Consulta: subjectFacets:"Chitosan"
Registros recuperados: 45
Data/hora: 10/06/2024 14:37:07

Efecto de quitina y quitosano sobre huevos y juveniles de nemátodos formadores de nódulos radiculares, Nacobbus aberrans  y Meloidogyne incognita bajo condiciones de in vitro e in vivo
Provedor de dados: 32
Autores: Sánchez Portillo, Juan Fernando.
El nematodo agallador Meloidogyne incognita Kofoid y White, 1919, Chitwood, 1949, distribuido en 23 de los 32 estados del país y Nacobbus aberrans Thorne 1935, Thorne and Allen, 1944, distribuido en 10 de 32 estados de la República Mexicana, su combate para ambas especies, casi siempre se hace aplicando diferentes agroquímicos, los cuales algunos ya tienen problemas de registro. Se necesita evaluar nuevos productos que sean otra alternativa a su manejo y mas amigables al ambiente. En el presente trabajo se evaluó el efecto de quitina-quitosano con diferentes grados de desacetilación, biopolímeros naturales que poseen propiedades nematicidas y utilizados como reguladores de la población de estos fitonematodos; los estudios se hicieron in vitro, sobre la...
Palavras-chave: Biopolímero natural; Meloidogyne incognita; Nacobbus aberrans; Desacetilación; Control; Quitina; Quitosano; Chitin; Chitinase; Natural biopolymer; Chitosan; Deacetylation; Fitopatología; Maestría.
Ano: 2010
URL: http://hdl.handle.net/10521/55

Efecto de quitina y quitosano sobre huevos y juveniles de nemátodos formadores de nódulos radiculares, Nacobbus aberrans  y Meloidogyne incognita bajo condiciones de in vitro e in vivo
Provedor de dados: 32
Autores: Sánchez Portillo, Juan Fernando.
El nematodo agallador Meloidogyne incognita Kofoid y White, 1919, Chitwood, 1949, distribuido en 23 de los 32 estados del país y Nacobbus aberrans Thorne 1935, Thorne and Allen, 1944, distribuido en 10 de 32 estados de la República Mexicana, su combate para ambas especies, casi siempre se hace aplicando diferentes agroquímicos, los cuales algunos ya tienen problemas de registro. Se necesita evaluar nuevos productos que sean otra alternativa a su manejo y mas amigables al ambiente. En el presente trabajo se evaluó el efecto de quitina-quitosano con diferentes grados de desacetilación, biopolímeros naturales que poseen propiedades nematicidas y utilizados como reguladores de la población de estos fitonematodos; los estudios se hicieron in vitro, sobre la...
Palavras-chave: Biopolímero natural; Meloidogyne incognita; Nacobbus aberrans; Desacetilación; Control; Quitina; Quitosano; Chitin; Chitinase; Natural biopolymer; Chitosan; Deacetylation; Fitopatología; Maestría.
Ano: 2010
URL: http://hdl.handle.net/10521/55

Effect of edible quinoa protein-chitosan based films on refrigerated strawberry (Fragaria × ananassa) quality
Provedor de dados: 69
Autores: Valenzuela,Carolina; Tapia,Cristian; López,Luis; Bunger,Andrea; Escalona,Victor; Abugoch,Lilian.
Background Strawberries are non-climacteric fruits with a low respiration rate, but are subject to serious fungal deterioration during postharvest handling. The edible coatings based on chitosan (CH), quinoa protein-chitosan (Q/CH) and quinoa protein-chitosan-sunflower oil (Q/CH/SO) may provide a solution to this problem. Thus, in this work CH, Q/CH and Q/CH/SO were elaborated and applied to fresh strawberries, and its effect on the strawberries shelf life during storage for 15 d was evaluated by mold and yeast count, fungal decay, carbon dioxide rate, physicochemical properties, and sensory evaluation. Results On all analysis days, the strawberries coated with the film-forming CH, Q/CH and Q/CH/SO solutions presented a significant lower amount of mold and...
Tipo: Journal article
Palavras-chave: Chitosan; Edible films; Quinoa protein; Strawberry; Sunflower oil.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582015000600004

Characterization of a Gelatin/Chitosan/Hyaluronan scaffold-polymer
Provedor de dados: 69
Autores: Enrione,Javier; Osorio,Fernando; López,Daniel; Weinstein-Oppenheimer,Caroline; Fuentes,Miguel A; Ceriani,Ricardo; Brown,Donald I; Albornoz,Fernando; Sánchez,Elizabeth; Villalobos,Patricio; Somoza,Rodrigo A; Young,Manuel E; Acevedo,Cristian A.
Gelatin, chitosan and hyaluronic acid are natural components used to prepare polymeric scaffold in tissue engineering. The physical properties of these materials confer an appropriate microenvironment for cells, which can be used as a regeneration system for skin and cartilage. In this work, we prepared and characterized a Gelatin/Chitosan/Hyaluronan lyophilized-polymer. Physical properties of lyophilized-polymer changed slightly with moisture, but when polymer was totally hydrated the elasticity changed significantly. Thermophysical characterisation indicated that temperatures higher than 30ºC could modify irreversibly the polymeric matrix probably due to protein denaturation. Besides, we used the polymer as scaffold to prepare a biosynthetic-skin,...
Tipo: Journal article
Palavras-chave: Chitosan; Fibrin; Gelatin; Hyaluronic acid; Scaffold.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000500020

