▎ 摘　　要

Post-implantation infections are regarded as a major issue in the biomedical field. Further, many investigations are continuous towards developing antibacterial biocompatible materials. In this regard, hydroxyapatite (HAP), erbium oxide (Eu2O3), and graphene oxide (GO) were introduced in nanocomposites combinations, including single, dual, and triple constituents. The nanoparticles of HAP, Eu2O3, and nanosheets of GO are synthesized separately, while dispersed in the nanocomposites simultaneously. The morphological investigation showed that HAP was configured in a rod-like shape while the nano ellipsoidal shape of Eu2O3 was confirmed. The particle size of the ternary nanocomposite containing HAP/Eu2O3/GO reached the length of 40 nm for the rods of HAP and around 28 nm for the length axis of ellipsoidal Eu2O3 nanoparticles. The roughness average increased to be about 54.7 nm for HAP/GO and decreased to 37.9 nm for the ternary nanocomposite. Furthermore, the maximum valley depth (R-v) increased from HAP to the ternary nanocomposite from 188.9 to 189.8 nm. Moreover, the antibacterial activity was measured, whereas the inhibition zone of HAP/Eu2O3/GO reached 13.2 +/- 1.1 mm for Escherichia coli and 11.4 +/- 0.8 mm for Staphylococcus aureus. The cell viability of the human osteoblast cell lines was evaluated to be 98.5 +/- 3% for the ternary composition from 96.8 +/- 4% for the pure HAP. The existence of antibacterial activity without showing cytotoxicity against mammalian cells indicates the compatibility of nanocomposites with biomedical applications.