Fabrication of biofunctionalized surfaces for Osteo-regeneration by directional seeding of lactoferrin at the solid-liquid interface

The preformation of a coherent biosurface in living organisms is essential for biomineralized materials, in which biogenic elements are intelligently orientated, shaped, and nano- and micropatterned. However, orchestrating rational organic-inorganic interactions for their artificial counterparts remains a challenge. Here, we propose a surface coating strategy to engineer a cell-proliferative, mineralization-stimulative, and antibacterial biosurface by directional seeding of lactoferrin at the solid-liquid interface. The β-sheet-enriched biosurface forms functional microdomains that synergize osteoblast anabolism and metal coordination. We demonstrate that this biosurface can be coated onto various scaffold materials to enable enhanced biofunctions in vitro and in vivo. Specifically, tibia-defected rats implanted with surface-biofunctionalized scaffolds showed outstanding osteoregeneration. The biocompatibility of the biosurface was also favorable without triggering a significant immune response, leading to a defect recovery rate that is double that of the control. Our study provides a powerful example of how nanostructured protein motifs enable a versatile platform for the rational design and preparation of functional nanomaterial surfaces.