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1.
Acta Cir Bras ; 35(5): e202000507, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32638846

RESUMO

PURPOSE: To develop a new wound dressing composed of alginate and Aloe vera gel and cross-linked with zinc ions. METHODS: The aloe-alginate film was characterized using scanning electron microscopy (SEM), swelling profile, mechanical properties, polysaccharide content and X-ray diffraction (XRD). Thirty Wistar rats were divided in two groups a) treated with aloe-alginate film and b) control (treated with sterile gauze). Wound contraction measurements and hystological analysis were performed on 7th, 14th and 21st days after wound surgery. RESULTS: The aloe-alginate film presented adequated mechanical resistance and malleability for application as wound dressing. There was no statistical difference in wound contraction between two groups. Histological assay demonstrated that aloe-alginate film presented anti-inflammatory activity, stimulated angiogenesis on proliferative phase and a more significant increased in collagen type I fibers and decreased type III fibers which promoted a mature scar formation when compared to control. CONCLUSIONS: The aloe-alginate film showed adequate physicochemical characteristics for wound dressing applications. The in vivo assay demonstrated that aloe-alginate film enhanced the healing process of incisional skin wounds.


Assuntos
Alginatos , Aloe , Cloretos , Preparações de Plantas , Cicatrização , Compostos de Zinco , Alginatos/farmacologia , Animais , Cloretos/química , Cloretos/farmacologia , Preparações de Plantas/farmacologia , Ratos , Ratos Wistar , Cicatrização/efeitos dos fármacos , Compostos de Zinco/química , Compostos de Zinco/farmacologia
2.
Food Chem ; 328: 127091, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32474237

RESUMO

Methanol is highly toxic for human, so methanol detection is valuable especially in water and ethanol medium without complicated and time consuming procedure. In this work, we present a new fluorescence probe for direct detection of methanol in aqueous and ethanol medium based on the ZnS:Mn2+ quantum dot (QDs) and soluble N-methylpolypyrrole (NMPPy) hybrid. Moreover, the number of spectroscopic techniques were used to study the chemical composition and optical properties of the resultant QDs as well as investigation on the sensing mechanism toward methanol. Also, methanol can be determined by using ZnS:Mn2+ QDs/NMPPy hybrid based switchable fluorescence sensing system, with high sensitivity, high selectivity and a very good detection limit of 1 mM with linearity in the concentration range of 25-230 mM (~0.1-0.9% v/v) in aqueous solution. Finally, the ZnS:Mn2+ QDs/NMPPy hybrid as optical sensor was successfully utilized to determine the amount of methanol in real alcoholic beverage samples.


Assuntos
Etanol/química , Metanol/análise , Polímeros/química , Pirróis/química , Pontos Quânticos/química , Espectrometria de Fluorescência/instrumentação , Sulfetos/química , Água/química , Compostos de Zinco/química , Corantes Fluorescentes/química , Humanos , Limite de Detecção , Magnésio/química , Metanol/química
3.
Acta Crystallogr C Struct Chem ; 76(Pt 5): 476-482, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32367829

RESUMO

Reaction of N,N'-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide), C20H18F2N4O2, (LF), with zinc chloride and mercury(II) chloride produced different types and shapes of neutral coordination complexes, namely, dichlorido[N,N'-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ2N,O]zinc(II), [ZnCl2(C20H18F2N4O2)], (1), and dichlorido[N,N'-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ4O,N,N',O']mercury(II), [HgCl2(C20H18F2N4O2)], (2). The organic ligand and its metal complexes are characterized using various techniques: IR, UV-Vis and nuclear magnetic resonance (NMR) spectroscopies, in addition to powder X-ray diffraction (PXRD), single-crystal X-ray crystallography and microelemental analysis. Depending upon the data from these analyses and measurements, a typical tetrahedral geometry was confirmed for zinc complex (1), in which the ZnII atom is located outside the bis(benzhydrazone) core. The HgII atom in (2) is found within the core and has a common octahedral structure. The in vitro antibacterial activities of the prepared compounds were evaluated against two different bacterial strains, i.e. gram positive Bacillus subtilis and gram negative Pseudomonas aeruginosa bacteria. The prepared compounds exhibited differentiated growth-inhibitory activities against these two bacterial strains based on the difference in their lipophilic nature and structural features.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Cloretos/farmacologia , Mercúrio/química , Compostos de Zinco/farmacologia , Zinco/química , Antibacterianos/química , Cloretos/química , Complexos de Coordenação/química , Cristalografia por Raios X , Difração de Raios X , Compostos de Zinco/química
4.
Chemosphere ; 254: 126866, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32348923

