Síntese de hidroxiapatia porosa com nanopartículas magnéticas de óxido de ferro
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Data
2012-08-14
Autores
Costa, Taciane Pereira da [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Nanopartículas de magnetita (Fe3O4) funcionalizadas com (3-aminopropil)trimetoxissilano (APTS) foram sintetizadas e inseridas em hidroxiapatita (HA) porosa a fim de se obter um biocompósito para tratamento de osteomielite e osteocarcinoma. A HA é conhecida por ser um constituinte dos ossos e por sua propriedade de osteocondução. As nanopartículas magnéticas são utilizadas em biomedicina como sensores magnéticos e transportadores devido à resposta ao campo magnético externo. Para a preparação da hidroxiapatita porosa, foi utilizado um molde de esferas de sílica. Durante a síntese das esferas, os parâmetros físico-químicos foram testados a fim de se obter esferas de tamanhos diferentes com estreita distribuição de diâmetros. Sendo escolhidas as esferas de 808, 402, e 223nm, o molde foi preparado modificando a superfície das esferas com peróxido de hidrogênio. O produto foi dispersado em etanol e deixado em sedimentação gravitacional, obtendo-se assim omolde empacotado. O método sol-gel foi usado para a síntese do precursor de hidroxiapatita. Calcinando o precursor a 700ºC, foi possível obter a fase hidroxiapatita. O molde foi infiltrado no gel precursor devidamente caracterizado, sendo que após o tratamento térmico, o molde de sílica foi removido com solução de hidróxido de sódio para a formação da hidroxiapatita porosa. Foram obtidas duas amostras, sendo uma com poros na ordem de 350nm, e outra com poros na ordem de 170nm. Como última etapa, nanopartículas de magnetita funcionalizadas com APTS com tamanhos na ordem de 5nm, foram preparadas por meio do método de co-precipitação em meio aquoso, sendo inseridas na hidroxiapatita porosa obtida. Por meio da análise de EDX, comprovou-se a presença das nanopartículas na hidroxiapatita porosa, entretanto a magnetização da amostra precisa ser melhorada para...
Magnetite nanoparticles (Fe3O4) were synthesized and functionalized with (3-aminopropyl)trimethoxysilane (APTS) to be inserted into hydroxyapatite (HA) porous in order to obtain a biocomposite for the treatment of osteomyelitis and osteocarcinoma. HA is known to be a constituent of bones and by its osteoconductivity properties. The magnetic nanoparticles are used in biomedicine as magnetic sensors and drug transporters due to their response to external magnetic field .For the preparation of porous hydroxyapatite, it was used a template of silica spheres. During the synthesis of such spheres, the physicochemical parameters were tested in order to obtain narrow size diameters distribution of different size spheres. Being chosen spheres of 808, 402, and 223nm, the template was prepared by modifying the surface of the spheres with hydrogen peroxide. The sample was then dispersed in ethanol and placed in gravitational sedimentation field, thereby obtaining the close-packed template. The sol-gel method was used for the synthesis of the hydroxyapatite precursor gel. Calcining the gel at 700°C, it was possible to obtain the hydroxyapatite phase. The template was infiltrated into the characterized gel precursor and after the thermal treatment the silica template was removed by a sodium hydroxide solution for the formation of porous hydroxyapatite. Two samples were obtained one having pores of the order of 350nm, and another one with pores ca.170nm. Functionalized magnetite nanoparticles with sizes of 5nm were prepared by the coprecipitation method in an aqueous medium, being inserted in porous obtained hydroxyapatite it was possible to prove the presence of the nanoparticles in porous hydroxyapatite by EDX analysis results. Nevertheless, the magnetization of the sample needs to be improved to the successful... (Complete abstract click electronic access below)
Magnetite nanoparticles (Fe3O4) were synthesized and functionalized with (3-aminopropyl)trimethoxysilane (APTS) to be inserted into hydroxyapatite (HA) porous in order to obtain a biocomposite for the treatment of osteomyelitis and osteocarcinoma. HA is known to be a constituent of bones and by its osteoconductivity properties. The magnetic nanoparticles are used in biomedicine as magnetic sensors and drug transporters due to their response to external magnetic field .For the preparation of porous hydroxyapatite, it was used a template of silica spheres. During the synthesis of such spheres, the physicochemical parameters were tested in order to obtain narrow size diameters distribution of different size spheres. Being chosen spheres of 808, 402, and 223nm, the template was prepared by modifying the surface of the spheres with hydrogen peroxide. The sample was then dispersed in ethanol and placed in gravitational sedimentation field, thereby obtaining the close-packed template. The sol-gel method was used for the synthesis of the hydroxyapatite precursor gel. Calcining the gel at 700°C, it was possible to obtain the hydroxyapatite phase. The template was infiltrated into the characterized gel precursor and after the thermal treatment the silica template was removed by a sodium hydroxide solution for the formation of porous hydroxyapatite. Two samples were obtained one having pores of the order of 350nm, and another one with pores ca.170nm. Functionalized magnetite nanoparticles with sizes of 5nm were prepared by the coprecipitation method in an aqueous medium, being inserted in porous obtained hydroxyapatite it was possible to prove the presence of the nanoparticles in porous hydroxyapatite by EDX analysis results. Nevertheless, the magnetization of the sample needs to be improved to the successful... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Físico-química, Hidroxiapatita, Magnetita, Hydroxyapatite
Como citar
COSTA, Taciane Pereira da. Síntese de hidroxiapatia porosa com nanopartículas magnéticas de óxido de ferro. 2012. 98 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Química, 2012.