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1.
Nat Commun ; 15(1): 1167, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38326434

RESUMEN

The Hume-Rothery rules governing solid-state miscibility limit the compositional space for new inorganic material discovery. Here, we report a non-equilibrium, one-step, and scalable flame synthesis method to overcome thermodynamic limits and incorporate immiscible elements into single phase ceramic nanoshells. Starting from prototype examples including (NiMg)O, (NiAl)Ox, and (NiZr)Ox, we then extend this method to a broad range of Ni-containing ceramic solid solutions, and finally to general binary combinations of elements. Furthermore, we report an "encapsulated exsolution" phenomenon observed upon reducing the metastable porous (Ni0.07Al0.93)Ox to create ultra-stable Ni nanoparticles embedded within the walls of porous Al2O3 nanoshells. This nanoconfined structure demonstrated high sintering resistance during 640 h of catalysis of CO2 reforming of methane, maintaining constant 96% CH4 and CO2 conversion at 800 °C and dramatically outperforming conventional catalysts. Our findings could greatly expand opportunities to develop novel inorganic energy, structural, and functional materials.

2.
Adv Mater ; 36(4): e2305684, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37725635

RESUMEN

Conjugated polymers with chiral side chains are of interest in areas including chiral photonics, optoelectronics, and chemical and biological sensing. However, the low dissymmetry factors of most neat polymer thin films have limited their practical application. Here, a robust method to increase the absorption dissymmetry factor in a poly-fluorene-thiophene (PF8TS series) system is demonstrated by varying molecular weight and introducing an achiral plasticizer, polyethylene mono alcohol (PEM-OH). Extending chain length within the optimal range and adding this long-chain alcohol significantly enhance the chiroptical properties of spin-coated and annealed thin films. Mueller matrix spectroscopic ellipsometry (MMSE) analysis shows good agreement with the steady-state transmission measurements confirming a strong chiral response (circular dichroism (CD) and circular birefringence (CB)), ruling out linear dichroism, birefringence, and specific reflection effects. Solid-state NMR studies of annealed hybrid chiral polymer systems show enhancement of signals associated with aromatic π-stacked backbone and the ordered side-chain conformations. Further studies using Raman spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), atomic force microscopy (AFM), and polarized optical microscopy (POM) indicate that PEM-OH facilitates mesoscopic crystal domain ordering upon annealing. This provides new insights into routes for tuning optical activity in conjugated polymers.

3.
Adv Mater ; 35(26): e2301007, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37002918

RESUMEN

Nanoparticles (NPs) at high loadings are often used in mixed matrix membranes (MMMs) to improve gas separation properties, but they can lead to defects and poor processability that impede membrane fabrication. Herein, it is demonstrated that branched nanorods (NRs) with controlled aspect ratios can significantly reduce the required loading to achieve superior gas separation properties while maintaining excellent processability, as demonstrated by the dispersion of palladium (Pd) NRs in polybenzimidazole for H2 /CO2 separation. Increasing the aspect ratio from 1 for NPs to 40 for NRs decreases the percolation threshold volume fraction by a factor of 30, from 0.35 to 0.011. An MMM with percolated networks formed by Pd NRs at a volume fraction of 0.039 exhibits H2 permeability of 110 Barrer and H2 /CO2 selectivity of 31 when challenged with simulated syngas at 200 °C, surpassing Robeson's upper bound. This work highlights the advantage of NRs over NPs and nanowires and shows that right-sizing nanofillers in MMMs is critical to construct highly sieving pathways at minimal loadings. This work paves the way for this general feature to be applied across materials systems for a variety of chemical separations.

4.
Chem Sci ; 14(5): 1205-1217, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36756340

RESUMEN

Branching phenomena are ubiquitous in both natural and artificial crystallization processes. The branched nanostructures' emergent properties depend upon their structures, but their structural tunability is limited by an inadequate understanding of their formation mechanisms. Here we developed an ensemble of Nickel-Based nano-Composites (NBCs) to investigate branching phenomena in solution-phase synthesis with precision and in depth. NBCs of 24 morphologies, including dots, core@shell dots, hollow shells, clusters, polyhedra, platelets, dendrites, urchins, and dandelions, were synthesized through systematic adjustment of multiple synthesis parameters. Relationships between the synthesis parameters and the resultant morphologies were analyzed. Classical or non-classical models of nucleation, nascent growth, 1D growth, 2D growth, 3D reconstruction, aggregation, and carburization were defined individually and then integrated to provide a holistic view of the formation mechanism of branched NBCs. Finally, guidelines were extracted and verified to guide the rational solution-phase syntheses of branched nanomaterials with emergent biological, chemical, and physical properties for potential applications in immunology, catalysis, energy storage, and optics. Demonstrating a systematic approach for deconvoluting the formation mechanism and enhancing the synthesis tunability, this work is intended to benefit the conception, development, and improvement of analogous artificial branched nanostructures. Moreover, the progress on this front of synthesis science would, hopefully, deepen our understanding of branching phenomena in nature.