RESUMO

Hydrochar, the product of hydrothermal carbonization of biomass, is a sustainable alternative to other carbonaceous environmental sorbents. However, its use has been limited due to its low surface area. A one-pot biomass/metal salt co-hydrothermal synthesis method might improve its sorptive properties while retaining its efficient production characteristic. Thus, bamboo sawdust and zinc chloride (ZnCl2) were combined in a hydrothermal reactor (200 °C, 7 h) for preparing modified hydrochar. Compared to the non-modified hydrochar, the hydrochar produced with the addition of ZnCl2 during hydrothermal treatment was more fully carbonized (C content increased from 54% to 64%), of higher surface area after acid washing (30 versus 1.7 m2 g-1), and enriched in O-containing functional groups and of greater aromaticity (according to FTIR and XRD analysis). Because of these improved properties, Methylene blue adsorption capacity of the modified hydrochar increased by nearly 90% and by 257% after it was rinsed with acid. This study highlights the potential of this one-pot co-hydrothermal treatment of biomass in presence of metal salt to provide a simple and effective hydrochar with properties suitable for environmental remediation and water treatment.


Assuntos
Cloretos/química , Purificação da Água/métodos , Compostos de Zinco/química , Adsorção , Biomassa , Carbono , Azul de Metileno , Temperatura
5.
Int J Nanomedicine ; 15: 1951-1965, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32256071

RESUMO

Introduction: Indium phosphide (InP) quantum dots (QDs) have shown a broad application prospect in the fields of biophotonics and nanomedicine. However, the potential toxicity of InP QDs has not been systematically evaluated. In particular, the effects of different surface modifications on the biodistribution and toxicity of InP QDs are still unknown, which hinders their further developments. The present study aims to investigate the biodistribution and in vivo toxicity of InP/ZnS QDs. Methods: Three kinds of InP/ZnS QDs with different surface modifications, hQDs (QDs-OH), aQDs (QDs-NH2), and cQDs (QDs-COOH) were intravenously injected into BALB/c mice at the dosage of 2.5 mg/kg BW or 25 mg/kg BW, respectively. Biodistribution of three QDs was determined through cryosection fluorescence microscopy and ICP-MS analysis. The subsequent effects of InP/ZnS QDs on histopathology, hematology and blood biochemistry were evaluated at 1, 3, 7, 14 and 28 days post-injection. Results: These types of InP/ZnS QDs were rapidly distributed in the major organs of mice, mainly in the liver and spleen, and lasted for 28 days. No abnormal behavior, weight change or organ index were observed during the whole observation period, except that 2 mice died on Day 1 after 25 mg/kg BW hQDs treatment. The results of H&E staining showed that no obvious histopathological abnormalities were observed in the main organs (including heart, liver, spleen, lung, kidney, and brain) of all mice injected with different surface-functionalized QDs. Low concentration exposure of three QDs hardly caused obvious toxicity, while high concentration exposure of the three QDs could cause some changes in hematological parameters or biochemical parameters related to liver function or cardiac function. More attention needs to be paid on cQDs as high-dose exposure of cQDs induced death, acute inflammatory reaction and slight changes in liver function in mice. Conclusion: The surface modification and exposure dose can influence the biological behavior and in vivo toxicity of QDs. The surface chemistry should be fully considered in the design of InP-based QDs for their biomedical applications.


Assuntos
Pontos Quânticos/toxicidade , Animais , Análise Química do Sangue , Feminino , Índio/química , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Fosfinas/química , Pontos Quânticos/química , Sulfetos/química , Propriedades de Superfície , Distribuição Tecidual , Compostos de Zinco/química
6.
J Environ Sci (China) ; 90: 216-233, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32081318

