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1.
Artigo em Inglês | MEDLINE | ID: mdl-35132327

RESUMO

Yi-Fei-Jie-Du-Tang (YFJDT) is a traditional Chinese medicine formulation. Our previous studies have demonstrated that YFJDT can be used to treat non-small-cell lung cancer (NSCLC), but its protective effect against NSCLC and its mechanisms remain unclear. In the present study, we evaluated the protective effects and potential mechanisms of YFJDT on a tumor-bearing mouse lung cancer model and A549 cell model. Tumor-bearing mice and A549 cells were treated with YFJDT, tumors were measured during the experiment, and tumor tissues and cell supernatants were collected at the end of the experiment to assess the levels of autophagy and epithelial-mesenchymal transition (EMT)-related proteins. The results showed that YFJDT treatment reduced tumor volume and mass, increased the expression of the autophagy marker LC3, and inhibited EMT-related proteins compared with the model group. Cell survival was reduced in the YFJDT-treated groups compared with the model group, and YFJDT also reduced the migration and invasion ability of A549 cells in a dose-dependent manner. Western blotting detected that YFJDT also upregulated FAT4 in the tumor tissue and A549 cells and downregulated the expression of vimentin. Meanwhile, apoptosis in both tissues and cells was greatly increased with treatment of YFJDT. We further interfered with FAT4 expression in cells and found that the inhibitory effect of YFJDT on EMT was reversed, indicating that YFJDT affects EMT by regulating FAT4 expression. Taken together, results of this study suggested that the inhibitory effect of YFJDT on EMT in lung cancer tumors is through upregulating FAT4, promoting autophagy, and thus inhibiting EMT in cancer cells.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33790982

RESUMO

OBJECTIVE: This study aimed to find new biomarkers of prognosis and metabolomic therapy for gastric carcinoma (GC) treated with chemotherapy and investigate the metabolic mechanism of the Jianpi Yangzheng Xiaozheng (JPYZXZ) decoction in the treatment of GC. METHODS: First, 36 patients with GC were randomly assigned to the treatment (chemotherapy plus JPYZXZ) and control (chemotherapy alone) groups. The clinical efficacy, side effects, and quality of life of patients in the two groups were evaluated after treatment. Then, the serum samples taken from 16 randomly selected patients (eight treatment cases and eight control cases with no evident pattern characters) and eight healthy volunteers were tested to identify the differential metabolite under the gas chromatography-time-of-fight mass spectrometry platform. The relevant metabolic pathways of differential substances were analyzed using multidimensional statistical analysis. RESULTS: JPYZXZ combined with chemotherapy resulted in a lower risk of leucopenia, thrombocytopenia, and gastrointestinal reaction (P < 0.05). Additionally, patients in the treatment group showed a higher Karnofsky (KPS) scale (P < 0.05). Compared with healthy persons, patients with GC were found to have 26 significant differential metabolites after chemotherapy; these metabolites are mainly involved in 12 metabolic pathways, such as valine, leucine, and isoleucine biosynthesis. JPYZXZ primarily influences the pentose phosphate pathway; glutathione metabolism; glyoxylate and dicarboxylate metabolism; porphyrin and chlorophyll metabolism; and glycine, serine, and threonine metabolism of patients with GC treated with chemotherapy. CONCLUSIONS: The metabolic characteristics of patients with GC after chemotherapy are mainly various amino acid metabolic defects, especially L-glutamine, L-leucine, L-alloisoleucine, and L-valine. These defects lead to a series of problems, such as decreased tolerance and effectiveness of chemotherapy, increased side effects, decreased immunity, and shortened survival time. In addition, the remarkable upregulation of the gluconolactone level in patients with GC suggests the high proliferative activity of GC cells. Thus, gluconolactone may be used as a potential prognostic and diagnostic evaluation index. Moreover, JPYZXZ can reduce the incidence of ADRs and improve the life quality of patients by the correction of L-glutamine, L-leucine, L-alloisoleucine, and L-valine metabolism deficiency. In addition, gluconolactone metabolism is inhibited by JPYZXZ. Such inhibition may be one of the antitumor mechanisms of JPYZXZ.

