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2.
Chem Commun (Camb) ; 55(67): 10019-10022, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31378803

RESUMO

We report a facile hydrothermal method to synthesize a novel mesoporous graphitic carbon nitride (MCN)@NiCo2O4 nanocomposite, which can be used as a solid phase microextraction coating for high efficiency extraction and preconcentration of trace polychlorinated biphenyls and polycyclic aromatic hydrocarbons in human serum samples.


Assuntos
Poluentes Ambientais/sangue , Nanocompostos/química , Nitrilos/química , Bifenilos Policlorados/sangue , Hidrocarbonetos Policíclicos Aromáticos/sangue , Cobalto/química , Humanos , Limite de Detecção , Níquel/química , Microextração em Fase Sólida/instrumentação , Microextração em Fase Sólida/métodos
3.
Analyst ; 144(17): 5284-5291, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31372627

RESUMO

5,10,15,20-Tetrakis(4-carboxyl phenyl)porphyrin (Por) modified Co(OH)2 deposited on the surface of GO nanocomposites (Por/Co(OH)2/GO) were prepared and characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and XRD. For the first time, H2TCPP/Co(OH)2/GO is found to have enhanced peroxidase-like activity and catalyze the oxidation of the substrate 3,3,5,5-tetramethylbenzidine (TMB) by hydrogen peroxide (H2O2). Notably, the colorless TMB rapidly transformed into blue oxTMB in just 60 s, which was easily observed visually. The catalytic kinetics of H2TCPP/Co(OH)2/GO is in accord with the Michaelis-Menten equation. The catalytic mechanism of H2TCPP/Co(OH)2/GO nanocomposites is attributed to hydroxyl radicals (˙OH), due to decomposition of H2O2, which is verified by using terephthalic acid as a fluorescent probe. What's more, H2O2 can be detected in a wide linear detection range from 5 to 35 mM with a detection limit of 0.385 mM. Furthermore, based on the excellent peroxidase-like activity of H2TCPP/Co(OH)2/GO, a colorimetric sensor is established to sensitively detect glutathione (GSH) in a linear range from 10 to 300 µM with a low detection limit of 9.5 µM.


Assuntos
Cobalto/química , Grafite/química , Hidróxidos/química , Nanocompostos/química , Peroxidases/química , Porfirinas/química , Benzidinas/química , Materiais Biomiméticos , Técnicas Biossensoriais/métodos , Catálise , Glutationa/análise , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Cinética , Limite de Detecção , Oxirredução , Sensibilidade e Especificidade , Propriedades de Superfície
4.
J Cancer Res Clin Oncol ; 145(9): 2199-2209, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31309302

RESUMO

PURPOSE: Radiofrequency (RF) ablation therapy is of great interest in cancer therapy as it is non-ionizing radiation and can effectively penetrate into the tissue. However, the current RF ablation technique is invasive that requires RF probe insertion into the tissue and generates a non-specific heating. Recently, RF-responsive nanomaterials such as gold nanoparticles (AuNPs) and iron oxide nanoparticles (IONPs) have led to tremendous progress in this area. They have been found to be able to absorb the RF field and induce a localized heating within the target, thereby affording a non-invasive and tumor-specific RF ablation strategy. In the present study, for the first time, we used a hybrid core-shell nanostructure comprising IONPs as the core and AuNPs as the shell (IO@Au) for targeted RF ablation therapy. Due to the magnetic core, the nanohybrid can be directed toward the tumor through a magnet. Moreover, IONPs enable the nanohybrid to be used as a magnetic resonance imaging (MRI) contrast agent. RESULTS: In vitro cytotoxicity experiment showed that the combination of IO@Au and 13.56-MHz RF field significantly reduced the viability of cancer cells. Next, during an in vivo experiment, we demonstrated that magnetically targeting of IO@Au to the tumor and subsequent RF exposure dramatically suppressed the tumor growth. CONCLUSION: Therefore, the integration of targeting, imaging, and therapeutic performances into IO@Au nanohybrid could afford the promise to improve the effectiveness of RF ablation therapy.


