RESUMOPesquisas tem sido realizada com objetivo de combinar propriedades dos materiais com a finalidade de melhorar o processo de regeneração. Portanto scaffolds como sistemas de liberação controlada de fármacos tem sido estudado a fim de proporcionar o crescimento do tecido ao mesmo tempo que a região esteja sendo tratada. Diante disso, essa pesquisa tem como objetivo desenvolver scaffolds de quitosana e avaliar a inserção do fármaco curcumina por meio dos métodos de reação de solução e adsorção visando obter um sistema quitosana/curcumina para liberação controlada do fármaco. Os scaffolds foram produzidos pelo método de agregação de esferas, onde as esferas foram inicialmente obtidas a partir do gotejamento da solução de quitosana e quitosana/curcumina em solução de sulfato de sódio (5%) e posteriormente agregadas pela solução de gelatina (5%). Foram realizadas as caracterizações de espectroscopia no infravermelho com transformada de Fourier (FTIR), microscopia ótica (MO), microscopia eletrônica de varredura (MEV) e calorimetria exploratória diferencial (DSC). Por FTIR sugeriu-se a interação da quitosana com a curcumina. A partir das avaliações morfológicas por MO e MEV foi possível identificar o fármaco no interior das estruturas pelos dois métodos utilizado. E por DSC observou-se para amostra de quitosana/curcumina o desaparecimento do pico de fusão característico da curcumina, indicando assim que a curcumina foi encapsulada na quitosana no estado amorfo, o que provavelmente ocasionará uma liberação mais lenta do fármaco. Dessa forma, constatou-se que as estruturas obtidas são promissoras para o estudo de liberação controlada de fármaco.Palavras-chave: Curcumina, Quitosana, Scaffolds. ____________________________________________________________________________________ ABSTRACTResearches have been conducted in order to match material properties to improve the regeneration process. Thereby, scaffolds as controlled drug delivery systems have been studied in order to enhance the obtained structure by providing tissue growth while the region is being treated. Thus, this research aims to develop scaffolds of chitosan, and avaluatinh the insertion of curcumin drug by the methods of , solutions reaction and adsorption, aiming at obtaining a chitosan/curcumin for controlled drug release system. The scaffolds were produced by beads aggregation method, in which the beads were originally obtained from the dropping of chitosan solution and chitosan / curcumin in sodium sulphate solution (5%) and then attached by the gelatin solution (5%). The following characterizations were performed: Fourier Transform Infrared Spectroscopy (FTIR), Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC). By FTIR analysis, it was possible to verify the likely interaction of chitosan with curcumin. From the morphological analysis by OM and SEM it was possible to identify the drug inside the structures by both methods. DSC analysis showed the total disappearance of the characteristic melting ...
In this paper, the synthesis by solution combustion (SCS) of tri-strontium aluminates (Sr 3 Al 2 O 6 ), using different fuel amounts, has been studied. The main objective was to understand the effect of the amount of fuel on phase formation, yield and purity of the product using urea as fuel. The combustion temperatures of each reaction were followed by digital pyrometry. Phase compositions were determined by X-ray diffraction (XRD). The microstructural characteristics during the SCS process were studied by field emission scanning electron microscopy (FESEM).The specific surface area was calculated with the BET model from adsorption data. The results showed that the Sr 3 Al 2 O 6 was the main phase obtained in all syntheses. This aluminate with high content of Sr is considered attractive for use in applications requiring radiopacity as biomaterials for dental and bone repair. The maximum measured temperature during synthesis, with excess fuel, was approximately 987°C. It was higher than that obtained in the case of using stoichiometric amounts of fuel which was 762°C. The product obtained in this second case had a submicrometer structure, with highly crystalline particles and a specific surface of 0.21 m 2 /g. It was higher than that obtained with excess of fuel (0.07 m 2 /g).
The incorporation of calcium phosphate in a polymer matrix for composites production combines the flexibility of the polymers with the resistance, hardness and bioactivity of the inorganic phase. This study aimed to obtain rigid biocomposites using hydroxyapatite as mineral phase and chitosan as a polymer binder for the application as a biomaterial. To obtain the biocomposites, hydroxyapatite was added under constant stirring to a solution of chitosan in order to satisfy a 70:30 (HA/CS) ratio. XRD results showed no significant change in the profile of hydroxyapatite with the incorporation of chitosan. The analysis of scanning electron microscopy (SEM) of the biocomposite HA/CS, indicated that there was an excellent dispersion of HA particles in the polymeric matrix. Infrared Spectroscopy with Fourier Transform (FTIR) analysis proved an existing interaction between chitosan and hydroxyapatite. The biocompatibility of biocomposites HA/CS was confirmed by the MTT assay. It is considered that the present biocomposites are a promising biomaterial for trabecular bone grafting
There is a growing need for new biomaterials that can gain predictable and controlled tissue response, this is, that as bone graft substitutes should initiate new bone formation, after which they should get reabsorbed and replaced by bone tissue. This combination aims to improve the mechanical properties, degradation rates and absorption rates of biocompatibility and biodegradability. The aim of this study was to propose a synthetic route in which the HA was obtained by reaction of precipitation directly on evaluating the influence of chitosan biopolymer in the middle of precipitation in the characteristics of hydroxyapatite obtained. XRD analysis revealed the presence of HA phase with low crystallinity. In the FTIR analysis identified the characteristic bands of hydroxyapatite, as well as bands that characterize an interaction between chitosan and hydroxyapatite, as the band around 1050cm-1. SEM analysis of the biocomposites chitosan/HA, showed a dispersion of HA particles in chitosan, revealing a homogenous material and microporous.
The objective of this work has been the synthesis of wollastonite by solution combustion method. The novelty of this work has been obtaining the crystalline phase without the need of thermal treatments after the synthesis. For this purpose, urea was used as fuel. Calcium nitrate was selected as a source of calcium and colloidal silica served as a source of silicon. The effect of the amount of fuel on the combustion process was investigated. Temperature of the combustion reaction was followed by digital pyrometry. The obtained products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and specific surface area. The results showed that the combustion synthesis provides nanostructured powders characterized by a high surface area. When excess of urea was used, wollastonite-2M was obtained with a submicronic structure.
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