Multifunctional amniotic membrane hydrogel with cytokine-loaded microspheres promotes healing of diabetic full-thickness burn wounds.

Full-thickness burn wounds under diabetic conditions are characterized by excessive oxidative stress, prolonged inflammation, impaired angiogenesis, and delayed tissue remodeling. The present study aimed to evaluate a multifunctional amniotic membrane-derived hydrogel co-loaded with interleukin-10 (IL-10), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) for enhanced immunomodulation and accelerated wound healing in a diabetic burn model. The engineered hydrogel exhibited successful decellularization, a highly interconnected porous architecture, high cytokine encapsulation efficiency, sustained release behavior over 14 days, favorable cytocompatibility, and improved compressive properties following microsphere incorporation; although microsphere loading slightly reduced porosity while preserving structural interconnectivity. Full-thickness burn wounds were induced in diabetic rats, followed by treatment with either pristine hydrogel or microsphere-loaded hydrogel. Wound healing progression was assessed through macroscopic evaluation, biochemical analysis of cytokines (VEGF, TGF-β, TNF-α, IL-1β), oxidative stress markers (SOD, CAT, GSH, MDA), histological and stereological analyses (fibroblast density, vascular density, inflammatory cells), collagen deposition, and biomechanical testing. Treatment with the microsphere-loaded hydrogel significantly accelerated wound closure compared to the control and hydrogel groups. This effect was associated with reduced pro-inflammatory cytokine levels and inflammatory cell infiltration, alongside increased VEGF and TGF-β expression. Enhanced angiogenesis was confirmed by elevated vascular density. Moreover, oxidative stress was attenuated, as evidenced by increased antioxidant enzyme activities and decreased lipid peroxidation. Histological findings demonstrated improved fibroblast proliferation, collagen deposition, and tissue organization, which translated into superior biomechanical strength of the regenerated tissue. Collectively, the microsphere-loaded hydrogel effectively promoted diabetic burn wound healing through coordinated modulation of inflammation, oxidative stress, angiogenesis, and tissue remodeling. This multifunctional platform may represent a promising therapeutic strategy for the management of complex burn injuries under diabetic conditions.