3.
J Control Release ; 333: 129-138, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33775685

RESUMO

The presence of the blood-brain barrier (BBB) remains a challenge in the treatment of central nervous system (CNS) diseases, as it hinders the infiltration of many therapeutic drugs into the brain parenchyma. Therefore, developing efficacious pharmacological agents that can traverse the BBB is crucial for optimal treatment of diseases of the CNS such as neurodegenerative conditions and brain tumors. Adeno-associated virus (AAV), one of the most promising gene therapy vectors, has been shown to cross the BBB safely and is non-pathogenic in nature and therefore has been utilized for numerous diseases of the CNS. Along with the development of protein engineering techniques such as directed evolution including DNA shuffling, a great number of BBB-crossing AAVs have been developed, that could be systemically injected for therapeutic benefit. In this review, we discuss several feasible approaches to improve transportation of therapeutic agents to the CNS. We also discuss the advantages of using BBB-crossing AAVs, their role as a gene delivery agent and highlight the different types of BBB-AAV vectors that have been developed in order to provide a greater insight into how they can be used in diseases of the CNS.


Assuntos
Barreira Hematoencefálica , Doenças do Sistema Nervoso Central , Doenças do Sistema Nervoso Central/terapia , Dependovirus/genética , Técnicas de Transferência de Genes , Terapia Genética , Humanos
4.
ACS Omega ; 6(8): 5764-5774, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33681615

RESUMO

This study aimed to reveal the interaction between self-assembled multilayers and dye molecules in the environment, which is closely related to the multilayers' stable performance and service life. In this work, the pH-responsive poly (N-isopropylacrylamide-co-2-(dimethylamino) ethyl methacrylate) microgels were prepared by free-radical copolymerization and self-assembled with sodium alginate (SA) into multilayers by the layer-by-layer deposition method. Quartz crystal microbalance (QCM) and atomic force microscopy (AFM) results confirmed the construction of multilayers and the absorbed mass, resulting in a decrease in the frequency shift of the QCM sensor and the deposition of microgel particles on its surface. The interaction between the self-assembled SA/microgel multilayers and anionic dyes in the aqueous solution was further investigated by QCM, and it was found that the electrostatic attraction between dyes and microgels deposited on the QCM sensor surface was much larger than that of the microgels with SA in multilayers, leading to the release of the microgels from the self-assembled structure and a mass loss ratio of 27.6%. AFM observation of the multilayer morphology exposed to dyes showed that 29% of the microgels was peeled off, and the corresponding microgel imprints were generated on the surface. In contrast, the shape and size of the remaining self-assembled microgel particles did not change.

5.
Life Sci ; 270: 119142, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33524419

RESUMO

Adeno-associated virus (AAV) vector, an excellent gene therapy vector, has been widely used in the treatment of various central nervous system (CNS) diseases. Due to the presence of the blood-brain barrier (BBB), early attempts at AAV-based CNS diseases treatment were mainly performed through intracranial injections. Subsequently, systemic injections of AAV9, the first AAV that was shown to have BBB-crossing ability in newborn and adult mice, were assessed in clinical trials for multiple CNS diseases. However, the development of systemic AAV injections to treat CNS diseases is still associated with many challenges, such as the efficiency of AAV in crossing the BBB, the peripheral toxicity caused by the expression of AAV-delivered genes, and the immune barrier against AAV in the blood. In this review, we will introduce the biology of the AAV vector and the advantages of systemic AAV injections to treat CNS diseases. Most importantly, we will introduce the challenges associated with systemic injection of therapeutic AAV in treating CNS diseases and suggest feasible solutions.


