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1.
J Nanobiotechnology ; 21(1): 244, 2023 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-37507785

RESUMEN

BACKGROUND: Neuroblastoma is one of the common extracranial tumors in children (infants to 2 years), accounting for 8 ~ 10% of all malignant tumors. Few special drugs have been used for clinical treatment currently. RESULTS: In this work, herbal extract ginsenosides were used to synthesize fluorescent ginsenosides carbon nanodots via a one-step hydrothermal method. At a low cocultured concentration (50 µg·mL- 1) of ginsenosides carbon nanodots, the inhibition rate and apoptosis rate of SH-SY5Y cells reached ~ 45.00% and ~ 59.66%. The in vivo experiments showed tumor volume and weight of mice in ginsenosides carbon nanodots group were ~ 49.81% and ~ 34.14% to mice in model group. Since ginsenosides were used as sole reactant, ginsenosides carbon nanodots showed low toxicity and good animal response. CONCLUSION: Low-cost ginsenosides carbon nanodots as a new type of nanomedicine with good curative effect and little toxicity show application prospects for clinical treatment of neuroblastoma. It is proposed a new design for nanomedicine based on bioactive carbon nanodots, which used natural bioactive molecules as sole source.


Asunto(s)
Ginsenósidos , Neuroblastoma , Humanos , Animales , Ratones , Ginsenósidos/farmacología , Ginsenósidos/uso terapéutico , Carbono/farmacología , Neuroblastoma/tratamiento farmacológico , Apoptosis
2.
Macromol Rapid Commun ; 42(2): e2000507, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33210416

RESUMEN

As a kind of temperature-responsive hydrogel, polystyrene-co-poly(N-isopropylacrylamide)/poly(N-isopropylacrylamide) (PS-co-PNIPAM/PNIPAM) core-shell nanoparticles prepared by two-step copolymerization are widely studied and used because of their specific structures and properties. Unlike most reports about the steady stability of PS-co-PNIPAM/PNIPAM core-shell nanoparticle hydrogel emulsion, in this work, the PS-co-PNIPAM/PNIPAM core-shell nanoparticle hydrogel emulsion (symbolized as PS/PNIPAM hydrogel emulsion), which is prepared after the second step of synthesis and without washing out a large number of PNIPAM polymer segments, shows a reversible temperature-dependent sol-gel transition characteristic during the temperature range of 34-80 °C. The PS/PNIPAM hydrogel emulsion is a normal solution at room temperature, and it changes from a sol to a gel statue when the temperature approaches up to low critical solution temperature (LCST). As the temperature continues to increase, the gel (core-shell nanoparticles as the crosslinkers and the linear PNIPAM chain as the 3D gel network) of the PS/PNIPAM hydrogel emulsion gradually shrinks and drains linearly. Compared with most crosslinked hydrogels, the hydrogel here can be arbitrarily changed in shape according to use needs, which is convenient for use, transportation, and storage. Here a new route is provided for the preparation of a PS/PNIPAM core-shell hydrogel nanoparticle system, as well as a new supramolecular crosslinking sol-gel system for application in biomedical materials, sensors, biological separation, drug release, macromolecular adsorption, and purification.


Asunto(s)
Hidrogeles , Nanopartículas , Resinas Acrílicas , Emulsiones , Poliestirenos , Temperatura
3.
Mikrochim Acta ; 187(3): 166, 2020 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-32055961

