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1.
J Am Chem Soc ; 146(4): 2484-2493, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38229260

RESUMEN

Organic cocrystals obtained from multicomponent self-assembly have garnered considerable attention due to their distinct phosphorescence properties and broad applications. Yet, there have been limited reports on cocrystal systems that showcase efficient deep-red to near-infrared (NIR) charge-transfer (CT) phosphorescence. Furthermore, effective strategies to modulate the emission pathways of both fluorescence and phosphorescence remain underexplored. In this work, we dedicated our work to four distinct self-assembled cocrystals called "pyrene box" cages using 1,3,6,8-pyrenetetrasulfonate anions (PTS4-), 4-iodoaniline (1), guanidinium (G+), diaminoguanidinium (A2G+), and hydrated K+ countercations. The binding of such cations to PTS4- platforms adaptively modulates their supramolecular stacking self-assembly with guest molecules 1, allowing to steer the fluorescence and phosphorescence pathways. Notably, the confinement of guest molecule 1 within "pyrene box" PTSK{1} and PTSG{1} cages leads to an efficient deep-red to NIR CT phosphorescence emission. The addition of fuming gases like triethylamine and HCl allows reversible pH modulations of guest binding, which in turn induce a reversible transition of the "pyrene box" cage between fluorescence and phosphorescence states. This capability was further illustrated through a proof-of-concept demonstration in shrimp freshness detection. Our findings not only lay a foundation for future supramolecular designs leveraging weak intermolecular host-guest interactions to engineer excited states in interacting chromophores but also broaden the prospective applications of room-temperature phosphorescence materials in food safety detection.

2.
Anal Bioanal Chem ; 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38602542

RESUMEN

Natural attapulgite (ATP) is a promising substitute for existing artificial nanozymes due to its intrinsic enzymatic activity. However, the active center of ATP's inherent enzymatic activity has not yet been revealed, which limits its further design and activity optimization. Studying the active center of mineral materials can be extremely challenging due to their complexity. Here, we demonstrated that Fe is the primary element in ATP responsible for peroxidase (POD)-like activity through theoretical speculation and experimental verification. More importantly, we found that the ratio of Fe2+/Fe3+ is responsible for the district POD-like activity of ATP from different regions with the same Fe content. Additionally, three facile strategies, including grinding, heat treatment, and acid treatment, were demonstrated to increase the relative Fe content and thus optimize the POD-like activity of ATP. Finally, ATP was used to detect the concentration of H2O2, enabling the detection of low concentrations (0.11-1.76 mM) of H2O2. This study serves as a novel reference for the future design and performance optimization of nanozymes that are based on ATP and clay minerals.

3.
Chemistry ; 29(27): e202300320, 2023 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-36794471

RESUMEN

Most organic thermochromic fluorescent materials exhibit thermo-induced hypsochromic emission due to the formation of excimers in ordered molecular solids; however, it is still a challenge to endow them with bathochromic emission despite its significance in making up the field of thermochromism. Here, a thermo-induced bathochromic emission in columnar discotic liquid crystals is reported realized by intramolecular planarization of the mesogenic fluorophores. A three-armed discotic molecule of dialkylamino-tricyanotristyrylbenzene was synthesized, which preferred to twist out of the core plane to accommodate ordered molecular stacking in hexagonal columnar mesophases, giving rise to bright green monomer emission. However, intramolecular planarization of the mesogenic fluorophores occurred in isotropic liquid increasing the conjugation length, and as a result led to thermo-induced bathochromic emission from green to yellow light. This work reports a new concept in the thermochromic field and provides a novel strategy to achieve fluorescence tuning from intramolecular actions.

