Injectable Dual‐Network Hydrogel System for Osteochondral Repair Combining Immunomodulation, Mechanical Adaptability, and Enhanced Tissue Integration

ABSTRACT Osteochondral defects involving articular cartilage and subchondral bone remain clinically challenging due to limited regenerative capacity and the suboptimal outcomes of current therapies. Recent studies underscore the critical role of the immune microenvironment, particularly macrophage polarization, in modulating chondrogenic and osteogenic differentiation, whereas dysregulated inflammation leads to fibrocartilage formation and impaired tissue regeneration. To address these challenges, we developed a UV‐triggered injectable dual‐network hydrogel, representing the first application of Bletilla striata polysaccharide (BSP) in osteochondral repair. By combining methacrylamide‐modified BSP (BSPMA) with nitrobenzaldehyde‐functionalized hyaluronic acid (HANB), the dual‐network hydrogel integrates immunomodulatory capacity, mechanical robustness, and tissue integration. BSPMA targets macrophage mannose receptors, suppressing pro‐inflammatory M1 polarization and promoting M2 phenotypes to establish a regenerative immune niche. Simultaneously, HANB forms dynamic Schiff base bonds with host tissue, enhancing interfacial integration and reducing secondary damage. This dual‐network strategy overcomes the mechanical and adhesive limitations of conventional BSP‐based systems, offering a promising platform for osteochondral tissue regeneration.