Abstract
Hydroxyapatite (HA), the synthetic analog to biogenic apatite, is an attractive and important material in environmental and medical applications. The physicochemical properties of HA consist of its biocompatibility, tunable particle size, and modifiable structure, making it applicable for disease treatment, augmentation of biological tissues, and controllable bioactive surface. Within the realm of nanotechnology, designing specific properties of HA nanocomposites with specific features is an important strategy in synthesis. Therefore, advanced research on HA nanomaterials focusing on functionalization and characterization methods has been explored. Some of the strategies for wide purposes include important schemes of HA development research, such as nanoparticle-doped HA, surface-functionalized HA, and HA nanocomposite formation with polymer and other metal oxides. One of the schemes for applying nanomaterials in the health sector is the development of bio-nanocomposites as functional materials that are synthesized according to the targeted characteristics. In this scheme, bone grafting technology and tissue engineering relying on functional bio-ceramics are growing very rapidly, as shown by the increasing number of studies and publications over10 years. Modifications and functionalization of hydroxyapatite are the strategies explored, including doping or metal ion replacement of HA structure with metals.