Application and prospects of nanomaterials in osteoporosis treatment

Osteoporosis is characterized by uncoupled bone remodeling, microarchitectural deterioration, and impaired fracture or defect healing, resulting in increased fragility and a high lifetime fracture burden. Current pharmacotherapies can reduce fracture risk, yet their impact is constrained by systemic exposure, adherence limitations, and the lack of direct mechanical restoration in localized defects. Nanomaterial-enabled biomaterials provide a means to localize therapy, engineer the osteoporotic microenvironment, and deliver defect-specific structural support. Unlike platform- or strategy-specific summaries, this review establishes a pathology-to-design framework that integrates drug-delivery nanosystems (lipid, polymeric, and inorganic carriers with bone- or osteoclast-targeting chemistries) with implantable or injectable nanocomposites (metal, ceramic, polymer, and composite matrices). Synthesis and processing parameters (composition, porosity, and micro/nanostructure) and surface chemistry (ion doping, bioactive coatings, and affinity motifs) are explicitly linked to targeted applications, including remodeling-preserving modulation of osteoclast-osteoblast coupling, osteoimmune regulation, angiogenesis support, and spatiotemporally programmed release. Advanced multifunctional approaches, such as staged antiresorptive-to-anabolic delivery, micro/nanotopography-guided interface engineering, and pH/enzyme/thermal/electroactive responsive systems, are critically evaluated in terms of performance trade-offs and failure modes. A translation-oriented evaluation and clinical-readiness roadmap is presented, emphasizing harmonized efficacy endpoints, chemistry, manufacturing and controls (CMC) and quality-by-design (QbD) for scalability, regulatory tractability for combination products, and long-term safety of nano-additives and degradation products.