Assuntos
Doenças do Sistema Nervoso Central/terapia , Dependovirus/genética , Terapia Genética/métodos , Absorção Fisiológica , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Linhagem Celular , Doenças do Sistema Nervoso Central/genética , Dependovirus/metabolismo , Técnicas de Transferência de Genes/efeitos adversos , Terapia Genética/tendências , Vetores Genéticos/genética , Humanos , Camundongos , Transdução Genética/métodos , Transgenes
6.
Cancer Lett ; 502: 34-43, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33429004

RESUMO

Group 2 innate lymphoid cells (ILC2s), characterized by secretion of type 2 cytokines, regulate multiple immune responses. ILC2s are found in different tumor tissues, and ILC2-derived interleukin (IL)-4, IL-5, and IL-13 act on the cells in tumor microenvironment to participate in tumor progression. ILC2s are abundant in colorectal cancer (CRC) tissue, but the role of ILC2s in CRC remains unclear. In this study, we found that the percentage of ILC2s was higher in CRC tissue than in the adjacent normal tissue and that these ILC2s were the dominant IL-9-secreting cell-subsets in CRC tissue, as shown by flow cytometry analysis. ILC2s-derived IL-9 could activate CD8+ T cells to inhibit tumor growth, while anti-IL-9 reversed this effect. In vivo experiments showed that neutralizing ILC2s promoted tumor growth, while tumor inhibition occurred by intravenous injection of IL-9. In conclusion, our results demonstrated that ILC2-derived IL-9 could activate CD8+ T cells to promote anti-tumor effects in CRC.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Neoplasias Colorretais/patologia , Interleucina-9/metabolismo , Linfócitos/imunologia , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/imunologia , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imunidade Inata , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Microambiente Tumoral
7.
Cancer Lett ; 496: 134-143, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33022290

RESUMO

Glioblastoma multiforme (GBM) is a brain tumor with a high mortality rate. Surgical resection combined with radiotherapy and chemotherapy is the standard treatment for GBM patients, but the 5-year survival rate of patients despite this treatment is low. Immunotherapy has attracted increasing attention in recent years. As the pioneer and the main effector cells of immunotherapy, T cells play a key role in tumor immunotherapy. However, the T cells in GBM microenvironment are inhibited by the highly immunosuppressive environment of GBM, posing huge challenges to T cell-based GBM immunotherapy. This review summarizes the effects of the GBM microenvironment on the infiltration and function of different T-cell subsets and the possible strategies to overcome immunosuppression, and thus enhance the effectiveness of GBM immunotherapy.


Assuntos
Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Imunoterapia , Terapia de Alvo Molecular , Subpopulações de Linfócitos T/imunologia , Microambiente Tumoral/imunologia , Animais , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Glioblastoma/imunologia , Glioblastoma/patologia , Humanos , Subpopulações de Linfócitos T/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos
8.
ACS Omega ; 5(30): 19247-19254, 2020 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-32775928

RESUMO

In this work, poly(ethylene terephthalate) (PET) chain-extending products with different molecular weights were prepared by reactive extrusion using isocyanate trimer (C-HK) as the trifunctional chain extender. The effect of the chain extender C-HK on the intrinsic viscosity, melt flow property, crystallization behavior, crystallization morphology, and mechanical property of PET was investigated. The results showed that when the content of the chain extender was increased from 0.6 to 1.4 wt%, the viscosity average molecular weight of PET was effectively increased from 2.36 × 104 to 5.46 × 104 g·mol-1. After the chain extending, the crystallinity and the time of semicrystallization of PET were significantly decreased. After the isothermal crystallization at 220 °C for 5 min, the spherulites formed by pure PET became larger. With the increase in molecular weight of PET after chain extension, its spherulite size was significantly decreased without changing the crystalline structure. The chain-extended PET also exhibited more excellent bending-resistant and impact-resistant properties. While the tensile strength of PET after chain extension was slightly decreased, the bending strength was increased by a maximum value of 56.8%, and the impact strength was increased by a maximum value of five times.

