Papers by Keyword: Merwinite

Abstract: The ceramics in the system CaO–MgO–SiO₂ has recently attracted a great deal of attention because they display a good in vitro bioactivity and have potential use as bone implants. Biphasic calcium-magnesium-silicate ceramics were prepared by a sol-gel method. The dried gel with chemical composition 3CaO.MgO.2SiO₂ was thermally treated at 1200 °C for 2 hrs. The structural behavior of the synthesized ceramics was examined by means of X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Merwinite crystalline phase and akermanite phase were recognized. Then, porous akermanite/merwinite scaffolds were prepared to utilize polymer sponge method and evaluated by employing SEM. Furthermore, bone marrow stromal cells (BMSC) adhesion and proliferation on the scaffolds were evaluated by MTT assay test. Differentiation of the cells was assessed by measuring alkaline phosphatase (ALP) activity. The results demonstrated that BMSC adhered and spread well on akermanite scaffolds and proliferated with the increase in the culture time, and the differentiation rate of osteoblasts on scaffolds was comparable to that on blank culture plate control. Thus, the obtained results presented that the akermanite/merwinite scaffolds deserve attention for bone tissue engineering applications.

Abstract: A novel merwinite/ Poly(lactic-co-glycolic) nanocomposite was synthesized by a solvent casting/salt leaching technique with varying merwinite contents from 10 to 30% (w/w). Poly(lactic-co-glycolic) /merwinite foams with a co-continuous structure of interconnected pores were formed. The microstructure of the pores and the walls was controlled by varying the merwinite content. The pore structure becomes more and more irregular with increasing merwinite content. Pore sizes ranging from several microns to a few hundred microns were obtained. The degradation assessment of the scaffolds is performed in phosphate-buffered saline (PBS) solution at 37°C. Weight loss during storage at 37°C in PBS (pH 7.4) was determined for the scaffolds. Weight loss increased from pure to high content during incubation time. The prepared merwinite/ (Polylactic-co-glycolic) nanocomposite with uniform microstructure may be used in bone tissue engineering applications.

Abstract: In this study, nanocomposites based on of β-tri calcium phosphate (β-TCP) and 2.5-10 wt% merwinite nanoparticles were prepared and sintered at 1100-1300°^c. The mechanical properties were investigated by measuring compressive strength and fracture toughness. Structural properties were evaluated by XRD, TEM and SEM analysis, and the in vitro bioactivity was studied by soaking the samples in simulated body fluid (SBF). The mechanical strength of the sintered samples were increased, by increasing the amount of merwinite phase up to 5 wt%, whereas it decreased when the samples were sintered at 1100 and 1200°^c. Nanostructured calcium phosphate layer was formed on the surfaces of the nanocomposites within 1 day immersion in simulated body fluid. Because of appropriate mechanical properties the composite is suggested to be used as substitute for hard tissue.

Abstract: Merwinite powders were synthesized by a sol-gel process. The bioactivity in vitro of merwinite was investigated by soaking the powders in simulated body fluid (SBF), the growth of hydroxyapatite(HAp) on the surface of the powder was evaluated in various time. It was found that hydroxyapatite was formed after soaking for 14 days. The results indicate that merwinite possessed apatite-formation ability might be a potential candidate biomaterial for hard tissue repair.