骨修復を促進する骨免疫調節と軽度光熱効果を組み合わせた骨標的マルチファンクショナルナノプラットフォーム

Bone fractures are often accompanied by poor bone healing and a disturbed osteoimmune microenvironment. Inspired by the native osteoimmune microenvironment, a bone-targeting multifunctional nanoplatform (RH@Ag₂S@MMSNs) was developed using Ag₂S/Mg²⁺-incorporated rhodamine B hydrazide (RH)-loaded mesoporous silica nanoparticles, which were then conjugated with alendronate and β-cyclodextrin. The nanoplatform not only showed bone-targeting ability ex vivo and in vivo but also exhibited pH-responsive biodegradable capability. The release of RH can efficiently scavenge inflammatory NO, regulate macrophage polarization, and balance the immune microenvironment. Moreover, the combination of Mg²⁺ and NIR-II imaging-guided mild photothermal therapy (PTT), triggered by near-infrared irradiation, promoted mesenchymal stem cell osteogenic differentiation. In vivo experiments demonstrated that the RH@Ag₂S@MMSNs nanoplatform integrated with anti-inflammation, mild PTT, NIR-II imaging, and osteogenic activities significantly accelerated the reconstruction of bone defects. Therefore, this work presents a distinctive strategy to design a bioactive multifunctional nanoplatform for promoting bone tissue regeneration.