An injectable multifunctional extracellular matrix-based hydrogel with antibacterial and pro-regenerative functions...

Infected wounds are characterized by a high bacterial burden and persistent inflammation, which frequently impair tissue regeneration. Conventional wound dressings and single-function hydrogels are often insufficient to simultaneously meet the demands of infection control and tissue regeneration. Consequently, the development of multifunctional wound-healing materials capable of addressing these challenges has emerged as a major focus in the field of wound repair. To address this issue, we developed an injectable composite system based on a "microsphere-in-hydrogel" structure, which integrates a native extracellular matrix (ECM) microenvironment, silver nanoparticle (AgNP)-mediated antibacterial functionality, and sustained release of basic fibroblast growth factor (bFGF) within a single platform, aiming to meet the therapeutic requirements at different stages of infected wound healing. The composite employs a porcine decellularized dermis-derived extracellular matrix (dECM) hydrogel as the matrix and incorporates silver nanoparticles (AgNPs) to establish an antibacterial microenvironment conducive to early infection control. Meanwhile, sodium alginate microspheres (SAMS) loaded with bFGF were embedded within the system to achieve sustained release of the growth factor through the microsphere structure. In vitro experiments demonstrated that the bifunctional composite exhibits effective antibacterial activity, good biocompatibility, and enhanced cell migration. A murine infected wound model further confirmed that the composite accelerates inflammation resolution and promotes angiogenesis and tissue regeneration, thereby significantly improving healing efficiency. Collectively, this composite demonstrates strong potential for application in infected wound repair.