Assuntos
Ablação por Cateter/métodos , Compostos Férricos/química , Ouro/química , Hipertermia Induzida/métodos , Nanopartículas de Magnetita/uso terapêutico , Neoplasias/cirurgia , Ablação por Radiofrequência/métodos , Animais , Compostos Férricos/uso terapêutico , Ouro/uso terapêutico , Imagem por Ressonância Magnética/métodos , Nanopartículas de Magnetita/química , Masculino , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Terapia de Alvo Molecular/métodos , Nanocompostos/química , Nanocompostos/uso terapêutico , Nanoconchas/química , Nanoconchas/uso terapêutico , Neoplasias/patologia , Células Tumorais Cultivadas
5.
Food Chem ; 298: 124981, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260993

RESUMO

Development of an effective sensor for sensing glucose in commercially available "sugar free" food products is important as people are becoming diabetic health conscious. Although multi-walled carbon nanotubes (MWCNTs) possess interesting electrical properties, their hydrophobic nature limits their applications. Their hydrophilicity can be improved through modification. In the present study, Inulin, that was isolated from Allium sativum L. using hot water diffusion and incorporated with titanium dioxide (TiO2), was used for the modification of MWCNTs. The as-synthesized MWCNT-Inulin-TiO2 bio-nanocomposite immobilized with glucose oxidase (GOx) was incorporated into the carbon paste matrix and was utilized for the sensing of glucose in food products. Differential pulse voltammetric studies revealed that the fabricated electrode demonstrated good linear range (1.6 nM to 1 µM) and was sensitive to nanomolar concentrations of glucose with a very low limit of detection up to 0.82 nM and exhibited a long term stability of 150 days.


Assuntos
Eletrodos , Análise de Alimentos/métodos , Glucose Oxidase/química , Glucose/análise , Nanocompostos/química , Enzimas Imobilizadas/química , Análise de Alimentos/instrumentação , Alho/química , Glucose/química , Inulina/química , Limite de Detecção , Nanotubos de Carbono/química , Sensibilidade e Especificidade , Titânio/química
6.
Anal Chim Acta ; 1078: 161-167, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358215

RESUMO

Sarcosine is a recently identified biomarker for prostate cancer. However, the rapid detection methods for sarcosine are relatively lack because of the low concentration and the presence of complicated interfering substances in serum or urine. In this manuscript, hollow nanospheres of Fe3O4 was synthesized and used as carrier to disperse Pt (Pt) nanoparticles. In order to achieve excellent electron transfer ability, we use polyaniline to coat Pt-Fe3O4 nanoparticles, and pyrolyze the polyaniline to carbon (C). Thus, hollow magnetic Pt-Fe3O4@C nanocomposites with good electron transfer ability are formed. The Pt-Fe3O4@C nanocomposites have high catalytic activity and stability. The nanocomposites were immobilized on glassy carbon electrode (GCE) to construct a nonenzyme hydrogen peroxide (H2O2) sensor (Pt-Fe3O4@C/GCE). We further construct a sensitive sarcosine biosensor by immobilizing sarcosine oxidase (SOx) on the Pt-Fe3O4@C/GCE. The high catalytic activity and good biocompatibility of Pt-Fe3O4@C nanocomposites greatly retained the bioactivity of immobilized SOx, and the prepared sarcosine biosensor has good electrocatalytic performance towards sarcosine. It has a linear detection range between 0.5 and 60 µM with a limit of detection (LOD) of 0.43 µM (the signal to noise ratio is 3), and the sensitivity is 3.45 nA µM-1 (48.8 nA µM-1 cm-2), which has the potential to be used for rapid screening of prostate cancer.


