Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Talanta ; 235: 122719, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517587

RESUMO

Here, a dual lock-and-key fluorescence probe was developed for visualizing the inflammatory process in myocardial H9C2 cells. The probe possessed two-photon properties, viscosity sensitivity, and hydrogen peroxide (H2O2) responsiveness. A thiocarbamate spacer between fluorophore and H2O2 responsive unit enabled the release of carbonyl sulfide (COS). This rapidly converts to the anti-inflammatory hydrogen sulfide (H2S) by the ubiquitous enzyme carbon anhydrase. The probe displayed a dual response towards hydrogen peroxide and viscosity in vitro. No obvious fluorescence changes were observed towards either hydrogen peroxide or viscosity alone. In cellular experiments, the probe demonstrated good biocompatibility, low toxicity, and was shown responses towards exogenous and endogenous hydrogen peroxide under viscosity conditions. LPS induced cell inflammation showed it was able to effectively alleviate the inflammation-caused damage by releasing H2S and eliminating H2O2. The new protocol demonstrates its promising to achieve diagnosis and treatment of cellular inflammatory process.


Assuntos
Corantes Fluorescentes , Sulfeto de Hidrogênio , Fluorescência , Células HeLa , Humanos , Peróxido de Hidrogênio , Inflamação/tratamento farmacológico , Viscosidade
2.
J Hazard Mater ; 417: 126130, 2021 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-34229397

RESUMO

Novel composite foam (CMCTS-PUF-s) was prepared by immobilizing carboxymethyl chitosan (CMCTS) on polyurethane foam (PUF) in which amino groups in CMCTS reacted with isocyanate groups in polyurethane prepolymer. The adsorption capacity of the optimal composite foam (CMCTS-PUF-5) reached to 118.2 mg/g with 5% CMCTS loading. The removal rate to methylene blue (MB) was up to 97.1%, which was obviously higher than 18.9% of PUF. After recycling for five times, the removal rate still reached 83.2%, which strongly proved the excellent reusability of immobilizing CMCTS modified PUF. The characterization results of FTIR and TG showed that CMCTS was well loaded on PUF by covalent bond. The Young's modulus and tensile strength of CMCTS-PUF-5 were increased by 252% and 97% compared with that of PUF. MIP characterization result showed the porosity of CMCTS-PUF-5 was 73.99% and the pore sizes were mainly distributed between 50 and 150 µm, which provide sufficient diffusion channels and active sites for MB dyes. The adsorption kinetics and isotherm proved pseudo-second-order kinetic model and Langmuir isotherm model could well describe the adsorption process of CMCTS-PUF-5. Therefore, CMCTS-PUF-s presents excellent recoverability, high stability and attractive adsorption efficiency, shows the potential application in future treatment of dye wastewater.


Assuntos
Quitosana , Poluentes Químicos da Água , Adsorção , Cinética , Azul de Metileno , Poliuretanos
3.
Analyst ; 146(14): 4659-4665, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34190222

RESUMO

A polarity-sensitive fluorescence probe AMN was developed to demonstrate the role of autophagy inhibitory drugs in the process of leather residue-induced neuroinflammation, promoting the knowledge of the relationship between autophagy and neuroinflammation. AMN showed a turn-on fluorescent signal in the process of autophagy inhibition via two-photon confocal imaging, which is different from the current popular autophagy probes. Therefore, AMN can offer high-sensitive imaging analysis of the autophagy inhibition process to better understand the role of autophagy in the process of neuroinflammation. The model of scrap leather-induced neuroinflammation using PC12 cells demonstrated that neuroinflammation can induce autophagy by releasing reactive oxygen species (ROS), and autophagy can alleviate neuroinflammation significantly via ROS scavenging.


Assuntos
Autofagia , Fótons , Animais , Corantes Fluorescentes , Células PC12 , Ratos , Espécies Reativas de Oxigênio
4.
Analyst ; 146(8): 2632-2637, 2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33660731

RESUMO

This study reports the development of a new, pH-sensitive, mitochondria-targeting two-photon ratiometric probe (Mito-BNO) for real-time tracking of mitophagy, a process that can be accelerated in brain tissue during stroke. Mito-BNO shows excellent capability for mitochondrial localisation (Pearson's correlation coefficient, r = 0.91), and can also effectively distinguish mitochondria from other subcellular organelles such as lysosomes and the endoplasmic reticulum (r = 0.40 and r = 0.33, respectively). Meanwhile, a rewarding pKa value (5.23 ± 0.03) and the pH reversibility suggest that Mito-BNO can track mitophagy in real time via confocal imaging. Most importantly, the relationship between mitophagy and neuroinflammation during stroke has been successfully demonstrated by evaluating the fluorescence of PC12 cells stained with Mito-BNO during an oxygen-glucose deprivation/reperfusion (OGD/R) process with and without anti-inflammatory treatment. The results indicate that the occurrence of mitophagy during stroke is caused by oxidative stress induced by neuroinflammation. This study will help further understanding stroke pathogenesis, can provide potential new targets for early diagnosis and treatment, and can also help to develop therapeutic drugs for stroke.


