Decellularized periosteum and sodium alginate-based photoresponsive dressing with copper selenide nanoparticles for infected-wound healing in diabetic mice.

Diabetes-related skin ulcers are of significant clinical concern. Although conventional dressings have been developed, their outcomes have not been adequate, indicating the need to investigate functional dressings for the treatment of diabetic ulcers. Copper selenide nanoparticles (Cu2 Se NPs) demonstrate outstanding photoresponsiveness, which is critical to the healing process. However, their limited solubility in water restricts their application. To synthesize the ODT-PMMA@Cu2 Se NP-doped decellularized periosteum‑sodium alginate functional dressing-ODT-PMMA@Cu2 Se/ECM-S (OP@Cu2 Se/ECM-S), Cu2 Se NPs were modified by n-octadecanethiol (ODT) end-functionalized poly (methacrylic acid) (PMAA) ligands homogeneously dispersed in a decellularized periosteum/sodium alginate matrix. This process improved the water solubility and stability. Moreover, under near-infrared irradiation (NIR), ODT-PMMA@Cu2 Se demonstrated robust photo-responsiveness along with photothermal and photodynamic effects, leading to rapid heating and stimulation of reactive oxygen species (ROS) generation. These two processes work in concert to exhibit excellent antibacterial ability; at 20 μg/mL concentration of Cu2 Se NPs, the bacterial activities of S. aureus and E. coli were 5.40 % and 0.96 %, respectively. Without the NIR laser irradiation, OP@Cu2 Se/ECM-S rapidly increased the vascular endothelial growth factor (VEGF) expression, triggered the phosphatidylinositide 3-kinases (PI3K) and protein kinase B (AKT) signaling pathway, affected the expression of bFGF and CD31, and promoted neovascularization, proliferation, and cell migration. In a diabetic mouse wound model, OP@Cu2 Se/ECM-S exhibited good biocompatibility and promoted epidermal regeneration, collagen deposition, and neovascularization. In a mouse model of subcutaneous abscesses, OP@Cu2 Se/ECM-S also showed excellent antibacterial activity, in vivo experiments confirmed a decrease in bacterial activity to 1.97 %. Thus, OP@Cu2 Se/ECM-S is a potentially useful approach for healing diabetic wounds.