PAsp-Ca/collagen co-assembly strategy creates artificial lamellar bone superseding autografts through structure-property-function integration

The composition and physical architecture of bone play vital roles in bone defect repair. Non-vascularized autografts are constrained by limited bone availability and unpredictable resorption. In this study, we synthesized artificial lamellar bone (ALB) by mimicking the physical structure of natural lamellar bone, integrating structure, properties, and function. Based on the principles of macromolecular crowding and charge shielding in regulating the hierarchical assembly of collagen, our strategy utilized the co -assembly of concentrated collagen with polyaspartic acid-Ca 2+ complexes (PAsp-Ca) to guide collagen ordered assembly and cross-linking, thereby fabricating a biomimetic organic scaffold. During assembly, abundant PAsp-Ca was embedded within the collagen, priming the dense collagen block for deep mineralization. The resulting mineralized ALB closely matched the structure, properties of natural bone and exhibited superior osteogenic performance to autograft in rat critical-sized mandibular defect models. The synergistic effect between new bone formation and material resorption persisted until ALB was completely replaced. This strategy establishes a new paradigm for enhancing the overall performance threshold of osteogenic materials.