Biomimetic de novo construction of hierarchically aligned and gradient-mineralized collagen for tendon-bone integrated regeneration

The tissues spanning from tendon to bone exhibit a highly specialized extracellular matrix (ECM) architecture, characterized by hierarchical collagen alignment and a gradient mineral composition, which together enable efficient force transfer and guide spatially organized cellular phenotypes. However, recapitulating such complex multi-scale organization and compositional gradients to achieve integrated soft-hard tissue remains challenging. Here, we report the de novo construction of biomimetic collagen–mineral matrices that mimic both the hierarchical organization and mineral gradient distribution of the native tendon-to-bone ECM. Through synergistic electro-assembly and post-treatment, collagen molecules self-organized into aligned fibrillar matrices with multi-scale architecture, replicating tendon-side morphology while providing robust tensile mechanics. At the opposing end, intrafibrillar and interfibrillar minerals were spatially patterned to emulate the mineral gradient from tendon to bone. This structural and compositional continuum enables smooth mechanical transition across the soft-hard tissue interface and promotes region-specific regeneration of aligned tendon-like tissue, fibrocartilage and bone. In vivo studies in rabbit models confirm that these de novo constructed matrices support histological reconstruction of multiple tissues from tendon to bone at the rotator cuff, and significantly improve functional recovery. This work presents a bottom-up biomimetic strategy for engineering multiscale collagen-based scaffolds and demonstrates the therapeutic potential of de novo constructed matrices for multiple tissue regeneration. Here, we report the de novo construction of biomimetic collagen-mineral matrices replicating the hierarchical organization and mineral gradient of native tendon-to-bone ECM. Synergistic electroassembly guides collagen self-organization into aligned, multiscale fibrillar matrices mimicking tendon morphology and mechanics. Spatially patterned intrafibrillar and interfibrillar minerals at the opposing end emulate the mineral gradient from tendon to bone. This structural continuum enables smooth mechanical transition and promotes spatially guided regeneration of tendon-like tissue, fibrocartilage and bone. In vivo rabbit rotator cuff studies confirm the integrated histological reconstruction from the tendon to bone and significant functional recovery. This work presents a bottom-up strategy for de novo engineering of multiscale biomimetic matrices with therapeutic potential for multi-tissue regeneration. • A biomimetic collagen-mineral matrix was constructed de novo to recapitulate both the hierarchical collagen alignment and gradient mineral composition found in native tissues from tendon to bone. • The spatial variations in the matrix's structure and composition provide gradient biological cues that guide the spatially selective differentiation of cells, thereby regenerating the phenotype gradient across the damaged tendon-to-bone tissues. • In vivo experiments in rabbits further demonstrate the effectiveness of this biomimetic strategy in coupling structure and composition with hierarchies and gradients in achieving integrated regeneration from tendon to bone and restoring animal motor function.