RESUMEN

Doubly charged pH-responsive core/shell hydrogel nanoparticles with green fluorescence were prepared and were shown to be viable bioprobes for active targeting tumor tissue and imaging of cancer cells. Via emulsionfree copolymerization hydrogel nanoparticles as VANPs were prepared, the core of which was polystyrene (Ps) and the shell was comprised of strongly positive electrolyte (ar-vinylbenzyl)trimethylammonium (VBTAC) with weak negative electrolyte acrylic acid (AA). Through conventional amidation, the shell was conjugated with cell-specific folic acid (FA), denoted as VANPs-FA. Then, negatively charged sulfonated 9,10-distyrylanthracene derivatives (SDSA) based on aggregation induced emission (AIE), was binding tightly to positively charged VBTAC of VANPs-FA shell. The prepared double charged fluorescent core/shell hydrogel nanoparticles abbreviated as VANPs-FS, showed excitation/emission wavelengths at ~420/528 nm. Dynamic light scattering (DLS) measurements were performed to determine the size and surficial zeta potential of VANPs-FS. Under proper ratio of VBTAC to AA, the VANPs-FS was stable (~ 64.63 nm, -20.2 mV) at high pH (> 7), started to aggregate (~ 683.0 nm, -3.2 mV) at pH around 6, and can redispers at low pH (< 5). The MTT analysis proved that VANPs-FS had good biocompatibility and low cytotoxicity. The targeting effectiveness of VANPs-FS was confirmed by confocal laser scanning microscopy (CLSM). Graphical abstract Detailed synthetic route of VANPs-FS (top) and schematic cancer tumor-target aggregation of pH-sensitive VANPs-FS with enhanced retention and rapid cancer cell imaging (bottom).


Asunto(s)
Acrilatos/química , Nanopartículas/química , Poliestirenos/química , Humanos , Concentración de Iones de Hidrógeno
4.
Anal Chem ; 90(24): 14578-14585, 2018 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-30472825

RESUMEN

The profiling of disease-related biomarkers is an essential procedure for the accurate diagnosis and intervention of metabolic disorders. Therefore, the development of ultrasensitive and highly selective fluorogenic biosensors for diverse biomarkers is extremely desirable. There is still a considerable challenge to prepare nanocluster-based fluorescence turn-on probes capable of recognizing multiple biomolecules. We herein provide a novel nanocluster-based chemical information processing system (CIPS) for the programmable detection of various metabolites and enzymes. This CIPS consists of biocatalytic reactions between substrates and their respective oxidases to generate H2O2, which was then employed to synthesize bright fluorescent silver nanoclusters (Ag NCs). Utilizing this system, we are able to accurately probe a series of substrates/corresponding oxidases with high sensitivity and specificity, including glucose/glucose oxidase, uric acid/uric acid oxidase, sarcosine/sarcosine oxidase, choline/choline oxidase, xanthine/xanthine oxidase, and lactic acid/lactic acid oxidase. Furthermore, this metabolite profiling CIPS can be integrated with binary logic operations, which create an intelligent tool for the high-throughput screening of various diseases in vitro (e.g., diabetes, gout, prostate cancer, cardiovascular disease, and lactic acidosis).


Asunto(s)
Biomarcadores/análisis , Nanopartículas del Metal/química , Espectrometría de Fluorescencia , Colorantes Fluorescentes/química , Humanos , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/metabolismo , Oxidorreductasas/metabolismo , Plata/química , Urato Oxidasa/metabolismo , Ácido Úrico/análisis
5.
Analyst ; 143(21): 5145-5150, 2018 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-30246811

RESUMEN

Gold nanoclusters have attracted widespread attention because of their unique optical and physical properties. However, traditional synthesis methods are complicated and require additional reducing agents, while the yield is often very low. Such resource and time-consuming synthesis processes limit their further application. Herein, a rapid sonochemical route is used to synthesize fluorescent Au nanoclusters in large quantities using glutathione (GSH) both as a capping and reducing agent. These Au nanoclusters are synthesized quickly (∼40 min) due to the presence of ultrasonic waves, and show orange red photoluminescence (Em = 598 nm), small size (∼2 nm) and good dispersion in aqueous solution. Moreover, GSH, as a protecting agent on the surface of resultant Au nanoclusters, has many functional groups including carboxyl and amino groups because of which the nanoclusters show high photo-, storage-, metal- and pH-stability. A stable Au nanoclusters-based nano-sensor is designed for highly sensitive and selective label-free detection of Cu2+ with a low limit of detection of 7 ppb (based on S/N = 3). The fluorescent probe can be used in versatile nanothermometry devices, because their photoluminescence intensity correlates strongly with temperature and varies considerably over a wide temperature range (20-80 °C). Therefore, the novel fluorescent sensing probe has great application prospects in Cu2+ detection and temperature sensing.

