Effect of nano-hydroxyapatite on Mg-Zn-Zr alloy biological properties in vitro

The nHA/Mg-2.5Zn-0.5Zr(mass fraction, %)composites, prepared by melting method in an argon gas atmosphere and electromagnetic stirring, were cultured with rat osteoblasts to investigate the biocompatibility in vitro compared to magnesium-matrix material. The results both of the two groups show no obvious cytotoxicity, while the cellular morphology is better and the cell density is higher in the nHA/Mg-2.5Zn-0.5Zr group than in the magnesium-matrix group. The cell growth curve shows osteoblast proliferation is greater on the nHA/Mg-2.5Zn-0.5Zr composites than on the magnesium-matrix material during the prescribed time periods, meanwhile, there are statistical differences between the two groups after 3 and 5 days of culture. Under the SEM observation, the cell responses to the samples were different, the osteoblasts attached very well to the composites with the shape of shuttle and/or triangular, and the cells were in a close contact with each other. The cells in the magnesium-matrix control group appeared with a spindle-shape, which indicated a weak adhesion to the material.