Zn-0.4Li alloy shows great potential for the fixation and healing of bone fractures at load-bearing sites

Biodegradable orthopedic implants, designed to promote vigorous bone healing and be safely absorbed by the body, are developing rapidly to complement the deficiency of conventional implants. Limited strength, however, has blocked their path to high load-bearing applications. In this study, we report a pioneering application of implants made of high-strength biodegradable Zn-Li alloy in a high load-bearing rabbit shift fracture model. The Zn-0.4Li based bone plates and screws showed comparable performance in bone fracture fixation compared to the Ti-6Al-4 V counterpart. The fracture was healed completely after 6 months. The osteogenic activity of Zn-0.4Li alloy, as a result of biodegradation, was verified in a rat femur model. Furthermore, the underlying mechanism could include activation of the PI3K-AKT pathway and stimulation of metallothionein proteins. The empirical findings here reveal the great potential of Zn-Li based alloys for degradable biomaterials in high load-bearing applications.