In the present study, hydroxyapatite (HAp) is synthesized from different biosources like eggshell, fish scale and bovine bone in a cost effective and ecofriendly way. HAp materials were synthesized from eggshell by wet precipitation method whereas thermal decomposition method was applied in case of fish scale and bovine bone. The phase purity and crystallinity of different calcined HAp powder were determined by XRD and FTIR analyses. The thermogravimetric analysis was carried out to show thermal stability of HAp powder. Average grain sizes of sintered samples were in submicron range. The morphology of the powders were observed under scanning electron microscopy (SEM). The dried powders were wet ball milled for several hours and surfactants like Triton-X small fillers (2 / 4 mm long rod-shaped) were made for in vitro testing. In order to verify the biocompatibility of HAp powders, cytotoxicity evaluation was carried out in RAW macrophage like cell line media for an incubation period of 72 h. The cell attachment studies on HAp compacts show an excellent affinity between cells and compact surface. These results proved high biocompatibility of HAp powders obtained from different biosources for tissue engineering applications.

In the present paper, synthesis of hydroxyapatite (HAp) powder from eggshell waste is produced through wet precipitation process at 50-55uC. The thoroughly washed and dried eggshell powder is treated with dilute nitric acid followed by diammonium hydrogen phosphate under controlled reaction conditions such as pH, temperature, stirring time, etc. to obtain white HAp precipitate. The formation of the HAp phase and its thermal stability were identified through thermogravimetric/differential thermal analysis, Fourier transform infrared spectroscopy and X-ray diffraction studies at different calcined temperatures. The dried powder at 90-100uC was wet ball milled for several hours and compacted to cylindrical shapes at a lower pressure of 850 kg cm 22 . The green compacts were sintered at different temperatures for 2 h in dry atmosphere. Average grain sizes of sintered samples are mostly in submicrometre range. The morphologies of the green as well as sintered compacts were observed by field emission scanning electron microscopy.