6.
Mikrochim Acta ; 185(1): 83, 2018 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-29594523

RESUMEN

The authors describe strongly red-emitting carbon dots (CDs) which were obtained via microwave synthesis using phenylenediamine as the carbon source. The structural and optical properties of the resultant CDs are studied in some detail. The CDs possess (a) longwave emission (peaking at 620 nm under 470 nm excitation), (b) a quantum yield of ~15%, (c) a size of typically 3.8 nm; and (d) good photostability. The CDs have a pH-dependet response that covers the pH 5 to 10 range, and their fluorescence is quenched by ferric ions. The CDs can detect ferric ions in aqueous samples in the 0 to 30 µM concentration range with a lower detection limit of 15 nM. The CDs were also used to image pH values and ferric ions in E. coli bacteria. Graphical abstract The red-emitting carbon dots with high stability are synthesized which show dual response to pH-values and ferric ions in aqueous solution and biological media simultaneously.

7.
Bioorg Chem ; 72: 168-181, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28460359

RESUMEN

G9a (also known as KMT1C or EHMT2) is initially identified as a H3K9 methyltransferase that specifically mono- and dimethylates 'Lys-9' of histone H3 (H3K9me1 and H3K9me2, respectively) in euchromatin. It is overexpressed in various human cancers and employed as a promising target in cancer therapy. We discovered a benzoxazole scaffold through virtual high-throughput screening, and designed, synthesized 24 derivatives and investigated for inhibition of G9a. After several rounds of kinase and anti-proliferative activity screening, we discovered a potent G9a antagonist (GA001) with an IC50 value of 1.32µM that could induce autophagy via AMPK in MCF7 cells. In addition, we found high concentration of GA001 could induce apoptosis via p21-Bim signal cascades in MCF7 cells. Our results highlight a new approach for the development of a novel drug targeting G9a with a potential to induce autophagy and apoptosis for future breast cancer therapy.


Asunto(s)
Antineoplásicos/farmacología , Autofagia/efectos de los fármacos , Bencimidazoles/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Inhibidores Enzimáticos/farmacología , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , Antineoplásicos/síntesis química , Antineoplásicos/química , Bencimidazoles/síntesis química , Bencimidazoles/química , Neoplasias de la Mama/patología , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Femenino , Antígenos de Histocompatibilidad/metabolismo , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Células MCF-7 , Modelos Moleculares , Estructura Molecular , Relación Estructura-Actividad
8.
Bioorg Chem ; 68: 112-23, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27479541

RESUMEN

A novel series of coumarin derivatives were designed, synthesized and investigated for inhibition of cholinesterase, including acetyl cholinesterase (AChE) and butyrylcholinesterase (BuChE). This biological study showed that these compounds containing piperazine ring had significant inhibition activities on AChE rather than BuChE. Further study suggested that 9x, as one of this kind of structure derivative, showed the strongest inhibition activity on AChE with an IC50 value of 34nM. Moreover, molecular docking, flow cytometry (FCM), and western blot assay suggested that 9x could induce cytoprotective autophagy to attenuate H2O2-induced cell death in human neuroblastoma SH-SY5Y cells. These findings highlight a new approach for the development of a novel potential neuroprotective compound targeting AChE with autophagy-inducing activity in future Alzheimer's disease (AD) therapy.


Asunto(s)
Acetilcolinesterasa/metabolismo , Apoptosis/efectos de los fármacos , Inhibidores de la Colinesterasa/farmacología , Cumarinas/farmacología , Diseño de Fármacos , Peróxido de Hidrógeno/antagonistas & inhibidores , Línea Celular Tumoral , Inhibidores de la Colinesterasa/síntesis química , Inhibidores de la Colinesterasa/química , Cumarinas/síntesis química , Cumarinas/química , Relación Dosis-Respuesta a Droga , Humanos , Peróxido de Hidrógeno/farmacología , Estructura Molecular , Relación Estructura-Actividad
9.
Bioorg Chem ; 69: 121-128, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27814565

