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1.
Nanomaterials (Basel) ; 13(20)2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37887937

RESUMO

Fe3C nanoparticles hold promise as catalysts and nanozymes, but their low activity and complex preparation have hindered their use. Herein, this study presents a synthetic alternative toward efficient, durable, and recyclable, Fe3C-nanoparticle-encapsulated nitrogen-doped hierarchically porous carbon membranes (Fe3C/N-C). By employing a simple one-step synthetic method, we utilized wood as a renewable and environmentally friendly carbon precursor, coupled with poly(ionic liquids) as a nitrogen and iron source. This innovative strategy offers sustainable, high-performance catalysts with improved stability and reusability. The Fe3C/N-C exhibits an outstanding peroxidase-like catalytic activity toward the oxidation of 3,3',5,5'-tetramethylbenzidine in the presence of hydrogen peroxide, which stems from well-dispersed, small Fe3C nanoparticles jointly with the structurally unique micro-/macroporous N-C membrane. Owing to the remarkable catalytic activity for mimicking peroxidase, an efficient and sensitive colorimetric method for detecting ascorbic acid over a broad concentration range with a low limit of detection (~2.64 µM), as well as superior selectivity, and anti-interference capability has been developed. This study offers a widely adaptable and sustainable way to synthesize an Fe3C/N-C membrane as an easy-to-handle, convenient, and recoverable biomimetic enzyme with excellent catalytic performance, providing a convenient and sensitive colorimetric technique for potential applications in medicine, biosensing, and environmental fields.

2.
Adv Sci (Weinh) ; 9(7): e2105072, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35060354

RESUMO

High-frequency responsive capacitors with lightweight, flexibility, and miniaturization are among the most vital circuit components because they can be readily incorporated into various portable devices to smooth out the ripples for circuits. Electrode materials no doubt are at the heart of such devices. Despite tremendous efforts and recent advances, the development of flexible and scalable high-frequency responsive capacitor electrodes with superior performance remains a great challenge. Herein, a straightforward and technologically relevant method is reported to manufacture a carbon fabric membrane "glued" by nitrogen-doped nanoporous carbons produced through a polyelectrolyte complexation-induced phase separation strategy. The as-obtained flexible carbon fabric bearing a unique hierarchical porous structure, and high conductivity as well as robust mechanical properties, serves as the free-standing electrode materials of electrochemical capacitors. It delivers an ultrahigh specific areal capacitance of 2632 µF cm-2 at 120 Hz with an excellent alternating current line filtering performance, fairly higher than the state-of-the-art commercial ones. Together, this system offers the potential electrode material to be scaled up for AC line-filtering capacitors at industrial levels.

3.
Mater Adv ; 2(15): 5203-5212, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34382003

RESUMO

This study deals with the facile synthesis of Fe1-x S nanoparticle-containing nitrogen-doped porous carbon membranes (denoted as Fe1-x S/N-PCMs) via vacuum carbonization of hybrid porous poly(ionic liquid) (PIL) membranes, and their successful use as a sulfur host material to mitigate the shuttle effect in lithium-sulfur (Li-S) batteries. The hybrid porous PIL membranes as the sacrificial template were prepared via ionic crosslinking of a cationic PIL with base-neutralized 1,1'-ferrocenedicarboxylic acid, so that the iron source was molecularly incorporated into the template. The carbonization process was investigated in detail at different temperatures, and the chemical and porous structures of the carbon products were comprehensively analyzed. The Fe1-x S/N-PCMs prepared at 900 °C have a multimodal pore size distribution with a satisfactorily high surface area and well-dispersed iron sulfide nanoparticles to physically and chemically confine the LiPSs. The sulfur/Fe1-x S/N-PCM composites were then tested as electrodes in Li-S batteries, showing much improved capacity, rate performance and cycle stability, in comparison to iron sulfide-free, nitrogen-doped porous carbon membranes.

4.
Macromol Rapid Commun ; 42(13): e2100077, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34061421

RESUMO

Herein, the fabrication of iron-containing porous polyelectrolyte membranes (PPMs) via ionic complexation between an imidazolium-based poly(ionic liquid) (PIL) and 1,1-ferrocenedicarboxylic acid is reported. The key parameters to control the microstructure of porous hybrid membranes are investigated in detail. Further aerobic pyrolysis of such porous hybrid membranes at 900 °C can transfer the ferrocene-containing PPMs into freestanding porous iron oxide films. This process points out a sacrificial template function of porous poly(ionic liquid) membranes in the fabrication of porous metal oxide films.