9.
ACS Omega ; 5(30): 19255-19267, 2020 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-32775929

RESUMO

In this study, organically modified montmorillonite (OMMT) was prepared by modifying MMT with a cationic surfactant cetyltrimethylammonium bromide (CTAB). The obtained OMMT of different loading contents (1, 2, 4, 6, and 8 wt %) was melt-blended with poly(acrylonitrile-co-butadiene-co-styrene) (ABS) to prepare a series of ABS/OMMT composites, which were laser marked using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser beam of 1064 nm under different laser current processes. X-ray diffraction (XRD), color difference spectrometer, optical microscope, water contact angle tests, scanning electron microscope (SEM), and Raman spectroscopy were carried out to characterize the morphology, structure, and properties of the laser-patterned ABS composites. The effects of the addition of OMMT and the laser marking process on the mechanical properties of ABS/OMMT composites were investigated through mechanical property tests. The results show that the obtained ABS/OMMT composites have enhanced laser marking performance, compared to the ABS. When the OMMT content is 2 wt % and the laser current intensity is 9 A, the marking on ABS composites has the highest contrast (ΔE = 36.38) and sharpness, and the quick response (QR) code fabricated can be scanned and identified with a mobile app. SEM and water contact angle tests showed that the holes, narrow cracks, and irregular protrusion are formed on the composite surface after laser marking, resulting in a more hydrophobic surface and an increased water contact angle. Raman spectroscopy and XRD indicate that OMMT can absorb the near-infrared laser energy, undergo photo thermal conversion, and cause the pyrolysis and carbonization of ABS to form black marking, and the crystal structure itself does not change significantly. When the 2 wt % of OMMT is loaded, the tensile strength, elongation at break, and impact strength of ABS/OMMT are increased by 15, 20, and 14%, respectively, compared to ABS. Compared with the unmarked ABS/OMMT, the defects including holes and cracks generated on the surface of the marked one lead to the decreased mechanical property. The desirable combination of high contrast laser marking performance and mechanical properties can be achieved at an OMMT loading content of 2 wt % and a laser current intensity of 9 A. This research work provides a simple, economical, and environmentally friendly method for laser marking of engineering materials such as ABS.

10.
Cell Commun Signal ; 18(1): 50, 2020 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-32228589

RESUMO

Interleukin (IL)-9 belongs to the IL-2Rγc chain family and is a multifunctional cytokine that can regulate the function of many kinds of cells. It was originally identified as a growth factor of T cells and mast cells. In previous studies, IL-9 was mainly involved in the development of allergic diseases, autoimmune diseases and parasite infections. Recently, IL-9, as a double-edged sword in the development of cancers, has attracted extensive attention. Since T-helper 9 (Th9) cell-derived IL-9 was verified to play a powerful antitumor role in solid tumors, an increasing number of researchers have started to pay attention to the role of IL-9-skewed CD8+ T (Tc9) cells, mast cells and Vδ2 T cell-derived IL-9 in tumor immunity. Here, we review recent studies on IL-9 and several kinds of IL-9-producing cells in tumor immunity to provide useful insight into tumorigenesis and treatment. Video Abstract.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Interleucina-9/imunologia , Mastócitos/imunologia , Neoplasias/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Linfócitos T CD8-Positivos/citologia , Humanos , Mastócitos/citologia , Linfócitos T Auxiliares-Indutores/citologia
11.
Carbohydr Polym ; 234: 115882, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32070505

RESUMO

In this study, Fe3O4 magnetic nanoparticles were synthesized in situ in the polyacrylamide/chitosan (PAAm/CS) hydrogel networks. The obtained hydrogels are characterized by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. The results confirm that the three-dimensional network structure of the hydrogels is incorporated with Fe3O4 nanoparticles. The adsorption properties of PAAm/CS/Fe3O4 hydrogels for methylene blue (MB) in aqueous solution were studied using Ultraviolet and visible spectrophotometry (UV-vis). The results show that when compared to PAAm/CS hydrogels, PAAm/CS/Fe3O4 hydrogels can adsorb MB with higher adsorption capacities of approximately 1603 mg/g, and the kinetics and isotherm models of the adsorption process could be better described by the pseudo-first order model and Langmuir isotherm model, respectively. Due to the facile preparation, high adsorption capacity, and low cost, the PAAm/CS/Fe3O4 hydrogels are good adsorbents for MB and exhibit significant potential in the treatment of sewage.