5.
ACS Sens ; 8(1): 243-253, 2023 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-36647806

RESUMEN

High performance with lower power consumption is one among the essential features of a sensing device. Minute traces of hazardous gases such as NO2 are difficult to detect. Tin disulfide (SnS2) nanosheets have emerged as a promising NO2 sensor. However, their poor room-temperature conductivity gives rise to inferior sensitivity and sluggish recovery rates, thereby hindering their applications. To mitigate this problem, we present a low-cost ultrasensitive NO2 gas sensor with tin disulfide/multiwalled carbon nanotube (SnS2/MWCNT) nanocomposites, prepared using a single-step hydrothermal method, as sensing elements. Relative to pure SnS2, the conductivity of nanocomposites improved significantly. The sensor displayed a decrease in resistance when exposed to NO2, an oxidizing gas, and exhibited p-type conduction, also confirmed in separate Mott-Schottky measurements. At a temperature of 20 °C, the sensor device has a relative response of about ≈5% (3%) for 25 ppb (1 ppb) of NO2 with complete recovery in air (10 min) and excellent recovery rates with UV activation (0.3 min). A theoretical lower limit of detection (LOD) of 7 ppt implies greater sensitivity than all previously reported SnS2-based gas sensors, to the best of our knowledge. The improved sensing characteristics were attributed to the formation of nano p-n heterojunctions, which enhances the charge transport and gives rise to faster response. The composite sensor also demonstrated good NO2 selectivity against a variety of oxidizing and reducing gases, as well as excellent stability and long-term durability. This work will provide a fresh perspective on SnS2-based composite materials for practical gas sensors.


Asunto(s)
Dióxido de Nitrógeno , Estaño , Temperatura , Disulfuros , Gases
6.
ACS Appl Mater Interfaces ; 15(4): 5439-5448, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36668703

RESUMEN

Hydrogen (H2), as a chemical energy carrier, is a cleaner alternative to conventional fossil fuels with zero carbon emission and high energy density. The development of fast, low-cost, and sensitive H2 detection systems is important for the widespread adoption of H2 technologies. Paper is an environment-friendly, porous, and flexible material with great potential for use in sustainable electronics. Here, we report a paper-based sensor for room-temperature H2 detection using ultrathin palladium nanowires (PdNWs). To elucidate the sensing mechanism, we compare the performance of polycrystalline and quasi-single-crystalline PdNWs. The polycrystalline PdNWs showed a response of 4.3% to 1 vol % H2 with response and recovery times of 4.9 and 10.6 s, while quasi-single-crystalline PdNWs showed a response of 8% to 1 vol % H2 with response and recovery times of 9.3 and 13.0 s, respectively. The polycrystalline PdNWs show excellent selectivity, stability, and sensitivity, with a limit of detection of 10 ppm H2 in air. The fast response of ultrathin polycrystalline PdNW paper-based sensors arises from the synergistic effects of their ultrasmall diameter, high-index surface facets, strain-coupled grain boundaries, and porous paper substrate. This paper-based sensor is one of the fastest chemiresistive H2 sensors reported and is potentially orders of magnitude less expensive than current state-of-the-art H2-sensing solutions. This brings low-cost, room-temperature chemiresistive H2 sensing closer to the performance of ultrafast optical sensors and high-temperature metal oxide-based sensors.

7.
J Biomed Mater Res A ; 111(1): 6-14, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36054416

RESUMEN

Dental implant clinical success is dependent on effective peri-implant tissue attachment to the trans-mucosal portion following placement. Modification of transmucosal implant surfaces can improve cellular adhesion and function leading to formation of an effective soft-tissue seal during healing, of which gingival fibroblasts are prominent cells to migrate to repair wounds and crucial for the development of a collagen rich connective tissue. Biocompatible loaded scaffold materials have been developed to allow local release of molecules with effective biological activity. Our previous studies indicate that strontium can promote gingival fibroblast metabolism, decrease apoptosis and support adhesion to titanium healing abutments. In this study, we developed a strontium-loaded alginate hydrogel scaffold which can be easily personalized to fit over any size and shape of implant transmucosal collar or healing abutment. Results indicate that biologically active strontium ions are effectively released from loaded alginate hydrogel material to promote fibroblast viability and migration to repair in vitro wounds similar to that of strontium citrate solution. Overall, this novel strontium-loaded alginate scaffold device displays good biocompatibility and functionality, demonstrating high potential as a system to provide local delivery of strontium to improve peri-implant mucosal healing following implant placement and clinical success.