RESUMEN

Five flavones, including four flavonoids and one prenylated chalcone (paratocarpin E), were isolated from E. humifusa. and their chemical structures were established by spectroscopic analyses. We assessed the efficacy of these compounds against the growth of human breast cancer, leukemic, kidney cancer cell lines. Among them, paratocarpin E showed significant cytotoxicity against these cancer cell lines with an IC50 of 19.6µM on the growth of MCF-7 cells. Paratocarpin E treatment of MCF-7 cells resulted in typical apoptotic features via increasing expression of activated caspase-8 and -9 and PARP cleavage. Moreover, paratocarpin E altered the expression of Bax and Bcl-2, leading to the release of cytochrome c from the mitochondria into the cytosol, suggesting that the mitochondria-mediated apoptosis was initiated. In addition, paratocarpin E increased the MDC-positive autophagic vacuoles, the ratio of LC3-II/LC3-I protein levels of Beclin-1, but decreased p62 expression, indicating the potent pro-autophagic effects of paratocarpin E in MCF-7 cells. Mechanistically, cell death induced by paratocarpin E is able to induce apoptosis of MCF-7 cells by activating p38 and JNK signaling pathway while inhibiting Erk pathway. Furthermore, paratocarpin E promotes the activation and nuclear translocation of NF-κB, which plays an important role in balancing paratocarpin E-mediated apoptosis and autophagy. The molecular docking study also revealed that paratocarpin E bound to Fas and NF-κB complex. These findings provide initial evidences that paratocarpin E can be used as a potential anti-cancer drug in future for breast cancer therapy.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Chalconas/farmacología , Euphorbia/química , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Proliferación Celular/efectos de los fármacos , Chalconas/química , Chalconas/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Modelos Moleculares , Estructura Molecular , Relación Estructura-Actividad , Células Tumorales Cultivadas
10.
Molecules ; 21(5)2016 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-27187326

RESUMEN

Cellular mesenchymal-epithelial transition factor (c-MET) is closely linked to human malignancies, which makes it an important target for treatment of cancer. In this study, a series of 3-methoxy-N-phenylbenzamide derivatives, N-(3-(tert-butyl)-1-phenyl-1H-pyrazol-5-yl) benzamide derivatives and N¹-(3-fluoro-4-methoxyphenyl)-N³-(4-fluorophenyl) malonamide derivatives were designed and synthesized, some of them were identified as c-MET inhibitors. Among these compounds with new scaffolds having different quinazoline, pyridine and tetrahydro-pyridothienopyrimidine head groups, compound 11c, 11i, 13b, 13h exhibited both potent inhibitory activities against c-MET and high anticancer activity against tested cancer cell lines in vitro. In addition, kinase selectivity assay further demonstrated that both 13b and 13h are potent and selective c-MET inhibitors. Molecular docking supported that they bound well to c-MET and VEGFR2, which demonstrates that they are potential c-MET RTK inhibitors for cancer therapy.


Asunto(s)
Descubrimiento de Drogas , Proteínas Proto-Oncogénicas c-met/antagonistas & inhibidores , Piridinas/química , Quinazolinas/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Modelos Moleculares , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Relación Estructura-Actividad
11.
Int J Mol Sci ; 16(7): 14979-96, 2015 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-26147427

RESUMEN

8-p-Hdroxybenzoyl tovarol (TAW) is a germacrane-type sesquiterpenoid that can be isolated from the roots of Ferula dissecta (Ledeb.) Ledeb. In this study, the growth inhibitory effects induced by TAW were screened on some types of tumor cells, and the mechanism was investigated on TAW-induced growth inhibition, including paraptosis and autophagy in human cervical cancer HeLa cells. TAW-induced paraptosis involved extensive cytoplasmic vacuolization in the absence of caspase activation. Additionally, TAW evoked cell paraptotic death mediated by endoplasmic reticulum (ER) stress and unfolded protein response (UPR). Autophagy induced by TAW was found to antagonize paraptosis in HeLa cells. This effect was enhanced by rapamycin and suppressed by the autophagy inhibitor, 3-methyladenine (3MA). Loss of beclin 1 (an autophagic regulator) function led to promote ER stress. Taken together, these results suggest that TAW induces paraptosis like cell death and protective autophagy in HeLa cells, which would provide a new clue for exploiting TAW as a promising agent for the treatment of cervical cancer.


