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1.
Carbohydr Polym ; 292: 119678, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35725173

RESUMO

To meet the requirement of personalization, there is an urgent need to develop a simple, efficient and versatile manufacturing method for customized contact lens manufabrication. Here, we report a novel electrofabrication methodology (i.e., electrodeposition) for the fabrication of hydrogel contact lenses, which can induce covalent cross-linking between chitosan and epichlorohydrin simultaneously. The transmittance and toughness of hydrogels are improved by electrochemical cross-linking without affecting their oxygen permeability. Furthermore, the geometry of the chitosan based hydrogel contact lenses can be customized simply by the electrode template, and its characteristics can be regulated by electrical signals and electrochemical cross-linking. The electrodeposited hydrogel contact lenses have good optical properties, mechanical properties and biocompatibility, and their anti-adhesion properties to Staphylococcus aureus are close to commercial contact lenses. This work reveals the mechanism of electrochemical cross-linking between chitosan and epichlorohydrin and provides an alternative method for contact lens fabrication.


Assuntos
Quitosana , Lentes de Contato , Quitosana/química , Galvanoplastia , Epicloroidrina , Hidrogel de Polietilenoglicol-Dimetacrilato , Hidrogéis/química
2.
J Assoc Physicians India ; 70(4): 11-12, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35443545

RESUMO

Epichlorohydrin is an organochlorine compound and a epoxide. It is a colourless liquid with a pungent, garlic like odour, moderately soluble in water, but miscible with most polar organic solvents. It is used in the production of glycerol, plastics, epoxy glues and resins, epoxy diluents and elastomers. Epichlorohydrin is a common chemical used in industry and Accidental exposure to Epichlorohydrin can occur in workers working in glycerol, plastics, epoxy glues and resins, epoxy diluents and elastomer factories. AIMS AND OBJECTIVES: To study the clinical profile of patients with Acute Epichlorohydrin Poisoning And identify the frequency and nature of lung involvement. MATERIALS AND METHOD: 30 patients of age 18 and above with Acute Epichlorohydrin poisoning were included in the study. Symptomatology and History, ABG, chest Xray and Hrct chest findings were included in the clinical profile. Distribution of responses were examined using frequencies and percentages and cross tabulation were done between various subgroups. OBSERVATION AND RESULTS: All the patients had accidental direct exposure to Epichlorohydrin. All the patients presented with acute onset respiratory distress and dry cough. Burning sensation and redness and watering from eyes with watering from nose were present in all the patients. Burning sensation in the throat was present in two third of the patient. Two third of the patients developed ARDS and of them 60 % developed moderate to severe ARDS. Two thirds of the patient required ICU admission and out of them 60 % required NIV support and rest 40% were managed by Oxygen via Facemask. Rest one third patient required admission in general ward. All the patients show heterogenous opacities in chest Xray. All the patients show patchy areas of consolidation with Ground Glass changes in HRCT Chest. Two third of the patients show pleural effusion in both Chest Xray and HRCT Chest and out of them 80 % patients show bilateral pleural effusion. CONCLUSION: ARDS of varying degree with mucosal irritation is the most common presenting feature of patients with ACUTE EPICHLOROHYDRIN POISONING. Pneumonia with HRCT chest showing Ground Glass Opacities are common.


Assuntos
Derrame Pleural , Síndrome do Desconforto Respiratório , Adolescente , Epicloroidrina , Resinas Epóxi , Glicerol , Humanos , Estudos Retrospectivos
3.
Anal Methods ; 14(16): 1611-1622, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35383795