Asunto(s)
Implantes Dentales , Estroncio , Estroncio/farmacología , Hidrogeles/farmacología , Encía , Fibroblastos , Titanio , Alginatos/farmacología
8.
J Phys Chem Lett ; 13(39): 9085-9095, 2022 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-36154023

RESUMEN

Advancing the emerging area of chiral photonics requires modeling-guided concepts of chiral material design to enhance optical activity and associated optical rotatory dispersion. Herein, we introduce conformational engineering achieved by tuning polymer backbone conjugation through introduction of thiophene structural units in a chiral fluorene polymer backbone. Our theoretical calculations reveal a relationship between the structural conformation and the resultant rotational strength. We further synthesize a series of chiral fluorene-based polymers copolymerized with thiophene whose optical chirality trend is in qualitative agreement with predictions of our quantum chemical calculations. Varying the number of thiophene units in the monomer building block allows us to modulate the rotational strength by tuning the intrafibril helicity of single-stranded polymer chains, whereby the monomer conjugation is retained throughout the whole length of the polymer backbone. Our design concept delineates an underexamined approach: the concept of tuning backbone conjugation and helicity within the main chain to enhance the optical activity of chiral polymer systems.


Asunto(s)
Polímeros , Tiofenos , Fluorenos , Conformación Molecular , Polímeros/química
9.
Angew Chem Int Ed Engl ; 61(43): e202210313, 2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-36006774

RESUMEN

Intraparticle ion motions are critical to the structure and properties of nanomaterials, but rarely disclosed. Herein, in situ visualization of ion motions in a single nanoparticle is presented by dark-field microscopy imaging, which shows HgCl2 -induced structural transformation of amorphous selenium nanoparticles (SeNPs) with the main composition of Se8 . Owing to the high binding affinity with selenium and coulomb interactions, Hg2+ ions can permeate into the interior of SeNPs, making the amorphous Se8 turn to polycrystalline Hg3 Se2 Cl2 . As a proof of concept, SeNPs then serve as a highly effective scavenger for selective removal of Hg2+ ions from solution. This new finding offers visual proof for the photophysical process involving intraparticle ion motion, demonstrating that tracking the ion motions is a novel strategy to comprehend the formation mechanism with the purpose of developing new nanostructures like nanoalloys and nano metal compounds.

10.
ACS Appl Mater Interfaces ; 14(35): 40382-40395, 2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-36001381

RESUMEN

Continuous detection of toxic and hazardous gases like nitric oxide (NO) and ammonia (NH3) is needed for environmental management and noninvasive diagnosis of various diseases. However, to the best of our knowledge, dual detection of these two gases has not been previously reported. To address the challenge, we demonstrate the design and fabrication of low-cost NH3 and NO dual gas sensors using tungsten disulfide/multiwall carbon nanotube (WS2/MWCNT) nanocomposites as sensing channels which maintained their performance in a humid environment. The composite-based device has shown successful dual detection at temperatures down to 18 °C and relative humidity of 90%. For 0.1 ppm ammonia, it exhibited a p-type conduction with response and recovery times of 102 and 261 s, respectively; on the other hand, with NO (10 ppb, n-type), these times were 285 and 198 s, respectively. The device with 5 mg MWCNTs possesses a superior selectivity along with a relative response of ≈7% (5 ppb) and ≈5% (0.1 ppm) for NO and NH3, respectively, at 18 °C. The response is less affected by relative humidity, and this is attributed to the presence of MWCNTs that are hydrophobic in nature. Upon simultaneous exposure to NO (5-10 ppb) and NH3 (0.1-5 ppm), the response was dominated by NO, implying clear discrimination to the simultaneous presence of these two gases. We propose a sensing mechanism based on adsorption/desportion and accompanied charge transfer between the adsorbed gas molecules and sensing surface. The results suggest that an optimized weight ratio of WS2 and MWCNTs could govern favorable sensing conditions for a particular gas molecule.