Growth of Cunninghamella elegans UCP 542 and production of chitin and chitosan using yam bean medium
Provedor de dados: 69
Autores: Stamford,Thayza Christina Montenegro; Stamford,Tânia Lucia Montenegro; Stamford,Newton Pereira; Barros Neto,Benicio de; Campos-Takaki,Galba Maria de.
Microbiological processes were used for chitin and chitosan productions by Cunninghamella elegans (UCP 542) grown in a new economic culture medium. The assay was carried out to evaluate the growth of C. elegans using yam bean (Pachyrhizus erosus L. Urban) medium, in different times of growth (24, 48, 72 and 96 hrs), incubated at 28ºC in an orbital shaker at 150 rpm. The lyophilized biomass was determined by gravimetry. The polysaccharides were extracted by alkali-acid treatment, and characterized by infrared spectroscopy, titration and viscosity. C. elegans grown in the yam bean medium and produced higher yields of biomass (24.3 g/ mL) in 96 hrs. The high level was chitosan (66 mg/g), and chitin (440 mg/g) were produced at 48 and 72 hrs of growth,...
Tipo: Journal article
Palavras-chave: Biopolymers; Chitin; Chitosan.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582007000100006

Design Polysaccharides of Marine Origin: Chemical Modifications to Reach Advanced Versatile Compounds
Provedor de dados: 5
Autores: Chopin, Nathalie; Guillory, Xavier; Weiss, Pierre; Le Bideau, Jean; Colliec-jouault, Sylvia.
Polysaccharides are among the most abundant macromolecules on Earth. These polymers are easily obtained from various marine resources such as algae, microorganisms and crustacean shells. The structure of these natural carbohydrates is innovative and quite complex. Marine biopolymers represent key scaffolds toward large challenging fields, such as biomedical applications (glycosaminoglycans, regenerative medicine and drug delivery) and tailored biomaterials. Chemical modifications can be applied to modify their final properties in a specific purpose. New functional glycans are achievable and represent a real potential with their intrinsic biocompatibility and biodegradability. Hydroxyl groups are ubiquitous in polysaccharides structure and involved in most...
Tipo: Text
Palavras-chave: Alginates; Carrageenans; Chemical modification; Chitin; Chitosan; Grafting; Marine polysaccharide; Polymer.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00199/31027/29902.pdf

Lactic acid bacteria selection for biopreservation as a part of hurdle technology approach applied on seafood
Provedor de dados: 5
Autores: Wiernasz, Norman; Cornet, Josiane; Cardinal, Mireille; Pilet, Marie-france; Passerini, Delphine; Leroi, Francoise.
As fragile food commodities, microbial and organoleptic qualities of fishery and seafood can quickly deteriorate. In this context, microbial quality and security improvement during the whole food processing chain (from catch to plate), using hurdle technology, a combination of mild preserving technologies such as biopreservation, modified atmosphere packaging and superchilling, are of great interest. Thirty-five lactic acid bacteria (LAB) belonging to the species Carnobacterium maltaromaticum, Carnobacterium inhibens, Lactococcus piscium, Leuconostoc gelidum, Vagococcus fluvialis, Vagococcus penaei and Aerococcus viridans, known to possess interesting antimicrobial activity, were chosen for their potential application as bioprotective agents as a part of...
Tipo: Text
Palavras-chave: Antimicrobial activity; Spoilage; Screening; Chitosan; Fish juice; Safety assessment.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00382/49342/49732.pdf

Preparation and in vitro characterization of chitosan nanoparticles containing Mesobuthus eupeus scorpion venom as an antigen delivery system
Provedor de dados: 80
Autores: Mohammadpour Dounighi,N; Eskandari,R; Avadi,MR; Zolfagharian,H; Mir Mohammad Sadeghi,A; Rezayat,M.
Hydrophilic nanoparticles have been widely investigated in recent years as delivery systems for therapeutic macromolecules such as antigens. In the present study Mesobuthus eupeus venom-loaded chitosan nanoparticles were prepared via ionic gelation of tripolyphosphate (TPP) and chitosan. The optimum encapsulation efficiency (91.1%) and loading capacity (76.3%) were obtained by a chitosan concentration of 2 mg/mL, chitosan-to-TPP mass ratio of 2 and M. eupeus venom concentration of 500 µg/mL. The average nanoparticle size at optimum conditions was determined by Zetasizer (Malvern Instruments, UK). The nanoparticle size was about 370 nm (polydispersity index: 0.429) while the zeta potential was positive. Transmission electron microscope (TEM) imaging showed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nanoparticle; Chitosan; Tripolyphosphate; Venom; Antigen delivery system; Mesobuthus eupeus.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992012000100006