4.
Pediatr Res ; 93(4): 852-861, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35854089

RESUMEN

BACKGROUND: Neuroblastoma is the most common cancer in infants and the most common extracranial solid tumor in childhood. DRR1 was identified to be downregulated in poorly differentiated ganglion cells from neuroblastoma model mice. However, the roles of DRR1 in neuroblastoma remain largely unclear. METHODS: The neuroblastoma cells were induced to differentiate, and the expression of DRR1 was detected. The expression of the neuroblastoma cell differentiation markers was analyzed in DRR1 shRNA- or DRR1-expressing vector-treated neuroblastoma cells. The downstream genes of DRR1 were screened with ChIP-seq assay. Finally, TNB1 cells were infected with DRR1 shRNA and CREB expressing vector containing lentivirus, and the expression of the cell differentiation markers, cell cycle distribution and tumor growth were analyzed. RESULTS: The expression of DRR1 was increased in differentiated neuroblastoma cells, and downregulation of DRR1 expression inhibited the differentiation of neuroblastoma cells. Further experiments indicated that CREB is a candidate downstream gene of DRR1, and it mediates neuroblastoma cell differentiation. Moreover, overexpression of CREB rescued the effect of DRR1 shRNA on cell differentiation, cell cycle distribution and tumor growth in neuroblastoma. CONCLUSIONS: DRR1-CREB axis modulates the differentiation of neuroblastoma cells and is associated with the outcome of neuroblastoma patients. IMPACT: DRR1 is involved in regulation of the differentiation of neuroblastoma. Binding with actin is essential for DRR1 to regulate neuroblastoma cell differentiation. CREB is a candidate downstream gene of DRR1 in regulating of the differentiation of neuroblastoma.


Asunto(s)
Células-Madre Neurales , Neuroblastoma , Animales , Ratones , Diferenciación Celular , Línea Celular Tumoral , Células-Madre Neurales/metabolismo , Neuroblastoma/metabolismo , Neuronas/metabolismo , ARN Interferente Pequeño , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo
5.
Nanotechnology ; 34(50)2023 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-37725954

RESUMEN

For accelerate construction of the energy and resource-saving and environmental-friendly society, cleaner preparation of low-cost and high-performance colorful near-infrared reflective inorganic pigments with the decorative function is indispensable to reduce the hazards of urban heat island and simultaneously beautify the appearance of the buildings. Due to the non-toxicity, good chemical stability and narrow band gap, BiVO4has been becoming a promising environment-friendly yellow inorganic pigments among the conventional heavy metals-containing inorganic pigments. In this study, the low-cost and brilliant kaolinite-based BiVO4hybrid pigments were fabricated by cleaner mechanochemical method based on cheap and abundant kaolinite using crystal water of the hydrated metal salts as trace solvent, which could effectively promote the interaction of the involved components at the molecular level during grinding and then decreased the mass transfer resistance for the formation of monoclinic scheelite BiVO4in the following calcination. The obtained hybrid pigments at the optimal preparation conditions exhibited brilliant color properties (D65-10°,L*= 83.45 ± 0.08,a*= 4.17 ± 0.08,b*= 88.59 ± 0.17), high near-infrared reflectance of 86.22%, infrared solar reflectance of 88.14% and high emissivity of 0.9369 in the waveband of 8-13µm. Furthermore, the hybrid pigments could be used for coloring epoxy resin with high emissivity of 0.8782 in 8-13µm. Therefore, the brilliant and low-cost kaolinite-based bismuth yellow hybrid pigments have the enormous potential to be served as colorful functional nanofillers for cooling roofing materials.

6.
Int J Mol Sci ; 23(4)2022 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-35216101

RESUMEN

Maturing male germ cells undergo a unique developmental process in spermiogenesis that replaces nucleosomal histones with protamines, the process of which is critical for testicular development and male fertility. The progress of this exchange is regulated by complex mechanisms that are not well understood. Now, with mouse genetic models, we show that barrier-to-autointegration factor-like protein (BAF-L) plays an important role in spermiogenesis and spermatozoal function. BAF-L is a male germ cell marker, whose expression is highly associated with the maturation of male germ cells. The genetic deletion of BAF-L in mice impairs the progress of spermiogenesis and thus male fertility. This effect on male fertility is a consequence of the disturbed homeostasis of histones and protamines in maturing male germ cells, in which the interactions between BAF-L and histones/protamines are implicated. Finally, we show that reduced testicular expression of BAF-L represents a risk factor of human male infertility.


