Investigation of  The Antibacterial Effect, Osteogenic Activity, and  Tracing Properties of Hydroxyapatite Co-Doped with Tb <sup>3+</sup> and Zn <sup>2+</sup>

Hydroxyapatite (HA) is a biomimetic biomaterial that has been widely used in bone repair for many years. However, increased risk of infection after surgery and long-time tracing for the material distribution & degradation during bone reconstruction remain challenges in the clinic. Here, the Tbz3+/Zn2+ co-doped hydroxyapatite (HA:Tb/Zn) was prepared to synchronously realize the antibacterial effect, osteogenic activity, and long-time tracing property. We found HA:Tb/Zn had a strong antibacterial effect on both gram-positive and gram-negative clinical infectious bacteria as well as improved osteogenic activity. Meanwhile, HA:Tb/Zn displayed stable green fluorescence in vitro and in vivo, which indicated great potential for recognizing the material changes during the bone reconstruction process. Combination of the ternary functions is of great significance to control the overuse of antibiotics and realize long-time tracing, and not limited to it, provide a versatile design on biomaterials and expand its applications in clinical practice.