Biomimetic Nanomedicine for Aging‐Impaired Bone Regeneration: From Microenvironmental Dysfunction to Precision Therapeutics

Aging‐impaired bone regeneration represents a major clinical challenge due to diminished regenerative capacity and a progressively deteriorated microenvironment. This dysfunction arises from the interplay of cellular senescence, chronic inflammation driven by the senescence‐associated secretory phenotype (SASP), vascular insufficiency, and disrupted neuroregulation, collectively limiting effective bone repair. Conventional therapies, largely relying on single‐target interventions or passive delivery, remain insufficient to address these multifactorial barriers. Biomimetic nanomedicine offers a promising strategy by integrating biologically inspired designs with therapeutic cargos. Based on the principal biological feature emulated, these systems can be organized into four operational categories: cell‐derived, extracellular vesicle‐inspired, biomolecule‐inspired, and microenvironment‐inspired platforms. Biomimetic features dictate biological recognition, localization, retention, and stimulus responsiveness, whereas therapeutic cargos or active materials mediate downstream regenerative effects. To bridge this design‐based taxonomy with the biology of aging‐impaired bone repair, this review organizes current evidence within a pathology–design–outcome framework centered on four major pathological barriers: cellular dysfunction, osteoimmune dysregulation, vascular impairment, and disrupted neural regulation. This framework links age‐related pathological deficits with biomimetic design principles and regenerative outcomes, while highlighting key priorities for more precise and clinically translatable bone regeneration.