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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pharmaceutical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Synthesis,precipitation,Nanocrystals,hydroxyapatite
- چکیده:
- چکیده انگلیسی: In this study, hydroxyapatite (HA) nanocrystals have been synthesized via chemical precipitation technique. Diammonium hydrogen phosphate and calcium nitrate 4-hydrate were used as starting materials and sodium hydroxide solution was used as the agent for pH adjustment. The powder sample was evaluated by techniques such as scanning electron microscope, transmission electron microscope, Fourier transform infra-red spectroscopy, differential thermal analysis, thermal gravimetric analysis, X-ray diffraction, atomic absorption spectroscopy and EDTA titration analyses. According to the above-experimental results, it was found that hydroxyapatite nanocrystals can successfully be produced through wet precipitation method. The bulk Ca/P molar ratio of synthesized hydroxyapatite was determined as 1.71 that was higher than stoichiometric ratio (1.667) which is expected for a pure HA phase. Finally, transmission electron microscopic technique demonstrated that the crystallites of prepared powder were nanosized with a needle-like morphology.
- انتشار مقاله: 29-09-1386
- نویسندگان: Mohammadreza Tahriri,Mehran Solati-Hashjin,Hossein Eslami
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pharmaceutical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Synthesis,Hydrothermal,hydroxyapatite,Nano-rods
- چکیده:
- چکیده انگلیسی: Hydroxyapatite (HA) nano-rods with uniform morphology and controllable size have been successfully synthesized in the presence of cationic and non-ionic surfactants by a hydrothermal method. (NH4) 2HPO4 and Ca(NO 3)2.4H2O were used as the phosphorus and calcium sources, respectively. The composition of synthesized powders was characterized using X-ray diffraction, and Fourier transform infrared spectrometer and morphology of the resulting powders were examined by scanning electron microscopy. Results revealed the as- prepared HA nano-rods have a typical diameter of about 60-80 nm and an average aspect ratio of about 10-12, which indicates that the mixture of cationic and non-ionic surfactants acts as a soft template to regulate the nucleation and crystal growth of HA. Also effect of hydrothermal temperature was studied on the system.
- انتشار مقاله: 19-09-1386
- نویسندگان: Mehrnaz Salariana,Mehran Solati-Hashjin,Azadeh Goudarzi,Seyedeh Sara Shafiei,Reza Salarian,Ziarat Ali Nemati
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Biotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: Biomaterials,Silk,Bone tissue engineering,Fiber reinforced polymer (FRP) composites
- چکیده:
- چکیده انگلیسی: A wide range of materials and scaffolding fabrication methods for bone tissue engineering have been
explored recently. Fiber reinforced polymers (FRP) system appears to be a suitable system. By the exclusive
use of biocompatible or bio-absorbable polymers and fibers, novel generation of scaffolds for applications
in tissue engineering can be prepared. Mulberry Silk as highlighted natural fiber with its specific economic,
mechanical and biological properties has been used for fabrication FRP scaffolds. In this study FRP scaffolds prepared by a combination of silk fibroin polymer, which is another configuration of silk fibers as a porous matrix and silk fibers as the reinforcement element. FRP scaffolds have been fabricated by the freeze-drying method. Microstructure has been analyzed by scanning electron microscopy and the results show an integrative structure. Mechanical properties have been evaluated by universal testing machine. Compressive mechanical modules as well as strength of FRP scaffolds increased about three times in magnitude in comparison with pure fibroin scaffolds. FRP scaffolds had a compressive module of ~3.6 MPa. Osteoblast viability and attachment on FRP scaffolds were investigated in vitro by MTT assay, which showed no cytotoxic response. Additionally, based on SEM results it is concluded that FRP scaffolds provide a good environment for osteoblast attachment.
- انتشار مقاله: 11-04-1391
- نویسندگان: Sahba Mobini,Mehran Solati-Hashjin,Habibollah Peirovi,Ali Samadi-kuchaksaraei
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Biotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: Coating,Alkaline treatment,apatite,Biomimetic,Simulated body fluid
- چکیده:
- چکیده انگلیسی: Biomimetic method was used to apply hydroxyapatite (HA) coating onto Ti6Al4V cylinders. This process is a physicochemical method in which a substrate is soaked in a solution simulating the physiological conditions, for a period of time enough to form a desirable layer of the calcium phosphate on the substrate. In the present study, specimens were soaked in 5, 10 M solutions of NaOH at temperatures of 60 or 80ºC for 24 and 72 h. Surface of samples were characterized using scanning electron microscopy (SEM) and thin film X-ray diffraction (TF-XRD). The optimum condition was found to be 72 h of soaking in 5 M NaOH at 80ºC. Specimens treated under these optimum conditions were subsequently heat-treated at 500, 600, and 700ºC for 1h in order to consolidate the sodium titanate hydrogel layer. Under the heat treatment condition of 600ºC for 1h and subsequent soaking in simulated body fluid (SBF), apatite formed within 3 days. It was observed that, apatite formation increased significantly, which is an indication of the materials ability for use as a load bearing implant.
- انتشار مقاله: 08-06-1394
- نویسندگان: Kambiz Fatehi,Fathollah Moztarzadeh,Mehran Solati-Hashjin
- مشاهده