Zwitterionic Powder-Based Gradient Adhesion-Lubrication Hydrogels for Efficient Hemostasis and Antiadhesion

Uncontrolled hemorrhage, particularly from deep, irregular, and noncompressible wounds, remains a critical challenge in emergency medicine. Conventional hemostatic agents are frequently limited by poor sprayability, inadequate conformability to complex wound geometries, insufficient mechanical robustness, and lack of asymmetric adhesion properties. To address these limitations, we engineered a novel powder (CS-PSBMA@OHA) composed of zwitterionic poly(sulfobetaine methacrylate)-grafted chitosan (CS-PSBMA) and oxidized hyaluronic acid (OHA). Upon contact with moist tissue, the powder undergoes rapid liquid-triggered gelation, forming a stable, dual-network hydrogel. This architecture integrates a dense physical network, formed by strong intra- and interchain electrostatic interactions of zwitterionic PSBMA, with a dynamic chemical network established via Schiff base bonds with OHA. The resultant hydrogel adheres firmly to tissues by combining the rapid interfacial dehydration driven by zwitterionic PSBMA with the dynamic cross-linking enabled by OHA. This synergistic mechanism confers exceptional mechanical stability and sustained adhesion, even under dynamic fluid conditions. In both rat liver laceration and femoral artery transection models, CS-PSBMA@OHA demonstrated superior hemostatic efficacy, significantly reducing blood loss and hemostasis time compared to gauze and Yunnan Baiyao. Furthermore, the hydrogel exhibits a gradient adhesive interface: the tissue-contacting surface maintains strong adhesion, while the opposing side forms a hydrated lubrication layer. This asymmetric design effectively mitigates postoperative adhesions, as evidenced in a rat intestinal adhesion model. Collectively, this self-gelling powder-based platform represents a promising strategy for the development of multifunctional biomaterials that integrate rapid hemostasis with antiadhesive properties, offering potential clinical advantages in trauma and surgical settings.