Biorthogonal click-immobilized probiotic membrane vesicles in a dynamic hydrogel for accelerated and scar-minimized wound healing

Chronic and complex wounds require materials capable of simultaneously regulating inflammation and promoting vascularized tissue regeneration. Here, we engineer a bioorthogonal vesicle–hydrogel that covalently integrates Lactobacillus casei –derived membrane vesicles (LCMVs) within a carboxymethyl chitosan/aldehyde-hyaluronic acid network to achieve sustained vesicle presentation and enhanced bioactivity. The resulting Gel-LCMVs composite exhibits an ECM-mimetic porous architecture, stable viscoelasticity, and controlled vesicle release, enabling marked stimulation of cell proliferation, migration, and endothelial tube formation while suppressing macrophage-derived pro-inflammatory signals. In a full-thickness excisional wound model, Gel-LCMVs achieved >50% closure by day 3 and nearly complete healing by day 10, with improved granulation tissue formation, thicker neo-dermis and enhanced collagen deposition, outperforming a commercial dressing (Tegaderm). Transcriptomic profiling reveals activation of PI3K–AKT, Wnt, and JAK–STAT pathways and suppression of inflammatory gene programs. This bioactive and cell-fre hydrogel platform demonstrates how precise materials–microbio-derived vesicle integration can synergetically steer wound microenvironment remodeling and enable scar-minimized wound repair. • Copper-free click chemistry (SPAAC) enabled stable covalent anchoring of LCMVs within a carboxymethyl chitosan/hyaluronic acid hydrogel network. • Covalent immobilization effectively minimized initial burst release and provided a sustained vesicle release profile for long-term wound management. • The Gel-LCMVs system significantly accelerated wound closure and neovascularization in full-thickness skin defect models, outperforming commercial dressings