Integrated haemostasis-immunomodulation-regeneration design: Shape-memory PGM sponges for noncompressible haemorrhage...

To achieve rapid haemostasis in noncompressible wounds, haemostatic sponges that combine high liquid absorption with rapid shape recovery are urgently required. However, conventional sponges struggle to balance high porosity with rapid shape restoration. In this study, we developed a water-triggered shape-memory haemostatic sponge loaded with MaBo powder (WSH-M). Oxidised pectin (OG) was crosslinked with a porcine acellular dermal matrix (PADM) via Schiff base reactions, yielding a highly porous (∼ 85%) three-dimensional interpenetrating network with rapid water-activated shape recovery. The PGM sponge exhibited excellent hydrophilicity (water uptake up to 39-fold) and robust cyclic compressive resilience, enabling active adaptation and tight conformation to irregular wound geometries to provide effective physical tamponade. Both in vitro and in vivo evaluations demonstrated outstanding haemostatic performance arising from the synergistic action of multiple components. MaBo powder rapidly absorbs fluids to concentrate the coagulation factors. Aldehyde groups in OG quickly crosslink with blood proteins to form an "artificial clot", and collagen within PADM effectively activates platelets, collectively initiating the intrinsic coagulation pathway. In rat models of tail amputation, liver injury, and femoral vein injury, the sponge achieved significantly faster haemostasis and reduced blood loss compared to commercial collagen sponges and gauze controls. Moreover, sponges exhibit immunomodulatory and pro-healing properties. In a diabetic full-thickness skin defect model, it promoted macrophage polarisation from the pro-inflammatory M1 phenotype toward the anti-inflammatory M2 phenotype, significantly decreased TNF-α and increased IL-10, optimised the wound microenvironment, and achieved a 95% wound closure rate by day 14. Overall, this study presents a multifunctional shape-memory sponge that integrates rapid physical sealing, chemical crosslinking-assisted haemostasis, bioactive activation, and smart immunomodulation, offering a promising biomaterial strategy for controlling haemorrhage in complex trauma and accelerating the healing of refractory diabetic wounds.