RESUMO

Widespread usage of engineered metallic quantum dots (QDs) within consumer products has evoked a need to assess their fate within environmental systems. QDs are mixed-metal nanocrystals that often include Cd2+ which poses a health risk as a nanocrystal or when leached into water. The goal of this work is to study the long-term metal cation leaching behavior and the factors affecting the dissolution processes of mercaptopropionic acid (MPA) capped CdSe/ZnS QDs in aphotic conditions. QD suspensions were prepared in different water conditions, and release of Zn2+ and Cd2+ cations were monitored over time by size exclusion chromatography-inductively coupled plasma-mass spectrometry. In most conditions with dissolved O2 present, the ZnS shell degraded fairly rapidly over ~1 week, while some of the CdSe core remained up to 80 days. Additional MPA, Zn2+, and Cd2+ temporarily delayed dissolution, indicating a moderate role for capping agent detachment and mineral solubility. The presence of H2O2 and the ligand ethylenediaminetetraacetate accelerated dissolution, while NOM had no kinetic effect. No dissolution of CdSe core was observed when O2 was absent or when QDs formed aggregates at higher concentrations with O2 present. The shrinking particle model with product layer diffusion control best describes Zn2+ and Cd2+ dissolution kinetics. The longevity of QDs in their nanocrystal form appears to be partly controlled by environmental conditions, with anoxic, aphotic environments preserving the core mineral phase, and oxidants or complexing ligands promoting shell and core mineral dissolution.


Assuntos
Compostos de Cádmio , Pontos Quânticos , Compostos de Selênio , Água/química , Peróxido de Hidrogênio , Cinética , Solubilidade , Sulfetos , Compostos de Zinco/química
7.
Anal Bioanal Chem ; 412(8): 1893-1899, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32016568

RESUMO

Superoxide dismutase (SOD), also known as liver protein, is a substance widely distributed in various biological cells. It has the function of catalyzing the disproportionation reaction of superoxide free radicals. SOD can form an antioxidant chain together with peroxidase, catalase, and other substances in the body of organisms, and thus, is one of the indispensable important substances in the body of organisms. In this work, we provided a simple and fast visual electrochemiluminescence (ECL) sensor for SOD detection. CuInZnS quantum dots (QDs) worked as the ECL luminophore with hydrogen peroxide as co-reactant. In the sensing process, SOD and CuInZnS QDs on a glassy carbon electrode (GCE) competed with each other for hydrogen peroxide to produce superoxide during electrochemical luminescence, thus quenching the ECL signal of CuInZnS QDs. The proposed sensor can quantify SOD with a limit of detection (LOD) of 0.03 µg/mL. In addition, the change in the CuInZnS QDs ECL signal was easily observed with a smartphone camera. The results indicated that this sensor could effectively work in the detection of SOD in human blood. Graphical abstract.


Assuntos
Cobre/química , Técnicas Eletroquímicas/métodos , Índio/química , Luminescência , Pontos Quânticos/química , Sulfetos/química , Superóxido Dismutase/análise , Compostos de Zinco/química , Técnicas Biossensoriais , Limite de Detecção , Reprodutibilidade dos Testes
8.
J Oleo Sci ; 69(2): 115-122, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32023578

RESUMO

A new difunctional Zn(II) coordination polymer (CP) with the chemical formula of [Zn(TBTA) (L)1.5]n (1) has been synthesized hydrothermally from tetrabromoterephthalic acid (H2TBTA) and 4,4'-bis(imidazole-1-yl)-biphenyl (L) ligands. Furthermore, due to its strong intense emission and open N donor sites, complex 1 could be used as a light-emitting sensor to determine 2,4,6-trinitrophenol (TNP) which has high selectivity and sensitivity. Furthermore, the anti-bacterial effect of the compound against P. gingivalis in vitro was evaluated by measuring the P. gingivalis growth curves after compound treatment. And the RT-PCR assay was performed to detect the relative expression of ragA and ragB, which are important for the P. gingivalis growth. The potential anti-infectious mechanism was further studied by using molecular docking technique.


Assuntos
Doenças Periodontais/tratamento farmacológico , Porphyromonas gingivalis/crescimento & desenvolvimento , Trinitrobenzenos/química , Trinitrobenzenos/uso terapêutico , Compostos de Zinco/química , Compostos de Zinco/uso terapêutico , Depressão Química , Humanos , Ligantes , Doenças Periodontais/microbiologia , Polímeros , Trinitrobenzenos/farmacologia , Compostos de Zinco/farmacologia
9.
Appl Spectrosc ; 74(5): 544-552, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32031010

