Background: Hydroxyapatite (HAp) is one of the most studied biomimic for biomedical applications. Specially, nano-HAp has been utilized for bone tissue engineering various orthopedic applications. HAp possesses various suitable properties such as bioactivity, biodegradability and cell proliferation efficiency for bone tissue engineering applications. Yet, lacks in self-antibacterial activity, high surface area and target efficiency.
Results: In this directioon, researchers have focused on exploring the required surface as well as the inherent properties of HAp at the nanoscale. These properties are largely dependent on the composition, size and morphology of the nano-HAp. Hence, nano-HAp has been found to be an excellent candidate with an attractive combination of properties for selection and use in biomedical applications, those required to enhanced biological responses. Further, depending on the type of application, these factors can be tuned to optimize the performance.
Conclusion: In this review article, we focus on the chemical structure of HAp and the routes chosen and used for the synthesis of the nano-HAp. The role of various parameters in controlling synthesis at the nanoscale are presented and briefly discussed. In addition, we provide an overview of the various applications for the pristine and doped nano-HAp with recent examples in areas spanning the following: (i) bone tissue engineering applications, (ii) drug delivery applications, (iii) surface coatings, and (iv) scaffolds. The effect of chemical composition on the mechanical properties, surface properties and biological properties are also highlighted. Nano-HAp is found to be highly proficient for its biomedical applications, especially for bone tissue engineering applications. The nano-sized properties enhances the biological responses. The dopant ions that replaces the Ca ion into the hydroxyapatite (HAp) lattice plays a crucial role in its biomedical applications