RESUMO

The uniformity and compactness of the surface of a viscoelastic sensitive film are among the most important factors that influence the characteristics of a surface acoustic wave (SAW) gas sensor, directly affecting the detection sensitivity of a SAW sensor on a target gas. In this paper, poly(epichlorohydrin) (PECH) with viscoelastic properties was used as sensitive film for the detection of 2-chloroethyl ethyl sulfide (CEES), a common simulant of the chemical agent mustard gas. Nanoscale films were prepared using a spin coating technology on a SAW delay line of 200 MHz. Films were evaluated using polarizing microscopy and atomic force microscopy and observed with uniform surface states and particle diameter in the cluster region of 4.52-5.22 µm. The interface parameters, including contact angle, surface tension, Gibbs free energy, work of adhesion, work of immersion, and spreading coefficient values were 9.31° to 39.63°, 22.475 to 29.945 mN m-1, -85.70 to -78.08 J m-2, 78.08 to 85.70 J m-2, -42.62 to -35.00 J m-2, and 0.46 to 8.08 J m-1, respectively. These values were obtained by experiments combined with the Young T equation and Gibbs adsorption isotherm, and the surface analysis was carried out theoretically. The glass transition temperature (-22.4 °C), viscosity, pyrolysis, and other physical characteristics of the prepared PECH were discussed. Five SAW sensors prepared at the same time were used to test the repeatability of CEES measurements at one concentration, where the consistency of the sensor preparation was confirmed. At a concentration of 13.6 mg m-3 for CEES, 10 consecutive detection results showed good repeatability (i.e., standard deviation = 0.295, coefficient of variance = 0.021, and population mean deviation = 0.364). At room temperature (20 °C ± 5 °C), different concentrations of CEES were detected using the developed sensor, which showed good linearity in the concentration range of 1.9-19.6 mg m-3 (y = 0.0309 + 1.13x, r = 0.99478). The limit of detection was 0.85 mg m-3, the limit of quantitation was 1.91 mg m-3, and the sensitivity of the SAW sensor was 1.13 mV (mg m-3). The adsorption mechanism related to PECH in the detection of CEES was also discussed.


Assuntos
Epicloroidrina , Som , Adsorção , Poli A , Temperatura
4.
Free Radic Res ; 56(2): 209-221, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35468014

RESUMO

Cardiovascular complications are a well-documented limitation of cancer chemotherapy. Cisplatin-induced cardiotoxicity threatens the health and life of patients, and limits the application of cisplatin. Oxidative stress is the main mechanism underlying cisplatin-induced cardiac toxicity. Luteolin (Lut) has been reported to possess cardioprotective properties by activating nuclear factor-E2-related factor 2 (Nrf2) -mediated antioxidant response. However, the effect of Lut on cisplatin-induced cardiac damage remains unclear. In this study, we revealed that Lut exerted a protective effect against cisplatin-induced cardiac dysfunction and injury in vivo. In HL-1 cells, Lut was observed to dramatically reduce cisplatin-induced apoptosis and oxidative stress by modulating the Kelch-like epichlorohydrin-associated protein 1 (Keap1)/Nrf2 pathway. Altogether, these findings suggested that Lut showed promise in attenuating cisplatin-induced cardiac injury and might be considered a protective drug candidate for chemotherapy-associated cardiovascular complications.


Assuntos
Cardiopatias , Fator 2 Relacionado a NF-E2 , Apoptose , Cisplatino/efeitos adversos , Epicloroidrina/farmacologia , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Luteolina/farmacologia , Luteolina/uso terapêutico , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Transdução de Sinais
5.
Colloids Surf B Biointerfaces ; 215: 112504, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35453062

RESUMO

Chitosan (CS) is becoming increasingly popular in food packaging due to its natural degradability and great film-forming properties. Nevertheless, its poor antibacterial properties and inadequate antioxidant properties prevent it from being used effectively. In this study, ß-cyclodextrin-epichlorohydrin (ß-CD-EP) oligomers were prepared and encapsulated with natural essential oils cinnamaldehyde and thymol, and then the inclusion complexes (IC) were incorporated into chitosan in various contents to afford a series of CS-IC composite films. The impacts of IC on the morphological, mechanical, thermal, and water resistance properties, antioxidant and antibacterial activities of chitosan films, as well as the loading and sustained release behavior of IC, were thoroughly examined. The results turned out that the essential oils were well-loaded with high encapsulation efficiency and showed a significant slow-release effect. It was also found that the tensile strength and the elongation at break decreased with increasing IC contents, while the thermal stability was enhanced. The incorporation of IC dramatically promoted the antioxidant and antibacterial properties of the chitosan films towards Gram-positive bacteria. Based on our findings, chitosan films containing essential oils-loaded ß-CD-EP oligomers may serve as an effective food packaging material.