Assuntos
Nanopartículas de Magnetita/química , Nanocompostos/química , Sarcosina/sangue , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Carbono/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Enzimas Imobilizadas/química , Humanos , Limite de Detecção , Platina/química , Sarcosina Oxidase/química
7.
Anal Chim Acta ; 1078: 42-52, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358227

RESUMO

Hemoglobin A1c (HbA1c) is a standard biomarker to measure long-term average glucose concentration for diagnosis and monitoring of diabetes. Various methods have been reported for measuring HbA1c, however, portable and precise determination is still challenging. Herein, a new highly sensitive electrochemical nanobiosensor is developed for the specific determination of HbA1c. A nanocomposite of reduced graphene oxide (rGO) and gold with hierarchical architecture structure was electrochemically deposited on a cheap and flexible graphite sheet (GS) electrode. The nanocomposite increased the surface area, improved the electron transfer on the electrode surface and augmented the signal. It also provided a suitable substrate for linkage of thiolated DNA aptamer as a bioreceptor on the electrode surface by strong covalent bonding. The quantitative label free detection was carried out by differential pulse voltammetry (DPV) in a phosphate-buffered saline (PBS) solution containing redox probe Fe(CN)63-/4-. The detection is based on insulating the surface in presence of HbA1c and decreasing the current, which is directly related to the HbA1c concentration. The nanobiosensor demonstrated high sensitivity of 269.2 µA. cm-2, wide linear range of 1 nM-13.83 µM with a low detection limit of 1 nM. The biosensor was successfully used for measuring HbA1c in blood real sample. Furthermore, it is promising to use it as a part of a point of care device for low-invasive screening and management of diabetes.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Hemoglobina A Glicada/análise , Grafite/química , Nanopartículas Metálicas/química , Papel , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Técnicas Biossensoriais/instrumentação , DNA/química , DNA/genética , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ouro/química , Humanos , Limite de Detecção , Nanocompostos/química , Reprodutibilidade dos Testes
8.
Food Chem ; 297: 125005, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253325

RESUMO

Multiwalled carbon nanotubes molybdenum disulfide 3D nanocomposite (MWCNT-MoS2 NC) was successfully synthesized via eco-friendly hydrothermal method. The microstructural characterization of synthesized nanocomposite was carried out using different spectroscopic and microscopic techniques. Nanocomposite was activated using glutaraldehyde chemistry and used as a platform to immobilize Lens culinaris ß-galactosidase (Lsbgal) which resulted in 93% of immobilization efficiency. Attachment of Lsbgal onto nanocomposite was confirmed by AFM, FE-SEM, FTIR, and CLSM. The nanobiocatalyst showed broadening in operational pH and temperature working range. Remarkable increase in thermal stability was observed as compared to soluble enzyme. Nanobiocatalyst showed outstanding increase in storage stability, retained 92% of residual activity over a period of 8 months. This offers good reusability as it retained ∼50% residual activity up to 21 reuses and exhibited higher rate of lactose hydrolysis in whey. MWCNT-MoS2 NC conjugated to biomolecules can serve as a potential platform for fabrication of lactose biosensor.


Assuntos
Lactose/metabolismo , Lens (Planta)/enzimologia , Nanocompostos/química , Soro do Leite/metabolismo , beta-Galactosidase/metabolismo , Biocatálise , Dissulfetos/química , Estabilidade Enzimática , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Molibdênio/química , Nanotubos de Carbono/química , Temperatura Ambiente , beta-Galactosidase/química
9.
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
10.
Anal Chim Acta ; 1074: 131-141, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159933

