An Overview of Synthesis Based Biomedical Applications of Hydroxyapatite Nanomaterials

Hydroxyapatite (HAp) is the mineral phase of animal bones embedded in the collagen-containing organic matrix of the bones. It is a naturally optimized material that provides physical support to the bones. Hydroxyapatitebased biomaterials, hence, find wide biomedical applications especially in orthopedics, dentistry, and tissue engineering due to their biocompatibility, bioactivity, osteoconductivity, and similar chemical composition of HAp to that of minerals present in animal bones. Different physicochemical synthetic methods and available natural biogenic sources have been reported for the preparation of nano-HAp. However, particle size, aspect ratio, morphology, crystallinity, and the distribution of HAp in biomaterials have significant effects on their biomedical applications. This paper has summarized some methods of extraction of nano-HAp from different biogenic sources including bio-wastes. Furthermore, it focuses on some facile wet chemical synthetic routes of preparing nano-HAp with controlled particle size and morphology, higher crystallinity, and native bone architectures. This review article aims to correlate some simplistic and cost-effective biosynthetic approaches of nano-HAp, its properties, characterization techniques, and its size and morphology-dependent biomedical applications.