Navegando por Palavras-chave "Transferência De Massa"

Agora exibindo 1 - 1 de 1
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Hidrogéis e micropartículas de fibroína de seda para liberação modificada de corantes
    (Universidade Federal de São Paulo (UNIFESP), 2020-03-04) Tomoda, Bruno Thorihara [UNIFESP]; Moraes, Mariana Agostini de [UNIFESP]; Universidade Federal de São Paulo
    Natural polymers are biodegradable materials, coming from natural sources and have been studied in the medical-pharmaceutical area. Silk fibroin, obtained from the cocoons of Bombyx mori silkworms, is a promising and versatile protein for application in this area. However, controlled-release systems made of natural polymers, such as silk fibroin, generally exhibit a very rapid release of the compound, reaching equilibrium around 2 hours of release. Thus, the present project proposed the development of a controlled release device through the incorporation of fibroin microparticles containing model dyes in fibroin hydrogels and the study of the release kinetics of the incorporated dyes. The fibroin microparticles were obtained by the atomization method and the incorporation of the model dyes was performed by adsorption. The microparticles were analyzed for their morphology, particle size, efficiency of incorporation of the model dyes and chemical properties. The hydrogels containing the microparticles were characterized in terms of their morphology, chemical, rheological and thermal properties. The release of the compounds was analyzed by UV / Vis spectroscopy, where empirical models were adjusted to the kinetic data. The model dyes showed an efficiency of incorporation in the fibroin microparticles above 70%. The releases of the model dyes of the microparticles were performed in approximately 90 minutes, with Fickian Diffusion being the predominant mechanism in this assay. The releases of the model dyes present in the microparticles incorporated in the fibroin hydrogels persisted for around 900 minutes, with the aid of a Protease XIV for the degradation of the protein, with the Anomalous Mechanism and Case Transport-II being the predominant mechanisms in this assay. Thus, the incorporation of microparticles in fibroin hydrogels proved to be an effective method and allowed to obtain a device capable of increasing the release time of the model dyes into the medium by approximately 10 times. This study opens new possibilities for the development of controlled release systems in several applications, allowing the control of release time.