de Doenças , Feminino , Masculino , Camundongos Endogâmicos C57BL , Nanotubos/ultraestrutura , Crânio/diagnóstico por imagem , Microtomografia por Raio-X
9.
Molecules ; 24(16)2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31416287

RESUMO

Electrochemical anodized titanium dioxide (TiO2) nanotubes are of immense significance as electrochemical energy storage devices owing to their fast electron transfer by reducing the diffusion path and paving way to fabricating binder-free and carbon-free electrodes. Besides these advantages, when nitrogen is doped into its lattice, doubles its electrochemical activity due to enhanced charge transfer induced by oxygen vacancy. Herein, we synthesized nitrogen-doped TiO2 (N-TiO2) and studied its electrochemical performances in supercapacitor and as anode for a lithium-ion battery (LIB). Nitrogen doping into TiO2 was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical performance of N-TiO2 nanotubes was outstanding with a specific capacitance of 835 µF cm-2 at 100 mV s-1 scan rate as a supercapacitor electrode, and it delivered an areal discharge capacity of 975 µA h cm-2 as an anode material for LIB which is far superior to bare TiO2 nanotubes (505 µF cm-2 and 86 µA h cm-2, respectively). This tailor-made nitrogen-doped nanostructured electrode offers great promise as next-generation energy storage electrode material.


Assuntos
Capacitância Elétrica , Fontes de Energia Elétrica , Eletrodos , Íons/química , Lítio/química , Nanotubos , Nitrogênio/química , Titânio/química , Técnicas Eletroquímicas , Eletroquímica , Nanotubos/ultraestrutura , Análise Espectral
10.
Biosens Bioelectron ; 142: 111557, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31400727

RESUMO

Nowadays, acquired immunodeficiency syndrome has become a formidable danger to human health, and its early diagnosis is urgent need with the increasing quantity of patients around the world. Herein, we first synthesized beta-cyclodextrin-functionalized CdS nanorods (ß-CD@CdS NRs) with high stability and desirable photo-electricity activity, and served as easy-to-assemble building modules to design a novel photoelectrochemical biosensor for human immune deficiency virus (HIV) DNA detection by coupling with catalytic hairpin assembly (CHA)-mediated biocatalytic precipitation and the host-guest interaction between adamantine (ADA) and ß-CD. In the presence of HIV DNA, CHA process was triggered with the aid of hairpin DNA1 and ADA-labelled hairpin DNA2, and then generated large amounts of G-quadruplex, which could be formed hemin/G-quadruplex DNAzyme to catalyze 4-chloro-1-naphthol to generate insoluble precipitation on photoelectrode surface, followed by the decreased photocurrent response due to the corresponding stereo-hindrance effect. Under optimized conditions, this biosensor exhibited wide linear dynamic range (10 fM - 1 nM) and low detection limit of 1.16 fM, as well as high sensitivity, excellent stability, and satisfactory feasibility in human-serum samples. Moreover, the prepared ß-CD@CdS NRs could be applied to the construction of other advanced sensing platform, showing great prospect in clinical diagnostics.


Assuntos
Compostos de Cádmio/química , DNA Viral/sangue , Infecções por HIV/sangue , HIV/isolamento & purificação , Nanotubos/química , Sulfetos/química , beta-Ciclodextrinas/química , Técnicas Biossensoriais/métodos , DNA Catalítico/química , DNA Viral/análise , Técnicas Eletroquímicas/métodos , Quadruplex G , Infecções por HIV/diagnóstico , Humanos , Limite de Detecção , Nanotubos/ultraestrutura
11.
Molecules ; 24(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340472