RESUMO

Fourier transform infrared (FT-IR) spectroscopic imaging and microscopy of single living cells are established label-free technique for the study of cell biology. The constant driver to improve the spatial resolution of the technique is due to the diffraction limit given by infrared (IR) wavelength making subcellular study challenging. Recently, we have reported, with the use of a prototype zinc sulfide (ZnS) transmission cell made of two hemispheres, that the spatial resolution is improved by the factor of the refractive index of ZnS, achieving a λ/2.7 spatial resolution using the synchrotron-IR microscopy with a 36× objective with numerical aperture of 0.5. To refine and to demonstrate that the ZnS hemisphere transmission device can be translated to standard bench-top FT-IR imaging systems, we have, in this work, modified the device to achieve a more precise path length, which has improved the spectral quality of the living cells, and showed for the first time that the device can be applied to study live cells with three different bench-top FT-IR imaging systems. We applied focal plane array (FPA) imaging, linear array, and a synchrotron radiation single-point scanning method and demonstrated that in all cases, subcellular details of individual living cells can be obtained. Results have shown that imaging with the FPA detector can measure the largest area in a given time, while measurements from the scanning methods produced a smoother image. Synchrotron radiation single-point mapping produced the best quality image and has the flexibility to introduce over sampling to produce images of cells with great details, but it is time consuming in scanning mode. In summary, this work has demonstrated that the ZnS hemispheres can be applied in all three spectroscopic approaches to improve the spatial resolution without any modification to the existing microscopes.


Assuntos
Espectroscopia de Infravermelho com Transformada de Fourier/instrumentação , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Células A549 , Humanos , Lentes , Microscopia Eletrônica de Varredura/instrumentação , Microscopia Eletrônica de Varredura/métodos , Sulfetos/química , Síncrotrons/instrumentação , Compostos de Zinco/química
10.
Anal Bioanal Chem ; 412(7): 1663-1673, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31993725

RESUMO

A novel room temperature phosphorescence chemosensor probe has been successfully developed and applied to the selective detection and quantification of inorganic arsenic (As(III) plus As(V)) in fish samples. The prepared material (IIP@ZnS:Mn QDs) was based on Mn-doped ZnS quantum dots coated with (3-aminopropyl) triethoxysilane and an As(III) ionic imprinted polymer. The novel use of vinyl imidazole as a complexing reagent when synthesizing the ionic imprinted polymer guarantees that both inorganic arsenic species (As(III) and As(V)) can interact with the recognition cavities in the ionic imprinted polymer. After characterization, several studies were performed to enhance the interaction between the targets (As(III) and As(V) ions) and the IIP@ZnS:Mn QDs nanoparticles. The optimization and validation process showed that the composite material offers high selectivity (high imprinting factor) for inorganic arsenic species. The limit of quantification for total inorganic As was 29.6 µg kg-1, value lower than the EU/EC regulation limits proposed for other foodstuffs than fish, such as rice. The proposed method is therefore simple, requires short analysis times and offers good sensitivity, precision (inter-day relative standard deviations lower than 10%), and quantitative analytical recoveries. The method has been successfully applied to assess total inorganic arsenic in several fishery products, showing good agreement with the total inorganic arsenic concentration (As(III) plus As(V)) found after applying other advanced and expensive methods such those based on high-performance liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry. Graphical abstract.


Assuntos
Arsênico/análise , Peixes , Manganês/química , Impressão Molecular/métodos , Polímeros/química , Pontos Quânticos/química , Dióxido de Silício/química , Sulfetos/química , Compostos de Zinco/química , Animais , Cromatografia Líquida de Alta Pressão/métodos , Concentração de Íons de Hidrogênio , Limite de Detecção , Espectrometria de Massas/métodos , Reprodutibilidade dos Testes , Propriedades de Superfície
11.
Mikrochim Acta ; 187(2): 104, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31912290

