Highly Malleable Personalized Prostheses with Hierarchical Microstructure Boost the Long‐Term Osteointegration in Irregular Craniofacial Reconstruction

The desired clinical bone prostheses should achieve satisfactory interface integration and osteoinduction, as well as good surgical convenience. Here, a highly malleable 3D printed prosthesis with compressive strength at 13 MPa is constructed by dopamine, polyvinyl alcohol, and micro‐sized hydroxyapatite (86 wt%) as composite bioinks, which is endowed with good plasticity and can quickly match irregular defects by easily trimming. Spatially decorated collagen and hyaluronan greatly enriched the hierarchical microstructure and biological activity of malleable prosthesis. This prosthesis accelerates the proliferation and osteogenic differentiation of stem cells, regulates M2 polarization of macrophage, and promotes endogenous stem cell recruitment and early angiogenesis. Meanwhile, it significantly reinforces biomineralized deposition and vascularization, reaches full coverage of new bone in the rabbit cranial defect after 15 weeks (Φ = 10 mm), and achieves well osseointegration capacity with interfacial binding strength at 71.2% of the natural skull. This osteoinductive prosthesis provides a new design idea for bone filling. Treatment of complex and irregular craniomaxillofacial defects by current prostheses is hindered by surgical inconvenience and dissatisfactory interface integration. Here, a highly malleable prosthesis spatially decorated collagen and hyaluronan is constructed to initiate osteogenesis and angiogenesis by macrophage polarization and endogenous stem cells recruitment, which realizes good interfacial binding strength and bone cover after 15 weeks of implantation.