Síntese e caracterização de estruturas densas e porosas de quitosana

Beppu, Marisa M.; Arruda, Eduardo José de; Santana, César Costapinto

doi:10.1590/s0104-14281999000400027

Cited by 21 publications

(16 citation statements)

References 2 publications

(1 reference statement)

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“…To estimate the applicability of chitosans obtained for biotechnology purposes, they were evaluated for film-forming capacity by production of dense films as presented by Beppu et al [5]. The films obtained were named as follows: F1551ss (semi-synthetic chitosan from strain 1551),F1551n (native chitosan from strain 1551), Fs (chitosan from Sigma Aldrich ® ) and Fc (chitosan from a commercial producer).…”

Section: Dense Film Preparationmentioning

confidence: 99%

“…Attention was made for the detection of native chitosan, which was treated separately from the chitosan obtained by deacetylation of chitin. In a preliminary attempt to verify the aptitude of these chitosans for applications, dense films were produced [5] and were described qualitatively. Commercial chitosans were compared with the chitosans obtained.…”

Section: Introductionmentioning

confidence: 99%

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Chitosans from Rhizopus stolonifer (strain CBMAI 1551): Characterization and Dense Film Formation

Cardoso

ConceiÃ§Ã£o

Giachini

et al. 2017

JBT

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I S S N 2348-6201 V o l u m e 6 N u m b e r 3 J o u r n a l o f A d v a n c e i n B i o t e c h n o l o g y | ABSTRACTChitosan is a bioactive amino polymer with wide applications. Mainly derived from chitin of marine sources, its traditional production still has some drawbacks such as irregular supply, low quality of product and lack of standardization. Farther, extraction processes are time-consuming with considerable environmental impacts, an extremely non-green process. Many works have shown the possibility of producingnative chitosan from Mucorales fungi, which is more easily extracted. Such process is advantageous due to low costs, process control and great possibility of high quality products. Moreover, the extraction of chitosan is faster and generates less pollutants. In this scenario, the possibility of standardized production allied with facilitated extraction and less probability of toxicological side effects from marine sources are characteristics that motivated this work. A Mucoralesisolate was cultured and the chitosans -native and semi-synthetic -obtained through heterogeneous extraction were compared. Results show substantial differences between them. Those differences are related to the processes required for extraction, yield, productivity, and quality. This work reinforces that Mucorales fungi excel as an alternative for chitosan production.

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Section: Dense Film Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Chitosans from Rhizopus stolonifer (strain CBMAI 1551): Characterization and Dense Film Formation

Cardoso

ConceiÃ§Ã£o

Giachini

et al. 2017

JBT

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“…No difratograma da quitosana observaram-se dois picos, um de alta intensidade em 19,8 o e um de menor intensidade em 37,7 o que evidenciam a parte cristalina e uma ampla faixa abaixo dos picos, variando de aproximadamente 8 a 80…”

Section: Difração De Raios-xunclassified

“…5,7 A reticulação da quitosana com GA a torna mais resistente do ponto de vista físico, químico e microbiológico. 8 O objetivo principal deste trabalho consistiu na preparação e caracterização de diversas proporções de misturas de QUI/PVA, com reticulação química por GA para aplicação potencial em engenharia de tecidos para obtenção de uma matriz dérmica.…”

Section: Introductionunclassified

Preparação e caracterização de blendas de quitosana/poli(álcool vinílico) reticuladas quimicamente com glutaraldeído para aplicação em engenharia de tecido

Junior¹,

Mansur²

2008

Quím. Nova

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Recebido em 3/10/07; aceito em 14/3/08; publicado na web em 1/9/08 PREPARATION AND CHARACTERIZATION OF CHITOSAN/POLY(VINYL ALCOHOL)BLEND CHEMICALLY CROSSLINKED BY GLUTARALDEHYDE FOR TISSUE ENGINEERING APPLICATION. In this study, novel Chitosan/PVA based films were chemically crosslinked by glutaraldehyde, under pH=(4,00 ±0,05), in order to achieve structures tailored for wound tissue engineering applications. Both precursors and developed films were characterized by FTIR, SEM and XRD in order to determine the presence of chemicals groups and nanostructural order, respectively. The results have shown that the glutaraldehyde crosslinking have altered the crystallinity of pure chitosan and the increase on the C=N bands and simultaneous decrease on NH 2 bands suggested that Chitosan/GA crosslinking has preference to occur in carbon-2 of the saccharide ring by the Schiff's base reaction. Also, FTIR spectroscopy clearly showed that crosslinking has also taken place with blends of PVA and chitosan. The mechanical properties presented high degree dependence with on the increase of the content of chitosan and glutaraldehyde. The results have indicated that, by controlling the ratio [PVA]/[chitosan] in the blends and the extent of chemical crosslinking, it was possible to tailor the hybrid network produced aiming to obtain properties of interest for the specific application.Keywords: chitosan; poly(vinyl alcohol); crosslinking. INTRODUÇÃONum sentido amplo a engenharia de tecidos visa fabricar partes de órgãos e tecidos de organismos vivos para sua substituição. Esse ramo do conhecimento tem se desenvolvido devido à crescente demanda por órgãos e tecidos em função de acidentes e/ou tratamentos de enfermidades diversas.1 De forma a suprir essa necessidade, as blendas de polímeros naturais e sintéticos têm se mostrado uma alternativa viável, pois é possível trabalhar diversas propriedades a fim de viabilizar as características específicas de cada aplicação.A quitosana (QUI) é um polímero obtido principalmente a partir da desacetilação alcalina da quitina, a qual é o segundo polí-mero natural mais abundante depois da celulose e é encontrado nos exoesqueletos de artrópodes e alguns fungos. Ela tem propriedades interessantes para aplicação em engenharia de tecido, tais como biocompatibilidade, biodegradabilidade, acelera a recuperação de lesões, reduz o nível do colesterol sanguíneo, estimula os efeitos do sistema imunológico, além de ter se mostrado um composto bacteriostático e fungistático, 2 bem como os resultados de sua degradação em organismos vivos que são as glicosaminas, substâncias não tóxicas. Uma das características mais importantes deste polissacarídeo é o seu grau de desacetilação (GD) que representa a proporção de resíduos acetilados ainda presentes no mesmo, após o processamento para sua obtenção. A quitosana se degrada pela hidrólise enzimática e apresenta cinética de degradação aparentemente relacionada ao grau de cristalinidade que é controlado principalmente pelo GD, 3 entretanto sua resistência mecânica e s...