RESUMO

Semiconducting single-walled carbon nanotubes (s-SWCNTs) have been demonstrated as an excellent material for transistors, miniaturized devices and sensors due to their high carrier mobility, stability, scattering-free ballistic transport of carriers etc. Herein, we have designed a biosensor to selectively detect methyl parathion (MP, organophosphorus pesticide) using glutaraldehyde (Glu) cross-linked with acetylcholinesterase (AChE) immobilized on s-SWCNTs wrapped with bovine serum albumin (BSA). The fabricated biosensor was characterized and confirmed by Fourier-transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV). In the presence of MP, the effective interaction between AChE and MP favours the accumulation of MP-AChE complex on the glassy carbon electrode (GCE) surface which reduces the electron transfer property. Based on this interaction, detection of various concentration of MP was demonstrated by SWV using BSA/AChE-Glu-s-SWCNTs composite modified electrode. The proposed biosensor exhibited a wide linear range (WLR) for MP target in 100 mM phosphate buffered saline solution (PBS) (pH 7.4) from 1 × 10-10 M to 5 × 10-6 M with a limit of detection (LOD) of 3.75 × 10-11 M. In addition, the BSA/AChE-Glu-s-SWCNTs/GCE biosensor showed good repeatability and reproducibility for MP detection. Moreover, the proposed biosensor showed better electrode stability when stored at 4 °C. This new electrochemical biosensor is also exhibited high selectivity and sensitivity for MP, which made it possible to test MP in real strawberry and apple juices. Furthermore, the BSA/AChE-Glu-s-SWCNTs/GCE offered a favourable electron transfer between the acetylthiocholine chloride (ATCl) and electrode interface than BSA/AChE-s-SWCNTs/GCE, s-SWCNTs/GCE and bare GCE.


Assuntos
Acetilcolinesterase/química , Inseticidas/análise , Metil Paration/análise , Nanocompostos/química , Nanotubos de Carbono/química , Soroalbumina Bovina/química , Animais , Técnicas Biossensoriais/métodos , Carbono , Bovinos , Reagentes para Ligações Cruzadas/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Electrophorus , Enzimas Imobilizadas/química , Contaminação de Alimentos/análise , Fragaria/química , Glutaral/química , Inseticidas/química , Limite de Detecção , Malus/química , Metil Paration/química , Reprodutibilidade dos Testes
11.
Anal Chim Acta ; 1074: 80-88, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159942

RESUMO

A rapid and sensitive electrochemical biosensor was constructed to detect Salmonella using invA gene biosensor. The biosensing was based on polyrrole-reduced graphene oxide (PPy-rGO) nanocomposite modified glassy carbon electrode (GCE) and signal amplification with horseradish peroxidase-streptavidin biofunctionalized gold nanoparticles (AuNPs-HRP-SA). PPy-rGO was prepared at 60 °C by chemical reduction of PPy-functionalized graphene oxide (PPy-GO) that was synthesized by in situ polymerization at room temperature. The detection signal was amplified via enzymatic reduction of H2O2 in the presence of hydroquinone (HQ) using AuNPs-HRP-SA as nanotag. Under optimal conditions, the differential pulse voltametric (DPV) signal from the biosensor was linearly related to the logarithm of target invA gene concentrations from 1.0 × 10-16 to 1.0 × 10-10 M, and the limit of detection (LOD) was 4.7 × 10-17 M. The biosensor can also detect Salmonella in the range of 9.6 to 9.6 × 104 CFU mL-1, with LOD of 8.07 CFU mL-1. The biosensor showed good regeneration ability, acceptable selectivity, repeatability and stability, which bode well as an alternative method for Salmonella screening.


Assuntos
Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana/métodos , Grafite/química , Nanopartículas Metálicas/química , Polímeros/química , Pirróis/química , Salmonella/isolamento & purificação , Técnicas Biossensoriais/métodos , Carbono , DNA Bacteriano/genética , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Enzimas Imobilizadas/química , Ouro/química , Peroxidase do Rábano Silvestre/química , Peróxido de Hidrogênio/química , Hidroquinonas/química , Limite de Detecção , Nanocompostos/química , Hibridização de Ácido Nucleico , Oxirredução , Salmonella/genética , Estreptavidina/química
12.
Chem Soc Rev ; 48(14): 3740-3770, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31206104

RESUMO

Among the wide range of materials used for remediating environmental contaminants, modified and functionalised nanoclays show particular promise as advanced sorbents, improved dispersants, or biodegradation enhancers. However, many chemically modified nanoclay materials are incompatible with living organisms when they are used in natural systems with detrimental implications for ecosystem recovery. Here we critically review the pros and cons of functionalised nanoclays and provide new perspectives on the synthesis of environmentally friendly varieties. Particular focus is given to finding alternatives to conventional surfactants used in modified nanoclay products, and to exploring strategies in synthesising nanoclay-supported metal and metal oxide nanoparticles. A large number of promising nanoclay-based sorbents are yet to satisfy environmental biocompatibility in situ but opportunities are there to tailor them to produce "biocompatible" or regenerative/reusable materials.