Asunto(s)
Antineoplásicos/farmacología , Autofagia/efectos de los fármacos , Parabenos/química , Extractos Vegetales/farmacología , Sesquiterpenos de Germacrano/química , Antineoplásicos/química , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Beclina-1 , Caspasas/metabolismo , Muerte Celular/efectos de los fármacos , Ferula/química , Células HeLa , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Parabenos/farmacología , Extractos Vegetales/química , Sesquiterpenos de Germacrano/farmacología , Respuesta de Proteína Desplegada
12.
Plant J ; 73(5): 814-23, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23206229

RESUMEN

Plant genomes encode a large number of proteins that potentially function as immune receptors in the defense against pathogen invasion. As a well-characterized receptor kinase consisting of 23 tandem leucine-rich repeats, a transmembrane domain and a serine/threonine kinase, the rice (Oryza sativa) protein XA21 confers resistance to a broad spectrum of Xanthomonas oryzae pv. oryzae (Xoo) races that cause bacterial blight disease. We report here that XA21 binding protein 25 (XB25) belongs to the plant-specific ankyrin-repeat (PANK) family. XB25 physically interacts, in vitro, with the transmembrane domain of XA21 through its N-terminal binding to transmembrane and positively charged domain (BTMP) repeats. In addition, XB25 associates with XA21 in planta. The downregulation of Xb25 results in reduced levels of XA21 and compromised XA21-mediated disease resistance at the adult stage. Moreover, the accumulation of XB25 is induced by Xoo infection. Taken together, these results indicate that XB25 is required for maintaining XA21-mediated disease resistance.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Oryza/genética , Enfermedades de las Plantas/inmunología , Proteínas de Plantas/genética , Xanthomonas/fisiología , Secuencia de Aminoácidos , Repetición de Anquirina , Resistencia a la Enfermedad , Regulación hacia Abajo , Datos de Secuencia Molecular , Oryza/inmunología , Oryza/fisiología , Enfermedades de las Plantas/microbiología , Hojas de la Planta/genética , Hojas de la Planta/inmunología , Hojas de la Planta/fisiología , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Unión Proteica , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Especificidad de la Especie , Técnicas del Sistema de Dos Híbridos
13.
Int J Biol Macromol ; 229: 168-180, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36587634

RESUMEN

Nervous system diseases (NSDs) are characterized by a wide range of symptoms, a complex pathophysiology, an unclear etiology, a great deal of variation in treatment response, and lengthy therapy cycles, all of which pose considerable hurdles to clinical treatment. A traditional valuable medicine known as Ganoderma lucidum (GL) has a significant role to play in preserving health and treating diseases. Ganoderma lucidum polysaccharides (GLP) is one of the cardinal effective active ingredients of GL, which has a number of pharmacological actions, including liver protection, immune regulation, antioxidant activity, anticancer activity, antibacterial activity, and antiviral activity. Recently, studies on the structural characterization and biological functions of GLP were presented in this article to review the progress of researches about GLP on NSDs and summarize the potential mechanisms of action. These studies were anticipated to provide new research ideas for GLP as a novel promising neuroprotective agent and provide a reference for better development and utilization of GLP.


Asunto(s)
Ganoderma , Fármacos Neuroprotectores , Reishi , Reishi/química , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Polisacáridos/farmacología , Polisacáridos/uso terapéutico , Polisacáridos/química , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Antioxidantes/química , Hígado
14.
ACS Omega ; 8(15): 14089-14096, 2023 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-37091385

