Material-Structure-Function Integrated Additive Manufacturing of Degradable Metallic Bone Implants for Load-Bearing Applications

The integration of bio-adaptable performance, elaborate structure, and biological functionality for degradable bone implants is crucial in harnessing the body's regenerative potential to remold load-bearing bone defects. Herein, material-structure-function integrated additive manufacturing (MSFI-AM) is deployed to innovate novel zinc-based bone implants, namely Zn-Mg-Cu alloy. In situ alloying of AM and boundary engineering strategy yield prominent mechanical properties, and the degradation products enable a mechanical self-strengthened effect, thus coordinating mechanical degeneration and promoting mechanical adaptability. In addition, MSFI-oriented Zn alloy implants successfully manifest in situ multifunctions of augmenting osteogenesis, immunoregulation, angiogenesis, and anti-infective activity in vitro and expediting bone ingrowth and regeneration in vivo through the sustained release of divalent metal cations and triply periodic minimal surface (TPMS) structure construction. Overall, MSFI-AMed Zn alloy implants signify promising clinical translation prospects for load-bearing applications, and an integrated approach is proposed to endow degradable bone implants with boosted bio-adaptable performance and in situ bio-multifunctions.