Induced porous structure with a slight change in mechanical properties of hydroxyapatite-based nanocomposites synthesized from waste bovine bone and their bioactivity

Porous hydroxyapatite (HAp) ceramics have been widely used in several biomedical applications. However, efforts to enhance the porous structure in HAp ceramics often lead to a decline in their mechanical properties. In the present study, by adding a small amount of aluminum nitride (AlN) nanoparticles to HAp ceramics, we achieved the formation of porous HAp with a slight change in grain size and mechanical properties. The starting powder of the HAp was obtained from a natural source of bovine bone. The HAp/xAlN nanocomposites were fabricated by a simple conventional technique. The 0.06 mol% AlN-added sample (HAp/0.06AlN) presented the maximum mechanical properties (Vickers hardness = 3.68 GPa, elastic modulus = 94.04 GPa, and fracture toughness = 0.97 MPa/m1/2) with favorable porosity. Simulated body fluid and cell viability assays showed that all the studied nanocomposites possessed desirable bioactivity with high cell viability. The HAp/0.06AlN samples were coated with antimicrobial agents. The samples coated with silver nitrate (AgNO3) had high antibacterial efficiency against S. aureus (66.2%) and P. aeruginosa (67.3%). Based on the obtained results, the nanocomposites exhibited promising potential for development and utilization in biomedical applications.