Assuntos
Materiais Biocompatíveis/química , Recuperação e Remediação Ambiental , Nanocompostos/química , Humanos , Tamanho da Partícula , Propriedades de Superfície
13.
J Environ Sci (China) ; 83: 73-84, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221389

RESUMO

Persulfate activation has been applied as one of the efficient advanced oxidation processes (AOPs) to remediate polluted environments. In this study, a novel α-FeOOH anchored by graphene oxide (GO)-carbon nanotubes (CNTs) aerogel (α-FeOOH@GCA) nanocomposite activated persulfate system (α-FeOOH@GCA + K2S2O8) was applied for decolorization of Orange II (OII). The decolorization of OII was remarkably enhanced to a level of ~99% in this system compared with that of pristine α-FeOOH (~44%) or GO-CNTs (~18%). The enhanced catalytic activity of α-FeOOH@GCA was due to the formation of a heterojunction by α-FeOOH and GO-CNTs as confirmed by the presence of Fe-O-C chemical bonds. The degradation intermediates of OII were comprehensively identified. The proposed degradation pathway of OII begins with the destruction of the conjugated structures of OII by the dominant reactive oxygen species, surface-bound SO4•-. The decolorization efficiency of OII by the α-FeOOH@GCA activated persulfate system decreased from the first to third cycle of recycling. Ultraviolet (UV) irradiation or introduction of a small amount of Fe2+ could restore the activation of this system. The results show that the α-FeOOH@GCA persulfate activation system promises to be a highly efficient environmental remediation method for organic pollutants.


Assuntos
Compostos Azo/química , Benzenossulfonatos/química , Recuperação e Remediação Ambiental/métodos , Compostos Férricos/química , Poluentes Químicos da Água/química , Grafite/química , Nanocompostos/química , Sulfatos/química
14.
An Acad Bras Cienc ; 91(2): e20190018, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31241710

RESUMO

Tissue engineering holds as a prominent technique to repair or replace the damaged human parts to recreate its native function. In this research, a novel scaffold based on polyurethane (PU) comprising megni oil was electrospun for tissue engineering applications. The obtained polyurethane blended with megni oil nanofibers were characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurement and atomic force microscopy (AFM). Furthermore, the blood compatibility of the fabricated nanocomposites evaluated through activated prothrombin time (APTT), partial thromboplastin time (PT) and hemolysis assay to determine the anticoagulant nature. The morphological results showed that the fabricated nanocomposites showed reduced fiber size (789 ± 143.106 nm) than the pristine control (890 ± 116.91 nm). The interaction between PU and megni oil was identified by the hydrogen bond formation evident in the FTIR. The incorporation of megni oil in the PU decreased the wettability behavior (113.3° ± 1.528) and improved the surface roughness (646 nm). Preliminary evaluation of blood compatibility assessments was carried out using APTT, PT and hemolysis assay revealed the enhanced antithrombogenicity nature of the fabricated nanocomposites than the PU. Hence, we conclude that the fabricated new nanocomposite membrane with desirable characteristics which might find potential application in the tissue engineering applications.


