Exosomes from rADSCs Stress-Preconditioned by Pathological Tissue Homogenate for Diabetic Wound Treatment

Diabetic wound healing is severely impaired by a pathological microenvironment, characterized by hyperinflammation, impaired angiogenesis, and disrupted ECM remodeling. Exosomes exhibit great potential for diabetic wound treatment, but the existing single-factor-stimulated exosomes often lack comprehensive reparative capabilities to simultaneously achieve matrix remodeling, inflammatory regulation, and angiogenesis. In this study, a multiple pathological preconditioning strategy using a diabetic wound homogenate (DWH) was developed to stimulate rat adipose-derived stem cells under stress, yielding exosomes (Aφ-exos) with enhanced multifaceted regenerative functions. Proteomic and miRNA sequencing revealed that A50-exos upregulated pro-healing factors (miR-21-5p, miR-126a-3p, HSP90, MMP9, etc.) and downregulated antihealing factors (miR-429, AGER, etc.) compared to those without DWH preconditioning (A0-exos). These multiple stress-preconditioned exosomes (A50-exos or A100-exos) synergistically enhanced fibroblast proliferation and migration, promoted M2 macrophage polarization, and improved endothelial angiogenesis under high-glucose conditions. When delivered via a GelMA hydrogel for sustained release, A50-exos or A100-exos significantly accelerated diabetic wound healing in vivo by enhancing collagen deposition, modulating inflammation, and stimulating vascularization. This biomimetic exosome engineering strategy precisely targets the multifaceted pathology of diabetic wounds by leveraging microenvironment-specific reprogramming, offering a potent, cell-free therapeutic platform for synergistic tissue regeneration.