Assuntos
Quitosana , Óleos Voláteis , beta-Ciclodextrinas , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Epicloroidrina , Embalagem de Alimentos/métodos , Óleos Voláteis/farmacologia
6.
J Am Chem Soc ; 144(11): 4764-4769, 2022 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-35285232

RESUMO

Sulfone-substituted bicyclo[1.1.0]butanes and housanes have found widespread application in organic synthesis due to their bench stability and high reactivity in strain-releasing processes in the presence of nucleophiles or radical species. Despite their increasing utility, their preparation typically requires multiple steps in low overall yield. In this work, we report an expedient and general one-pot procedure for the synthesis of 1-sulfonylbicyclo[1.1.0]butanes from readily available methyl sulfones and inexpensive epichlorohydrin via the dialkylmagnesium-mediated formation of 3-sulfonylcyclobutanol intermediates. Furthermore, the process was extended to the formation of 1-sulfonylbicyclo[2.1.0]pentane (housane) analogues when 4-chloro-1,2-epoxybutane was used as the electrophile instead of epichlorohydrin. Both procedures could be applied on a gram scale with similar efficiency and are shown to be fully stereospecific in the case of housanes when an enantiopure epoxide was employed, leading to a streamlined access to highly valuable optically active strain-release reagents.


Assuntos
Epicloroidrina , Sulfonas , Butanos , Dimetil Sulfóxido , Indicadores e Reagentes
7.
J Org Chem ; 87(6): 4333-4342, 2022 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-35199527

RESUMO

Chiral hydroxy- and aminohydroxysulfonic acids are widespread in the marine and terrestrial environment. Here we report simple methods for the synthesis of d- and l-cysteinolic acid (from (Boc-d-Cys-OH)2 and (Boc-l-Cys-OH)2, respectively), R- and S-3-amino-2-hydroxypropanesulfonate (from S- and R-epichlorohydrin, respectively), and R- and S-2,3-dihydroxypropanesulfonate (from S- and R-epichlorohydrin, respectively). d-Cysteinolate bile salts were generated by coupling with cholic and chenodeoxycholic acids. A series of single-crystal 3D X-ray structures confirmed the absolute configurations of the aminosulfonates. By comparison of optical rotation, we assign naturally occurring 3-amino-2-hydroxypropanesulfonate from Gateloupia livida as possessing the R-configuration. This simple synthetic approach will support future studies of the occurrence, chemotaxonomic distribution, and metabolism of these alkylsulfonates.


Assuntos
Ácidos e Sais Biliares , Epicloroidrina , Ácido Quenodesoxicólico/metabolismo , Cisteína/análogos & derivados
8.
J Org Chem ; 87(6): 4097-4106, 2022 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-35226494

RESUMO

Despite the variety of energetic polyoxetane binders, the oxirane-based glycidyl azide polymer (GAP) has largely succeeded in the market due to its advantageous properties. Nevertheless, it suffers from various drawbacks such as non-uniform chain termination, possible chlorine content (flame retardant), and toxic epichlorohydrin required for its synthesis. These problems can be bypassed using the structurally related poly(3-azidooxetane). Unfortunately, it is only accessible in moderate yield by polymerization of 3-azidooxetane. Herein, we describe its synthesis by polymer-analogous transformation using the new polymers poly(3-tosyloxyoxetane) and poly(3-mesyloxyoxetane) as precursors. This results in a significantly increased yield and improved safety as handling of the very sensitive 3-azidooxetane is avoided. The aforementioned prepolymers were prepared using boron trifluoride etherate as well as triisobutylaluminum as catalysts. The latter provides polymers of particularly high molecular weight, and the corresponding poly(3-azidooxetane) species was obtained and studied for the first time. In order to shed light on the applicability of poly(3-azidooxetane) as a GAP substitute, it was thoroughly studied with regard to thermal behavior, energetic performance (EXPLO5), plasticizer compatibility, and curing. Moreover, the aquatic toxicity of all involved monomers was analyzed and compared to epichlorohydrin. Here, poly(3-azidooxetane) turned out as a fully adequate, if not more environmentally benign, substitute.


Assuntos
Epicloroidrina , Polímeros , Polimerização
9.
Int J Biol Macromol ; 199: 318-330, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35026221