Assuntos
Materiais Biocompatíveis/química , Nanocompostos/química , Óleos/química , Poliuretanos/química , Engenharia Tecidual/métodos , Teste de Materiais , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Anal Bioanal Chem ; 411(20): 5175-5186, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31187200

RESUMO

An ultrasensitive electrochemiluminescence (ECL) immunosensor for alpha-fetoprotein (AFP) detection based on a poly(aniline-luminol)/graphene oxide nanocomposite was developed. The nanocomposite, which was prepared using a fast and simple chemical oxidation strategy for the first time, showed excellent ECL performance. This outstanding ECL performance is due to the formation of poly(aniline-luminol) on the graphene oxide (GO) surface and the excellent electron-transfer properties of GO. Moreover, the poly(aniline-luminol)/graphene oxide nanocomposite has abundant amino groups at its surface, making it a good platform for biomacromolecule labeling. Using the nanocomposite, a novel ECL immunosensor for the determination of AFP was successfully developed. Anti-AFP was immobilized on the surface of a poly(aniline-luminol)/graphene oxide nanocomposite-modified electrode using a glutaraldehyde crosslinking method to form the ECL immunosensor. The AFP was then captured at the modified electrode surface through an antigen-antibody immunoreaction. When the AFP was captured by its antibody, the ECL intensity decreased. This ECL immunosensor for the detection of AFP exhibited a linear range of 1.7 × 10-12 to 1.7 × 10-8 mg mL-1 and a detection limit of 5 × 10-13 mg mL-1, indicating high sensitivity and linearity across a wide concentration range. Furthermore, the immunosensor was successfully applied to determine AFP in a real-world human serum sample. Graphical abstract A new poly(aniline-luminol)/graphene oxide nanocomposite was prepared using a fast and simple strategy for the first time, and an ultrasensitive electrochemiluminescence (ECL) immunosensor for alpha-fetoprotein (AFP) detection based on this nanocomposite was developed.


Assuntos
Compostos de Anilina/química , Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Grafite/química , Luminescência , Luminol/química , Nanocompostos/química , alfa-Fetoproteínas/análise , Humanos , Limite de Detecção , Microscopia Eletrônica de Transmissão , Reprodutibilidade dos Testes , Soro , Espectrofotometria Ultravioleta , Análise Espectral Raman , alfa-Fetoproteínas/imunologia
16.
Food Chem ; 293: 429-437, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151631

RESUMO

To achieve a low methoxy-pectin nanocomposite film with maximum resistance to water and acceptable mechanical properties, the interactions of different glycerol concentrations and Ca2+ ions in both steps of crosslinking on the swelling degree (SD) and mechanical properties of prepared films were investigated using response surface methodology (RSM). Accordingly, quadratic second-order models were fitted to the SD and tensile strength responses; while the cubic model demonstrated a good relation between independent variables and elongation at break respectively. As a compromise between water resistance and mechanical properties of the prepared films, the use of 0.5% Ca2+, 0.75% Gly1 and 7.5% Gly2 is suggested as the optimum condition. Generally, crosslinking of pectin polymer with Ca2+ cations in the second step along with incorporation of nanocellulose into pectin film led to the formation of more flexible and completely water insoluble pectin nanocomposite film in comparison to the other polymers crosslinked with Ca2+ cations.


Assuntos
Cálcio/química , Glicerol/química , Nanocompostos/química , Pectinas/química , Água/química , Cátions/química , Celulose/química , Polímeros , Resistência à Tração
17.
Int J Nanomedicine ; 14: 3845-3860, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31213805