Assuntos
Líquidos Iônicos , Compostos Férricos , Membranas Artificiais , Metalocenos , Porosidade
5.
Macromolecules ; 53(20): 8951-8959, 2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33132419

RESUMO

We report a side group modification strategy to tailor the structure of a polymer of intrinsic microporosity (PIM-1). PIM-1 with an average of ∼50% of the repeat units converted to tetrazole is prepared, and a subsequent reaction then introduces three types of pseudo-ionic liquid tetrazole-like structures (PIM-1-ILx). The presence of pseudo-ionic liquid functional groups in the PIM-1 structure increases gas selectivities for O2/N2 and CO2/N2, while it decreases pure-gas permeabilities. The overall gas separation performance of PIM-1-ILx is close to the 2008 Robeson upper bound. Since the tetrazoles are versatile groups for building a wide variety of ionic liquids, the modification method can be expanded to explore a broad spectrum of functional groups.

6.
Int J Biol Macromol ; 164: 356-370, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32682976

RESUMO

One of the most effective approaches for treatment of chronic rhinosinusitis is the use of hydrogel scaffolds with the sustained release of a given required drug. With this in mind, first, we synthesized and characterized poly (lactide-co-glycolide) (PLGA) micro and nano particles loaded with dexamethasone (DEX). We observed a 7-day release of DEX from nanoparticles, while the microparticles showed a 22-day release profile. Due to their slower rate of release, the PLGA microparticles loaded with DEX (PLGADEX microparticles) were specifically chosen for this study. As a second step, chitosan/polyvinylpyrrolidone (PVP) based hydrogels were prepared in various weight ratios and the PLGADEX microparticles were optimized in their structure based on variable gelation times. The morphological studies showed PLGADEX microparticles homogenously dispersed in the hydrogels. Moreover, the effect of weight ratio in the presence and absence of optimum percentage of PLGADEX microparticles was studied. The resultant hydrogels demonstrated a range of advantages, including good mechanical strength, porous morphology, amorphous structure, high swelling ratio, controlled biodegradability rate, and antibacterial activity. Additionally, a cytotoxicity analysis confirmed that the hydrogel scaffolds do not have adverse effects on the cells; our release studies in the hydrogel with the highest PVP content also showed 80% release after 30 days. Based on these results we were able to predict and control some of the mechanical properties, including the microstructure of the scaffolds, as well as the drug release, by optimizing the polymers - microparticle concentration, plus their resulting interactions. This optimized hydrogel can become part of a suitable alternative for treatment of allergic rhinitis and chronic sinusitis.


Assuntos
Quitosana/química , Dexametasona/administração & dosagem , Portadores de Fármacos/química , Hidrogéis/química , Microesferas , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Pesquisa Biomédica/métodos , Fenômenos Químicos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Hidrólise , Tamanho da Partícula , Porosidade , Análise Espectral , Engenharia Tecidual
7.
Int J Biol Macromol ; 143: 533-545, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31816374

RESUMO

One of the most effective approaches for treatment of cartilage involves the use of porous three-dimensional scaffolds, which are useful for improving not only cellular adhesion but also mechanical properties of the treated tissues. In this study, we manufactured a composite scaffold with optimum properties to imitate nasal cartilage attributes. Cartilage extracellular matrix (ECM) was used in order to improve the cellular properties of the scaffolds; while, chitosan and agarose were main materials that are used to boost the mechanical and rheological properties of the scaffolds. Furthermore, we explored the effect of the various weight ratios of chitosan, agarose, and ECM on the mechanical and biomedical properties of the composite scaffolds using the Taguchi method. The resulting composites display a range of advantages, including good mechanical strength, porous morphology, partial crystallinity, high swelling ratio, controlled biodegradability rate, and rheological characteristics. Additionally, we performed the cytotoxicity tests to confirm the improvement of the structure and better cell attachments on the scaffolds. Our findings illustrate that the presence of the ECM in chitosan/agarose structure improves the biomedical characteristics of the final scaffold. In addition, we were able to control the mechanical properties and microstructure of the scaffolds by optimizing the polymers' concentration and their resulting interactions. These results present a novel scaffold with simultaneously enhanced mechanical and cellular attributes comparing to the scaffolds without ECM for nasal cartilage tissue engineering applications.


