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| Registros recuperados: 45 | |
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| Tang,ZhenXing; Qian,JunQing. |
| The aim of this study was to optimize the preparation of chitosan gel and to use it for protein purification. The optimized preparation parameters were chitosan concentration 2.0%, glutaraldehyde concentration 0.6%, low cross-linking rate, NaOH concentration 1.6%, amount of NaBH4 0.4 g. In order to use the chitosan gel, the elution conditions were optimized as follows. NaCl concentration 0.05 mol/L in the tris-HCl (pH 9.05) at the flow rate of 2.03.0 mL/min. Particle size of chitosan gel was 120-140 µm. Neutral protease could be separated into four ingredients through chitosan gel column. The yield of enzyme was more than 90%. Albumin bovine serum could be separated into two ingredients through gel column and the total yield of albumin bovine serum was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitosan; Gel; Preparation; Application. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000200015 |
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| Li,Huiying; Shi,Binlin; Yan,Sumei; Zhao,Tianzhang; Li,Junliang; Guo,Xiaoyu. |
| An in vitro experiment was conducted to study the effects of chitosan on the secretion of cytokines and expression of inducible nitric oxide synthase mRNA in peritoneal macrophages of broiler chicken. In the experiment, peritoneal macrophages were incubated for 24 h in culture medium supplemented with 0 (control), 40, 80, 160 and 320 µg/mL chitosan. The results showed that chitosan tended to increase quadratically the levels of interleukin-1 (P = 0.093) and interleukin-2 (P = 0.106) in the culture fluid of peritoneal macrophage. Chitosan also significantly enhanced inducible nitric oxide synthase mRNA expression of peritoneal macrophage in a quadratic dose-dependent manner (P < 0.05) and tended to promote quadratically the secretion of nitric oxide (P =... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitosan; Broiler chicken; Peritoneal macrophages; Cytokine; Inducible nitric oxide synthase. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000400466 |
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| Oliveira Junior,Enio Nazaré de; Melo,Itamar Soares de; Franco,Telma Teixeira. |
| In this work, changes in the hyphal morphology due to chitosan treatment in some fungal species were studied. Scanning electron microscope (SEM) observations revealed that chitosans with molar fraction of acetyl groups (F A 0.16 and 0.18) and degree of polymerization (DP 1,089 and 1,242) had a direct effect on the morphology of the chitosan-treated fungi, reflecting its potential for causing a delay in the growth of Alternaria alternata (500 µg × mL-1), Botrytis cinerea (1,000 µg × mL-1), Penicillium expansum (1,000 µg × mL-1) and Rhizopus stolonifer (500 µg × mL-1). Mycelial aggregation and structural changes such as excessive branching, swelling of the cell wall and hyphae size reduction were observed in the micrographs. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitosan; Alternative control of fungi; Antifungal activity; Plant pathogenic fungi; Fungal morphology. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000500001 |
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| Darolt,Josiane Cecília; Rocha Neto,Argus Cezar da; Di Piero,Robson Marcelo. |
| Abstract Apple is one of the most important temperate fruit to Brazil economy, and the use of synthetic chemicals has been the main method for reducing postharvest diseases, such as the blue mold, caused by Penicillium expansum. This work intends to evaluate the practical utilization of chitosan for blue mold control. For this purpose, fruits were treated in a preventive and curative way, immersing the fruits in chitosan solution (5 or 10 mg mL-1), or adding a single drop of this solution (10 mg mL-1) directly into the injuries. The eradicative effect of the polysaccharide was also evaluated in vitro and in vivo. Chitosan did not show a curative effect against the blue mold, and its eradicative effect was only evidenced on the higher concentration (10 mg... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antimicrobial activity; Alternative control; Chitosan; Malus domestica; Polysaccharide. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822016000401014 |
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| Franco,Luciana de Oliveira; Maia,Rita de Cássia C.; Porto,Ana Lúcia F.; Messias,Arminda Sacconi; Fukushima,Kazutaka; Campos-Takaki,Galba Maria de. |
| Chitin and chitosan were extracted from mycelial biomass of Cunninghamella elegans and the performance for copper, lead and iron biosorption in aqueous solution was evaluated. The growth curve of C. elegans was accomplished by determination of biomass, pH, glucose and nitrogen consumption. Chitin and chitosan were extracted by alkali-acid treatment and the yields were 23.8 and 7.8%, respectively. For the adsorption analysis, the process of heavy uptake metal sorption was evaluated using polysaccharides solutions (1% w/v). The rate of metallic biosorption was dependent upon the concentration and pH of metal solutions, and the best results were observed with pH 4.0. Chitosan showed the highest affinity for copper and chitin for iron adsorption. The results... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cunninghamella elegans; Chitin; Chitosan; Bioremediation; Biosorption. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822004000200013 |
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| Segala,Karen; Nista,Silvia Vaz Guerra; Cordi,Lívia; Bizarria,Maria Trindade Marques; Ávila Júnior,José de; Kleinubing,Sirlene Adriana; Cruz,Deborah Cristina; Brocchi,Marcelo; Lona,Liliane Maria Ferrareso; Caballero,Nelson Eduardo Durán; Mei,Lucia Helena Innocentini. |
