▎ 摘　　要

Variety of ion-doped apatite coatings, especially strontium substituted hydroxyapatite (SrHA), have attracted eventful attention for medical metal surface modifications due to their excellent cytocompatibility and organi-zational affinity. However, they are still not commercially used in clinics because of their inappropriate biomechanical properties, and lack of osteoinductivity and antibacterial capabilities. Here, silver (Ag) doped SrHA (SrAgHA)/graphene oxide (GO) composite coatings were fabricated on titanium (Ti) substrate via elec-trodeposition (ED) and this combination has been reported for the first time. Morphological observations revealed that GO facilitated HA pricker-like crystals to grow in longitudinal directions, changing into a bone-like microneedles structure. SrAgHA/GO showed good mechanical properties to ensure mechanical strength required for the bone repair coating. The roughness of samples decreased from 120 & PLUSMN; 19 mu m for the SrAgHA/GO coated Ti to 527 & PLUSMN; 66 mu m for HA coated Ti. Although the introduction of GO makes the composite coating have a sig-nificant decreased roughness, it has no effect on the hydrophilicity of the composite coating, which is almost superpotropic. Ion release evaluation demonstrated that the presence of GO slowed the release rate of Sr and Ag, which was beneficial to reduce the cytotoxicity accompanying high concentration of Ag release. Simultaneously, GO increased the surface hydrophilicity and mechanical strength of the SrAgHA/GO. In addition, the corrosion rates of investigated coatings increased in the following order: SrAgHA/GO < SrHA/GO < SrAgHA < HA < Ti. SrAgHA/GO coatings demonstrated an effective antibacterial effect against common bacteria in clinical. The co -doping of Sr and GO in SrAgHA/GO coatings can effectively mitigate the cytotoxicity of Ag and promote the cytocompatibility of HA. The SrAgHA/GO coating did not exhibit any cytotoxicity, which can greatly promote adhesion, extension, proliferation and early differentiation of osteoblasts. Therefore, high cytocompatibility, excellent antimicrobial activity, and good mechanical properties of the SrAgHA/GO-coated Ti samples combined with its exceptional corrosion resistance performance displayed the beautiful prospect of the SrAgHA/GO-coated Ti for applications in hard tissue implant.