RESUMO

Chitosan (Ch, a natural polymer) and kaolin (K, a natural mineral) composite (Ch-K) was produced with the help of two crosslinkers, epichlorohydrin and tripolyphosphate, and then moulded into uniform beads in tripolyphosphate solution. The synthesis was proved by the analyses involving FT-IR and SEM-EDX. The beads were then used as the natural adsorbent for removal of the auramine O (AO), a frequently-used industrial dye, in aqueous solutions. Adsorbent performance of the Ch-K composite for AO dye molecules was optimized: 500 mg L-1 at pH 7.5 at 25 °C. The Langmuir model found 0.118 mol kg-1 for the maximum adsorption capacity of the Ch-K and the D-R isotherm model showed that the nature of the adsorption process was physical. Kinetics of the adsorption could be explained by using both IPD (intraparticle diffusion) and PSO (pseudo second order) models. Thermodynamic parameters demonstrated that the behaviour of the adsorption was an endothermic and spontaneous. The activity of the composite adsorbent was recovered (88%) after the five sequential adsorption/desorption cycles. Supported by experimental findings, the results obtained from in silico modeling at M06-2X/6-31+G (d,p) level helped hypothesise a mechanism for the formation of the Ch-K composite, and shed some light onto the adsorption behaviour of AO dye by assuming several favourable intermolecular interactions.


Assuntos
Quitosana , Poluentes Químicos da Água , Purificação da Água , Adsorção , Benzofenoneídio , Quitosana/química , Teoria da Densidade Funcional , Epicloroidrina/química , Concentração de Íons de Hidrogênio , Caulim , Cinética , Polifosfatos , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Poluentes Químicos da Água/química , Purificação da Água/métodos
10.
Food Chem ; 370: 130933, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34507211

RESUMO

Cyanidin-3-glucoside (C3G), an anthocyanin constituent of fruits and vegetables. It has been proven to possess numerous health benefits with no side effects. However, the poor stability of C3G is an intractable property that limits its application. Hence, the aim of this study is to improve the stability of C3G through the formation of well dispersed nanoparticles. In this study, C3G loaded ß-CD-EP-CMC nanoparticles exhibited nearly spherical with good disperse and homogeneous morphology. Results also indicated that the nanoparticles formation of grafting of C3G to ß-CD-EP-CMC could significantly improve the stability of C3G to against thermal or light degradation. Collectively, current results strongly aligned with the prospective purpose that the grafting of C3G to ß-CD-EP-CMC nanoparticles could be treated as an effective approach for improving the stability. This study opens a new avenue for the utilization and development of novel wall materials ß-CD-EP-CMC in C3G associated nutraceutical.


Assuntos
Quitosana , beta-Ciclodextrinas , Antocianinas , Epicloroidrina , Estudos Prospectivos
11.
Int J Mol Sci ; 22(24)2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34948364

RESUMO

Curcumin (Cur) is an anti-inflammatory polyphenol that can be complexed with polymeric cyclodextrin (CD) to improve solubility and bioavailability. The aim of the present work was to prepare a CurCD hydrogel to treat inflammatory skin conditions. Epichlorohydrin-ß-CD (EpißCD) was used as polymeric CD. To characterize the binary system, solid-state and in-solution studies were performed. Afterwards, an experimental design was performed to optimize the hydrogel system. Finally, the CurEpißCD hydrogel system was tested for anti-inflammatory activity using a HaCat psoriasis cell model. Co-grinded Cur/EpißCD binary system showed a strong interaction and Curcumin solubility was much improved. Its combination with Pluronic® F-127/hyaluronate hydrogel demonstrated an improvement in release rate and Curcumin permeation. After testing its anti-inflammatory activity, the system showed a significant reduction in IL-6 levels. Hydrogel-containing CurEpißCD complex is a great alternative to treat topical inflammatory diseases.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Curcumina/administração & dosagem , Portadores de Fármacos/química , Epicloroidrina/química , beta-Ciclodextrinas/química , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Linhagem Celular , Curcumina/química , Curcumina/farmacologia , Liberação Controlada de Fármacos , Humanos , Psoríase/tratamento farmacológico , Solubilidade
12.
Int J Biol Macromol ; 193(Pt B): 1400-1408, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34740690

RESUMO

A series of lignin-based epoxy resins (LEPs) were prepared by the reaction of epichlorohydrin with lignin oligomers derived from partial reductive depolymerization of lignin. To overcome the high viscosity and brittleness defects in practical applications, the LEPs were blended with renewable epoxied cardanol glycidyl ether (ECGE) and then cured with methyltetrahydrophthalic anhydride (MeTHPA) to form high-performance epoxy thermosets. The effects of degree of lignin depolymerization, chemical composition of lignin oligomers and dosage of ECGE on thermal and mechanical properties of the cured products were investigated. The LEP/MeTHPA thermosets exhibited good thermal and mechanical properties. Especially, by separating monomer-rich fractions from lignin oligomers, the thermal and mechanical properties of the cured product were improved obviously. Notably, the incorporation of ECGE also possessed a positive effect on reinforcing and toughening the cured products. With 20 wt% ECGE loadings, the tensile, flexural and impact strength of the cured product reached the maximum value of 77 MPa, 115 MPa and 14 kJ/m2, respectively, which were equivalent to the commercial bisphenol A epoxy resins thermosets. These findings indicated that the novel bio-based epoxy resins from lignin oligomers and cardanol could be utilized as renewable alternatives for BPA epoxy resins.


