Nacre‐inspired layered composite with excellent mechanical support and osteogenic potential for cervical interbody cage

Abstract Degenerative cervical disease is widespread and disabling. Anterior cervical discectomy and fusion (ACDF) is the predominant surgical procedure, relying on an interbody cage to restore intervertebral height and provide stability. Yet, existing cages still suffer from mechanical mismatch, fatigue susceptibility, or limited degradability. Here we develop a multicomponent, degradable, nacre‐inspired layered cervical interbody cage composite in which constituent phases synergistically stabilize the structure and promote osteogenic compatibility. Within the bioinspired layered structure, the confined interlamellar organic matrix enables nanoplatelet shear sliding coupled with reversible dehydration‐and‐rehydration, amplifying z ‐directional swelling‐and‐shrinking while limiting lateral expansion. This anisotropic deformation maintains intervertebral stability without encroaching on the spinal canal. Under small‐strain cyclic compression, the nacre‐like composite dissipates greater hysteresis energy and resists damage accumulation more effectively than the isotropic counterpart. In vitro assays confirmed cytocompatibility and sustained osteogenic activity. In vivo assays confirmed intervertebral height preservation, good systemic tolerance, and continuous bone bridging across the interbody space. Relative to existing cages, the nacre‐like composite offers a more balanced set of key attributes. Our findings establish nacre‐like layered structure as a design framework for degradable cervical interbody cages that mitigate brittle failure, enhance cyclic energy dissipation, and more broadly, advance bioinspired structural design for load‐bearing, energy‐dissipative biomedical materials.