Síntese e caracterização de arcabouços de quitosana com agente antineoplásicos

Abstract

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...

Recovery of chitin and chitosan from shrimp waste with microwave technique and versatile application

“…Thus, the derivatives of chitin obtained at a degree of deacetylation higher than or equal to 50% are known as chitosan. The relative proportions of these units generate different structural features, such as the degree of deacetylation and the molecular mass, which are related to the physico-chemical and biological properties of the polymer (CRUZ et al, 2016). When the degree of deacetylation is higher than 70%, chitosan becomes soluble in acidic aqueous solutions and it behaves as a cationic polyelectrolyte suitable for various applications (ABREU et al, 2013).…”

Release of Semiochemicals: Natural Polymers

“…The porous structures of the polymer, when in acidic solutions and coagulated in NaOH solution, have been the subject of many review articles. (Borba Da Cruz et al, 2016;Souza et al, 2014) When used as a molecule releaser, it is interesting that chitosan becomes inert and for this it uses bifunctional agents, crosslinking agents or intercrossing agents such as glutaraldehyde. Crosslinking is normally achieved using an excess of the bifunctional agent that will provide the surface of the chitosan matrix with groups different from the initial amines.…”

Antibacterial Potential of Chitosan Scaffolds Incorporated with Oregano and Thyme Essential Oils against Escherichia coli

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