The hydroxyapatite (HAp) is a ceramic biomaterial with wide application in the bone regeneration. It can be obtained by different routes and different precursors. In this study, the synthesis of HAp was carried out by precipitation and subsequent thermal treatment using different calcium precursors: calcium hydroxide from synthetic origin and calcium oxide obtained from the eggshell. The obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. By SEM, variations of the crystal size and the concentration of agglomerates were observed. FTIR and XRD analyses proved the formation of HAp and how the (mineral and biological) precursors affected the microstructure. The thermal decomposition process of the calcium oxide obtained from the eggshell showed to be more effective for the synthesis of the hydroxyapatite, resulting in more stable morphology and microstructure.
Medicine seeks increasingly to treat problems related to bone regeneration and tissue in order to minimize surgical trauma and some bone diseases. The technology advancement in the biomaterials field allows develop materials that assist in reconstructive procedures of body parts and increase treatments improving the life quality of human beings. Due to the biodegradability, biocompatibility and biofunctionality characteristics, chitosan has attracted attention of researchers in order to obtain new materials. Its unique features promote the incorporation of other materials such as calcium phosphate ceramics which are used in this bone replacement and bone regeneration due to submit biocompatibility, bioactivity, osteoconductivity in addition to allowing the bone cells proliferation, collagen and proteins in their surfaces, thus allowing tissue regeneration. This study aimed to develop biodegradable chitosan membranes with 1%, 3% and 5% calcium phosphate for use in bone regeneration. The composites were prepared and Characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and angle contact wettability. The results indicates the composite formation and show an increased crystallinity in the chitosan membrane through the phosphate incorporation, besides confirming the composites hydrophilicity. Preliminary results indicates that the composite is a promising biomaterial.
Synthetic nanohydroxyapatite (nHA) is a prominent material to be applied in bone tissue engineering devices, due to nHA similarity with the main component of the bone inorganic phase, biocompatibility, biodegradability, and bioactivity. The specific characteristics of the nHA crystals are dependent on the synthesis method. Therefore, the aim of this work was to evaluate the structure of the nHA obtained through chemical precipitation, for the understanding of nHA physico-chemical and biological properties. nHA was produced by dropwise addition of 1600 mL of 0.7 M aqueous Ca(NO 3) 2 .4H 2 O (pH 5.5) on 1100 mL of 0.5 M (NH 4) 2 HPO 4 (pH 10.4, adjusted with concentrated NH 3) under stirring at 80°C. The reaction mixture was aged 24 h then vacuum filtered and washed with water and ethanol. The precipitated nHA was dried at 80 °C for 24 h. The structure obtained nHA was characterized by X-Ray Diffraction and the Rietveld refinement method, Transmission Electron Microscopy and Fourier Transform Infrared Spectroscopy. Preliminary results indicate that the material consisted of calcium deficient hydroxyapatite nanocrystals with lattice parameters a=b=9.43019 Å and c=6.88162 Å, and c-axis preferentially oriented. Nanoparticles, shaped as rods, presented mean crystallite size of ~21 nm (~47 nm length and ~8 nm width) and specific surface area of 90.1 m 2 /g. According to the obtained results the method of synthesis of nHA seems to be reproducible and effective to prepare large quantities of nHA to be evaluated as biomaterials.
Ceramic biomaterials have been largely applied as a means for replacement and / or repair of biological tissue such as orthopedic and dental implants, grafts, among others, because they have similarity shown with bone tissue, chemical stability, high hardness and wear resistance. Among these, we highlight the zirconia, for possessing biocompatibility without mutagenic effects, bacterial adhesion and better periointegration. The development of a porous zirconia aims to enhance the biological properties of this ceramic in order to optimize and accelerate osteointegration. The zirconium oxide (ZrO 2 ) used was obtained commercially and produced by the method of chemical decomposition. The Structural characterization of ZrO 2 powder will be held by the techniques of X-ray Diffraction (XRD) and Rietveld refinement method, optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Preliminary results of XRD and Rietveld refinement, indicate the presence of crystalline phases in nanometric dimensions tetragonal and monoclinic ZrO 2 with concentrations of 71% and 29%, respectively. The tetragonal phase, which has improved properties, only exists at room temperature, due to the presence of substitutional of yttrium, in this case 10%. Preliminary results indicate that the ZrO 2 used, has excellent characteristics for the application of dental implants.
O avanço científico e tecnológico para desenvolvimento de cimentos ósseos, vem sofrendo modificações, de modo a obter propriedades que se adéquem para aplicações específicas. A incorporação de outros materiais tais como quitosana, colágeno, óxidos, polietilenoglicol, entre outros, que substituam ou até mesmo incorporem características não presentes, são bem exploradas, entretanto, a influência do beneficiamento dos pós cerâmicos, vem sendo pouco estudadas. Neste sentido, o presente trabalho obteve o cimento ósseo de brushita/SrO/quitosana através do método de dissolução/precipitação, utilizando uma mistura de pó wollastonita/estrôncio aplicado os métodos de remoção de umidade por estufa e dessecador. As amostras foram caracterizadas através da análise do tempo de cura e de pega, resistência a compressão, difração de raios X (DRX) e microscopia ótica (MO). Os resultados mostraram que o método de remoção de umidade, promove variação de fases formadas nos cimentos, conforme observado no DRX, gerando uma melhora na resistência compressiva. A temperatura e tempo dos cimentos apresentaram redução durante sua cura para as amostras MPC. A análise microscópica mostrou que o método de remoção da umidade, promoveu uma maior porosidade na estrutura interna do cimento, o que pode proporcionar uma melhora em sua compatibilidade a região óssea aplicada.
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