Películas y cubiertas de quitosana en la conservación de vegetales
Provedor de dados: 20
Autores: García, M. A.
El uso de películas y cubiertas de quitosana en vegetales constituye un método alternativo para su conservación y contribuye, además, a minimizar la contaminación ambiental debida a los desechos generados por el empleo de envases no biodegradables y el vertimiento a los mares de los desechos de la industria de mariscos. Se discuten algunas propiedades y aplicaciones de este biopolímero en la industria alimentaria.
Tipo: Journal Contribution
Palavras-chave: Shelf life; Reviews (literature); Vegetables; Chitosan.
Ano: 2008
URL: http://hdl.handle.net/1834/4843

Envasado activo de embutidos
Provedor de dados: 20
Autores: García, M.A.; Díaz, R.; Puerta, F.; Beldarraín, T.; Castillo, A.; González, J.; Duarte, C.
El objetivo del estudio fue evaluar la influencia de coberturas de quitosana en lascas de jamón cocido y jamón Visking envasadas al vacío. En ambos productos se observó un incremento de la acidez, mayor en los productos con coberturas de quitosana. Se produjo un aumento de la dureza con el tiempo, sin que existieran diferencias significativas (p≤0,05) atribuibles a la aplicación de coberturas. Se encontró un efecto favorable de las coberturas de quitosana en cuanto a retardar el desarrollo de los psicrófilos. La calidad sensorial fue el parámetro que más se afectó durante el almacenamiento; en el jamón cocido el sabor se tornó ácido y se observó un exudado lechoso y en el jamón Visking los jueces refirieron olores y sabores atípicos y una disminución...
Tipo: Journal Contribution
Palavras-chave: Conservation; Cold storage; Packaging materials; Sausages; Hams; Chitosan; Wrapping.
Ano: 2008
URL: http://hdl.handle.net/1834/4892

Preservación de pimientos con aplicación de coberturas de quitosana
Provedor de dados: 20
Autores: García, M.; Díaz, R.; Casariego, A.; Bolumen, S.; de Hombre, R.; González, I.; Rodríguez, I.; Salgado, J. M.
Se aplicaron coberturas de quitosana en pimientos (Capsicum annuum L.) con el objetivo de evaluar su influen- cia en el mejoramiento de la calidad y prolongación del perío- do de conservación. Cada lote de pimientos fue tratado en forma diferente, considerando muestras sin tratar y tratadas con disoluciones de quitosana. Las coberturas se aplicaron mediante pinceladas con disoluciones a 1 y 2 % (m/v) de quitosana en ácido láctico a 1 %. Posterior al secado de los frutos, estos se envasaron en bolsas de polietileno de baja densidad. Se determinaron varios parámetros de calidad du- rante el almacenamiento de 10 a 12 ºC: pérdida de peso, textu- ra, sólidos solubles, pH y evaluación sensorial mediante el análisis descriptivo cuantitativo. Las coberturas de...
Tipo: Journal Contribution
Palavras-chave: Preservation (organisms); Green peppers; Bell peppers; Chitosan.
Ano: 2009
URL: http://hdl.handle.net/1834/5059

Modelación de las propiedades mecánicas de películas de quitosana
Provedor de dados: 20
Autores: Casariego, A.; Díaz, R.; Sergrañes, Y.; Nieto, O. M.; Durán, C.; López, N; Rodríguez, M.; González, J.
Se elaboraron películas a partir de disoluciones a 3 % (m/v) de quitosana en ácido láctico a 1% (v/v), empleando glicerina, sorbitol o polietilenglicol como plastificante en concentraciones de 0,25 a 0,50 mL/g de quitosana. Se midieron el esfuerzo tensil, elongación, fuerza de ruptura, deformación y el espesor de las películas, con el objetivo de evaluar la influencia de la masa molar y concentración de plastificante sobre sus propiedades mecánicas. Se obtuvieron los modelos matemáticos que relacionan estos factores. Las películas con polietilenglicol, presentaron mayor esfuerzo tensil y fuerza de ruptura normalizada que las plastificadas con glicerina o sorbitol, pero resultaron menos elásticas y deformables, además, mientras mayor fue la concentración de...
Tipo: Journal Contribution
Palavras-chave: Mechanical properties; Chitosan; Biopolymers; Elasticity.
Ano: 2009
URL: http://hdl.handle.net/1834/5095