RESUMEN

It is widely known that in the water flooding development process of ordinary heavy oil, the fingering phenomenon is obvious, there are a lot of unswept areas, and absolutely, the recovery is really very low. In addition, for some shallow and thin ordinary heavy oil reservoirs limited by the geological conditions of the reservoir, the thermal recovery technology also has serious heat loss and high development cost. Therefore, there is an urgent need to transform the development and further improve the enhanced oil recovery (EOR). In this paper, the mechanism of EOR by polymer flooding was investigated for high-porosity and high-permeability terrestrial ordinary heavy oil reservoirs. Through laboratory experiments, we analyzed the characteristics of oil-water relative permeability curves, mobility control ability, and microscopic seepage characteristics during polymer flooding of ordinary heavy oil reservoirs. On this basis, the effect of the mobility ratio on seepage characteristics and the mechanism of EOR enhancement were clarified. The results show that the polymer can effectively improve the mobility control effect of the displacing fluid. As the polymer solution and ordinary heavy oil have the characteristics of high viscosity and low mobility, there is a minimum mobility ratio in the process of polymer flooding. Namely, the characteristics of dual low mobility exist in the process of polymer flooding for the ordinary heavy oil. It effectively enhances the profile control and plugging ability of the polymer, thus expanding the sweep volume of larger pores and improving the displacement efficiency of smaller pores. Based on the two factors mentioned above, it is found that the dual low mobility characteristics can improve the recovery of ordinary heavy oil by polymer flooding. Therefore, it is proposed that an enhanced profile control and plugging effect due to the dual low mobility characteristics is an important EOR mechanism for ordinary heavy oil development by polymer flooding.

15.
ACS Omega ; 8(44): 41469-41479, 2023 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-37969982

RESUMEN

In recent years, antibiotic-based carbon nanodots have been extensively developed and studied, because of their excellent synergistic fluorescence and antibacterial properties. These antibacterial carbon nanodots have also been developed with various new applications, such as heavy iron detection, pH sensitivity, temperature response, and bacterial count detection in various environments. In this article, using vancomycin hydrochloride as the only precursor, vancomycin hydrochloride carbon nanodots were rapidly synthesized by a one-step microwave method. The diameter of the vancomycin hydrochloride carbon nanodots was concentrated at 0.899 ± 0.40 nm with a uniform size and excitation-dependent fluorescence. Vancomycin hydrochloride carbon nanodots showed better antibacterial activity than the original vancomycin hydrochloride with low biological toxicity and good stability. In the pH range of approximately 7-13, there was a good linear relationship between the fluorescence intensity of the carbon nanodots and the pH value (R2 = 0.98516). Moreover, vancomycin hydrochloride carbon nanodots could quickly and specifically detect poisonous Sn4+ through changes in their fluorescence intensity, with a detection limit of approximately 5.2 µM. Multifunctional vancomycin hydrochloride carbon nanodots have good application prospects in the fields of antibacterial, toxic Sn4+ detection, and pH-sensitive aspects.

16.
J Biol Chem ; 285(12): 9030-40, 2010 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-20118241

RESUMEN

The UDP-sugar interconverting enzymes involved in UDP-GlcA metabolism are well described in eukaryotes but less is known in prokaryotes. Here we identify and characterize a gene (RsU4kpxs) from Ralstonia solanacearum str. GMI1000, which encodes a dual function enzyme not previously described. One activity is to decarboxylate UDP-glucuronic acid to UDP-beta-l-threo-pentopyranosyl-4''-ulose in the presence of NAD(+). The second activity converts UDP-beta-l-threo-pentopyranosyl-4''-ulose and NADH to UDP-xylose and NAD(+), albeit at a lower rate. Our data also suggest that following decarboxylation, there is stereospecific protonation at the C5 pro-R position. The identification of the R. solanacearum enzyme enables us to propose that the ancestral enzyme of UDP-xylose synthase and UDP-apiose/UDP-xylose synthase was diverged to two distinct enzymatic activities in early bacteria. This separation gave rise to the current UDP-xylose synthase in animal, fungus, and plant as well as to the plant Uaxs and bacterial ArnA and U4kpxs homologs.