RESUMO

In this study, the photothermal-induced bactericidal activity of phospholipid-decorated gold nanorods (DSPE-AuNR) suspension against Pseudomonas aeruginosa planktonic and biofilm cultures was investigated. We found that the treatment of planktonic culture of Pseudomonas aeruginosa with DSPE-AuNR suspension (0.25-0.03 nM) followed by a continuous laser beam exposure resulted in ~6 log cycle reduction of the bacterial viable count in comparison to the control. The percentage reduction of Pseudomonas aeruginosa biofilm viable count was ~2.5-6.0 log cycle upon laser excitation with different concentrations of DSPE-AuNR as compared to the control. The photothermal ablation activity of DSPE-AuNR (0.125 nM) loaded into poloxamer 407 hydrogel against Pseudomonas aeruginosa biofilm resulted in ~4.5-5 log cycle reduction in the biofilm viable count compared to the control. Moreover, transmission electron microscope (TEM) images of the photothermally-treated bacteria revealed a significant change in the bacterial shape and lysis of the bacterial cell membrane in comparison to the untreated bacteria. Furthermore, the results revealed that continuous and pulse laser beam modes effected a comparable photothermal-induced bactericidal activity. Therefore, it can be concluded that phospholipid-coated gold nanorods present a promising nanoplatform to eradicate Pseudomonas aeruginosa biofilm responsible for common skin diseases.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Ouro/farmacologia , Nanotubos/química , Plâncton/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Biofilmes/efeitos da radiação , Contagem de Colônia Microbiana , Ouro/química , Hidrogéis/química , Terapia com Luz de Baixa Intensidade/métodos , Microscopia Eletrônica de Transmissão , Nanotubos/ultraestrutura , Fosfatidiletanolaminas/química , Plâncton/crescimento & desenvolvimento , Plâncton/efeitos da radiação , Poloxâmero/química , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/efeitos da radiação , Pseudomonas aeruginosa/ultraestrutura
12.
Cells ; 8(6)2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31234435

RESUMO

Tunneling nanotubes (TNTs) are thin membranous tubes that interconnect cells, representing a novel route of cell-to-cell communication and spreading of pathogens. TNTs form between many cell types, yet their inception mechanisms remain elusive. We review in this study general concepts related to the formation and stability of membranous tubular structures with a focus on a deviatoric elasticity model of membrane nanodomains. We review experimental evidence that tubular structures initiate from local membrane bending facilitated by laterally distributed proteins or anisotropic membrane nanodomains. We further discuss the numerical results of several theoretical and simulation models of nanodomain segregation suggesting the mechanisms of TNT inception and stability. We discuss the coupling of nanodomain segregation with the action of protruding cytoskeletal forces, which are mostly provided in eukaryotic cells by the polymerization of f-actin, and review recent inception mechanisms of TNTs in relation to motor proteins.


Assuntos
Nanotubos/química , Anisotropia , Extensões da Superfície Celular/metabolismo , Citoesqueleto/metabolismo , Nanotubos/ultraestrutura , Lipossomas Unilamelares/química
13.
Biosens Bioelectron ; 140: 111352, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31163397

RESUMO

Atrazine (ATZ) is one of the most widely used and highly toxic triazine herbicides in the world. Photoelectrochemical (PEC) method is an attractive and sensitive alternate for ATZ. However, for conventional PEC sensors, recognition elements usually need to immobilize on electrode surface, where a complex procedure is unavoidable and the reproducibility of sensors fabrication is usually poor. Therefore, we herein proposed a new and feasible strategy for developing a signal-on immobilization-free PEC aptasensor to ATZ. Aptamer for ATZ is combined with graphene to obtain APT-GN complex, serving as the recognition element in solution. TiO2 nanotubes (NTs) electrode deposited with Au nanoparticles (NPs) is used as the substrate electrode. After further self-assembled with 1-Mercaptooctane (MCT), the photo-generated carriers transfer between the resultant electrode and the electrolyte will be blocked, leading to a signal-off of the photocurrent. But when sensing ATZ, aptamers on APT-GN will be grasped by ATZ, leaving free graphene to assemble onto MCT/Au NPs/TiO2 NTs, which will largely "turn on" the photocurrent response of the substrate electrode due to the efficient carrier transport efficiency of graphene. Meanwhile, simultaneous addition of deoxyribonuclease I (DNase I) can bring about further cycling amplification of the signal enhancement. The as-designed PEC aptasensor exhibits a linear range from 50.0 fM to 0.3 nM with detection limit of 12.0 fM for ATZ. Since the reaction of recognition elements and targets ATZ occurs in homogeneous solution rather than on the photoelectrode surface, this PEC aptasensor exhibits advantages of high stability, anti-interference ability, reproducibility, and wide pH and ion strength feasibility range. A promising immobilization-free aptasensing platform has thus been provided not only for ATZ but also for other kinds of environmental pollutants.