Assuntos
Cartilagem/metabolismo , Quitosana/química , Condrócitos/metabolismo , Matriz Extracelular/química , Sefarose/química , Engenharia Tecidual , Alicerces Teciduais/química , Cartilagem/citologia , Condrócitos/citologia , Humanos , Teste de Materiais
8.
Int J Biol Macromol ; 139: 1168-1181, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31419553

RESUMO

Novel injectable thermosensitive PNIPAM/hyaluronic acid hydrogels containing various amounts of chitosan-g-acrylic acid coated PLGA (ACH-PLGA) micro/nanoparticles were synthesized and designed to facilitate the regeneration of cartilage tissue. The ACH-PLGA particles were used in the hydrogels to play a triple role: first, the allyl groups on the chitosan-g-acrylic acid shell act as crosslinkers for PNIPAM and improved the mechanical properties of the hydrogel to mimic the natural cartilage tissue. Second, PLGA core acts as a carrier for the controlled release of chondrogenic small molecule melatonin. Third, they could reduce the syneresis of the thermosensitive hydrogel during gelation. The optimum hydrogel with the minimum syneresis and the maximum compression modulus was chosen for further evaluations. This hydrogel showed a great integration with the natural cartilage during the adhesion test, and also, presented an interconnected porous structure in scanning electron microscopy images. Eventually, to evaluate the cytotoxicity, mesenchymal stem cells were encapsulated inside the hydrogel. MTT and Live/Dead assay showed that the hydrogel improved the cells growth and proliferation as compared to the tissue culture polystyrene. Histological study of glycosaminoglycan (GAG) showed that melatonin treatment has the ability to increase the GAG synthesis. Overall, due to the improved mechanical properties, low syneresis, the ability of sustained drug release and also high bioactivity, this injectable hydrogel is a promising material system for cartilage tissue engineering.


Assuntos
Resinas Acrílicas/química , Cartilagem/citologia , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Ácido Hialurônico/química , Hidrogéis/farmacologia , Engenharia Tecidual , Cartilagem/efeitos dos fármacos , Técnicas de Química Sintética , Humanos , Hidrogéis/administração & dosagem , Hidrogéis/síntese química , Hidrogéis/química , Injeções , Melatonina/química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Microesferas , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Alicerces Teciduais/química
9.
Int J Biol Macromol ; 126: 193-208, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30583002

RESUMO

Injectable hydrogels and biodegradable nanoparticles are using in tissue engineering applications and drug delivery systems. To improve physiochemical properties of biomaterials and to develop their applications, hybrid systems consist of hydrogels, and biodegradable nanoparticles were synthesized. In this study, hybrid systems based on double crosslinked hyaluronic acid and PLGA/Dexamethasone sodium phosphate (PLGADEX) nanoparticles are designed and synthesized in several steps. At the first step, poly(l-lactide-co-glycolide) (PLGA) in a ratio of LLA:GA = 85:15 mol% was synthesized via ring-opening polymerization. Then, PLGADEX nanoparticles were synthesized in different ratios using the partially modified emulsification-diffusion method and fully characterized, and desirable nanoparticle was selected (PLGADEX20). At the second step, a double cross-linked hyaluronic acid (XHA) was prepared by mixing various ratios of amino-hyaluronic acid and aldehyde-hyaluronic acid in the presence of genipin. Finally, by mixing of various ratios of PLGADEX20 and Dexamethasone sodium phosphate (DEX) with different ratios of XHA, hybrid systems were prepared. Based on the characterization of hybrid samples and the release studies, hydrogels containing nanoparticles showed a controlled drug release, while the best sample with 3% of optimized nanoparticle was chosen. According to physiochemical and biological properties, these hybrid systems can be good candidates for anti-adhesion barriers, wound dressings, and novel drug delivery systems.


Assuntos
Fenômenos Químicos , Reagentes de Ligações Cruzadas/química , Dexametasona/farmacologia , Ácido Hialurônico/síntese química , Hidrogéis/síntese química , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Reologia , Calibragem , Cromatografia em Gel , Cor , Liberação Controlada de Fármacos , Fibroblastos/citologia , Humanos , Ácido Hialurônico/química , Hidrogéis/química , Iridoides/química , Tamanho da Partícula , Espectroscopia de Prótons por Ressonância Magnética , Análise de Regressão , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo
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