12.
Talanta ; 198: 350-357, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30876572

RESUMO

Ultrasensitive Surface Plasmon Resonance (SPR) detection of small molecules can be achieved using nanoparticles to both enhance the SPR signals and pre-concentrate low levels of target analytes in the sample. However, the short effective penetration depth of the SPR evanescent field, and steric hindrance of binding when immobilizing small molecules on surfaces, limits the applicability of using relatively large nanoparticles (≥100 nm) for SPR detection. To overcome the issues of steric hindrance, this paper investigates the role of the molecular linkers to tether both the antibodies to the magnetic nanoparticles, and to bind the small molecules to the surface of the SPR chips. By extending the distance of the small molecule (progesterone) away from the SPR chip surface and improving the antibody orientation on the large magnetic nanoparticles, a sensitive SPR detection for progesterone was achieved in buffer (0.013 ng mL-1). The results of the SPR assay for progesterone in milk were in good correlation with ELISA results, and could be used to verify the onset of estrus in cows.


Assuntos
Nanopartículas/química , Progesterona/análise , Bibliotecas de Moléculas Pequenas/análise , Ressonância de Plasmônio de Superfície , Ensaio de Imunoadsorção Enzimática
13.
Artigo em Inglês | MEDLINE | ID: mdl-30271456

RESUMO

Non-small cell lung cancer (NSCLC) is a serious threat to people's health. This study aims to determine the possible effect of Gujin Xiaoliu Tang (GJXLT) on NSCLC, which is an empirical formula from Professor Dai-Han Zhou. In this study, chromatographic fingerprinting of GJXLT and A549 cell model in vitro and in vivo was established. We cultured A549 cells in vitro and found that GJXLT inhibited A549 cell growth and induced apoptosis. Compared with the control group, the expression of p-STAT3 and VEGF proteins in the GJXLT groups was decreased. Similar findings were also observed in vivo. First, GJXLT inhibited the growth of transplanted tumor and did not reduce the weight of the tumor-bearing mice in comparison with that of the control group. Then, the Ki-67 expression of transplanted tumor in the GJXLT groups was decreased. In addition, the apoptosis rate of transplanted tumor in the GJXLT groups was increased. Overall, our data showed that GJXLT inhibited A549 cell proliferation and induced apoptosis in vivo and in vitro. Furthermore, GJXLT inhibited the growth of lung cancer xenograft in nude mice model with no obvious side effects. The anti-tumor effect of GJXLT might also be related to the inhibition of p-STATS and VEGF expression in the JAK2/STAT3 pathway. Our results demonstrated the potential of GJXLT as a novel treatment for NSCLC.

14.
Anal Biochem ; 539: 149-151, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29066102

RESUMO

Solution based protein conjugation of small molecules involves multiple steps of chemical syntheses, bio-conjugation and purifications which are labor intensive and time-consuming. Since many small molecules have limited water solubility, conjugation to a protein is also a relatively low efficiency process in aqueous solutions. In this study, a model in situ protein conjugation of small molecules was achieved onto SPR surfaces, using progesterone and ovalbumin as a model small-molecule-protein system. The in situ protein conjugation not only eliminated the requirement for wet chemistry, but also provided an easy way to optimize the assay performance and screen various molecular linkers.


Assuntos
Proteínas Imobilizadas/análise , Imunoensaio/métodos , Ovalbumina/química , Progesterona/química , Anticorpos/imunologia , Ouro/química , Proteínas Imobilizadas/química , Proteínas Imobilizadas/imunologia , Ressonância de Plasmônio de Superfície , Propriedades de Superfície
15.
Anal Biochem ; 508: 46-9, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27288558

RESUMO

Functionalization of a gold surface is usually accomplished by covalent binding via self-assembled monolayers (SAMs) on the gold surface, followed by attachment of flexible polymeric linker layers such as dextran hydrogels. However, these techniques require multiple steps and also have nonspecific interactions and steric problems. In this study, a self-assembled carboxylated terthiophene monolayer was formed onto a gold surface to create a sensitive and stable surface plasmon resonance (SPR) biosensing system. Compared with a commercial carboxymethyl dextran chip (CM5), the terthiophene SAM surface provided more than six times more antibody-binding signals and nearly three times the SPR assay sensitivity for progesterone (P4).