RESUMO

Background: Delay or failure of bone union is a significant clinical challenge all over the world, and it has been reported that bone marrow mesenchymal stem cells (BMSCs) offer a promising approach to accelerate bone fracture healing. Se can modulate the proliferation and differentiation of BMSCs. Se-treatment enhances the osteoblastic differentiation of BMSCs and inhibiting the differentiation and formation of mature osteoclasts. The purpose of this study was to assess the effects of porous Se@SiO2 nanocomposite on bone regeneration and the underlying biological mechanisms. Methods: We oxidized Se2- to develop Se quantum dots, then we used the Se quantum dots to form a solid Se@SiO2 nanocomposite which was then coated with polyvinylpyrrolidone (PVP) and etched in hot water to synthesize porous Se@SiO2 nanocomposite. We used XRD pattern to assess the phase structure of the solid Se@SiO2 nanocomposite. The morphology of porous Se@SiO2 nanocomposite were evaluated by scanning electron microscope (SEM) and the biocompatibility of porous Se@SiO2 nanocomposite were investigated by cell counting kit-8 (CCK-8) assays. Then, a release assay was also performed. We used a Transwell assay to determine cell mobility in response to the porous Se@SiO2 nanocomposite. For in vitro experiments, BMSCs were divided into four groups to detect reactive oxygen species (ROS) generation, cell apoptosis, alkaline phosphatase activity, calcium deposition, gene activation and protein expression. For in vivo experiments, femur fracture model of rats was constructed to assess the osteogenic effects of porous Se@SiO2 nanocomposite. Results: In vitro, intervention with porous Se@SiO2 nanocomposite can promote migration and osteogenic differentiation of BMSCs, and protect BMSCs against H2O2-induced inhibition of osteogenic differentiation. In vivo, we demonstrated that the porous Se@SiO2 nanocomposite accelerated bone fracture healing using a rat femur fracture model. Conclusion: Porous Se@SiO2 nanocomposite promotes migration and osteogenesis differentiation of rat BMSCs and accelerates bone fracture healing, and porous Se@SiO2 nanocomposite may provide clinic benefit for bone tissue engineering.


Assuntos
Células da Medula Óssea/citologia , Diferenciação Celular/efeitos dos fármacos , Fraturas do Fêmur/terapia , Consolidação da Fratura/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Nanocompostos/química , Osteogênese/efeitos dos fármacos , Selênio/farmacologia , Dióxido de Silício/farmacologia , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Citoproteção/efeitos dos fármacos , Modelos Animais de Doenças , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/patologia , Peróxido de Hidrogênio/toxicidade , Nanocompostos/ultraestrutura , Porosidade , Ratos Sprague-Dawley , Transdução de Sinais , Microtomografia por Raio-X
18.
Int J Nanomedicine ; 14: 3439-3454, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190802

RESUMO

Objective: The microbial, physico-chemical and optical corruptions threaten a variety of foods and drugs and consequently the human biological safety and its accessible resources. The humanbeing's tendency towards bio-based materials and natural plant-extracts led to an increase in the usage of antimicrobial biocomposites based on medicinal herbs. Miswak (Salvadora persica L.) extract (SPE) has been proved effective for its antimicrobial and other biological activities. Therefore, in this study, titanium dioxide (TiO2) nanoparticles (TONP) and SPE were applied to fabricate antimicrobial carboxymethyl cellulose (Na-CMC) based bio-nanocomposites which would simultaneously promote some thermo-physical and barrier properties. Methods: CMC-neat film (C1), CMC/TONP-2% (C2) and CMC/TONP-2% with 150, 300 and 450 mg/mL SPE (SPE150, SPE30 and SPE450, respectively) were fabricated. The physical and mechanical properties; elemental mapping analysis (MAP), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA-DTG); fourier transform infrared (FTIR), energy-dispersive X-ray (EDX) and UV-vis spectroscopies were done to further validate the results. Results: Addition of TONP (2%) improved the blocking of UV light at 280 nm while SPE-containing nanocomposites completely blocked it. FTIR, XRD and SEM confirmed the formation of homogeneous films and high miscibility of applied materials. TONP led to an increase in Young's modulus (YM) and stress at break (SB) while SPE decreased them and enhanced the elongation to break (EB) (flexibility) of the active nanocomposites. Compared to CMC-film, the thermo-gravimetric analysis (TGA-DTG) showed a higher thermal stability for CMC/TONP and CMC/TONP/SPE nanocomposites. The EDX spectroscopy and elemental mapping analysis (MAP) proved the existence and well-distributedness of Na, K, Cl, S, Ti, F and N elements in SPE-activated nanocomposites. The pure SPE and SPE-activated nanocomposites showed a favorable antimicrobial activity against both gram-positive (Staphylococcus aureus) and negative (Escherichia coli) bacteria. Conclusion: The CMC-TiO2-SPE nanocomposites were homogeneously produced. Combination of TiO2 nanoparticles and dose-dependent SPE led to an improvement of thermal stability, and high potential in antimicrobial and UV-barrier properties. These results can generally highlight the role of the fabricated antimicrobial bio-nanocomposites as a based for different applications especially in food/drug packaging or coating.