Physiology and postharvest conservation of ‘Paluma’ guava under coatings using Jack fruit seed-based starch
Provedor de dados: 94
Autores: Rodrigues,Antonio Augusto Marques; Silva,Silvanda de Melo; Dantas,Ana Lima; Silva,Antonio Fernando da; Santos,Leonardo da Silva; Moreira,Dayse das Neves.
Abstract  The aim of this work was to evaluate the effect of jackfruit seed starch-based (S) coatings, added to chitosan and alginate on the physiology and maintenance of quality of cold stored ‘Paluma’ guavas, followed by transfer to the room condition. The design was the completely randomized, in a 4x2 factorial scheme, in 4 replications, with 4 coatings (dispersion of S - 4%; S 2% + chitosan - 2% (SC); S - 2% + alginate - 2% (SA); and the uncoated control), in 2 environments (refrigerated (10±2 °C e 80±2% RH) with transfer to room condition (25±3 °C e 75±4% HR)), on the 16th and 20th day of cold storage. The SC and SA coatings were efficient in reducing the respiratory rate in fruits during 10 days at room condition. The SC coating delayed fruit...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Artocarpus heterophyllus; Fruit waste; Chitosan; Sodium alginate; Fruit quality.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452018000200303

Effect of Chitosan Coating on Some Quality Properties of Thomson Orange during Storage (A case study in Iran)
Provedor de dados: 111
Autores: Taghinezhad, Ebrahim; Rasooli Sharabiani, Vali.
 Most of the world's consumers have used the natural coatings instead of chemical coatings. In this research, some quality properties of Thomson orange were evaluated using Chitosan edible coating (at concentrations of 0.5, 1 and 2%) and chemical coating of fungicide (Ortho Phenyl Phenol) as compared to uncoated samples during storage for three months. Fruit were maintained in cold storage at 6 °C temperature and 85-90% relative humidity, then pH, total soluble solid (TSS) of orange juice and percentage of fruit weight loss were measured during storage every month. The results showed that weight loss of fruit with 2% chitosan coating was lower than other treatments. Also this treatment had high resistance against fungal attacks due to high values of pH, so...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chitosan; Citrus; Fungicide; Quality; Storage.
Ano: 2018
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/4189

Synthesis of calcium-phosphate and chitosan bioceramics for bone regeneration
Provedor de dados: 42
Autores: FINISIE,MELLATIE R.; JOSUÉ,ATCHE; FÁVERE,VALFREDO T.; LARANJEIRA,MAURO C. M.
Bioceramic composites were obtained from chitosan and hydroxyapatite pastes synthesized at physiological temperature according to two different syntheses approaches. Usual analytical techniques (X-ray diffraction analysis, Fourier transformed infrared spectroscopy, Thermo gravimetric analysis, Scanning electron microscopy, X-ray dispersive energy analysis and Porosimetry) were employed to characterize the resulting material. The aim of this investigation was to study the bioceramic properties of the pastes with non-decaying behavior from chitosan-hydroxyapatite composites. Chitosan, which also forms a water-insoluble gel in the presence of calcium ions, and has been reported to have pharmacologically beneficial effects on osteoconductivity, was added to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bioceramic; Chitosan; Hydroxyapatite; Composites; Bone regeneration.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000400006

Antibacterial activity of chitosan biofilm for the conservation of fertile and table eggs
Provedor de dados: 45
Autores: Prado,R.O.F.; Tellez,I.G.; García,M.L.J.; Aldaco,L.L.E.; García,C.A.C.
ABSTRACT The aim of this study was to develop a chitosan biofilm against Salmonella enteritidis, for the conservation of fertile and table eggs. Two experiments were performed. Experiment 1: 400 specific pathogen-free table eggs were divided in a completely randomized design into four treatments, five replicates and each replicate with 20 table eggs. Experimental groups were assigned to control and 1, 5 and 10% chitosan treatment. The eggs were immersed in the chitosan solution. They were then exposed to Salmonella enteritidis and stored for 1, 24, 96 and 168h at 4ºC. The eggs were then washed with 10mL of physiological saline solution. Experiment 2: 80 specific pathogen-free fertile eggs were tested, the assays were assigned to control and 1, 5 and 10%...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chitosan; Fertile eggs; Table eggs; Salmonella enteritidis.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352020000100208

Greenhouse and field assessment of different organic compounds against guava-parasitic Meloidogyne enterolobii
Provedor de dados: 53
Autores: Almeida,Alexandre Macedo; Souza,Ricardo Moreira; Gomes,Vicente Martins; Miranda,Guilherme Bessa.
Guava decline is a complex disease involving Meloidogyne enterolobii and Fusarium solani and it has caused major direct losses to Brazilian growers. Although several strategies have been sought to control the nematode, the use of organic soil amendments is currently the best approach to manage this disease. To assess the best amount of meat and bone meal (MBM) to be incorporated into the soil, guava seedlings inoculated with M. enterolobii were treated with 1-5% v/v of the MBM. Ninety days later variables related to nematode reproduction and plant development were evaluated, which indicated a potential nematicidal effect of the MBM at 3%. Another experiment assessed nematode- and plant-related variables 90 days after treatment of the seedlings with MBM,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Psidium guajava; Fusarium solani; Neem cake; Chitosan; Shrimp shell; Cultural control; Guava decline; Meat and bone meal.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052012000100011