Asunto(s)
Histonas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Protaminas/metabolismo , Espermatogénesis/fisiología , Animales , Biomarcadores/metabolismo , Regulación del Desarrollo de la Expresión Génica/fisiología , Células Germinativas/metabolismo , Humanos , Infertilidad Masculina/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Espermátides/metabolismo , Testículo/metabolismo
7.
Int J Mol Sci ; 23(14)2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35887011

RESUMEN

Tripartite Motif 67 (TRIM67) is an important member of TRIM family proteins, which participates in different cellular processes including immune response, proliferation, differentiation, carcinogenesis, and apoptosis. In recent years, a high fat diet (HFD) has remained one of the main causes of different metabolic diseases and increases in intestinal permeability as well as inducing intestinal inflammation. The current study investigated the protective effects of TRIM67 in the ileum and colon of obese mice. 4-week-old wild-type (WT) C57BL/6N mice and TRIM67 knockout (KO) C57BL/6N mice were selected and randomly divided into four sub-groups, which were fed with control diet (CTR) or HFD for 14 weeks. Samples were collected at the age of 18 weeks for analysis. To construct an in vitro obesity model, over-expressed IPEC-J2 cells (porcine intestinal cells) with Myc-TRIM67 were stimulated with palmitic acid (PA), and its effects on the expression level of TRM67, inflammatory cytokines, and barrier function were evaluated. The KO mice showed pathological lesions in the ileum and colon and this effect was more obvious in KO mice fed with HFD. In addition, KO mice fed with a HFD or CTR diet had increased intestinal inflammation, intestinal permeability, and oxidative stress compared to that WT mice fed with these diets, respectively. Moreover, IPEC-J2 cells were transfected with TRIM67 plasmid to perform the same experiments after stimulation with PA, and the results were found consistent with the in vivo evaluations. Taken together, our study proved for the first time that HFD and TRIM67 KO mice have synergistic damaging effects on the intestine, while TRIM67 plays an important protective role in HFD-induced intestinal damage.


Asunto(s)
Dieta Alta en Grasa , Obesidad , Animales , Proteínas del Citoesqueleto , Dieta Alta en Grasa/efectos adversos , Inflamación/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Obesos , Obesidad/metabolismo , Porcinos , Proteínas de Motivos Tripartitos/metabolismo
8.
Biochem Biophys Res Commun ; 558: 36-43, 2021 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-33895549

RESUMEN

Down-regulated in renal cell carcinoma 1 (DRR1), a unique stress-induced protein, is highly expressed in the nervous system. This study investigated the roles of DRR1 in the brain by examining its expression pattern at different developmental stages of a rat brain and in cultured primary hippocampal neurons. High expression of DRR1 was observed in all developmental stages of a rat brain and cultured primary hippocampal neurons. We then focused on the role of DRR1 in promoting neurite outgrowth during the early stage of hippocampal neuron development. Results showed that down-regulation of DRR1 suppressed axon outgrowth. Mass spectrometry analysis revealed that tropomodulin-2 (Tmod2) is a novel binding partner of DRR1. Our results showed that both DRR1 and Tmod2 mediate axon formation during the early stage of hippocampal neuron development. Suppression of TMOD2 expression rescued the abnormal axon outgrowth induced by DRR1 knockdown during the early stage of hippocampal neuron development.


Asunto(s)
Hipocampo/crecimiento & desarrollo , Hipocampo/metabolismo , Proyección Neuronal/genética , Proyección Neuronal/fisiología , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Animales , Encéfalo/citología , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Células Cultivadas , Regulación hacia Abajo , Femenino , Regulación del Desarrollo de la Expresión Génica , Hipocampo/citología , Neurogénesis/genética , Neurogénesis/fisiología , Neuronas/metabolismo , Embarazo , Unión Proteica , ARN Interferente Pequeño/genética , Ratas , Ratas Sprague-Dawley , Tropomodulina/antagonistas & inhibidores , Tropomodulina/genética , Tropomodulina/metabolismo , Proteínas Supresoras de Tumor/antagonistas & inhibidores
9.
Molecules ; 25(5)2020 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-32182848

RESUMEN

To overcome the poor stability of natural lutein to environmental factors, layered double hydroxide was incorporated by a green mechanical grinding process. The influences of external factors (chemical reagents, heating and light) on the stability of lutein before and after being loaded were evaluated. The results confirmed that lutein was mainly adsorbed on the surface of layered double hydroxide (LDH) via the chemical interaction. Compared with pure lutein, the thermal decomposition of lutein/LDH was improved from 100 °C to 300 °C, and the retention ratio of lutein was increased by about 8.64% and 21.47% after 96 h of light exposure and accelerated degradation, respectively. It is expected that the stable lutein/LDH composites may constitutean additive in animal feed.