Assuntos
Técnicas de Química Analítica/métodos , Dextranos/química , Progesterona/análise , Ressonância de Plasmônio de Superfície , Tiofenos/química , Ouro/química , Estrutura Molecular , Progesterona/química , Propriedades de Superfície
16.
Methods Mol Biol ; 627: 113-29, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20217617

RESUMO

Sensitive detection of small molecules using surface plasmon resonance (SPR) presents significant challenges as the antigen cannot serve as a signal generator because of its low mass; efficient binding of the target requires the binding event to be spaced from the sensor surface through a specialist linker conjugation. Competitive immunoassay of steroid hormones can be performed by conjugation through a rationally designed linker system at positions distant from existing antigenic functional groups. The binding signal from the primary antibody can then be further enhanced by sequential addition of secondary antibody or conjugated gold nanoparticles which can produce 13-fold signal enhancements through both their mass and co-operative plasmon coupling.


Assuntos
Imunoensaio/métodos , Progesterona/análise , Processamento de Sinais Assistido por Computador , Ressonância de Plasmônio de Superfície/métodos , Anticorpos/imunologia , Ouro/química , Nanopartículas Metálicas/química , Peso Molecular , Progesterona/química , Progesterona/imunologia
17.
Anal Chim Acta ; 656(1-2): 63-71, 2009 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-19932816

RESUMO

Ochratoxins are a group of mycotoxins produced as secondary metabolites by fungi which contaminate a large variety of food and feed commodities. Due to their teratogenic and carcinogenic properties, ochratoxins present a serious hazard to human and animal health. There is an increasing need to establish a simple sensitive method to detect these toxins. Here we report a rapid and highly sensitive surface plasmon resonance (SPR) assay of ochratoxin A (OTA) using Au nanoparticles for signal enhancement on a mixed self-assembled monolayer (mSAM) surface. A competitive immunoassay format was used for the development of the OTA immunoassay, which is based on the immobilization of target OTA through its ovalbumin (OVA) conjugate with a polyethylene glycol (PEG) linker. The new OTA conjugate (OTA-PEG-OVA) showed remarkably enhanced performance characteristics compared with those based on the immobilization of a commercial bovine serum albumin BSA-OTA conjugate without a PEG linker. Although OTA concentrations as low as 1.5 ng mL(-1) could be directly detected on this surface, the limit of detection (LOD) can be dramatically improved to 0.042 ng mL(-1) for OTA by applying large gold nanoparticles (40 nm) for signal enhancement. Various chemical conditions to minimize the influence of the food matrix on assay performance were also investigated. Grain samples were simply extracted with 50% methanol and liquid samples treated with poly(vinylpyrrolidone) (PVP) (3 or 5%), without any sample clean-up or pre-concentration step prior to analysis. The LODs for OTA in oats and corn were 0.3 and 0.5 ng g(-1), respectively, while in wine and other beverages, LODs ranged from 0.058 to 0.4 ng mL(-1). No cross-reactivity was observed with three other common mycotoxins. In addition, the mSAM/OTA-PEG-OVA surface exhibited high stability with over 600 binding/regeneration cycles. This approach with simple sample preparation provides a powerful tool for the rapid and sensitive quantitative determination of OTA in food matrices.