Soybean β-Glucosidase immobilisated on chitosan beads and its application in soy drink increase the aglycones
Provedor de dados: 52
Autores: Grade,Luciana Carvalho; Moreira,Amanda Aleixo; Varea,Geni da Silva; Mandarino,José Marcos Gontijo; Silva,Josemeyre Bonifácio da; Ida,Elza Iouko; Ribeiro,Mara Lúcia Luiz.
The objective of this study was to investigate the immobilisation efficiency of soybean β-glucosidase (181.6 U/mL; 23.8 mg protein/mL) on activated chitosan beads. Central Composite Rotational Design (CCDR) 23 was used and the application of immobilised enzyme in commercial soy drink was evaluated. The activation of chitosan beads was achieved with established 2.5% glutaraldehyde, pH 7.5, 8 h incubation time (6 h with agitation and 2 h without agitation) at 37ºC. The highest immobilisation efficiency (%) of soybean β-glucosidase on chitosan beads obtained was 37.74 U/mL and 18.84 mg protein/4 chitosan beads at pH 7.5 and 20 h coupling time of enzyme-matrix (7 h with agitation and 13 h without agitation) at 4ºC. The immobilised enzyme incubated at 50ºC, pH...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Β-glucosidase soybean; Immobilisation; Chitosan; Aglycones.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000500766

Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan
Provedor de dados: 52
Autores: Ortega-Ortiz,Hortensia; Gutiérrez-Rodríguez,Baltazar; Cadenas-Pliego,Gregorio; Jimenez,Luis Ibarra.
The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid)-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antibacterial activity; Chitosan; Complexes; Poly(acrylic acid); Polyelectrolytes.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000300016

Effects of Emerita brasiliensis flour supplementation on normotensive (Wistar) and spontaneously hypertensive rats (SHR)
Provedor de dados: 52
Autores: Cavargere,Victor Agati; França,Camille Feitoza; Cardoso,Ricardo; Vianna,Lucia Marques.
Several studies characterize the connection of overweight and obesity with chronic diseases. Therefore, new alternatives are being studied for controlling hypertension, such as chitin and chitosan fibers, commonly found on crustacean's carapace like Emerita brasiliensis. Rats from two different strains were divided into control and supplemented groups (n=6). The Wistar strain experiment started with a 14-days baseline period, followed by supplementation of E.brasiliensis flour added to the diet in the doses of 5, 10 and 20%, for a 14-days period each. With the optimal dose of 20%, the study was undertaken with SHR rats, starting with a 7-days baseline period, followed by three weeks of supplementation. Data were evaluated using one-way ANOVA and p&lt;0.05...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chitin; Chitosan; Emerita brasiliensis; Blood pressure.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000400006

Immobilization of Lipases Produced by the Endophytic Fungus Cercospora kikuchii on Chitosan Microparticles
Provedor de dados: 52
Autores: Carneiro,Lara Aparecida Buffoni Campos; Costa-Silva,Tales Alexandre; Souza,Cláudia Regina Fernandes; Bachmann,Luciano; Oliveira,Wanderley Pereira; Said,Suraia.
This work studied the immobilization of Cercospora kikuchii lipases on chitosan microparticles by chemical attachment on chitosan acetate microparticles activated by glutaraldehyde (CAM) added before or after the enzyme and physical adsorption on highly deacetylated chitosan hydrochloride microparticles (CHM). Lipases covalently immobilized on pre-activated CAM showed better performance retaining 88.4% of the enzymatic activity, with 68.2% of immobilization efficiency (IE). The immobilized enzyme retained an activity of about 53.5 % after five reuses, using p-NPP as substrate. Physical adsorption of lipase onto highly deacetylated CHM showed 46.2 % of enzymatic activity and 28.6% of IE. This immobilized derivative did not lose activity up to 80 days of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Enzyme immobilization; Chitosan; Cercospora kikuchii; Lipase.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000400578

A comparative study on fungal laccases immobilized on chitosan
Provedor de dados: 52
Autores: Araújo,José Hilton Bernardino de; Uemura,Vinicius Oliveira; Moraes,Flavio Faria de; Barbosa,Aneli de Melo; Zanin,Gisella Maria.
The phenoloxidase enzyme laccase from the cultures of the Pleurotus ostreatus and Botryosphaeria sp. and a commercial laccase from Aspergillus sp. were immobilized on chitosan of pharmaceutical degree by adsorption followed by crosslinking. Different immobilization conditions in relation to the granulometry of support and amount of enzymatic laccase extract used were tested, aiming at reaching high enzymatic activity with the immobilized enzyme. Two different substrates, ABTS and DMP, were used for the determination of enzymatic activity. The highest enzymatic activity was obtained when 1.0mg/mL of the enzymatic laccase extract from Botryosphaeria sp. was used with 1.0g of support (200 mesh). These immobilized enzymes are to be applied to the improvement...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Laccases; Immobilization; Chitosan.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000400001