Asunto(s)
Oxidorreductasas de Alcohol/química , Carboxiliasas/química , Regulación Bacteriana de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Complejos Multienzimáticos/química , Plantas/microbiología , Ralstonia solanacearum/metabolismo , Azúcares de Uridina Difosfato/química , Uridina Difosfato Xilosa/química , Oxidorreductasas de Alcohol/fisiología , Secuencia de Aminoácidos , Carboxiliasas/fisiología , Clonación Molecular , Escherichia coli/metabolismo , Espectroscopía de Resonancia Magnética , Modelos Biológicos , Modelos Químicos , Datos de Secuencia Molecular , Complejos Multienzimáticos/fisiología , Filogenia , Homología de Secuencia de Aminoácido
17.
Front Chem ; 9: 787886, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34900945

RESUMEN

Wound infections are serious medical complications that can endanger human health. Latest researches show that conductive composite materials may make endogenous/exogenous electrical stimulation more effective, guide/comb cell migration to the wound, and subsequently promote wound healing. To accelerate infected wound healing, a novel medical silver nanoparticle-doped conductive polymer-based hydrogel system (Ag NPs/CPH) dressing with good conductivity, biocompatibility, and mechanical and antibacterial properties was fabricated. For the hydrogel dressing, Ag NPs/CPH, polyvinyl alcohol (PVA), and gelatin were used as the host matrix materials, and phytic acid (PA) was used as the cross-linking agent to introduce conductive polyaniline into the matrix, with antibacterial Ag NPs loaded via impregnation. After a series of analyses, the material containing 5 wt% of PVA by concentration, 1.5 wt% gelatin, 600 µL of AN reactive volume, and 600 µL of PA reactive volume was chosen for Ag NPs/CPH preparation. XPS and FTIR analysis had been further used to characterize the composition of the prepared Ag NPs/CPH. The test on the swelling property showed that the hydrogels had abundant pores with good water absorption (≈140% within 12 h). They can be loaded and continuously release Ag NPs. Thus, the prepared Ag NPs/CPH showed excellent antibacterial property with increasing duration of immersion of Ag NPs. Additionally, to evaluate in vivo safety, CCK-8 experiments of HaCat, LO2 and 293T cells were treated with different concentrations of the Ag NPs/CPH hydrogel soaking solution. The experimental results showed the Ag NPs/CPH had no significant inhibitory effect on any of the cells. Finally, an innovative infection and inflammation model was designed to evaluate the prepared Ag NPs/CPH hydrogel dressing for the treatment of severely infected wounds. The results showed that even when infected with bacteria for long periods of time (more than 20 h), the proposed conductive antibacterial hydrogel could treat severely infected wounds.

18.
Biophys J ; 99(7): 2318-26, 2010 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-20923667

RESUMEN

The use of nondestructive NMR spectroscopy for enzymatic studies offers unique opportunities to identify nearly all enzymatic byproducts and detect unstable short-lived products or intermediates at the molecular level; however, numerous challenges must be overcome before it can become a widely used tool. The biosynthesis of acetyl-coenzyme A (acetyl-CoA) by acetyl-CoA synthetase is used here as a case study for the development of an analytical NMR-based time-course assay platform. We describe an algorithm to deconvolve superimposed spectra into spectra for individual molecules, and further develop a model to simulate the acetyl-CoA synthetase enzyme reaction network using the data derived from time-course NMR. Simulation shows indirectly that synthesis of acetyl-CoA is mediated via an enzyme-bound intermediate (possibly acetyl-AMP) and is accompanied by a nonproductive loss from an intermediate. The ability to predict enzyme function based on partial knowledge of the enzymatic pathway topology is also discussed.


Asunto(s)
Acetato CoA Ligasa/química , Arabidopsis/enzimología , Complejos Multienzimáticos/química , Acetato CoA Ligasa/metabolismo , Algoritmos , Biocatálisis , Análisis de los Mínimos Cuadrados , Espectroscopía de Resonancia Magnética , Complejos Multienzimáticos/metabolismo , Factores de Tiempo
19.
J Ethnopharmacol ; 248: 112050, 2020 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-31265887