Assuntos
Aptâmeros de Nucleotídeos/química , Atrazina/análise , Técnicas Biossensoriais/instrumentação , Praguicidas/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental/instrumentação , Desenho de Equipamento , Ouro/química , Grafite/química , Limite de Detecção , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Nanotubos/química , Nanotubos/ultraestrutura , Tanques/análise , Reprodutibilidade dos Testes , Titânio/química
14.
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
15.
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
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.
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
18.
Nanoscale ; 11(26): 12460-12464, 2019 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-31120079

RESUMO

Quantitative PAINT (qPAINT) is a useful method for counting well-separated molecules within nanoscale assemblies. But whether cross-reactivity in densely-packed arrangements perturbs measurements is unknown. Here we establish that qPAINT measurements are robust even when target molecules are separated by as little as 3 nm, sufficiently close that single-stranded DNA binding sites can interact.


Assuntos
DNA de Cadeia Simples/química , Nanotubos/química , Nanotubos/ultraestrutura
19.
Nano Lett ; 19(6): 3751-3760, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31140279

RESUMO

Self-assembled DNA nanostructures have potential applications in therapeutics, diagnostics, and synthetic biology. A challenge in using DNA nanostructures in biological environments or cell culture, however, is that they may be degraded by enzymes found in these environments, such as nucleases. Such degradation can be slowed by introducing alternative substrates for nucleases, or by coating nanostructures with membranes or peptides. Here we demonstrate a means by which degradation can be reversed in situ through the repair of nanostructure defects. To demonstrate this effect, we show that degradation rates of DNA nanotubes, micron-scale self-assembled structures, are at least 4-fold lower in the presence of tiles that can repair nanotube defects during the degradation process. Micrographs of nanotubes show that tiles from solution incorporate into nanotubes and that this incorporation increases nanotube lifetime to several days in serum. We use experimental data to formulate a simple model of nanostructure self-healing. This model suggests how introducing even a relatively low rate of repair could allow a nanostructure to survive almost indefinitely because of a dynamic equilibrium between microscale repair and degradation processes. The ability to repair nanostructures could thus allow particular structures or devices to operate for long periods of time and might offer a single means to resist different types of chemical degradation.


Assuntos
DNA/química , Nanotubos/química , Polietilenoglicóis/química , Soro/metabolismo , Animais , Bovinos , DNA/metabolismo , Nanotecnologia , Nanotubos/ultraestrutura , Conformação de Ácido Nucleico , Polietilenoglicóis/metabolismo
20.
Molecules ; 24(10)2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31096628

RESUMO

We present a p-n-p monolayer graphene photodetector doped with titanium dioxide nanotubes for detecting light from visible to near-infrared (405 to 1310 nm) region. The built-in electric field separates the photo-induced electrons and holes to generate photocurrent without bias voltage, which allows the device to have meager power consumption. Moreover, the detector is very sensitive to the illumination area, and we analyze the reason using the energy band theory. The response time of the detector is about 30 ms. The horizontal p-n-p device is a suitable candidate in zero-bias optoelectronic applications.


Assuntos
Técnicas Biossensoriais , Grafite , Luz , Nanotubos , Titânio , Grafite/química , Nanotubos/química , Nanotubos/ultraestrutura , Análise Espectral , Titânio/química
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