Hemoglobin‐Mediated Dual‐Crosslinked Silk Fibroin With Enhanced Elasticity, Rigidity, Toughness, and Shapeability for Tracheal Tissue Application

Abstract The study presents an elastic, rigid, and shapeable silk fibroin (SF)‐based scaffold with a dual‐crosslinked network for tracheal tissue engineering. Hemoglobin (Hb), a biocompatible and cost‐effective natural protein, is introduced as both a catalyst and a crosslinker. The in situ chemical crosslinking occurred via a dityrosine reaction in the presence of hydrogen peroxide. Subsequently, freeze‐drying induced the formation of β‐sheet crystals, further physically crosslinking the SF chains, resulting in a 3D porous Hb‐SF scaffold. Additionally, the α‐helix subunits in Hb acted as “molecular springs”, enhancing the scaffold's mechanical strength, elasticity, and toughness. The biomechanical properties of the Hb‐SF scaffold are tunable by adjusting the SF content, enabling precise shape fidelity, self‐recovery, and durability. Notably, the Hb‐SF scaffold exhibited high fatigue resistance, enduring multiple compressive cycles without damage. In vitro tests confirmed its cytocompatibility and potential for cartilage regeneration. Furthermore, in vivo implantation of chondrocyte‐seeded scaffolds resulted in a biomimetic trachea with structural and mechanical properties closely resembling those of the native trachea. This Hb‐mediated, dual‐crosslinked SF scaffold demonstrates enhanced elasticity, rigidity, toughness, and shapeability, presenting a viable option for tracheal tissue regeneration applications.