Icariin-based bone scaffold for treating steroid-induced necrosis of femoral head by restoring angiogenesis and promoting osteogenesis

• LT-RP-fabricated ICA/TCP scaffolds avoid high-temperature sintering, preserving bioactivity through low-temperature rapid prototyping technology. • Optimized α/β-TCP ratio achieves balanced mechanical strength and degradation rate matching new bone formation. • Gelatin-encapsulated ICA enables sustained release enhancing dual osteogenesis and angiogenesis. • In vivo AVN model validation shows bone regeneration with functional vascularization via implant-host integration. Steroid-induced femoral head avascular necrosis (SFHN), a devastating orthopedic condition characterized by ischemic bone collapse, urgently requires interventions addressing both impaired angiogenesis and compromised osteogenesis. Here, we developed an icariin (ICA)-functionalized β-tricalcium phosphate (β-TCP) composite scaffold through an innovative low-temperature rapid prototyping (LT-RP) technique. This strategy fundamentally resolves the critical limitation of conventional high-temperature sintering that compromises bioactivity through thermal degradation. Additionally, by adjusting the ratio of α-TCP to β-TCP, we optimized the mechanical properties of the scaffold, enhancing its suitability for bone repair and ensuring that its degradation rate matches the rate of new bone formation. Furthermore, gelatin was introduced into the porous structure of the scaffold, successfully encapsulating ICA, allowing for sustained release during bone repair. This innovative design significantly improved the osteogenic and angiogenic effects of the scaffold. Animal experiments showed that the ICA-loaded reconstruction scaffold effectively promoted new bone formation and angiogenesis, enhancing the integration between the implant and bone tissue. This bioengineered approach establishes a paradigm for reconstructing necrotic subchondral bone while preserving joint biomechanics.