Asunto(s)
Hidróxidos/química , Complejos de Proteína Captadores de Luz/química , Luteína/química , Calefacción/efectos adversos , Luz/efectos adversos , Complejos de Proteína Captadores de Luz/efectos de la radiación , Luteína/efectos de la radiación , Estabilidad Proteica/efectos de la radiación
10.
Angew Chem Int Ed Engl ; 59(24): 9408-9413, 2020 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-32160382

RESUMEN

A modulated bi-phase synthesis towards large-scale manganese 1,4-benzenedicarboxylate (MnBDC) MOFs with a precise control over their morphology (bulk vs. layered) is presented. Metal precursors and organic ligands are separated to reduce the kinetic reaction rates for better control over the crystallization process. Based on scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy studies, the continuous ligand supply along with the presence of pyridine capping agent are highly effective in promoting the layer-by-layer growth and achieving large crystal sizes. Once layered MnBDC is stabilized, topotactic intercalation chemistry was used to demonstrate the feasibility of bromine intercalation on these layered materials. Bromine intercalation is possible between the MOFs layers for the first time. Bromine intercalation causes colossal reduction in layered MnBDC band gap while it has no observable effect on bulk MOFs.

11.
Macromol Rapid Commun ; 40(17): e1800471, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30277631

RESUMEN

By combining the virtues of conventional linear and hyperbranched polymers, long-chain hyperbranched polymers (LCHBPs) have attracted great attention. Therefore, a comprehensive summary of the research progress of LCHBPs is presented, with a particular focus on their synthetic strategies, unique properties, and potential applications. The synthetic methodologies are rationalized into four main classes according to their construction process or mechanism, namely ABx (x ≥ 2), A2  + Bx (x ≥ 3), AB + ABx (x ≥ 2), and self-condensing vinyl polymerization. Some of their rheological properties, self-assembly behavior, and stimuli-response features are then discussed. Finally, the emergent applications including biomedicine, electrical conductivity, chemical sensing, and catalyst carrier, are outlined. It is anticipated that this review will stimulate more inspiration for advancing the development of this novel kind of LCHBP.


Asunto(s)
Sustancias Macromoleculares/química , Nanomedicina , Polímeros/química , Humanos , Estructura Molecular , Polimerizacion
12.
J Environ Sci (China) ; 75: 346-358, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30473300

RESUMEN

The utilization of waste products as valuable materials was a technical imperative for waste management. In this study, the cost-effective attapulgite/carbon (APT/C) composite was developed for wastewater treatment using waste hot-pot oil as a carbon precursor through a facile one-step calcination process. The APT/C composite prepared at 300°C exhibited the excellent adsorption capacity and rapid equilibrium rate over a broad pH range for the removal of various pollutants. More importantly, the removal ratios of the composites toward Methyl Violet and tetracycline still remained 77.6% and 60.2% of the initial adsorption capacity after ten adsorption-regeneration cycles via a facile thermal regeneration strategy, respectively. Beyond all doubt, this research provided a feasible and economical way for the sustainable utilization of waste hot-pot oil in wastewater treatment, achieving the concept of disposal waste with waste and recycling.


Asunto(s)
Residuos Industriales , Compuestos de Magnesio , Compuestos de Silicona , Eliminación de Residuos Líquidos/métodos , Adsorción , Carbono , Cinética , Residuos , Aguas Residuales , Contaminantes Químicos del Agua
13.
Langmuir ; 34(4): 1340-1346, 2018 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-29293350

RESUMEN

The quality of nanoparticle dispersion in a polymer matrix significantly influences the macroscopic properties of the composite material. Like general polymer-nanoparticle composites, electrospun nanofiber nanoparticle composites do not have an adopted quantitative model for dispersion throughout the polymer matrix, often relying on a qualitative assessment. Being such an influential property, quantifying dispersion is essential for the process of optimization and understanding the factors influencing dispersion. Here, a simulation model was developed to quantify the effects of nanoparticle volume loading (ϕ) and fiber-to-particle diameter ratios (D/d) on the dispersion in an electrospun nanofiber based on the interparticle distance. A dispersion factor is defined to quantify the dispersion along the polymer fiber. In the dilute regime (ϕ < 20%), three distinct regions of the dispersion factor were defined with the highest quality dispersion shown to occur when geometric constraints limit fiber volume accessibility. This model serves as a standard for comparison for future experimental studies and dispersion models through its comparability with microscopy techniques and as a way to quantify and predict dispersion in electrospinning polymer-nanoparticle systems with a single performance metric.

