Tannic acid coated core-shell fibers with antibacterial and antioxidant properties for diabetic wound healing

• A novel core–shell fiber with tannic acid coating. • Tannic acid coating enhances the mechanical properties and hydrophilicity of the core–shell fiber. • Curcumin loaded by core–shell fiber exhibits antibacterial, antioxidant and anti-inflammatory properties. • Curcumin loaded by core–shell fiber promotes angiogenesis and collagen deposition. Diabetic wounds are exacerbated by a local high-sugar environment, leading to vascular and nerve damage, impaired angiogenesis, reduced collagen deposition, and increased inflammation and oxidative stress, ultimately halting the healing process. With the rising prevalence of diabetes, the number of patients with diabetic wounds is also increasing. In this context, a novel fiber dressing for diabetic wounds has been developed using coaxial electrospinning combined with self-assembly coating technology. The uniform distribution of the TA (tannic acid) coating enhances the mechanical properties, hydrophilicity, and cell adhesion of PLGA-PCL core–shell fibers while imparting anti-inflammatory, antibacterial, and antioxidant capabilities. The drug Cur (curcumin), loaded in the core layer of the coaxial electrospun fibers, promotes angiogenesis, collagen deposition, and cellular anti-senescence capacity, while the shell layer facilitates drug encapsulation and sustained release. In vivo experiments, the electrospun fibers serve as an active skin substitute, creating a favorable microenvironment for diabetic wound healing. Overall, TA-coated PLGA-PCL core–shell fibers show great potential as wound dressings for diabetic wound repair.