Assuntos
Resinas Epóxi/química , Lignina/química , Fenóis/química , Compostos Benzidrílicos/química , Epicloroidrina/química , Compostos de Epóxi/química , Anidridos Ftálicos/química , Temperatura , Viscosidade
13.
Biomacromolecules ; 22(10): 4155-4168, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34473483

RESUMO

The collection, storage, and use of energy and information are important issues for overcoming the global energy shortage while satisfying the demand for information transmission. This research reports a nano-Fe3O4 and erythritol (ER)-functionalized, cross-linked methyl cellulose aerogel (MC-EP) composite that has the characteristics of phase-change energy storage as the magnetic and ultraviolet responses requisite for light-to-heat conversion and storage. The nano-Fe3O4 particles in MC-EP-ER-75 were fixed and filled into pore structures in MC-EP. ER was used to form an effective combination with MC-EP. The addition of nano-Fe3O4 compensated for the low thermal conductivity of ER. The MC-EP-ER-75 was able to store solar radiation-induced energy due to the loading of ER at a photothermal conversion efficiency of 79.67% and a light-to-heat conversion efficiency of 79.67%. The results of thermal stability (TGA) analysis showed that MC-EP-ER-75 was thermally degraded acceptably below 200 °C. The differential scanning calorimetry curve and latent heat values (melting/crystallization enthalpies of 314.8 and 197.9 J/g, respectively) of MC-EP-ER-75 did not change after 100 cycles. In addition, it exhibited excellent saturation magnetization, super-paramagnetism, and ultraviolet shielding, as well as a rapid response to the ultraviolet and magnetic fields. This provided a way to prepare light-to-heat conversion-storage-release materials and ultraviolet-magnetic sensors that can be used in renewable resources.


Assuntos
Epicloroidrina , Metilcelulose , Temperatura Alta , Fenômenos Magnéticos , Condutividade Térmica
14.
Mar Drugs ; 19(9)2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34564141

RESUMO

Hydrogels, possessing high biocompatibility and adaptability to biological tissue, show great usability in medical applications. In this research, a series of novel cross-linked chitosan quaternary ammonium salt loading with gentamicin sulfate (CTMCSG) hydrogel films with different cross-linking degrees were successfully obtained by the reaction of chitosan quaternary ammonium salt (TMCS) and epichlorohydrin. Fourier transform infrared spectroscopy (FTIR), thermal analysis, and scanning electron microscope (SEM) were used to characterize the chemical structure and surface morphology of CTMCSG hydrogel films. The physicochemical property, gentamicin sulphate release behavior, cytotoxicity, and antibacterial activity of the CTMCSG against Escherichia coli and Staphylococcus aureus were determined. Experimental results demonstrated that CTMCSG hydrogel films exhibited good water stability, thermal stability, drug release capacity, as well as antibacterial property. The inhibition zone of CTMCSG hydrogel films against Escherichia coli and Staphylococcus aureus could be up to about 30 mm. Specifically, the increases in maximum decomposition temperature, mechanical property, water content, swelling degree, and a reduction in water vapor permeability of the hydrogel films were observed as the amount of the cross-linking agent increased. The results indicated that the CTMCSG-4 hydrogel film with an interesting physicochemical property, admirable antibacterial activity, and slight cytotoxicity showed the potential value as excellent antibacterial wound dressing.


