Diferentes estratégias para a reticulação de quitosana

Gonsalves, Arlan de Assis; Araújo, Cleônia Roberta Melo; Soares, Nivaldo A; Goulart, Marília Oliveira Fonseca; Abreu, Fabiane Caxico de

doi:10.1590/s0100-40422011000700021

Cited by 57 publications

(41 citation statements)

References 40 publications

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“…Este fato decorreu provavelmente da penetração do líquido nos arcabouços porosos e da interação da água (através de ligações de hidrogênio) com pontos reativos (-NH3+, NH2 e -OH). Os grupos -NH3+ estão presentes, principalmente, nas unidades GlcN da quitosana com pH inferior a 7,2 [18].…”

Section: Figura 4: Difratogramas Da Quitosana Pó (A) 14-naftoquinonunclassified

Síntese e caracterização de arcabouços de quitosana com agente antineoplásicos

Cruz¹,

Catão²,

Barbosa³

et al. 2016

Matéria (Rio J.)

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RESUMOO sistema de liberação controlada de fármacos através da utilização de biomateriais poliméricos associados a compostos com ação antineoplásica pode ser empregado como alternativa de tratamento de neoplasias. Desta forma, este trabalho teve como objetivo a síntese e caracterização de sistemas de arcabouços de quitosana com o agente antineoplásico (1,4-naftoquinona), cuja taxa de liberação pode ser controlada pela utilização de um agente reticulante como o tripolifosfato de sódio (TPP). O método de preparação consistiu da solubilização da quitosana em ácido acético, adição do fármaco, congelamento, liofilização e reticulação com TPP. Todas as amostras foram caracterizadas por Difração de Raios X (DRX), Microscopia Eletrônica de Varredura (MEV), Espectroscopia de Energia Dispersiva de Raios X(EDS), grau de intumescimento e biodegradação enzimática. Na MEV foi evidenciada a formação de poros interconectados com tamanhos e formas variadas em todas as estruturas estudadas caracterizando a formação de arcabouços. Já no EDS foi observada a presença de elementos químicos característico da composição química de cada material. No entanto foi observada a presença do sódio que pode estar relacionado ao agente neutralizante utilizado. A reticulação de parte dos arcabouços foi comprovada pelo DRX, EDS e aumentou a taxa de degradação enzimática in vitro dos mesmos. A incorporação do fármaco foi confirmada por DRX, grau de intumescimento e EDS. Desta forma, pode-se concluir que ocorreu à formação de arcabouços reticulados e não reticulados porosos, com propriedades morfológicas e físico-químicas que podem contribuir para carrear fármacos antineoplásicos, sendo possível controlar a taxa de degradação dos mesmos e provável liberação do fármaco.Palavras chaves: Quitosana, Neoplasia, Reticulação, Arcabouços. ABSTRACTThe controlled release system of drugs through the use of polymeric biomaterials compounds associated with antineoplastic action can be employed as an alternative treatment of neoplasms. Thus, this study had as objective the synthesis and characterization of the systems of scaffolds of chitosan loaded with the antineoplastic agent (1,4-naphthoquinone), whose release rate can be controlled by using a crosslinking agent such as sodium tripolyphosphate (TPP). The preparation method consisted of solubilizing the chitosan in acetic acid, drug addition, freezing, lyophilization and crosslinking TPP. All samples were characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), degree of swelling and enzymatic biodegradation. SEM showed the formation of interconnected pores with varying shapes and sizes in all the studied structures characterizing the formation of scaffolds. In EDS the presence of chemical elements characteristic of the chemical composition of each material was observed. However, the presence of sodium was observed which can be related to the neutralization agent used. The crosslinking of the scaffolds was confirmed by XRD and EDS which increased...

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Section: Figura 4: Difratogramas Da Quitosana Pó (A) 14-naftoquinonunclassified

Síntese e caracterização de arcabouços de quitosana com agente antineoplásicos

Cruz¹,

Catão²,

Barbosa³

et al. 2016

Matéria (Rio J.)

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“…Among the possible crosslinking agents, genipin has been widely studied due to its natural origin, low cytotoxicity, and great biocompatibility compared to other conventional crosslinkers [14]. It presents in its chemical structure two reactive sites through which occur its connection with a polymer matrix, forming the three-dimensional polymer network.…”

Section: Introductionmentioning

confidence: 99%

Chitosan Hydrogels Crosslinked by Genipin and Reinforced with Cellulose Nanocrystals: Production and Characterization

Pomari

Montanheiro²,

Siqueira

et al. 2019

J. Compos. Sci.

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In this work, chitosan hydrogels crosslinked with genipin and reinforced with cellulose nanocrystals (CNC) were developed and characterized with the aim of future biomedical applications. CNC was produced by acid hydrolysis and characterized by atomic force microscopy (AFM). Chitosan/CNC nanocomposite hydrogels were produced with different CNC concentrations (w/w): 0%, 2%, 4%, and 6%. The genipin was used as a crosslinking agent in a genipin/chitosan molar proportion of 1:8. The hydrogels were characterized by porosity measurements, scanning electron microscopy (SEM), swelling test, and mechanical compression test. No significant differences were observed concerning the porosity of the hydrogels; however, a trend of decreasing porosity was observed with increasing CNC content. The SEM images showed a better pore structure as the CNC concentration increased. A decrease in the swelling degree with increasing CNC content in the chitosan/CNC nanocomposite hydrogel was verified in the swelling tests. An increase in the CNC concentration in the chitosan/CNC nanocomposite hydrogel caused a gradual increase in the maximum stress and maximum strain as observed in the compression tests, showing a significant difference between chitosan/CNC 6 wt % and neat chitosan hydrogel.

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“…The synthesis of chitosan‐based polyelectrolyte complexes has been extensively reported . Zhu et al .…”

Section: Introductionmentioning

confidence: 99%

Hydrogels based on alkylated chitosan and polyelectrolyte copolymers

Palacio

Urbano

Rivas

2018

J of Applied Polymer Sci

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Hydrogels formed by alkylated chitosan with N‐(3‐chloro‐2‐hydroxypropyl) trimethylammonium chloride and synthetic copolymers forming polyelectrolyte complexes are presented. The copolymer polyelectrolytes were synthesized through free‐radical polymerization. Their compositions and reactivity parameters were determined by the Finemann–Ross and Kelen–Tüdos methods. The copolymers have structures that tend to be alternating. The hydrogels were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, scanning electron microscopy, and water solubility tests at different pH values. For the formation of the hydrogels, they were prepared using different molar ratios of alkylated chitosan and polyelectrolyte copolymers. Their stability was determined by rheological analysis, evaluating the response as a function of strain and frequency. The rheological tests showed that the stability of the polyelectrolyte complexes followed the trend ChT‐CP2 > ChT‐CP3 > ChT‐CP1 due to the presence of greater electrostatic interactions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46556.

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Diferentes estratégias para a reticulação de quitosana

Cited by 57 publications

References 40 publications

Síntese e caracterização de arcabouços de quitosana com agente antineoplásicos

Síntese e caracterização de arcabouços de quitosana com agente antineoplásicos

Chitosan Hydrogels Crosslinked by Genipin and Reinforced with Cellulose Nanocrystals: Production and Characterization

Hydrogels based on alkylated chitosan and polyelectrolyte copolymers

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