Wood-inspired highly anisotropic scaffold activated with in situ mineralized collagen for advanced bone regeneration

Addressing bone defects, limited by inherent regenerative capacities, has catalyzed the development of biomimetic scaffolds. Despite the extensive exploration of collagen-hydroxyapatite scaffolds, they frequently fail to accurately replicate the intricate nanostructure of natural bone. We introduce the wood-collagen- hydroxyapatite (WCH) scaffold, a novel biomimetic structure inspired by the analogous architectures of wood and bone, aimed at substantially improving bone regeneration. Comprising a wood-based matrix, collagen interface, and hydroxyapatite mineralization, the WCH scaffold embodies the critical components of bone tissue. The scaffold's wood-derived framework imparts an anisotropic structure and notable mechanical strength, closely mimicking natural bone's nanoarchitecture. Significantly, the scaffold's longitudinal (L) orientation outperforms its radial counterpart in biocompatibility and bioactivity, reflecting bone's directional properties and promoting superior cell proliferation, adhesion, and osteogenic differentiation. Validated in a rabbit femur defect model, the L directional WCH scaffold significantly accelerated new bone formation, tissue ingrowth, and bone tissue maturation. This innovative wood-inspired scaffold, characterized by its highly anisotropic structure and enhanced with in-situ mineralized collagen, holds significant promise for advancing bone regeneration techniques.