RESUMO

Authors report on a new fluoro-graphene-plasmonic nanohybrid aptamer-based fluorescent nanoprobe for cocaine. To construct the nanoprobe, newly synthesized glutathione-capped ZnS/Ag2Se quantum dots (QDs) were first conjugated to graphene oxide (GO) to form a QD-GO nanocomposite. The binding interaction resulted in a fluorescence turn-ON. Thereafter, cetyltrimethylammonium bromide (CTAB)-gold nanoparticles (AuNPs) were directly adsorbed on the QD-GO nanocomposite to form a novel QD-GO-CTAB-AuNP nanohybrid assembly that resulted in a fluorescence turn-OFF. Streptavidin (strep) was then adsorbed on the QDs-GO-CTAB-AuNP nanohybrid assembly which allowed binding to a biotinylated MNS 4.1 anticocaine DNA aptamer (B) receptor. The addition of cocaine into the strep-B-QDs-GO-CTAB-AuNP aptamer nanoprobe system aided affinity to the aptamer receptor and in turn turned on the fluorescence of the nanoprobe in a concentration-dependent manner. Under optimum experimental conditions, we found the strep-B-QD-GO-CTAB-AuNP to be far superior in its sensitivity to cocaine than the tested strep-B-QDs (no GO and CTAB-AuNPs), strep-B-QD-CTAB-AuNP (no GO) and strep-B-QD-GO (no CTAB-AuNP). In addition, the investigation of localized surface plasmon resonance (LSPR) amplified signal from tested plasmonic NPs shows that CTAB-AuNPs was far superior in amplifying the fluorescence signal of the nanoprobe. A detection limit of 4.6 nM (1.56 ng.mL-1), rapid response time (~2 min) and excellent selectivity against other drugs, substances and cocaine metabolites was achieved. The strep-B-QD-GO-CTAB-AuNP aptamer-based fluorescent nanoprobe was successfully applied for the determination of cocaine in seized adulterated cocaine samples. Graphical abstractSchematic representation of the streptavidin-biotin-quantum dot-graphene oxide-cetyltrimethylammonium bromide-gold nanoparticle aptamer-based fluorescent nanoprobe for cocaine.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Cocaína/análise , Pontos Quânticos/química , Compostos de Selênio/química , Compostos de Prata/química , Sulfetos/química , Compostos de Zinco/química , Inibidores da Captação de Dopamina/análise , Contaminação de Medicamentos , Corantes Fluorescentes/química , Glutationa/química , Ouro/química , Grafite/química , Drogas Ilícitas/análise , Limite de Detecção , Nanopartículas Metálicas/química , Nanocompostos/química , Espectrometria de Fluorescência/métodos
12.
Bioelectrochemistry ; 132: 107434, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31821901

RESUMO

In this study, a novel signal-amplified immunosensor was designed by using a microwave-assisted self-assembly method to synthesize ZnFe2O4-Ag/rGO nanocomposites. The conductivity of ZnFe2O4-rGO nanocomposites was significantly improved due to the effective inhibition of rGO accumulation by the insertion of ZnFe2O4 and Ag nanoparticles (NPs) into graphene sheets. Excellent sensitivity and reproducibility were achieved through the microwave-assisted preparation of ZnFe2O4-Ag/rGO nanocomposites as a substrate, with the Ag NPs enhancing the signal because of the effective conductive matrix. The layer assembly process of the immunosensor was verified by cyclic voltammetry and electrochemical impedance spectroscopy. Under optimal conditions, the fabricated immunosensor showed good linearity over a wide concentration range from 1 pg mL-1 to 200 ng mL-1 with a low detection limit of 0.98 pg mL-1, and exhibited excellent specificity, good stability, and reproducibility. These qualities can contribute to the successful application of a label-free immunosensor in the detection of AFP in human serum.


Assuntos
Compostos Férricos/química , Grafite/química , Nanopartículas Metálicas/química , Micro-Ondas , Prata/química , Compostos de Zinco/química , alfa-Fetoproteínas/análise , Humanos , Limite de Detecção
13.
Talanta ; 206: 120228, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514892

RESUMO

The asymmetric flow field-flow fractionation (AF4) coupled on-line with elemental (inductively coupled plasma-mass spectrometry, ICP-MS) and molecular (fluorescence and UV) detection has been investigated as a powerful tool for the characterization of bioinorganic nano-conjugates. In this study, we described methods for the characterization of biotin-antibody complexes bioconjugated with streptavidin quantum dots (QDs-SA-b-Ab). Operating parameters of AF4 separation technique were optimized and two procedures are proposed using a channel thickness of 350 µm and 500 µm. The use of a 500 µm spacer allowed to achieve an efficient AF4 separation of the QDs-SA-b-Ab complexes from the excess of individual species used in the bioconjugation that was required for a proper characterization of the bioconjugates. Optimization of the AF4 allowed a separation resolution good enough to isolate the QDs-SA-b-Ab bioconjugates from the free excess of b-Ab and QD-SA. The efficiency of the bioconjugation process could be then calculated, obtaining a value of 86% for a 1 QDs-SA: 5 b-Ab bioconjugation ratio. In addition, sample recovery around 90% was achieved.


