Sharif Digital Repository

Three-dimensional biocompatible porous structures can be fabricated using different methods. However, the biological and mechanical behaviors of scaffolds are the center of focus in bone tissue engineering. In this study, tricalcium phosphate scaffolds with similar porosity contents but different pore morphologies were fabricated using two different techniques, namely, the replica method and the pore-forming agent method. The samples fabricated using the pore-forming agent showed more than two times higher compressive and bending strengths and more than three times higher compressive moduli. Furthermore, a thin layer of agarose coating improved the compressive and bending strength of both... 

Two different hydroxyapatite based composites reinforced by oxide ceramic (20 wt%) nano crystals were synthesized by high-energy ball milling and sintered by pressure less technique. Alumina and titania nanoparticles as secondary phases improved densification and mechanical behavior of apatite and postponed its decomposition to the tricalcium phosphate (TCP) phases at elevated temperatures. Increasing the relative density of apatite using nano reinforcements leads to enhance the bending strength by more than 40% and 27% (as compared to the pure HA) and increase the hardness from 2.52 to 5.12 (Al2O3 composite) and 4.21 (TiO2 addition) GPa, respectively. Transmission electron microscopy (TEM),... 

Thermoplastic starch (TPS), as a natural based polymer, is known to have the capability to be used in biological applications due to its biocompatibility and biodegradability. In this study, mechanical properties of TPS are enhanced by incorporating bioactive β-tricalcium phosphate (β-TCP) particles for bone tissue engineering applications. Starch-based nanocomposites containing 3, 5, and 10 wt% of β-TCP nanoparticles (TT3, TT5, TT10) were made using a co-rotating twin-screw extruder. Dynamic light scattering (DLS) and X-ray diffraction (XRD) techniques were employed to analyze the nanocomposites. Moreover, degradability, swelling degree, and biomineralization in a simulated body fluid (SBF)... 

The aim of this study was to investigate the thermal behavior of Mg-doped calcium phosphate compounds. Nanocrystalline HA and β-TCP mixtures containing different magnesium contents were synthesized via an alkoxide sol gel method. The ratio of (Ca+Mg)P was kept constant at 1.67, and the Mg content ranged between 0 and 3 mol%. The influence of magnesium on the phase composition, chemical structure, thermal behavior and morphological characteristics of nanopowders was analyzed using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Simultaneous Thermogravimetry and Differential Thermal Analysis (STA/DTA), Scanning Electron Microscopy (SEM) and Transmission Electron...