Use of chitosan gel for the purification of protein
Provedor de dados: 52
Autores: 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

Effects of Chitosan on the Secretion of Cytokines and Expression of Inducible Nitric Oxide Synthase mRNA in Peritoneal Macrophages of Broiler Chicken
Provedor de dados: 52
Autores: 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 &lt; 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

Changes in hyphal morphology due to chitosan treatment in some fungal species
Provedor de dados: 52
Autores: 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

DNA-lipid systems: A physical chemistry study
Provedor de dados: 56
Autores: Dias,R.; Antunes,F.; Miguel,M.; Lindman,S.; Lindman,B.
It is well known that the interaction of polyelectrolytes with oppositely charged surfactants leads to an associative phase separation; however, the phase behavior of DNA and oppositely charged surfactants is more strongly associative than observed in other systems. A precipitate is formed with very low amounts of surfactant and DNA. DNA compaction is a general phenomenon in the presence of multivalent ions and positively charged surfaces; because of the high charge density there are strong attractive ion correlation effects. Techniques like phase diagram determinations, fluorescence microscopy, and ellipsometry were used to study these systems. The interaction between DNA and catanionic mixtures (i.e., mixtures of cationic and anionic surfactants) was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: DNA; Cationic surfactants; Catanionic mixtures; Chitosan; Phase behavior; Polyelectrolyte-oppositely charged surfactant systems.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000500002

Lactoferrin, chitosan and Melaleuca alternifolia-natural products that show promise in candidiasis treatment
Provedor de dados: 58
Autores: Felipe,Lorena de Oliveira; Silva Júnior,Willer Ferreira da; Araújo,Katialaine Corrêa de; Fabrino,Daniela Leite.
Abstract The evolution of microorganisms resistant to many medicines has become a major challenge for the scientific community around the world. Motivated by the gravity of such a situation, the World Health Organization released a report in 2014 with the aim of providing updated information on this critical scenario. Among the most worrying microorganisms, species from the genus Candida have exhibited a high rate of resistance to antifungal drugs. Therefore, the objective of this review is to show that the use of natural products (extracts or isolated biomolecules), along with conventional antifungal therapy, can be a very promising strategy to overcome microbial multiresistance. Some promising alternatives are essential oils of Melaleuca alternifolia...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Candida; Lactoferrin; Melaleuca alternifolia; Chitosan; Natural products.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000200212

Potential of chitosan from Mucor rouxxi UCP064 as alternative natural compound to inhibit Listeria monocytogenes
Provedor de dados: 58
Autores: Bento,Roberta A.; Stamford,Tânia L.M.; Campos-Takaki,Galba M. de; Stamford,Thayza C.M.; Souza,Evandro L. de.
Listeria monocytogenes is widely distributed in nature and the infection listeriosis is recognized as a potential threat for human health because of its mortality rate. The objective of this study was to evaluate the growth profile and chitosan production by Mucor rouxxi UCP 064 grown in yam bean (Pachyrhizus erosus L. Urban) medium. It was also to assess the anti-L. monocytogenes efficacy of the obtained chitosan. Higher values of biomass of M. rouxxi (16.9 g.L¹) and best yield of chitosan (62 mg.g-1) were found after 48 h of cultivation. Residual glucose and nitrogen in the growth media were 4.1 and 0.02 g.L¹ after 96 h, respectively. Obtained chitosan presented 85 % of degree of deacetylation and 2.60 x 10(4) g.mol-1of viscosimetric molecular weight....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chitosan; Mucor rouxxi; Antilisterial property; Biocontrol.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000300022

Effects of the protective, curative, and eradicative applications of chitosan against Penicillium expansum in apples
Provedor de dados: 58
Autores: 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

Growth rate inhibition of phytopathogenic fungi by characterized chitosans
Provedor de dados: 58
Autores: Oliveira Junior,Enio N.; Gueddari,Nour E. El; Moerschbacher,Bruno. M.; Franco,Telma T.
The inhibitory effects of fifteen chitosans with different degrees of polymerization (DP) and different degrees of acetylation (F A) on the growth rates (GR) of four phytopathogenic fungi (Alternaria alternata, Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer) were examined using a 96-well microtiter plate and a microplate reader. The minimum inhibitory concentrations (MICs) of the chitosans ranged from 100 µg × mL-1 to 1,000 µg × mL-1 depending on the fungus tested and the DP and F A of the chitosan. The antifungal activity of the chitosans increased with decreasing F A. Chitosans with low F A and high DP showed the highest inhibitory activity against all four fungi. P. expansum and B. cinerea were relatively less susceptible while A....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chitosan; Antifungal activity; Fungal morphology; Phytopathogenic fungi.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000200046

