Synthesis, structural and 3-D architecture of lanthanum oxide added hydroxyapatite composites for bone implant applications: Enhanced microstructural and mechanical properties

Abstract In the present study, pure hydroxyapatite (HAp) nano powder was prepared successfully via microwave irradiation method. To enhance the mechanical properties of pure HAp, La 2 O 3 was taken as an additive. HAp composites were synthesized with addition of different concentrations of La 2 O 3 (0.1, 0.2, 0.3 and 0.5 wt%) by conventional solid state route. The HAp-La 2 O 3 powders were sintered at 1200 °C for 3 h. On the basis of XRD results, formation of HAp-La 2 O 3 was confirmed. The surface morphology of the composite samples was studied by scanning electron microscopy (SEM). Transmission electron microscopy (TEM) confirmed the presence of tiny particles of La 2 O 3 in the HAp matrix with adequate porosity. The mechanical properties of the pure HAp and its composites were determined by universal testing machine (UTM). The 0.5 wt% of HAp-La 2 O 3 sample exhibited the highest density, 2.85 g/cm 3 and mechanical strength ~ 108.89 MPa. The calculated values of Young's modulus, fracture toughness and load bearing capability are 90.75 GPa, 130.06 MJ/m 3 and ~ 3.85 kN respectively. It was observed that the addition of La 2 O 3 significantly improved the mechanical properties of HAp. To see the cytotoxicity effect on HAp-La 2 O 3 composites (0.1 and 0.5 wt%), MTT assay were performed using osteoblast cells.