Biodegradable Zn–Li–Sr alloy implants with antioxidant properties for improved bone osseointegration under diabetic conditions†

The repair of bone defects under diabetes mellitus remains challenging due to the hyperglycaemic environment that tends to initiate oxidative stress, leading to poor bone healing. Therefore, the biodegradable, antioxidant and pro-osseointegration properties of bone implants are essential for the healing of diabetic bone defects. Addressing this issue requires bone implants with specialized properties, including biodegradability, antioxidant activity, and the ability to enhance pro-osseointegration. Herein, we developed a novel degradable Zn–Li–Sr ternary alloy aimed at alleviating oxidative stress and promoting the regeneration of diabetic bone defects. Results have shown that the coupling of Zn, Li and Sr not only resists oxidative damage, but also promotes the proliferation and differentiation of osteoblasts. The Zn–Li–Sr alloy implants have been shown to possess multifunctional properties, such as promoting osteogenesis and exhibiting antioxidant activity in vitro, while also facilitating bone ingrowth and osseointegration in vivo. Beyond biological advantages, the alloying of Li and Sr endowed the Zn alloy with significantly improved tensile strength for mechanical support with up to 6 times the UTS and 8 times the YS of pure Zn, and a uniform degradation mode to prevent localized rupture. Overall, Zn–Li–Sr alloy implants demonstrate promising applications for bone regeneration under diabetic conditions, their multifunctional properties not only address the physiological challenges posed by diabetes but also provide robust mechanical support and controlled degradation. This study provides valuable insights into the design and potential clinical applications of implants for bone regeneration under diabetic conditions.