Assuntos
Bebidas/análise , Grão Comestível/química , Ocratoxinas/análise , Ressonância de Plasmônio de Superfície/métodos , Ouro/química , Nanopartículas Metálicas/química , Ovalbumina/química , Polietilenoglicóis/química , Ressonância de Plasmônio de Superfície/instrumentação , Propriedades de Superfície
18.
Steroids ; 74(10-11): 819-24, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19465041

RESUMO

For the quantitative evaluation of low levels of an estriol metabolite of estriol (estriol-16-glucuronide (E3-16G)) in liquid media, we developed a simple and highly sensitive immunoassay using a surface plasmon resonance (SPR) biosensor which did not require any time-consuming sample pretreatment steps. E3-16G was conjugated to ovalbumin (OVA) through an oligoethylene glycol (OEG) linker to form protein conjugates (E3-16G-OEG-OVA), which were then immobilized on a carboxymethyl dextran-coated sensor chip via amine coupling to develop inhibition immunoassays. A limit of detection (LOD) of 76 pg/mL was achieved using a rabbit anti-sheep primary antibody as a binding agent. The detection limit was further improved by using synthesized gold colloids (15 nm) as high mass labels conjugated to the primary antibody. In this Au nanoparticle-enhanced assay, the concentration of E3-16G in aqueous samples could be determined in 7.5 min at a level as low as 14 pg/mL. In addition, the high stability of the E3-16G-OEG-OVA surface gave no obvious drop in antibody-binding capability after more than 1000 binding/regeneration cycles which significantly lowered the research cost.


Assuntos
Poluentes Ambientais/análise , Estriol/análogos & derivados , Imunoensaio/métodos , Ressonância de Plasmônio de Superfície/métodos , Animais , Anticorpos/imunologia , Bovinos , Poluentes Ambientais/química , Poluentes Ambientais/imunologia , Estriol/análise , Estriol/química , Estriol/imunologia , Ouro/química , Proteínas Imobilizadas/química , Imunoensaio/instrumentação , Imunoconjugados/imunologia , Injeções , Nanopartículas Metálicas/química , Peso Molecular , Ovalbumina/química , Polietilenoglicóis/química , Coelhos , Coloração e Rotulagem , Ressonância de Plasmônio de Superfície/instrumentação , Fatores de Tempo , Água/química
19.
Anal Biochem ; 390(1): 97-9, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19358818

RESUMO

A surface plasmon resonance (SPR) assay without surface regeneration was developed for rapid and sensitive detection of chloramphenicol (CAP). A CAP-amine derivative was synthesized using a polyethylene glycol chain attached to the CAP through a carbamate linkage and immobilized onto a Biacore dextran surface. This chemically modified surface significantly changed the binding behavior between antibody and CAP, shown by both fast association and fast dissociation rates, and created a rapid and sensitive SPR immunoassay of the CAP without any regeneration. The limits of detection achieved for CAP were 32.2 pg/ml in aqueous buffer and 42.4 pg/ml in honey-spiked samples.


Assuntos
Cloranfenicol/análise , Imunoensaio/métodos , Ressonância de Plasmônio de Superfície/métodos , Anticorpos/química , Anticorpos/imunologia , Cloranfenicol/química , Sulfato de Dextrana/química , Polietilenoglicóis/química , Propriedades de Superfície
20.
Anal Chem ; 80(21): 8329-33, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18837517

RESUMO

We report a rapid and ultrasensitive surface plasmon resonance (SPR) assay of chloramphenicol (CAP) by using large gold nanoparticles (40 nm) for signal enhancement on a mixed self-assembled monolayer (mSAM) sensor surface. After immobilization of the target antibiotic CAP through its ovalbumin (OVA) conjugates with an oligoethylene glycol (OEG) linker on the mSAM surface, sequential binding of anti-CAP antibody and IgG/nanogold (40 nm) onto the sensor surface afforded a rapid (<10 min) and ultrasensitive assay format for CAP. A limit of detection (LOD) for CAP as low as 0.74 fg/mL was achieved in aqueous buffer, and the linear working range was between 1-1000 fg/mL. While the LOD of CAP in a honey spiked-specimen is 17.5 fg/mL, the detection range is 80-5000 fg/mL. The mSAM sensor surface was also shown to be highly stable with over 400 binding/regeneration cycles performed.


Assuntos
Cloranfenicol/análise , Ressonância de Plasmônio de Superfície/métodos , Cloranfenicol/química , Reações Cruzadas/imunologia , Ouro/química , Nanopartículas Metálicas/química , Estrutura Molecular , Sensibilidade e Especificidade , Propriedades de Superfície
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