Assuntos
Pontos Quânticos/análise , Água/química , Anticorpos/química , Biotina/química , Compostos de Cádmio/análise , Compostos de Cádmio/química , Fluorescência , Fracionamento por Campo e Fluxo/métodos , Limite de Detecção , Espectrometria de Massas/métodos , Pontos Quânticos/química , Espalhamento de Radiação , Compostos de Selênio/análise , Compostos de Selênio/química , Estreptavidina/química , Sulfetos/análise , Sulfetos/química , Compostos de Zinco/análise , Compostos de Zinco/química
14.
Mater Sci Eng C Mater Biol Appl ; 106: 110181, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753367

RESUMO

I-III-VI chalcopyrite ternary quantum dots have emerged as a good alternative over the conventional II-VI and IV-VI chalcogenide binary QDs that usually consist of heavy metals such as Cd and Pb which has limited their bioapplications. Among the chalcopyrite QDs, AgInSe2 QDs has been the least developed due to the imbalanced cation reactivity, unwanted impurities, broad size distribution and resultant large particle sizes. In addition, the cell viability of these QDs still needs to be investigated on different cell lines both normal and cancerous ones. Herein, large-scale synthesis of water-soluble thioglycolic acid (TGA) capped and gelatin-stabilized AgInSe2 (AISe) core and AgInSe2/ZnSe (AISe/ZnSe) core/shell QDs in the absence of an inert atmosphere and their cell viability against different cell lines are reported. The optical and structural characteristics of the as-synthesized QDs were investigated by UV-visible (vis) absorption, photoluminescence (PL) and Fourier-transmission infrared (FTIR) spectroscopies, dynamic light scattering (DLS), X-ray diffraction (XRD), and high-resolution transmission electron microscope (HRTEM) techniques. Growth of ZnSe shell on the core AISe resulted in the blue shifting of the emission maximum position with the increased PL intensity. The QDs are small and spherical in shape with an average particle diameter of 2.8 nm and 3.2 nm for AISe and AISe/ZnSe QDs respectively. The in vitro cell viability assay revealed that the as-synthesized AISe/ZnSe QDs are not toxic towards cancerous (HeLa -cervical cancer and A549-lung cancer) and normal (BHK21 -Kidney) cell lines.


Assuntos
Pontos Quânticos/química , Tioglicolatos/química , Água/química , Sobrevivência Celular/fisiologia , Difusão Dinâmica da Luz , Humanos , Compostos de Selênio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Compostos de Zinco/química
15.
Colloids Surf B Biointerfaces ; 185: 110591, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31704606

RESUMO

Aluminium doped phosphate based bioglasses have potential applications in the field of bone tissue engineering, because of their excellent bioactivity and biocompatibility along with high mechanical strength and controlled dissolution. In the present study, 8ZnO-22Na2O-(24-x)CaO-46P2O5-xAl2O3 (where x = 0, 2, 4, 6, 8 and 10 mol%) glass system was synthesized and investigated by means of XRD, FTIR, SEM and EDS before and after immersion in SBF for 3, 7, 14 and 21days, the physic-chemical properties of the samples, including density and microhardness, evaluation of pH and weight loss of glasses in physiological fluid and cell cultural studies like cell viability, cytocompatability and cell proliferation by seeding rMSCs cells on the glass samples in order to throw some light on their structural properties. The results showed that, the density and Vickers hardness found to be increased with the increase in content of alumina due to the slight increase in the number of octahedrally coordinated Al3+ ions and stronger ionic cross linkages due to insertion of Al3+ ions between phosphate networks. The initial rise in pH and controlled solubility in SBF strongly supports the apatite layer development. The growth of the rMSCs cells on all samples showing good cytocompatability and proliferation up to 6 mol% Al2O3 after that decreases slightly with an increase in alumina content due to network forming action of Al3+ ions in zinc phosphate based glasses. The results confirmed the suitability of these glasses for clinical trials towards bone repair and regeneration resorbable implants.


Assuntos
Óxido de Alumínio/química , Materiais Biocompatíveis/farmacologia , Osso e Ossos/citologia , Cerâmica/química , Teste de Materiais , Células-Tronco Mesenquimais/citologia , Fosfatos/química , Compostos de Zinco/química , Animais , Materiais Biocompatíveis/química , Osso e Ossos/efeitos dos fármacos , Sobrevivência Celular , Células Cultivadas , Células-Tronco Mesenquimais/efeitos dos fármacos , Ratos , Engenharia Tecidual
16.
Anal Chim Acta ; 1096: 26-33, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31883588

