Mechanical Intelligence in Bone Regeneration: Bridging Material and Cellular Memory for Enhanced Healing

Mechanical cues shape bone regeneration, but treatments for delayed union, nonunion, and mechanically mismatched repair often still treat them as static constraints. In this review, we use mechanical intelligence to describe the time-dependent capacity of biomaterials, cells, and therapeutic devices to store, transform, and transmit mechanical history during repair. Two forms of memory are central to this view. Scaffolds and implants can preserve or release previous mechanical states through relaxation, residual stress, shape recovery, evolving stiffness, and architecture, whereas cells can carry earlier stiffness or loading exposure into later mechanotransduction, lineage commitment, and niche remodeling. The key question is when these two forms of memory meet during healing, from cell recruitment and matrix formation to callus maturation, load sharing, and rehabilitation. Coupling material and cellular memory may help match scaffold mechanics to cellular decision windows and tissue competence, support osteogenesis, reduce maladaptive responses such as stress shielding or fibrosis, and guide stage-specific scaffolds, adaptive fixation, sensing-assisted modelling, and mechanically timed rehabilitation for personalized bone repair.