Synthesis of Porous Bioceramic Scaffolds for Bone Tissue Engineering: Effects of Experimental Parameters.

This study investigates the synthesis of hydroxyapatite nanoparticles via aqueous precipitation at pH 9 and Ca/P molar ratio of 1.67, exploring the effects of various synthesis parameters. Moreover, porous hydroxyapatite scaffolds were created using a pore-forming agent. These parameters' effects on the crystal structure, chemical composition, morphology, porosity, and pore size of hydroxyapatite powders and porous scaffolds were determined by various analytical techniques such as x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), simultaneous thermal analysis (TGA/DSC), electron microscopy (SEM), pycnometry, and optical microscopy (OM). The XRD results revealed good crystallization of the hydroxyapatite with the formation of TCP and TTCP secondary phases resulting from the decomposition of hydroxyapatite (HA). The FTIR spectra of sintered HA confirmed the presence of the main absorption bands corresponding to phosphate and hydroxide groups with different peaks in intensity. The TGA/DSC analysis confirmed the results previously obtained by FTIR and XRD. SEM analysis showed the formation of various shapes of hydroxyapatite nanoparticles. According to different synthesis parameters, a porous HA scaffold up to 61% porosity can be prepared using ammonium bicarbonate as a pore-forming agent. [ABSTRACT FROM AUTHOR]