Assuntos
Antibacterianos , Quitosana , Gentamicinas , Hidrogéis , Compostos de Amônio Quaternário , Animais , Antibacterianos/administração & dosagem , Antibacterianos/química , Bandagens , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quitosana/administração & dosagem , Quitosana/química , Reagentes para Ligações Cruzadas/química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Liberação Controlada de Fármacos , Epicloroidrina/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Gentamicinas/administração & dosagem , Gentamicinas/química , Hidrogéis/administração & dosagem , Hidrogéis/química , Camundongos , Permeabilidade , Compostos de Amônio Quaternário/administração & dosagem , Compostos de Amônio Quaternário/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Resistência à Tração , Água/química , Cicatrização/efeitos dos fármacos
15.
Curr Opin Pharmacol ; 60: 281-290, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34500407

RESUMO

Nutraceuticals activating the Kelch-like epichlorohydrin (ECH)-associated protein 1 (Keap1)-nuclear factor erythroid-derived 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway are widely used for nonalcoholic fatty liver disease (NAFLD) because no specific drugs are approved yet. The pathology of NAFLD is summarized as the 'two-hit' hypothesis. The 'first hit' includes insulin resistance and lipid accumulation. Oxidative stress, lipid peroxidation, and inflammation are regarded as the 'second hit'. Now there is controversial evidence about the roles of the Keap1-Nrf2-ARE pathway and its activators in NAFLD. When the 'first hit' occurs, the hepatocyte-specific Nrf2 deficiency reduces insulin resistance and significantly attenuates lipid accumulation. However, when the 'second hit' occurs, Nrf2 activation reduces oxidative stress and combats inflammation. We reviewed the roles of the Keap1-Nrf2-ARE pathway as a double-edged sword in the development of NAFLD, its inhibitors as a novel therapeutic approach for early NAFLD, and the nutraceutical character of its activators.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Elementos de Resposta Antioxidante , Epicloroidrina , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Estresse Oxidativo , Transdução de Sinais
16.
Carbohydr Polym ; 271: 118435, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364575

RESUMO

Nickel (Ni) is one of the most common heavy metals. In this study, nano-sized magnetic ion-imprinted polymers (MIIPs) were synthesized using chitosan as the functional monomer, and used for selective adsorption and recovery of Ni(II) from solutions. The results showed MIIPs possessed high sorption selectivity for Ni(II), and the change in pH (5.0-9.0) exerted insignificant influence on the ion adsorption, allowing almost complete elution and recovery of adsorbed Ni(II) ions by using 0.5% EDTA-Na solution. Moreover, the sorption capacity of the recycled MIIPs decreased by only about 10% after 15 adsorption-desorption cycles. The time required for establishing the adsorption equilibrium was less than 1 h. The sorption process was predominant and endothermic, and could be well described by both Langmuir isotherm model and pseudo-second-order kinetic model. Therefore, the synthesized MIIPs was a suitable adsorbent for highly selective, fast and efficient removal and recovery of low-concentration Ni(II) ions from wastewaters.


Assuntos
Quitosana/química , Nanopartículas de Magnetita/química , Níquel/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Reagentes para Ligações Cruzadas/química , Epicloroidrina/química , Fenômenos Magnéticos , Níquel/química , Polifosfatos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
17.
Int J Biol Macromol ; 184: 170-180, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34052273

RESUMO

Bone defect is usually difficult to recover quickly, and bone scaffold transplantation is considered to be an effective method. Biomaterials have a wide range of application prospects in bone tissue repair, and the two key problems are the selection of materials and cells. The object of this study was to discuss the structural characteristics of bone scaffold materials and their effects on bone repair in vivo. The chitin-hydroxyapatite (HAP)-collagen composite scaffolds (CHCS) was prepared with epichlorohydrin (ECH) as crosslinking agent. The structure was characterized and the compressive strength, porosity, water absorbency and stability were investigated. The biocompatibility and osteogenic differentiation of CHCS in vitro were detected, and the effect of defect repair in vivo was evaluated. The results suggested that HAP not only enhanced the compressive strength of CHCS, but also promoted the formation of calcium nodules due to its bone conductivity. Histological staining showed that collagen promoted collagen deposition and new bone formation. X-ray images also indicated that CHCS transplantation accelerated bone repair. Therefore, CHCs has immense potential in bone regeneration.


