Hydroxyapatite Nanoparticle-Coated 3D-Printed Porous Ti6Al4V and CoCrMo Alloy Scaffolds and Their Biocompatibility to Human Osteoblasts.

Hydroxyapatite nanoparticles were prepared by hydrothermal method using calcium nitrate and phosphoric acid as precursors and ammonia aqueous solution as a pH value adjustor. The 3D-printed porous Ti6Al4V and CoCrMo alloy scaffolds were effectively coated with hydroxyapatite nanoparticles in the hydrothermal synthesis process by deposition method. Coating hydroxyapatite nanoparticles on the implant surfaces increased their biocompatibility and bioactivity. HAP-deposited Ti6Al4V or HAP-deposited CoCrMo scaffold induced no statistical increase in terms of apoptosis in hFOB1.19 cells compared with bare Ti6Al4V or bare CoCrMo. Interestingly, HAP coating groups presented CCK-8 values compared with bare groups suggesting that HAP could enhance cell proliferation.