Pesquisa e desenvolvimento de microesferas de poli(vinil álcool) com alta cristalinidade para utilização em embolização e quimioembolização
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Data
2012-06-28
Autores
Semenzim, Vinícius Ladeia [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Partículas poliméricas com tamanho e morfologia controlados e propriedades físico-químicas adequadas são amplamente utilizadas em várias aplicações biomédicas, especialmente em embolização, uma técnica cirúrgica minimamente invasiva utilizada em tratamentos de diversas doenças vasculares e quimioembolização, que associa a embolização e a quimioterapia. Ela é realizada com uso de materiais denominados agentes embólicos, sendo as partículas de poli(vinil álcool) (PVA) amplamente utilizadas por apresentarem um alto grau de desempenho. As partículas de PVA estão disponíveis no mercado nas morfologias esféricas e floculares, sendo as esféricas as que apresentam menores riscos para o procedimento. Dessa forma, o presente trabalho teve como objetivo sintetizar e caracterizar microesferas de PVA para serem utilizadas em embolização e quimioembolização. Juntamente com a equipe de pesquisadores da empresa Braile Biomédica, a intenção é desenvolver um produto que ainda não é fabricado pela indústria nacional para ser comercializado a menores custos. Materiais e Métodos: As microesferas de poli(vinil álcool) (PVA) foram sintetizadas pelo método de polimerização em suspensão, seguida de hidrólise alcalina (ou saponificação). Na etapa de saponificação, diferentes concentrações de NaOH foram utilizadas. As amostras sintetizadas foram caracterizadas por Microescopia Eletrônica de Varredura (MEV), Difração de Raios-X (DRX), Calorimetria Diferencial de Varredura (DSC), Ressonância Magnética Nuclear de 13 C - cross polarization / magic angle spinning ( 13 C RMN CP/MAS) e Potencial Zeta (ζ). Resultados: A análise de MEV indicou que foram obtidas partículas esféricas. Os dados complementares de DRX, DSC e 13 C RMN CP/MAS indicam que à medida que se aumenta a concentração...
Polymeric particles with size and morphology controlled and appropriate physicochemical properties are widely used in several biomedical applications, especially in embolization, a minimally invasive procedure routinely used in treatments of some vascular diseases, and chemoembolization, which combines embolization and chemotherapy. It is performed using materials called embolic agents, being poly(vinyl alcohol) (PVA) particles often used because its high performance. These particles are commercially available in spherical and flocculate morphologies, however spherical particles present lower risks than flocculates ones during the procedure. Thus, this study proposes to develop and improve spherical PVA particles to be used in embolization and chemoembolization. The development are being conducted by the researchers group from Braile Biomédica, the goal is to develop a product that is not yet produced in the national industry, commercializing it at lower costs. Materials and Methods: PVA microspheres were synthesized by suspension polymerization method, followed by alkali hydrolysis (or saponification). In the saponification step, different concentrations of NaOH were used. The samples synthesized were characterized by Scanning Electronic Microscopy (SEM), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), 13 C Nuclear Magnetic Resonance - cross polarization / magic angle spinning ( 13 C CP/MAS NMR) and Zeta Potential (ζ). Results: SEM analysis indicated that spherical particles were obtained. The complementary data of XRD, DSC and 13 C CP/MAS NMR indicate that the use of high NaOH concentrations (in the saponification process) determines reordering in the lateral chains of the polymer, which causes an increase of material’s crystallinity. Zeta Potential (ζ) data of the samples indicated that, in an... (Complete abstract click electronic access below)
Polymeric particles with size and morphology controlled and appropriate physicochemical properties are widely used in several biomedical applications, especially in embolization, a minimally invasive procedure routinely used in treatments of some vascular diseases, and chemoembolization, which combines embolization and chemotherapy. It is performed using materials called embolic agents, being poly(vinyl alcohol) (PVA) particles often used because its high performance. These particles are commercially available in spherical and flocculate morphologies, however spherical particles present lower risks than flocculates ones during the procedure. Thus, this study proposes to develop and improve spherical PVA particles to be used in embolization and chemoembolization. The development are being conducted by the researchers group from Braile Biomédica, the goal is to develop a product that is not yet produced in the national industry, commercializing it at lower costs. Materials and Methods: PVA microspheres were synthesized by suspension polymerization method, followed by alkali hydrolysis (or saponification). In the saponification step, different concentrations of NaOH were used. The samples synthesized were characterized by Scanning Electronic Microscopy (SEM), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), 13 C Nuclear Magnetic Resonance - cross polarization / magic angle spinning ( 13 C CP/MAS NMR) and Zeta Potential (ζ). Results: SEM analysis indicated that spherical particles were obtained. The complementary data of XRD, DSC and 13 C CP/MAS NMR indicate that the use of high NaOH concentrations (in the saponification process) determines reordering in the lateral chains of the polymer, which causes an increase of material’s crystallinity. Zeta Potential (ζ) data of the samples indicated that, in an... (Complete abstract click electronic access below)
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Palavras-chave
Biologia molecular, Biofísica, Polimeros de vinil, Polimeros cristalinos, Poly(vinyl alcohol)
Como citar
SEMENZIM, Vinícius Ladeia. Pesquisa e desenvolvimento de microesferas de poli(vinil álcool) com alta cristalinidade para utilização em embolização e quimioembolização. 2012. 94 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências, Letras e Ciências Exatas, 2012.