Multi-crosslinking and Topological Entanglement Enable Silk Fibroin Hydrogels with Sustained Mechanical Softness for Neural Regeneration

• • SG hydrogel maintains a storage modulus of ~1.2 kPa for 28 days, whereas pure SF hydrogels stiffen to ~6 kPa, a 5-fold increase. This sustained softness is critical for TBI repair, as matrix stiffness above 3 kPa triggers astrogliosis and inhibits neurite outgrowth. • • The SG hydrogel degrades at 12% per week in vivo, matching the rate of neural tissue regeneration. This controlled degradation ensures mechanical support during early repair while avoiding chronic foreign body response, a common failure mode of permanent implants. • • In a rat TBI model, SG implantation reduced glial scar formation by 40% and improved neurological function scores by 30% at 8 weeks (p < 0.01). These outcomes demonstrate clinical potential for reducing secondary injury and promoting functional recovery. • • The multi-crosslinking network, including covalent bonds, electrostatic repulsion, hydrogen bonding, and π-π stacking, achieves a 2.5-fold increase in βIII-tubulin expression and 1.8-fold increase in GFAP expression after 14 days, indicating enhanced neuronal differentiation and astrocyte maturation without pathological scarring.