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Si-Miao-Yong-An decoction (SMYAD) is a traditional Chinese herbal formulation. SMYAD first appeared in the Eastern Han Dynasty according to the "Shen Yi Mi Zhuan". Then the formula was recorded in the "Yan Fang Xin Bian" edited by medical scientist Bao Xiangao in the Qing Dynasty. This well-known prescription has been traditionally used for gangrene and vascular vasculitis. It is mainly used for cardiovascular and endocrine diseases in current clinical applications and research. AIM OF STUDY: In this study, the potential mechanisms of SMYAD against cardiac fibrosis and hypertrophy in the ß-adrenoceptor agonist isoprenaline induced heart failure model were investigated. MATERIALS AND METHODS: The heart failure animal model was established via injected isoprenaline in rats. Echocardiography was used to detect the structure and function of the heart. HE staining and Masson's trichrome staining was performed to assess myocardial tissue morphology. The serum biochemical indexes were detected by dedicated biochemical kit. BNP was tested by ELISA kit. The levels of mRNA were detected by RT-qPCR. Cardiomyocyte morphology was assessed by immunofluorescence. Phosphorylated and total p38, Akt were analyzed by Western blot. The production of reactive oxygen species (ROS) was tested by CM-H2DCFDA probe. Formula identification of chemical constituents of SMYAD in plasma was disclosed through ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). RESULTS: SMYAD was able to improve the heart function in ISO induced heart failure rat model via protecting rat from developing cardiac hypertrophy and fibrosis. SMYAD also decreased plasma expression of these biochemical indexes. It was found that SMYAD could regulate cardiac hypertrophy and fibrosis makers' mRNA levels in vitro and vivo. In addition, SMYAD inhibited the phosphorylation of p38 and Akt, which are key mediators in the pathological process of ISO-induced cardiac hypertrophy and myocardial fibrosis. It also showed that the components of SMYAD in rat plasma exerted myocardial cell protective activity. CONCLUSION: In summary, SMYAD may comprise more than one active ingredient to the pursuit of combination therapies instead of specifically target a single disease-causing molecule. These experimental results suggest that SMYAD may be a potential drug candidate in diseases of cardiac hypertrophy and myocardial fibrosis caused by ß-adrenoceptor abnormalities.


Asunto(s)
Cardiomegalia/prevención & control , Medicamentos Herbarios Chinos/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Animales , Cardiomegalia/etiología , Línea Celular , Doxorrubicina , Medicamentos Herbarios Chinos/farmacología , Fibrosis , Insuficiencia Cardíaca/inducido químicamente , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/metabolismo , Isoproterenol , Masculino , Miocardio/citología , Miocardio/metabolismo , Miocardio/patología , Fitoquímicos/análisis , Fitoquímicos/farmacología , Fitoquímicos/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
20.
Acta Biomater ; 113: 614-626, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32565370

RESUMEN

Osteoporosis is one of the most prevalent age-related diseases worldwide and is characterized by a systemic deterioration of bone strength (bone mineral density and bone quality) with a resulting increase in fragility fractures. Due to the complex osteoporotic pathological environment, it is a huge challenge to induce bone regeneration under osteoporosis conditions. In this study, we successfully nanoengineer a bioinspired mineralized hydrogel from the supramolecular assembly of nano-hydroxyapatite, sodium carbonate, and polyacrylic acid, termed as CHAp-PAA. The resultant nanocomposite hydrogels can maintain their initial morphology and mechanical properties under physiological conditions, while exhibiting good primary stability, biocompatibility, bioactivity, and osteoconductivity. We demonstrate that this optimized hydrogel scaffold has shown superior performance for bone marrow stem cells (BMSCs) proliferation, differentiation, and extracellular matrix production in vitro. Remarkably, the mineralized CHAp-PAA hydrogels could be used as scaffolds for the critical-sized bone defect (6.0 mm diameter and 10.0 mm depth) in the osteoporotic rabbit model. Without the delivery of additional therapeutic agents or stem cells, these CHAp-PAA hydrogel scaffolds can improve bone ingrowth and accelerate new bone formation even in complex osteoporotic pathological environments. Therefore, this work presents a type of bioinspired multifunctional mineral hydrogel that offers an alternative strategy to manage osteoporosis. STATEMENT OF SIGNIFICANCE.


Asunto(s)
Nanocompuestos , Osteoporosis , Animales , Regeneración Ósea , Hidrogeles/farmacología , Osteogénesis , Osteoporosis/terapia , Conejos , Andamios del Tejido
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