14.
Langmuir ; 33(36): 9066-9072, 2017 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-28809504

RESUMEN

Developing electrospun nanofiber/nanoparticle composites (ENNCs) is an emerging strategy for immobilizing functional particles for a variety of applications. The radial location of the particle along the fiber, either at the surface or in the bulk, has implication into the resulting properties. To explore particle location along fibers, ZIF-8 impregnated poly(ethylene oxide) (PEO) nanofibers are formed by electrospinning particle suspensions. Fibers impregnated with two different ZIF-8 particle sizes (200 nm and 12.5 µm) were electrospun and shown by nitrogen porosimetry to be nearly completely wrapped by PEO in each case at loadings near 10 wt %. This was favorably compared to developed theory of polymeric membrane encapsulated particles and extended to other electrospun fiber/particle composites through a brief literature review. ENNCs with varying loadings of nanosized ZIF-8 particles were then fabricated and tested with nitrogen porosimetry to find that the particles became available for adsorption at the surface of the fibers starting from 25 wt % (28 vol %) loading. This suggests that the particles are kinetically trapped at this loading level since, if allowed to exhibit random close-packing, the ZIF-8 would be expected to fully imbedded inside the fibers up to 56 vol % loading.

15.
Acc Chem Res ; 47(4): 979-88, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24467652

RESUMEN

Nanoparticles and nanoengineered platforms have great potential for technologies involving biomoleuclar detection or cell-related biosensing, and have provided effective chemical interfaces for molecular recognition. Typically, chemists work on the modification of synthetic polymers or macromolecules, which they link to the nanoparticles by covalent or noncovalent approaches. The motivation for chemical modification is to enhance the selectivity and sensitivity, and to improve the biocompatibility for the in vivo applications. In this Account, we present recent advances in the development and application of chemical interfaces for molecular recognition for nanoparticles and nanoengineered platforms, in particular single-walled carbon nanotubes (SWNTs). We discuss emerging approaches for recognizing small molecules, glycosylated proteins, and serum biomarkers. For example, we compare and discuss detection methods for ATP, NO, H2O2, and monosaccharides for recent nanomaterials. Fluorometric detection appears to have great potential for quantifying concentration gradients and determining their location in living cells. For macromolecular detection, new methods for glycoprofiling using such interfaces appear promising, and benefit specifically from the potential elimination of cumbersome labeling and liberation steps during conventional analysis of glycans, augmenting the currently used mass spectrometry (MS), capillary electrophoresis (CE), and liquid chromatography (LC) methods. In particular, we demonstrated the great potential of fluorescent SWNTs for glycan-lectin interactions sensing. In this case, SWNTs are noncovalently functionalized to introduce a chelated nickel group. This group provides a docking site for the His-tagged lectin and acts as the signal modulator. As the nickel proximity to the SWNT surface changes, the fluorescent signal is increased or attenuated. When a free glycan or glycosylated probe interacts with the lectin, the signal increases and they are able to obtain loading curves similar to surface plasmon resonance measurements. They demonstrate the sensitivity and specificity of this platform with two higher-affined glycan-lectin pairs: fucose (Fuc) to PA-IIL and N-acetylglucosamine (GlcNAc) to GafD. Lastly, we discuss how developments in protein biomarker detection in general are benefiting specifically from label-free molecular recognition. Electrical field effect transistors, chemi-resistive and fluorometric nanosensors based on various nanomaterials have demonstrated substantial progress in recent years in addressing this challenging problem. In this Account, we compare the balance between sensitivity, selectivity, and nonspecific adsorption for various applications. In particular, our group has utilized SWNTs as fluorescence sensors for label-free protein-protein interaction measurements. In this assay, we have encapsulated each nanotube in a biocompatible polymer, chitosan, which has been further modified to conjugate nitrilotriacetic acid (NTA) groups. After Ni(2+) chelation, NTA Ni(2+) complexes bind to his-tagged proteins, resulting in a local environment change of the SWNT array, leading to optical fluorescence modulation with detection limit down to 100 nM. We have further engineered the platform to monitor single protein binding events, with an even lower detection limit down to 10 pM.