Assuntos
Antibacterianos/farmacologia , Nanocompostos/química , Nanopartículas/química , Extratos Vegetais/farmacologia , Salvadoraceae/química , Temperatura Ambiente , Titânio/química , Elementos , Humanos , Umidade , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Permeabilidade , Espectrofotometria Ultravioleta , Staphylococcus aureus/efeitos dos fármacos , Vapor , Termogravimetria , Difração de Raios X
19.
J Photochem Photobiol B ; 196: 111508, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31152936

RESUMO

Cardiovascular malady (CVM) isn't just the essential driver of death in created western nations, yet additionally, its sickness load is expanding in China. Oxidative pressure initiated free radicals assume a basic job in cell forms involved in atherosclerosis and numerous other heart illnesses. Quercetin (QC) is cancer prevention agents medicate which is demonstrated that successfully secures against CVMs. Encapsulations of medications in polymeric materials are generally utilized in creating continued and controllable medication discharge, or to keep away from the debasement of non-discharged medications. In this present work, a novel arrangement of polymeric superparamagnetic nano-silica (SiN)@poly(lactic-co-glycolic acid) (PLGA) (SiN@PLGA) stacked with QC was created by means of lyophilization method so as to improve poor watery solvency and steadiness of the medication with the point of preventing atherosclerosis. The aftereffects of SEM investigation and the checking, TEM affirmed the manufacture of the circular nanocomposite, smooth surface, and thin size dispersion. The discharge profile of QC from the particles was explored by deciding the medication sum discharged at explicit interims for by iridescence. The data got from this investigation encourages the structure and manufacture of nanocomposite as conceivable conveyance frameworks for epitome, assurance and controlled arrival of the flavonoid QC which is expecting to secure against CVMs.


Assuntos
Nanocompostos/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Quercetina/química , Dióxido de Silício/química , Animais , Aterosclerose/patologia , Aterosclerose/prevenção & controle , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Liberação Controlada de Fármacos , Camundongos , Miocárdio/metabolismo , Miocárdio/patologia , Nanocompostos/toxicidade , Quercetina/metabolismo , Quercetina/uso terapêutico
20.
Chemosphere ; 232: 96-112, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31152909

RESUMO

Heavy metal contamination in aqueous system has attracted global attention due to the toxicity and carcinogenicity effects towards living bodies. Among available removal techniques, adsorptive removal by nanosized materials such as metal oxide, metal organic frameworks, zeolite and carbon-based materials has attracted much attention due to the large active surface area, large number of functional groups, high chemical and thermal stability which led to outstanding adsorption performance. However, the usage of nanosized materials is restricted by the difficulty in separating the spent adsorbent from aqueous solution. The shift towards the use of adsorptive composite membrane for heavy metal ions removal has attracted much attention due to the synergistic properties of adsorption and filtration approaches in a same chamber. Thus, this review critically discusses the development of nanoadsorbents and adsorptive nanocomposite membranes for heavy metal removal over the last decade. The adsorption mechanism of heavy metal ions by the advanced nanoadsorbents is also discussed using kinetic and isotherm models. The challenges and future prospect of adsorptive membrane technology for heavy metal removal is presented at the end of this review.


Assuntos
Recuperação e Remediação Ambiental , Metais Pesados/química , Adsorção , Carbono , Filtração , Íons , Cinética , Estruturas Metalorgânicas , Metais Pesados/análise , Nanocompostos/química , Óxidos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Zeolitas/química
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