| abstract This study examines the antimicrobial activity of silver nanoparticles incorporated into nanostructured membranes made of cellulose acetate (CA) and blends of chitosan/poly-(ethylene oxide, CTS/PEO) and prepared by electrospinning. The formation of chemically synthesized Ag nanoparticles (AgNPs) was monitored by UV-visible spectroscopy (UV-Vis) and characterized by transmission electron microscopy (TEM). The size distribution of the AgNPs was measured by dynamic light scattering (DLS), with an average size of approximately 20 nm. The presence of AgNPs on the surface of electrospun nanofibers was observed by field emission electron microscopy (FEG) and confirmed by TEM. The antimicrobial activity of AgNPs incorporated into nanostructured membranes... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrospinning; Silver nanoparticles/antibacterial activity; Cellulose acetate; Chitosan. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502015000400911 |
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| Lacerda,Gabriel José Silveira; Piantino,Beatriz Lemos; Gonzaga,Edeilson Vitor; Naves,Valéria de Moura Leite; Pedreiro,Liliane Neves; Gremião,Maria Palmira Daflon; Pereira,Gislaine Ribeiro; Carvalho,Flávia Chiva. |
| This study evaluates various techniques for producing mesalamine (5ASA)-loaded particles employing chitosan as a biopolymer: (1) the polyelectrolyte complexation of chitosan with phthalate hypromelose (HP), (2) the chemical crosslinking of chitosan with genipin and (3) the water-in-oil emulsion method associated with chemical crosslinking with genipin. Systems were characterized by dynamic light scattering, zeta potential (ζ), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR) and a drug release profile. Method (1) was efficiently produced unloaded nanoparticles (491 nm, PdI=0.26 and ζ = 23.2), but the conditions for chitosan and HP cross-linking enhanced the precipitation of 5ASA. Method (2) caused the degradation of the drug.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Emulsion method; Polyelectrolyte crosslinking; Chemical cross-linking; Chitosan; Mesalazine. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502019000100602 |
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| Vijayaraj,Surendran; Palei,Narahari N; Archana,Devalapalli; Lathasri,Kuppam; Rajavel,Ponnusamy. |
| Rutin is a flavonoid glycoside, mainly consists of phenolic compounds, responsible for many biological activities. The objective of the present study was to develop and validate a precise, simple, robust, rapid and reliable reverse phase high -performance liquid chromatography (RP-HPLC) technique by using Qbd approach for evaluating the rutin in nanoparticles. Central composite design (CCD) was employed for optimizing the experimental conditions of RP-HPLC method. Buffer pH, methanol content in the mobile phase composition, flow rate, and wavelength were selected as independent variables whereas retention time, peak area, and asymmetry factor was selected as dependent variables. The retention time, peak area and asymmetric factor of rutin by using... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rutin; Chitosan; Sodium aliginate; Nanoparticles; RP-HPLC; Central composite design; QbD. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502020000100632 |
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| Gonçalves,Melissa Marques; Carneiro,Jaqueline; Justus,Barbara; Espinoza,Joel Toribio; Budel,Jane Manfron; Farago,Paulo Vitor; Paula,Josiane Padilha de. |
| Antibacterial activity and good mechanical properties are some of the characteristics required for an appropriate film dressing. A novel polymer blend was developed for wound healing application. Twenty-four formulations using the polymers chitosan, poly(vinyl alcohol) and/or ɛ-Polylysine and the plasticizer glycerol were designed using factorial design and then the films were prepared by the casting/solvent evaporation method. Seventeen films were obtained among the twenty-four proposed formulations that were characterized by Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Mechanical properties, such as tensile strength (σ), elongation at break (ɛ) and Young’s modulus (Y) as well as antibacterial... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitosan; Poly(vinyl alcohol); Ɛ-Polylysine; Semi-occlusive dressing. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502020000100631 |
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| Tilkan,Müşerref Günseli Yüksel; Özdemir,Nurten. |
| ABSTRACT Flurbiprofen (FLB), a NSAID, widely used for preventing pain generally for arthritis or dental problems. In this study, FLB loaded chitosan microspheres were prepared by ionotropic gelation method. In this method, microspheres were formed by dropping chitosan solutions containing FLB into sodium alginate solutions including sodium tripolyphosphate (TPP). A variety of formulation parameters like drug:polymer ratio, drug concentration, polymer’s molecular weight, polymer concentration, pH and the concentration of TPP solutions, drying method and stirring time were analyzed. The dissolution studies were performed in a shaking water bath in pH 7.4 phosphate buffer saline (PBS) at 37 °C. Laser diffractometer was used for particle size analysis, and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Flurbiprofen; Chitosan; Tripolyphosphate; Ionotropic gelation; Microsphere. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502017000400621 |
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| Gatti,Tiago Henrique Honorato; Eloy,Josimar Oliveira; Ferreira,Leonardo Miziara Barboza; Silva,Isabel Cristine da; Pavan,Fernando Rogério; Gremião,Maria Palmira Daflon; Chorilli,Marlus. |
| Abstract Mucoadhesive nanoparticles are particularly interesting for delivery through nasal or pulmonary routes, as an approach to overcome the mucociliary clearance. Moreover, these nanoparticles are attractive for peptide and protein delivery, particularly for insulin to treat diabetes, as an alternative to conventional parenteral administration. Thus, chitosan, a cationic mucoadhesive polysaccharide found in shells of crustaceans, and the negatively-charged dextran sulfate are able to form nanoparticles through ionic condensation, representing a potential insulin carrier. Herein, chitosan/dextran sulfate nanoparticles at various ratios were prepared for insulin loading. Formulations were characterized for particle size, zeta potential, encapsulation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Insulin; Chitosan; Dextran-Sulfate; Nanoparticles; Mucoadhesion.. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502018000100623 |
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| Registros recuperados: 45 | |
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