RESUMO

Accurate and sensitive detection of dopamine (DA) is fundamental to monitor and diagnose certain neurological diseases. Herein, highly ordered mesoporous ZnFe2O4 (OM-ZnFe2O4) is prepared via a facile nanocasting method and shows the highly sensitive in the electrochemical detection of DA. The optimized OM-ZnFe2O4-40 shows the most excellent activity for DA oxidation in a wide linear range from 2 to 600 nM with a quick response time of 5 s, high sensitivity of 0.094 nA nM-1 and a lower detection limit of 0.4 nM (S/N = 3). The electrode modified with OM-ZnFe2O4 is further successfully used to monitor the increase of DA concentration induced by K+-stimulation of living PC12 cells in a neurological environment. This work offers a simple and powerful strategy for designing electrodes for detecting DA in biological systems.


Assuntos
Dopamina/análise , Técnicas Eletroquímicas/instrumentação , Compostos Férricos/química , Compostos de Zinco/química , Animais , Técnicas Eletroquímicas/métodos , Desenho de Equipamento , Limite de Detecção , Células PC12 , Porosidade , Ratos
17.
Talanta ; 208: 120430, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816682

RESUMO

Early detection of cancer increases the possibility for an adequate and successful treatment of the disease. Therefore, in this work, a disposable electrochemical immunosensor for the front-line detection of the ExtraCellular Domain of the Human Epidermal growth factor Receptor 2 (HER2-ECD), a breast cancer biomarker, in a simple and efficient manner is presented. Bare screen-printed carbon electrodes were selected as the transducer onto which a sandwich immunoassay was developed. The affinity process was detected through the use of an electroactive label, core/shell CdSe@ZnS Quantum Dots, by differential pulse anodic stripping voltammetry in a total time assay of 2 h, with an actual hands-on time of less than 30 min. The proposed immunosensor responded linearly to HER2-ECD concentration within a wide range (10-150 ng/mL), showing acceptable precision and a limit of detection (2.1 ng/mL, corresponding to a detected amount (sample volume = 40 µL) of 1.18 fmol) which is about 7 times lower than the established cut-off value (15 ng/mL). The usefulness of the developed methodology was tested through the analysis of spiked human serum samples. The reliability of the presented biosensor for the selective screening of HER2-ECD was confirmed by analysing another breast cancer biomarker (CA15-3) and several human serum proteins.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias da Mama/sangue , Receptor ErbB-2/sangue , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Antígenos/química , Antígenos/imunologia , Compostos de Cádmio/química , Técnicas Eletroquímicas , Humanos , Imunoensaio , Imunoglobulina G/química , Imunoglobulina G/imunologia , Masculino , Pontos Quânticos/química , Receptor ErbB-2/imunologia , Compostos de Selênio/química , Soroalbumina Bovina/química , Soroalbumina Bovina/imunologia , Sulfetos/química , Compostos de Zinco/química
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 229: 117962, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31865104

RESUMO

ZnS quantum dots (QDs) and their core/shell (CdSe/ZnS) structures were studied for Zn based precursor reactivities. ZnS and CdSe/ZnS QDs were prepared selecting aqueous route and then characterized via XRD, TEM, EDX, PL, RAMAN and FTIR practices. Core/shell nanostructures were synthesized by taking dissimilar precursors for the shell formation. Photoluminescence spectra of prepared QDs corroborate the effectual luminescence. Prepared QDs have large surface area that make them useful alternative as organic antimicrobial agent which are highly irritant and unstable. Study of antimicrobial behavior of QD structures was carried out by disk diffusion method. Antimicrobial study of QDs and their core/shell structures was performed against gram negative and gram positive bacteria, E. coli, A. baumanni and Bacillus subtilis respectively. It is found that elemental composition and size of QDs plays important role in antimicrobial behavior. Prepared QDs are fluorescent and have a key role in complex microbial population studies and identification of bacteria.


