Ultraelastic adaptive Bletilla striata polysaccharide hydrogel bandage for rapid sealing, hemostasis and infection-resistant healing.

Uncontrolled bleeding and unstable sealing of irregular, dynamic wounds remain a major clinical challenge, particularly in emergency trauma, surgery, and organ injuries. Herein, this work incorporated the active substance Bletilla striata polysaccharide (BSP) into a multi-network system composed of polyethyleneimine (PEI), carboxymethyl chitosan (CMCS), and polyacrylamide (PAAm) to construct a self-sealing living hydrogel bandage (CAP@BSP-H). Benefiting from the electrostatic-hydrophobic synergy and a dynamic hydrogen-bond network, the hydrogel exhibits strong wet adhesion (94.55 kPa) and ultrahigh stretchability (>2000%), enabling the hydrogel bandage to achieve rapid self-sealing (approximately 10 s) and synchronous deformation with the wound surface. It features a unique dual hemostatic mechanism, combining physical sealing with BSP-mediated biological coagulation, which achieved a ∼94.8% reduction in blood loss (1.67 mg) and a ∼96.3% shortening of hemostasis time (3.5 s) in a mouse liver hemorrhage model. Furthermore, CAP@BSP-H demonstrates potent antibacterial and antioxidant activities, promotes angiogenesis, and achieved a 98.57% wound closure rate within 14 days in a rat infected wound model. In summary, this CAP@BSP-H bandage achieves autonomous self-sealing, synchronized deformation, and rapid hemostasis on dynamically moving wound surfaces, which shows great potential for clinical applications in emergency hemostasis, complex trauma, and infected wound care.