Mineralized collagen plywood contributes to bone autograft performance

Autologous bone (AB) is the gold standard for bone-replacement surgeries¹, despite its limited availability and the need for an extra surgical site. Traditionally, competitive biomaterials for bone repair have focused on mimicking the mineral aspect of bone, as evidenced by the widespread clinical use of bioactive ceramics². However, AB also exhibits hierarchical organic structures that might substantially affect bone regeneration. Here, using a range of cell-free biomimetic-collagen-based materials in murine and ovine bone-defect models, we demonstrate that a hierarchical hybrid microstructure-specifically, the twisted plywood pattern of collagen and its association with poorly crystallized bioapatite-favourably influences bone regeneration. Our study shows that the most structurally biomimetic material has the potential to stimulate bone growth, highlighting the pivotal role of physicochemical properties in supporting bone formation and offering promising prospects as a competitive bone-graft material.