11.
Angew Chem Int Ed Engl ; 61(35): e202206870, 2022 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-35773200

RESUMEN

Mesoporous silica is a versatile material for energy, environmental, and medical applications. Here, for the first time, we report a flame aerosol synthesis method for a class of mesoporous silica with hollow structure and specific surface area exceeding 1000 m2 g-1 . We show its superior performance in water purification, as a drug carrier, and in thermal insulation. Moreover, we propose a general route to produce mesoporous nanoshell-supported nanocatalysts by in situ decoration with active nanoclusters, including noble metal (Pt/SiO2 ), transition metal (Ni/SiO2 ), metal oxide (CrO3 /SiO2 ), and alumina support (Co/Al2 O3 ). As a prototypical application, we perform dry reforming of methane using Ni/SiO2 , achieving constant 97 % CH4 and CO2 conversions for more than 200 hours, dramatically outperforming an MCM-41 supported Ni catalyst. This work provides a scalable strategy to produce mesoporous nanoshells and proposes an in situ functionalization mechanism to design and produce flexible catalysts for many reactions.

12.
ACS Sens ; 7(1): 225-234, 2022 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-35025508

RESUMEN

Palladium has long been explored for use in gas sensors because of its excellent catalytic properties and its unique property of forming hydrides in the presence of H2. However, pure Pd-based sensors usually suffer from low response and a relatively high limit of detection. Palladium nanosheets (PdNS) are of particular interest for gas sensing applications due to their high surface area and excellent electrical conductivity. Here, we demonstrate the design and fabrication of low-cost PdNS-based dual gas sensors for room-temperature detection of H2 and CO over a wide concentration range. We fabricated sensors using multiwalled carbon nanotube@PdNS (MWCNT@PdNS) composites and compared their performance against pure PdNS devices for hydrogen sensing based on electrical resistive response. Devices using PdNS alone had a response and response time of 0.4% and 50 s, respectively, to 1% H2 in air. MWCNT@PdNS (1:5 mass ratio) showed enhanced performance at a lower hydrogen concentration with a limit of detection (LODH2) of 5 ppm. Nearly an order of magnitude increase in response was observed on increasing the amount of MWCNT to 50 mass % in the nanocomposite, but the response fell off at low H2 concentration. Overall, these PdNS-based sensors were found to show good repeatability, stability, and performance under humid conditions. Their response was selective for H2versus CH4, CO2, and NH3; the response to CO was comparable in magnitude but opposite in sign to the response to H2. Upon simultaneous exposure to equal concentrations (10 ppm each) of H2 and CO, the response to CO was dominant. The PdNS showed high sensitivity to CO, detecting as little as 1 ppm CO in air at room temperature. The sensitivity to CO could be used either in a stand-alone room-temperature CO detector, where H2 is known not to be present, or in combination with CO and combustible gas detectors to distinguish H2 from other combustible gases.

13.
ACS Nano ; 15(11): 18260-18269, 2021 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-34747170

RESUMEN

Peptide sequence engineering can potentially deliver materials-selective binding capabilities, which would be highly attractive in numerous biotic and abiotic nanomaterials applications. However, the number of known materials-selective peptide sequences is small, and identification of new sequences is laborious and haphazard. Previous attempts have sought to use machine learning and other informatics approaches that rely on existing data sets to accelerate the discovery of materials-selective peptides, but too few materials-selective sequences are known to enable reliable prediction. Moreover, this knowledge base is expensive to expand. Here, we combine a comprehensive and integrated experimental and modeling effort and introduce a Bayesian Effective Search for Optimal Sequences (BESOS) approach to address this challenge. Through this combined approach, we significantly expand the data set of Au-selective peptide sequences and identify an additional Ag-selective peptide sequence. Analysis of the binding motifs for the Ag-binders offers a roadmap for future prediction with machine learning, which should guide identification of further Ag-selective sequences. These discoveries will enable wider and more versatile integration of Ag nanoparticles in biological platforms.