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“…Membranas de polissulfona tiveram sua superfície modificada através da aplicação de uma fina camada de quitasana. O glutaraldeído foi utilizado como agente de ligação cruzada, com o intuito de conferir uma melhor estabilidade química à camada de quitosana (TSAI et alli., 2008, BEPPU et al, 1999 , 1996;HABERT et al, 2006;BAKER, 2004) A classificação das membranas densas anisotrópicas também deve distinguir o material que constitui suas diferentes regiões na seção transversal (o filme superficial denso e a parte porosa). Caso ambas as camadas sejam constituídas do mesmo material, a membrana é dita integral.…”

Section: Lista De Tabelasunclassified

Síntese e caracterização de membranas de filme fino composto de polissulfona/quitosana reticulada com glutaraldeído.

Nogueira¹

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pela co-orientação, imprescindível para a realização desta pesquisa; Ao meu marido, Claiton, e meus filhos, Lucas e Carolina, pelo carinho, apoio, incentivo e paciência; Aos meus pais, Togo e Ivone, pelo imenso apoio e pelo constante incentivo;A Luana Di Beo Rodrigues, Cristiane Naomi Kamikawachi, Karolina da Silva Borgo, Guilherme Yamakita e Cláudia Nunes, pela enorme colaboração na realização deste trabalho;Aos amigos do CIRRA, que de alguma forma estiveram presentes, me apoiando sempre; À Solvay Química do Brasil Ltda., em especial à Mônica Freire Dias Martins, pelo fornecimento da polissulfona; À Crane Nonwovens, pela doação dos suportes inertes para a fabricação das membranas; À FAPESP pelo financiamento dessa pesquisa; ABSTRACTA major obstacle to be overcome in order to have a greater use of membrane technology in liquids purification is the phenomenon of fouling. As a consequence, the development of membranes less prone to fouling is now the objective of numerous studies. Among the processes evaluated, the development of thin film composite membranes has has been the focus of many researches since it is possible to improve each layer independently, in order to improve the membrane performance as a whole.This work aimed to study the synthesis and characterization of thin film composite chitosan, crosslinked with glutaraldehyde, and polysulfone (PSF) membranes. PSF ultrafiltration membranes were produced by phase inversion via immersion precipitation to be used as porous support for the chitosan layer. The influence of PSF concentration in the polymeric solution; temperature of synthesis; air humidity, and membrane nonwoven support, CU414 and CU424 (Crane Nonwovens), on the membrane characteristics and performance were studied. The effect polyvinyl alcohol (PVA), crosslinked with glutaraldehyde, between PSF and chitosan layers, on the cast membrane structural stability was investigated. The influence of glutaraldehyde as a chitosan crosslinking agent on membrane selectivity, permeability, chemical stability, and toxicity was also evaluated. The results showed that increasing PSF concentration, decreasing temperature and increasing air humidity resulted in less porous membranes.The support media used were not suitable for the production of PSF membranes under the conditions used in this work due to its high porosity. The solution used to crosslink the PVA layer, composed of glutaraldehyde in aqueous solution of acetone, attacked the support media and the PSF membrane, preventing the application of the PVA layer between the PSF and chitosan layers. The use of glutaraldehyde as a chitosan crosslinking agent made the membrane less rough and more hydrophilic. Additionally, increasing glutaraldehyde concentration in the chitosan solution led to a decrease in membrane permeability, wich was attibutted to a compaction of the membrane structure, leading to a decreased mobility of polymer chains and a decrease in the membrane void volume.Membranes separation capacity was evaluated using two different ionic solutions...

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Síntese e caracterização de estruturas densas e porosas de quitosana

Cited by 21 publications

References 2 publications

Chitosans from Rhizopus stolonifer (strain CBMAI 1551): Characterization and Dense Film Formation

Chitosans from Rhizopus stolonifer (strain CBMAI 1551): Characterization and Dense Film Formation

Preparação e caracterização de blendas de quitosana/poli(álcool vinílico) reticuladas quimicamente com glutaraldeído para aplicação em engenharia de tecido

Síntese e caracterização de membranas de filme fino composto de polissulfona/quitosana reticulada com glutaraldeído.

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