Nano-size hydroxyapatite extracted from tilapia scale using alkaline heat treatment method

In biomedical research, hydroxyapatite (HAp) has been commonly used as the coating materials, filler and as a drug delivery system. This is mainly due to the similarity of the chemical composition of HAp to human bone and teeth that make it have excellent bioactivity and biocompatibility. Hence, the recovery of HAp from a natural resource such as from the animal scale and bone is a promising alternative to produce natural HAp, which is much similar to the human bone. Thus, in this research, the nano-size HAp was extracted from tilapia fish scale using alkaline heat treatment. The fish scale was pre-treated with 0.1% HCl to deproteinize the scale prior to the alkaline heat treatment. The alkaline heat treatment was performed in two stages to ensure complete removal of the organic compound from the tilapia scale. Upon completing the procedure, off white HAp powder was obtained. The HAp powder was characterised using X-ray diffraction analysis (XRD), field emission scanning electron microscopy analysis (FESEM), energy dispersive spectroscopy (EDS), and fourier-transform infrared spectroscopy (FTIR). The XRD pattern demonstrated that the obtained powder was a pure crystalline HAp. The FESEM micrograph revealed that the HAp powder exhibited rod shapes with a size ranged between 50 and 60 nm width and 30200 nm length. The EDS result revealed that the extracted HAp powder had a Ca/P ratio of 1.74, which was higher compared to stoichiometric HAp. Lastly, the corresponding functional groups of PO43- and CO32- were identified using FTIR were corresponded to the HAp functional group. In summary, the natural HAp extracted from the tilapia scales using alkaline heat treatment method has the potential to be used as biomaterials for the biomedical implant. (C) 2019 Elsevier Ltd. All rights reserved.