Asunto(s)
Oro , Nanopartículas del Metal , Plata , Teorema de Bayes , Péptidos
14.
ACS Appl Mater Interfaces ; 13(48): 57814-57821, 2021 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-34842415

RESUMEN

Syntheses of Cu-, Ag-, and Ag-Cu-Co3O4 nanomaterials are of interest for a wide range of applications including electrochemistry, thermal catalysis, energy storage, and electronics. However, Co3O4-based nanomaterials have not been explored for surface-enhanced Raman scattering (SERS). Here, we present Cu-, Ag-, and Ag-Cu-Co3O4 nanomaterials of a hierarchical flower shape comprising two separate phases: a pure Cu or Ag core and multiple Co3O4 branches, in which the optical properties of the core and the magnetic properties of the branches are integrated. In addition, a series of nonmagnetic Cu-dominant Cu-Co-O polyhedra without Co3O4 branches were derived from Cu-Co3O4. The polyhedron morphology can be controlled and transformed among cubes, cuboctahedra, and truncated octahedra by tuning the amounts of ligands and additives to vary the potential energy and growth rate of specific crystal facets. The flowerlike Cu-, Ag-, and Ag-Cu-Co3O4 were characterized for SERS enhancement, showing that Ag-Cu-Co3O4 does not enhance SERS from 4-mercaptobenzoic acid (4-MBA) but dramatically and selectively does so for adsorbed rhodamine 6G. Obviously, the synergy of Ag and Cu within the Co3O4 flower constraint promotes the SERS activity. This type of spinel with not only excellent SERS activity but also ferromagnetism could be of great potential in tandem SERS detection/magnetic separation and related applications.

15.
ACS Nano ; 15(7): 12119-12128, 2021 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-34254506

RESUMEN

Nanoporous silica membranes exhibit excellent H2/CO2 separation properties for sustainable H2 production and CO2 capture but are prepared via complicated thermal processes above 400 °C, which prevent their scalable production at a low cost. Here, we demonstrate the rapid fabrication (within 2 min) of ultrathin silica-like membranes (∼3 nm) via an oxygen plasma treatment of polydimethylsiloxane-based thin-film composite membranes at 20 °C. The resulting organosilica membranes unexpectedly exhibit H2 permeance of 280-930 GPU (1 GPU = 3.347 × 10-10 mol m-2 s-1 Pa-1) and H2/CO2 selectivity of 93-32 at 200 °C, far surpassing state-of-the-art membranes and Robeson's upper bound for H2/CO2 separation. When challenged with a 3 d simulated syngas test containing water vapor at 200 °C and a 340 d stability test, the membrane shows durable separation performance and excellent hydrothermal stability. The robust H2/CO2 separation properties coupled with excellent scalability demonstrate the great potential of these organosilica membranes for economic H2 production with minimal carbon emissions.

16.
Chem Soc Rev ; 50(12): 7132-7249, 2021 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-33973579

RESUMEN

The synthesis of nanomaterials, with characteristic dimensions of 1 to 100 nm, is a key component of nanotechnology. Vapor-phase synthesis of nanomaterials has numerous advantages such as high product purity, high-throughput continuous operation, and scalability that have made it the dominant approach for the commercial synthesis of nanomaterials. At the same time, this class of methods has great potential for expanded use in research and development. Here, we present a broad review of progress in vapor-phase nanomaterial synthesis. We describe physically-based vapor-phase synthesis methods including inert gas condensation, spark discharge generation, and pulsed laser ablation; plasma processing methods including thermal- and non-thermal plasma processing; and chemically-based vapor-phase synthesis methods including chemical vapor condensation, flame-based aerosol synthesis, spray pyrolysis, and laser pyrolysis. In addition, we summarize the nanomaterials produced by each method, along with representative applications, and describe the synthesis of the most important materials produced by each method in greater detail.

17.
ACS Appl Mater Interfaces ; 13(15): 17618-17628, 2021 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-33821611

RESUMEN

We introduce a flame-based aerosol process for producing supported non-noble metal nanocatalysts from inexpensive aqueous metal salt solutions, using catalysts for the dry reforming of methane (DRM) as a prototype. A flame-synthesized nickel-doped magnesia (MgO) nanocatalyst (NiMgO-F) was fully physicochemically characterized and tested in a flow reactor system, where it showed stable DRM activity from 500 to 800 °C. A kinetic study was conducted, and apparent activation energies were extracted for the temperature range of 500-650 °C. It was then compared with a Ni-decorated MgO nanopowder prepared by wet impregnation of (1) flame-synthesized MgO (NiMgO-FI) and (2) a commercial MgO nanopowder (NiMgO-CI) and with (3) a NiMgO catalyst prepared by co-precipitation (NiMgO-CP). NiMgO-F showed the highest catalytic activity per mass and per metallic surface area and was stable for continuous H2 production at 700 °C for 50 h. Incorporation of potential promoters and co-catalysts was also demonstrated, but none showed significant performance improvement. More broadly, nanomaterials produced by this approach could be used as binary or multicomponent catalysts for numerous catalytic processes.