Asunto(s)
Técnicas Biosensibles/métodos , Nanoestructuras , Adenosina Trifosfato/análisis , Biomarcadores/sangre , Técnicas Biosensibles/instrumentación , Cromatografía Liquida/métodos , Electroforesis Capilar/métodos , Diseño de Equipo , Peróxido de Hidrógeno/análisis , Espectrometría de Masas/métodos , Monosacáridos/análisis , Nanotecnología/métodos , Nanotubos de Carbono , Óxido Nítrico/análisis , Sistemas de Atención de Punto , Polisacáridos/análisis , Proteínas/análisis , Propiedades de Superficie
16.
Chemistry ; 21(12): 4523-8, 2015 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-25644377

RESUMEN

Saccharides recognition is challenging due to their low affinity for substrates, yet this recognition is critical for human immunity and glycobiology. Herein, we demonstrate that a polymer or surfactant corona phase surrounding a single-walled carbon nanotube can substantially modify the selectivity of pre-adsorbed phenyl-boronic acids (PBA) for mono-, di-, and poly-saccharides. A library of 17 PBAs including carboxy, nitro, and amino PBA with ortho-, meta-, or para- substitutions are used to generate 144 distinct corona phases. Six in particular demonstrate significantly increased selectivity to specific saccharides including ribose (0.42 mol per total mol), arabinose (0.36), and glucose (0.25), but unusually diminished binding to fructose (0.02). Recognition proceeds by saccharide adsorption into the corona, followed by PBA reaction in a consecutive second order reaction. The results extend to larger saccharides, such as glycosaminoglycans, suggesting promise for protein glycosylation.


Asunto(s)
Ácidos Borónicos/química , Monosacáridos/química , Nanotubos de Carbono/química , Polisacáridos/química , Ácidos Borónicos/metabolismo , Monosacáridos/metabolismo , Polisacáridos/metabolismo , Tensoactivos/química
17.
J Am Chem Soc ; 136(2): 713-24, 2014 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-24354436

RESUMEN

Temporal and spatial changes in neurotransmitter concentrations are central to information processing in neural networks. Therefore, biosensors for neurotransmitters are essential tools for neuroscience. In this work, we applied a new technique, corona phase molecular recognition (CoPhMoRe), to identify adsorbed polymer phases on fluorescent single-walled carbon nanotubes (SWCNTs) that allow for the selective detection of specific neurotransmitters, including dopamine. We functionalized and suspended SWCNTs with a library of different polymers (n = 30) containing phospholipids, nucleic acids, and amphiphilic polymers to study how neurotransmitters modulate the resulting band gap, near-infrared (nIR) fluorescence of the SWCNT. We identified several corona phases that enable the selective detection of neurotransmitters. Catecholamines such as dopamine increased the fluorescence of specific single-stranded DNA- and RNA-wrapped SWCNTs by 58-80% upon addition of 100 µM dopamine depending on the SWCNT chirality (n,m). In solution, the limit of detection was 11 nM [K(d) = 433 nM for (GT)15 DNA-wrapped SWCNTs]. Mechanistic studies revealed that this turn-on response is due to an increase in fluorescence quantum yield and not covalent modification of the SWCNT or scavenging of reactive oxygen species. When immobilized on a surface, the fluorescence intensity of a single DNA- or RNA-wrapped SWCNT is enhanced by a factor of up to 5.39 ± 1.44, whereby fluorescence signals are reversible. Our findings indicate that certain DNA/RNA coronae act as conformational switches on SWCNTs, which reversibly modulate the SWCNT fluorescence. These findings suggest that our polymer-SWCNT constructs can act as fluorescent neurotransmitter sensors in the tissue-compatible nIR optical window, which may find applications in neuroscience.