Faster chitosan production by mucoralean strains in submerged culture
Provedor de dados: 58
Autores: Amorim,Rosa Valéria da Silva; Souza,Wanderley de; Fukushima,Kazutaka; Campos-Takaki,Galba Maria de.
Production of chitosan was conducted using two Mucoralean strains, Mucor racemosus and Cunninghamella elegans. Chitosan was extracted from mycelia of M. racemosus and C. elegans at different growth phases on YPD medium. In both fungi, chitosan was rapidly produced, while highest yield of extractable chitosan was found in 24h of cultivation in submerged culture. The yield of chitosan isolated from dry mycelia of M. racemosus was about 40% higher than from C. elegans. The degree of N-acetylation of chitosan was 49% in M. racemosus and 20% in C. elegans, and the D-glucosamine contents were about 48% and 90%, respectively.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chitosan; Submerged culture; Mucor racemosus; Cunninghamella elegans.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822001000100005

Heavy metal biosorption by chitin and chitosan isolated from Cunninghamella elegans (IFM 46109)
Provedor de dados: 58
Autores: 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

Preparation and characterization of novel, mucoadhesive ofloxacin nanoparticles for ocular drug delivery
Provedor de dados: 60
Autores: Taghe,Shiva; Mirzaeei,Shahla.
The efficacy of conventional ocular formulations is limited by poor corneal retention and permeation, resulting in low ocular bioavailability. Mucoadhesive chitosan (CS)/ tripolyphosphatesodium (TPP) and chitosan (CS)/ tripolyphosphatesodium (TPP)-alginate (ALG) nanoparticles were investigated for the prolonged topical ophthalmic delivery of ofloxacin. A modified ionotropic gelation method was used to produce ofloxacin-loaded nanoreservoir systems. The ofloxacin-loaded CS/TPP and CS/TPP-ALG nanoparticles were characterized for particle size, morphology, zeta potential, encapsulation efficiency, subsequent release and corneal penetration study. The designed nanoparticles have a particle size from 113.8 nm to 509 nm and zeta potential from 16.2 mV to 40.3 mV...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ocular drug delivery; Nanoparticles; Corneal penetration; Ofloxacin; Chitosan.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502019000100519

Silver nanoparticles incorporated into nanostructured biopolymer membranes produced by electrospinning: a study of antimicrobial activity
Provedor de dados: 60
Autores: 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

Evaluation of polyelectrolyte and emulsion covalent crosslink of chitosan for producing mesalasine loaded submicron particles
Provedor de dados: 60
Autores: 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

Targeting of temozolomide using magnetic nanobeads: an in vitro study
Provedor de dados: 60
Autores: Gürten,Berna; Yenigül,Elçin; Sezer,Ali Demir; Altan,Cem; Malta,Seyda.
Temozolomide, a chemotherapeutic drug that is often administered for the treatment of brain cancer has severe side effects and a poor aqueous solubility. In order to decrease the detrimental effect of the drug over healthy cells, a novel drug delivery vehicle was developed where the therapeutic drug was encapsulated within the hydrophobic cavities of b-CD modified magnetite nanoparticles, which are embedded in chitosan nanobeads prepared by salt addition. In-vitro studies have shown that the magnetic properties of the novel delivery vehicle are adequate for targeted drug delivery applications under an external magnetic field. Additionally, an increase in the amount of chitosan was shown to exhibit a strong shielding effect over the magnetic properties of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Temozolomide; Magnetite; Cyclodextrin; Chitosan; Targeting; Anticancer.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502020000100574

Quality by design (Qbd) approach to develop stability indicating HPLC method for estimation of rutin in chitosan-sodium alginate nanoparticles
Provedor de dados: 60
Autores: 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

Preparation and characterization of a novel antimicrobial film dressing for wound healing application
Provedor de dados: 60
Autores: 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

Investigation of the parameters affecting the release of flurbiprofen from chitosan microspheres
Provedor de dados: 60
Autores: 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

Insulin-loaded polymeric mucoadhesive nanoparticles: development, characterization and cytotoxicity evaluation
Provedor de dados: 60
Autores: 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