18.
Nanoscale ; 13(9): 4828-4834, 2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33650624

RESUMEN

We report the colloidal synthesis of quaternary kesterite CZTS-CZTSe heterostructures via anion exchange reactions on a kesterite CZTS template. The crystal phase selectivity during the synthesis (kesterite vs. wurtzite) is due to the initial nucleation of cubic Cu9S5 seeds, followed by incorporation of Zn and Sn. Upon injection of Se-precursor, which triggered simultaneous anion exchange and overgrowth of the pristine CZTS template, sandwich CZTS-CZTSe (core-tip) nanoheterostructures were obtained. X-ray photoelectron spectroscopy (XPS) and optical band gap measurement results suggest a change of intrinsic electronic structure of CZTS by Se-treatment. Our study not only provides insight into mechanisms of formation of kesterite CZTS nanocrystals (NCs) and subsequent anion exchange reactions, but also opens doors to access novel CZTSSe nanostructures for potential applications.

19.
J Mater Chem B ; 9(10): 2505-2514, 2021 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-33657198

RESUMEN

Cannabidiol (CBD) has been shown to slow cancer cell growth and is toxic to human glioblastoma cell lines. Thus, CBD could be an effective therapeutic for glioblastoma. In the present study, we explored the anticancer effect of cannabidiol loaded magnesium-gallate (CBD/Mg-GA) metal-organic framework (MOF) using the rat glioma brain cancer (C6) cell line. Bioactive and microporous magnesium gallate MOF was employed for simultaneous delivery of two potential anticancer agents (gallic acid and CBD) to the cancer cells. Gallic acid (GA), a polyphenolic compound, is part of the MOF framework, while CBD is loaded within the framework. Slow degradation of CBD/Mg-GA MOF in physiological fluids leads to sustained release of GA and CBD. CBD's anti-cancer actions target mitochondria, inducing their dysfunction and generation of harmful reactive oxygen species (ROS). Anticancer effects of CBD/Mg-GA include a significant increase in ROS production and a reduction in anti-inflammatory responses as reflected by a significant decrease in TNF-α expression levels. Molecular mechanisms that underlie these effects include the modulation of NF-κB expression, triggering the apoptotic cascades of glioma cells. CBD/Mg-GA MOF has potential anti-cancer, anti-inflammatory and anti-oxidant properties. Thus, the present study demonstrates that CBD/Mg-GA MOF may be a promising therapeutic for glioblastoma.


Asunto(s)
Cannabidiol/química , Cannabidiol/farmacología , Portadores de Fármacos/química , Ácido Gálico/química , Glioblastoma/tratamiento farmacológico , Magnesio/química , Estructuras Metalorgánicas/química , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Cannabidiol/uso terapéutico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Glioblastoma/patología , Humanos , FN-kappa B/metabolismo , Especies Reactivas de Oxígeno/metabolismo
20.
Adv Funct Mater ; 31(10): 2008054, 2021 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-33613147

RESUMEN

SARS-CoV-2 and other respiratory viruses spread via aerosols generated by infected people. Face masks can limit transmission. However, widespread use of disposable masks consumes tremendous resources and generates waste. Here, a novel material for treating blown polypropylene filtration media used in medical-grade masks to impart antimicrobial activity is reported. To produce thin copper@ZIF-8 core-shell nanowires (Cu@ZIF-8 NWs), Cu NWs are stabilized using a pluronic F-127 block copolymer, followed by growth of ZIF-8 to obtain uniform core-shell structures. The Cu@ZIF-8 NWs are applied to filtration media by dip coating. Aerosol filtration efficiency decreases upon exposure to ethanol (solvent for dip-coating), but increases with addition of Cu@ZIF-8 NWs. Cu@ZIF-8 NWs shows enhanced antibacterial activity, compared to Cu NWs or ZIF-8 alone, against Streptococcus mutans and Escherichia coli. Antiviral activity against SARS-CoV-2 is assayed using virus-infected Vero E6 cells, demonstrating 55% inhibition of virus replication after 48 h by 1 µg of Cu@ZIF-8 NWs per well. Cu@ZIF-8 NWs' cytotoxicity is tested against four cell lines, and their effect on inflammatory response in A549 cells is examined, demonstrating good biocompatibility. This low-cost, scalable synthesis and straightforward deposition of Cu@ZIF-8 NWs onto filter media has great potential to reduce disease transmission, resource consumption, and environmental impact of waste.

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