Assuntos
Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Osso e Ossos/lesões , Quitina/química , Colágeno/química , Durapatita/farmacologia , Animais , Materiais Biocompatíveis/química , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Diferenciação Celular , Linhagem Celular , Força Compressiva , Durapatita/química , Epicloroidrina/química , Masculino , Células-Tronco Mesenquimais/citologia , Camundongos , Osteogênese/efeitos dos fármacos , Porosidade , Ratos , Engenharia Tecidual , Tecidos Suporte
18.
Int J Biol Macromol ; 183: 132-144, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33905801

RESUMO

Due to the unique properties of cellulose-based materials, they are attractive to be developed in industrial pharmaceutics and biomedical fields. Carboxymethyl-diethyl amino ethyl cellulose scaffold (CM-DEAEC) has been synthesized in the current work as a smart novel derivative of cellulose with a great functionality in drug delivery systems. The scaffolds were well cross-linked with 2% (v/v) epichlorohydrin (ECH), loaded with curcumin (Cur), and then were analyzed by FT-IR, XRD, SEM, and mechanical strength. While developing the ideal delivery platform, curcumin (an important chemotherapeutic agent) was chosen due to its hydrophobicity and poor bioavailability. Thus, we developed a novel scaffold for efficient loading and controlled releasing of curcumin. The swelling ratio of 136%, high curcumin entrapment efficiency (up to 83.7%), sustained in vitro drug release profile, and appropriate degradability in three weeks confirmed significant properties of the CM-DEAEC scaffold. More than 99% antibacterial activity has been observed by the cross-linked curcumin loaded CM-DEAEC scaffolds. Cytotoxicity studies using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 4',6-diamidino-2-phenylindole (DAPI) staining showed that cross-inked curcumin loaded CM-DEAEC scaffolds did not show any toxicity using L929 cells. All experiments were compared with CMC scaffolds and better characteristics of the novel scaffold for drug delivery have been confirmed.


Assuntos
Antibacterianos/química , Celulose/síntese química , Curcumina/química , Portadores de Fármacos , Animais , Antibacterianos/farmacologia , Antibacterianos/toxicidade , Linhagem Celular , Celulose/análogos & derivados , Celulose/toxicidade , Reagentes para Ligações Cruzadas/química , Curcumina/farmacologia , Curcumina/toxicidade , Preparações de Ação Retardada , Composição de Medicamentos , Liberação Controlada de Fármacos , Epicloroidrina/farmacologia , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Resistência à Tração
19.
J Nanosci Nanotechnol ; 21(9): 4974-4979, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33691902

RESUMO

In this study, we prepared chitosan beads cross-linked with epichlorohydrin (CB-ECH) to improve the removal of nitrate in groundwater. It was confirmed that CB-ECH exhibited higher thermal stability and well-developed nano-pores compared to the pure chitosan beads (CB) by the thermogravimetric analyzer, nitrogen gas adsorption and desorption isotherm, and field emission scanning microscopy analysis. The CB-ECH showed a higher nitrate adsorption amount than the pure CB. Nitrate adsorption behaviors of CB-ECH were further investigated using adsorption isotherm, adsorption kinetics, adsorption energy distribution, and Gibbs free energy distribution models. The adsorption equilibrium and kinetics of nitrate ion on CB-ECH were well explained by the Sips isotherm and homogeneous surface diffusion model, respectively. It was also found from the AED analysis that the CB-ECH represent the heterogeneous adsorption behaviors for nitrate.


Assuntos
Quitosana , Poluentes Químicos da Água , Adsorção , Epicloroidrina , Concentração de Íons de Hidrogênio , Cinética , Nitratos , Água
20.
Carbohydr Polym ; 260: 117817, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33712161

RESUMO

While green bioplastic based on carbohydrate polymers have showed considerable promise, the methods typically used to prepare them in a single material have remained a significant challenge. In this study, a simple approach is proposed to fabricate high performance cellulose films composed of chemically and physically dual-crosslinked 2,2,6,6-tetramethylpiperidine-1-oxy-oxidized cellulose nanofibers (DC TEMPO-CNFs). The hydroxyl groups of TEMPO-CNF suspensions were firstly crosslinked chemically with epichlorohydrin (ECH), and subsequently TEMPO-CNF matrices were crosslinked physically via the strong electrostatic interaction between carboxylate and Ca2+ ions. It was found that the optimized DC TEMPO-CNF films exhibit a good transmittance (90 %) and a high tensile strength (303 MPa). Furthermore, these DC TEMPO-CNF films revealed superior thermal stability and excellent water resistance compared to neat TEMPO-CNF films without crosslinked domains. We believe that these results will pave the way to preparing practical polysaccharide bioplastics with simple, environmentally-friendly manufacturing processes.


Assuntos
Celulose/química , Nanofibras/química , Cálcio/química , Celulose Oxidada/química , Epicloroidrina/química , Íons/química , Piperidinas/química , Eletricidade Estática , Temperatura , Resistência à Tração , Água/química
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