Preparation and characterization of microcapsules of Pterodon pubescens Benth. by using natural polymers
Provedor de dados: 60
Autores: Reinas,Alexandre Espada; Hoscheid,Jaqueline; Outuki,Priscila Miyuki; Cardoso,Mara Lane Carvalho.
An oleaginous fraction obtained from an alcohol extract of the fruit of Pterodon pubescensBenth. (FHPp) was microencapsulated in polymeric systems. These systems were developed using a complex coacervation method and consisted of alginate/medium-molecular-weight chitosan (F1-MC), alginate/chitosan with greater than 75% deacetylation (F2-MC), and alginate/low-molecular-weight chitosan (F3-MC). These developed systems have the potential to both mask the taste of the extract, and to protect its constituents against possible chemical degradation. The influence of the formulation parameters and process were determined by chemical profiling and measurement of the microencapsulation efficiency of the oleaginous fraction, and by assessment of microcapsule...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pterodon pubescensBenth./pharmacognosy; Sucupira; Microcapsules/preparation; Vouacapans; Alginate; Chitosan; Coacervation method; Natural polymers; Natural products.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502014000400919

Amphotericin-B and vancomycin-loaded chitosan nanofiber for antifungal and antibacterial application
Provedor de dados: 60
Autores: Karimi,Soroush; Moradipour,Pouran; Azandaryani,Abbas Hemati; Arkan,Elham.
In the present study, a mucoadhesive non-woven fiber mat (d= 116 nm) was fabricated by the electrospinning method using chitosan (80% Wt), polyethylene oxide (10% Wt), cysteine (4% Wt) and drugs (6% Wt), respectively. In addition, a comparative study was conducted to define effect of drugs and mucoadhesive agent on the nanofiber formation. FTIR, SEM, DSC and DMA were used to investigate the chemical and physical properties of the nanofibers. In vitro release of the drugs was assessed over a 48-hour period by the total immersion method. Release data were ﬁtted to kinetic models, including the zero-order, ﬁrst-order, Higuchi matrix, and Hixson-Crowell. Zone inhibition investigations were used to describe the inhibition content of vancomycin and amphotericin...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mucoadhesive; Vancomycin; Amphotericin-B; Electrospinning; Aphthous; Chitosan.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502019000100521

Controlled release alginate-chitosan microspheres of tolmetin sodium prepared by internal gelation technique and characterized by response surface modeling
Provedor de dados: 60
Autores: Elsayed,Mahmoud M. A.
Tolmetin sodium (TS) is a powerful non-steroidal mitigating drug for the treatment of rheumatoid joint inflammation, osteoarthritis, and adolescent rheumatoid joint pain. In addition to its gastrointestinal (GIT) problems, TS has a short biological half-life (1 hr). In a trial to overcome these side effects and control the rate of (TS) release, chitosan coated alginate microspheres are recommended. A Box-Behnken experimental design was employed to produce controlled release microspheres of TS in the sodium alginate and chitosan copolymers (Alg-Ch) by emulsification internal gelation methodology. The effect of critical formulation variables namely, drug to polymer ratio (D:P ratio), speed of rotation and span 80% on drug encapsulation efficiency (% EE),...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tolmetin Sodium; Controlled Release; Alginate; Chitosan; Response Surface.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502020000100604

Floating ability and drug release evaluation of gastroretentive microparticles system containing metronidazole obtained by spray drying
Provedor de dados: 60
Autores: Nohemann,Laís; Almeida,Marina Penteado de; Ferrari,Priscileila Colerato.
Abstract Gastroretentive floating microparticles were developed and evaluated for the controlled metronidazole delivery for treatment of gastric disease. Floating microparticles, varying in proportions of chitosan and hydroxypropyl methylcellulose or ethylcellulose, were obtained by spray drying. Floating microparticles were characterized by physicochemical and in vitro studies, according to their floating ability and drug delivery. Microparticles presented mean diameter from 1.05 to 2.20 µm. The infrared spectroscopy confirmed the drug encapsulation and showed no chemical linkage between microparticles components. X-ray diffraction showed changes in the drug`s solid state, from crystalline to amorphous, indicating partial drug encapsulation, due to the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Floating microparticle; Chitosan; Ethylcellulose; Hydroxypropyl methylcellulose; Controlled drug delivery.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502017000100611

Scale-up in the synthesis of nanoparticles for encapsulation of agroindustrial active principles
Provedor de dados: 64
Autores: Duarte,Dirliane Santos; Nascimento,José Augusto de Almeida; Britto,Douglas de.
ABSTRACT Given the potentiality of nanoparticles (NP) to load substances as active principle of drugs, cosmetics and food, there is interest in increasing its production. Particularly in the agroindustrial area, the byproducts are source of functional compounds that must be stabilized by encapsulation, for example, to allow its application. Considering the amount of generated byproducts, it is necessary to understand the encapsulation synthesis in a high scale dimension. In this way, the active compounds vitamin C (from the byproduct of the acerola processing) and polyphenols (from the byproduct of grape processing) were nanoencapsulated into chitosan NP at three reactional volumes: 0.1; 1.0 and 10.0 dm3. The NP were characterized for yield, particle size,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Vitamin C; Polyphenols; Byproduct; Chitosan.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542019000100406