Showing 3 results for M. Ashuri
M. Ashuri, F. Moztarzadeh, N. Nezafati, A. Ansari Hamedani, M. R. Tahriri,
Volume 31, Issue 1 (Jun 2012)
Abstract
In the present study, a bioceramic-based composite with remarkable mechanical properties and in vitro apatite forming ability was synthesized by sintering compacts made up of mixtures of hydroxyapatite (HA) and sol-gel derived bioactive glass (64SiO2-26CaO-5MgO-5ZnO) (based on mole %). HA was synthesized through co-precipitation method. The stabilization temperature of the bioactive glass was set to be 700 ºC according to simultaneous thermal analysis (STA). Laser Particle Size Analysis (LPSA) was used to compare the particle size distributions of the synthetic powders. HA matrix was mixed with different weight percentages of bioactive glass (5, 10, 15, 20, 25 and 30 wt. %) and compressed by 80 MPa pressure. After sintering the uniaxial compression test of the samples was done and the specimen with the highest compressive strength (20 wt. % bioactive glass) was selected to be immersed in the Simulated Body Fluid (SBF) for 3, 7 and 14 days. The results showed that the compressive strength of the sample decreased after keeping it in the SBF. Also, inductively coupled plasma analysis (ICP) was used to study the ion release behavior of the sample in the SBF. Finally, phase composition, microstructure and functional groups in the composite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infra-red spectroscopy (FTIR) techniques, respectively.
M.tahriri, F. Moztarzadeh, M. Raz , M. Ashuri,
Volume 32, Issue 1 (Jun 2013)
Abstract
In this study, magnetite (Fe3O4) nanoparticles were synthesized by chemical co-precipitation from the solution containing iron salts in alkaline medium under N2 gas and room temperature. Magnetite nanoparticles were characterized by X- ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), differential thermal analysis (DTA), Brunauer-Emmet-Teller (BET), and vibrating-sample magnetometer (VSM). The rheological properties of magnetite ferrofluid were examined by rheology apparatus. The biocompatibility and cytotoxity of magnetite nanoparticles were evaluated by 3T3 and fibroblast cells. The results showed that the Fe3O4 magnetite nanoparticles coated by polyvinyl alcohol (PVA) could be an appropriate candidate for biomedical applications.
M. Raz, F. Moztarzadeh, M.a. Shokrgozar, M. Ashuri, M. Tahriri,
Volume 32, Issue 2 (Dec 2013)
Abstract
In this project, we prepared biomimetic nanocomposite scaffolds from gelatin and chitosan and hydroxyapatite and subsequently the scaffolds were evaluated by common used bulk technique. For this purpose, the nanocomposite hydrogel/apatite bone tissue engineering scaffolds were fabricated using applied biomimetic method accompanied with freeze drying technique. The apatite was precipitated using double diffusion mechanism within gelatin hydrogel in similar pH and temperature to the human body. Chitosan initial percentage (20, 30 and 40%) was set as variables. Nanocomposites were soaked in glutaraldehyde solution in order to enhance mechanical properties and make them insoluble in water. Diffusion of calcium and phosphate from lateral hydrogel into the middle hydrogel caused formation of parallel white layer-formed precipitate. Analysis of precipitates formed within middle hydrogel for the samples, showed that detected materials are composed of carbonated hydroxyapatite and dicalcium phosphate dihydrate (DCPD, brushite). Also, mechanical behavior obtained for the scaffolds were comparable with spongy bone. With increasing chitosan in the composite scaffold, the water up-take was increased from 379 to 661%. Phase composition, microstructure and structural groups in the composite samples were also characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infra-red (FTIR) analyses. Eventually, the obtained results showed that the composite contains 20% chitosan had appropriate properties for fabricating bone scaffold.
