Caracterização dos constituintes do látex e da borracha natural que estimulam a angiogênese
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Data
2009-04-30
Autores
Agostini, Deuber Lincon da Silva [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
As membranas de borracha natural são usadas frequentemente como material biológico na indução de angiogênese e neoformação. Neste trabalho foram realizados estudos com objetivo de identificar os componentes do látex que são responsáveis pelo processo de angiogênese e neoformação. O látex, as fases centrifugadas do látex e as membranas da borracha natural, tratados termicamente em 60, 85 e 120ºC, foram liofilizados para a redução de água nos mesmos. A caracterização de tais materiais foi realizada por espectroscopia infravermelha (FTIR), micro-Raman, ressonância magnética nuclear (NMR - 1H e 13C), difração de raio x (DRX), microscopia eletrônica de varredura (MEV) e microscopia de força atômica (AFM), análise do termogravimétrica (TG) acoplado com infravermelho (TG/FT-IR), calorimetria exploratória diferencial (DSC), análise dinâmico mecânica (DMA) e o método de Bradford. Nos resultados de espectroscopia no infravermelho, micro de Raman, NMR (1H e 13C), de raios x e TG/FT-IR; os componentes químicos do látex, das fases centrifugadas do látex e das membranas da borracha natural foram identificados. A técnica de TG foi utilizada para avaliar a estabilidade térmica e os resultados mostraram que as membranas obtidas a 60ºC possuem maior estabilidade. Nos resultados de DSC notou-se que a transição vítrea acontece em ~ -68ºC, para todos os materiais que contêm isopreno e a degradação estrutural ocorrem em torno de 376ºC. As transições de vítreas foram confirmadas através dos resultados de DMA. O látex centrifugado apresenta três fases: partículas de borracha (F1), lutóides (F2) e Frey-Wyssling (F3). Nas frações F2 e F3 o isopreno é ausente, ou apresenta pequena proporção, mas contêm diversos componentes químicos: proteínas, ácidos aminados e grupos funcionais que podem induzir o angiogênese e a neoformação em tecidos biológicos...
Natural latex and natural rubber membranes are frequently used as biomaterial in the angiogenesis induction and neoformation of biological tissues. Our studies aimed to study and identify the latex components that are responsible for angiogenesis and neoformation processes. The natural latex, the centrifuged latex phases and the natural rubber membranes were thermally treated at 60, 85 and 120ºC and afterward all samples were lyophilized. The characterization of such materials were carried out using infrared (FT-IR), micro Raman spectroscopy, nuclear magnetic resonance (NMR - 1H e 13C), X-ray diffraction, scanning electronic microscopy (SEM) and atomic force microscopy (AFM), thermogravimetry analysis coupled with infrared (TG/FT-IR), differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA) and the method of Bradford. From the results of infrared and micro Raman spectroscopy, NMR (1H e 13C), X-rays and TG/FT-IR the chemical components present in the latex, in the centrifuged latex phases and in natural rubber membranes were identified. TG technique was used to evaluate the thermal stability and results showed that membranes obtained at 60ºC present greater stability, up to 350ºC. From DSC results it was found that the glass transition happens at –68ºC, for all materials containing isoprene, and the structural degradation occurs at 376ºC. Glass transitions were confirmed also by DMA results. Centrifuged latex presents three phases: rubber particles (F1), lutoids (F2) and Frey-Wyssling (F3). In the fractions F2 and F3 the isoprene is absent but they contain several chemical components: proteins, amino acids and functional groups that can induce angiogenesis and neoformation on biological tissues. The treated membrane 60ºC of natural rubber showed the highest angiogenesis and neoformation activities. Furthermore, membranes containing pores favor the cicatrization process and the vascularization processes.
Natural latex and natural rubber membranes are frequently used as biomaterial in the angiogenesis induction and neoformation of biological tissues. Our studies aimed to study and identify the latex components that are responsible for angiogenesis and neoformation processes. The natural latex, the centrifuged latex phases and the natural rubber membranes were thermally treated at 60, 85 and 120ºC and afterward all samples were lyophilized. The characterization of such materials were carried out using infrared (FT-IR), micro Raman spectroscopy, nuclear magnetic resonance (NMR - 1H e 13C), X-ray diffraction, scanning electronic microscopy (SEM) and atomic force microscopy (AFM), thermogravimetry analysis coupled with infrared (TG/FT-IR), differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA) and the method of Bradford. From the results of infrared and micro Raman spectroscopy, NMR (1H e 13C), X-rays and TG/FT-IR the chemical components present in the latex, in the centrifuged latex phases and in natural rubber membranes were identified. TG technique was used to evaluate the thermal stability and results showed that membranes obtained at 60ºC present greater stability, up to 350ºC. From DSC results it was found that the glass transition happens at –68ºC, for all materials containing isoprene, and the structural degradation occurs at 376ºC. Glass transitions were confirmed also by DMA results. Centrifuged latex presents three phases: rubber particles (F1), lutoids (F2) and Frey-Wyssling (F3). In the fractions F2 and F3 the isoprene is absent but they contain several chemical components: proteins, amino acids and functional groups that can induce angiogenesis and neoformation on biological tissues. The treated membrane 60ºC of natural rubber showed the highest angiogenesis and neoformation activities. Furthermore, membranes containing pores favor the cicatrization process and the vascularization processes.
Descrição
Palavras-chave
Latex, Neovascularização, Isopreno, Natural rubber, Angiogenesis
Como citar
AGOSTINI, Deuber Lincon da Silva. Caracterização dos constituintes do látex e da borracha natural que estimulam a angiogênese. 2009. 87 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências de Bauru, 2009.