Asunto(s)
Colorantes Fluorescentes/química , Microscopía Fluorescente/métodos , Nanotubos de Carbono/química , Neurotransmisores/análisis , Adsorción , Estructura Molecular
18.
Phys Chem Chem Phys ; 16(17): 7872-80, 2014 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-24643731

RESUMEN

The graphene-MnO2-polyaniline (rGO-MnO2-PAn) ternary composites were prepared via in situ chemical oxidative polymerization of polyaniline on the MnO2 decorated graphene sheets. The graphene sheets were treated with KMnO4 in a water-ethylene glycol system using the hydrothermal method to complete the loading of MnO2 on the graphene sheets, while the graphene oxide (GO) sheets were hydrothermally reduced to reduced graphene oxide (rGO). The glycol was introduced as a reductant to react with MnO4(-), and GO was protected from consumption in the process of deposition of MnO2. The structures and morphologies of the resulting ternary composites are characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of the composites as potential electrode materials for supercapacitors were investigated using different electrochemical techniques including cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS). The specific capacitance of a rGO-MnO2-PAn composite electrode was 395 F g(-1) at 10 mA cm(-2) in 1 M H2SO4 solution. The composites displayed good cycle stability retaining 92% of their original specific capacitance after 1200 cycles by continuous cyclic voltammetric scans at 100 mV s(-1).

19.
Biomater Adv ; 162: 213932, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38917648

RESUMEN

Clay minerals have attracted wide attention as biomedical materials due to the unique crystal structure, abundant morphology and good biocompatibility. However, the relevant studies on the abundant natural mixed clay deposits were scarcely reported. Herein, the hemostatic performance of natural mixed-dimensional attapulgite clay (MDAPT) composed of one-dimensional attapulgite and multiple two-dimensional clay were systematically investigated based on the structural evolution using oxalic acid for different time. The results of hemostatic evaluation showed that MDAPT leached by oxalic acid with 1 h presented the shortest clotting time (134 ± 12.17 s), a 15.09 % and 41.74 % reduction of relative hemoglobin absorbance at 180 s and 120 s when compared with the control group, respectively, and an increase of 19.45 % of the blood clotting index in vitro, as well as MDAPT obtained the shortest bleeding time (158.5 ± 6.9 s), nearly 66 % and 31 % reduction blood loss as compared to the blank group and the YNBY group in vivo. This improvement was primarily ascribed to the synergistic effect of lamellar non-expandable illite, and nano rod-like attapulgite. Furthermore, the rapid hemostasis of MDAPT was also due to the joint effect of superhydrophobic property toward blood, minimizing blood loss, surface negative charge, metal ions from MDAPT structural skeleton, promoting an average increase of 21 % for platelet activation. The results suggested that MDAPT could be served as a promising efficient inorganic hemostatic materials, which provided a feasible strategy to realize the high-valued utilization of natural mixed clay resources.


Asunto(s)
Arcilla , Compuestos de Magnesio , Compuestos de Silicona , Compuestos de Magnesio/química , Compuestos de Magnesio/farmacología , Arcilla/química , Animales , Compuestos de Silicona/química , Hemostáticos/farmacología , Hemostáticos/química , Coagulación Sanguínea/efectos de los fármacos , Coagulación Sanguínea/fisiología , Hemostasis/efectos de los fármacos , Hemostasis/fisiología , Silicatos de Aluminio/química , Humanos
20.
Nat Commun ; 15(1): 903, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38291054

RESUMEN

Light-harvesting is an indispensable process in photosynthesis, and researchers have been exploring various structural scaffolds to create artificial light-harvesting systems. However, achieving high donor/acceptor ratios for efficient energy transfer remains a challenge as excitons need to travel longer diffusion lengths within the donor matrix to reach the acceptor. Here, we report a polymeric supramolecular column-based light-harvesting platform inspired by the natural light-harvesting of purple photosynthetic bacteria to address this issue. The supramolecular column is designed as a discotic columnar liquid crystalline polymer and acts as the donor, with the acceptor intercalated within it. The modular columnar design enables an ultrahigh donor/acceptor ratio of 20000:1 and an antenna effect exceeding 100. Moreover, the spatial confinement within the supramolecular columns facilitates control over the energy transfer process, enabling dynamic full-color tunable emission for information encryption applications with spatiotemporal regulation security.

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