Assuntos
Mitocôndrias , Mitofagia , Acidente Vascular Cerebral , Animais , Inflamação/metabolismo , Lisossomos/metabolismo , Ratos
5.
Eur J Med Chem ; 213: 113201, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33524687

RESUMO

The widespread nature of several viruses is greatly credited to their rapidly altering RNA genomes that enable the infection to persist despite challenges presented by host cells. Within the RNA genome of infections is RNA-dependent RNA polymerase (RdRp), which is an essential enzyme that helps in RNA synthesis by catalysing the RNA template-dependent development of phosphodiester bonds. Therefore, RdRp is an important therapeutic target in RNA virus-caused diseases, including SARS-CoV-2. In this review, we describe the promising RdRp inhibitors that have been launched or are currently in clinical studies for the treatment of RNA virus infections. Structurally, nucleoside inhibitors (NIs) bind to the RdRp protein at the enzyme active site, and nonnucleoside inhibitors (NNIs) bind to the RdRp protein at allosteric sites. By reviewing these inhibitors, more precise guidelines for the development of more promising anti-RNA virus drugs should be set, and due to the current health emergency, they will eventually be used for COVID-19 treatment.


Assuntos
Antivirais/uso terapêutico , COVID-19/tratamento farmacológico , RNA-Polimerase RNA-Dependente de Coronavírus/antagonistas & inibidores , Reposicionamento de Medicamentos , Inibidores Enzimáticos/uso terapêutico , Animais , Antivirais/química , COVID-19/epidemiologia , Inibidores Enzimáticos/química , Humanos , Nucleosídeos/química , Nucleosídeos/uso terapêutico , Pandemias , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/enzimologia
6.
Food Funct ; 11(10): 9129-9143, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33026011

RESUMO

Herein, a sturgeon skin gelatine film combined with esculin and ferric citrate was developed as an edible food packaging material to prevent Enterococcus faecalis (E. faecalis) contamination. E. faecalis is able to hydrolyse esculin in the film, and then the hydrolysed product, esculetin, combines with ferric citrate to form a brown-black phenol iron complex. This phenomenon can be observed easily after 48 h of contamination under visible light, and it can be determined under 365 nm ultraviolet light with high sensitivity. With the addition of esculin and ferric citrate, the film showed better mechanical properties and water vapour permeability than those of the unmodified gelatine. When an increased amount of esculin was added, an increase in thermal stability, antioxidant activity, and antioxidant stability of the film was observed. These physicochemical characteristics are beneficial for developing a packaging material for food storage that mitigates foodborne illness caused by E. faecalis.

7.
J Agric Food Chem ; 67(5): 1504-1512, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30644748

RESUMO

Collagen, a sustainable and biodegradable biomass material, has many applications in different scope including application in food packaging. However, owing to its poor mechanical properties, this kind of application is limited. In this work, collagen was cross-linked with catechin under the incubation of laccase to improve the mechanical properties of collagen, and the cross-linked collagen exhibited properties of excellent antioxidant capacity and lower swelling ratio. Meanwhile, Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results provide evidence for changes in the structure of collagen after being cross-linked with the catechin. From the aspects of the thermal stability, tensile strength, elongation, antioxidant capacity, swelling, solubility, and morphological analysis, the cross-linked collagen has better physical properties in comparison with natural collagen. This indicates that the physical properties and antioxidant capacity of collagen after being cross-linked with catechins were improved significantly. Therefore, the cross-linked collagen can be used as green food-packaging materials.


Assuntos
Catequina/química , Colágeno/química , Proteínas Fúngicas/química , Lacase/química , Biocatálise , Biomassa , Embalagem de Alimentos/instrumentação , Fungos/enzimologia , Temperatura Alta , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Difração de Raios X
8.
Food Sci Biotechnol ; 27(3): 705-713, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30263796

RESUMO

A bacterial cellulose (BC) synthesizing strain (Gluconacetobacter xylinus ZHCJ618) was isolated from kombucha and selected as the species for commercial applications owing to its high phenotypic stability and sustainable production capacity of 7.56 ± 0.57 g/L under static culturing conditions and 8.31 ± 0.79 g/L under shaking conditions. The morphological, physiological and biochemical characteristics of the strain were similar to those of Gluconacetobacter genus. The 16S rDNA sequence homologies with G. xylinus NCIB 11664 reached 99%, showing that the isolated strain can be identified as G. xylinus. The material properties of BC were studied by fourier transform infrared spectroscopy, scanning electronic microscopy, X-ray diffraction, thermogravimetric analysis, and tensile test. The results showed that BC synthesized under static conditions exhibited stronger tear strength, higher crystallinity, superior waterhold and rehydration rate than BC synthesized under shaking conditions.

9.
J Surfactants Deterg ; 17: 959-965, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25152609

RESUMO

With oleic acid grafting modification, a series of hyperbranched-linear polymer surfactants (HLPS) were prepared by hydroxyl-terminated hyperbranched polymer (HBP), which was gained through a step synthesis method using trimethylolpropane and AB2 monomer. The AB2 monomers were obtained through the Michael addition reaction of methyl acrylate and diethanol amine. The structures of HLPS were characterised by Fourier transform infrared spectrophotometer and nuclear magnetic resonance (NMR), which indicated that HBP was successfully modified by oleic acid. Furthermore, the properties of surface tension and critical micelle concentration of HLPS solution showed that HLPS can significantly reduce the surface tension of water. The morphology of the HLPS solution was characterised by dynamic light scattering, which revealed that HLPS exhibited a nonmonotonic appearance in particle size at different scattering angles owing to the different replaced linear portions. The relationships of the surface pressure to monolayer area and time were measured using the Langmuir-Blodgett instrument, which showed that the surface tension of monolayer molecules increased with the increasing of hydrophobic groups. In addition, the interface conditions of different replaced HLPS solutions were simulated.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...