Assuntos
Anti-Infecciosos/farmacologia , Compostos de Cádmio/farmacologia , Luminescência , Pontos Quânticos/química , Compostos de Selênio/farmacologia , Sulfetos/farmacologia , Compostos de Zinco/farmacologia , Anti-Infecciosos/química , Bactérias/efeitos dos fármacos , Compostos de Cádmio/química , Testes de Sensibilidade Microbiana , Pontos Quânticos/ultraestrutura , Compostos de Selênio/química , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Sulfetos/química , Difração de Raios X , Compostos de Zinco/química
19.
ACS Appl Mater Interfaces ; 12(3): 3415-3429, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31875453

RESUMO

Mesenchymal stem cell (MSCs) therapy has recently received profound interest as a targeting platform in cancer theranostics because of inherent tumor-homing abilities. However, the terminal tracking of MSCs engraftment by fluorescent in situ hybridization, immuno-histochemistry, and flow-cytometry techniques to translate into clinics is still challenging because of a dearth of inherent MSCs-specific markers and FDA approval for genetic modifications of MSCs. To address this challenge, a cost-effective noninvasive imaging technology based on multifunctional nanocrystals (NCs) with enhanced detection sensitivity, spatial-temporal resolution, and deep-tissue diagnosis is needed to be developed to track the transplanted stem cells. A hassle-free labeling of human umbilical cord Wharton's Jelly (WJ)-derived MSCs with Mn2+ and Gd3+ co-doped CuInS2-ZnS (CIS-ZMGS) NCs has been demonstrated in 2 h without requiring an electroporation process or transfection agents. It has been found that WJ-MSCs labeling did not affect their multilineage differentiation (adipocyte, osteocyte, chondrocyte), immuno-phenotypes (CD44+, CD105+, CD90+), protein (ß-actin, vimentin, CD73, α-SMCA), and gene expressions. Interestingly, CIS-ZMGS-NCs-labeled WJ-MSCs exhibit near-infrared (NIR) fluorescence with a quantum yield of 84%, radiant intensity of ∼3.999 × 1011 (p/s/cm2/sr)/(µW/cm2), magnetic relaxivity (longitudinal r1 = 2.26 mM-1 s-1, transverse r2 = 16.47 mM-1 s-1), and X-ray attenuation (78 HU) potential for early noninvasive multimodality imaging of a subcutaneous melanoma in B16F10-tumor-bearing C57BL/6 mice in 6 h. The ex vivo imaging and inductively coupled plasma mass-spectroscopy analyses of excised organs along with confocal microscopy and immunofluorescence of tumor results also significantly confirmed the positive tropism of CIS-ZMGS-NCs-labeled WJ-MSCs in the tumor environment. Hence, we propose the magnetofluorescent CIS-ZMGS-NCs-labeled WJ-MSCs as a next-generation nanobioprobe of three commonly used imaging modalities for stem cell-assisted anticancer therapy and tracking tissue/organ regenerations.


Assuntos
Rastreamento de Células/métodos , Células-Tronco Mesenquimais/química , Nanopartículas/química , Neoplasias/terapia , Geleia de Wharton/química , Animais , Rastreamento de Células/instrumentação , Fluorescência , Gadolínio/química , Humanos , Manganês/química , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/diagnóstico por imagem , Pontos Quânticos/química , Coloração e Rotulagem , Sulfetos/química , Cordão Umbilical/química , Compostos de Zinco/química
20.
Mikrochim Acta ; 187(1): 10, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31797114

RESUMO

A lateral-flow immunochromatographic assay with excellent sensitivity and wide application potential is described. The bovine serum albumin (BSA) antibody was immobilized in the test line for universality, and preincubation was introduced for high method sensitivity. Carboxy-modified CdSe/ZnS core-shell nanoparticles were used as label, and the fluorescence peaking at 605 nm was detected. The fluorescence in the test line was negative against the relevant analyte content. The chloramphenicol (CAP) and the aflatoxin M1 (AFM1) in milk were detected using the same strip to validate the universality. After optimization, the detection limit for CAP is 10 pg·mL-1, which is three times less that of a conventional assay (30 pg·mL-1). The detection limit for AFM1 was 6 pg·mL-1, which was 13 times less than that of a conventional assay (8 pg·mL-1). The method was applied in the analysis of spiked milk samples. The performance was compared with that of the commercial ELISA kit, and good agreement was observed. Graphical abstractSchematic representation of the universal and sensitive combined immunochromatographic assay (USICA) and conventional immunochromatographic assay (TICA) of chloramphenicol (CAP) and aflatoxin M1.


Assuntos
Aflatoxina M1/análise , Anticorpos Imobilizados/química , Compostos de Cádmio/química , Cloranfenicol/análise , Imunoensaio/métodos , Nanopartículas/química , Compostos de Selênio/química , Sulfetos/química , Compostos de Zinco/química , Aflatoxina M1/química , Anticorpos Imobilizados/imunologia , Cloranfenicol/química , Limite de Detecção , Soroalbumina Bovina/imunologia
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