Wound ulceration caused by diabetes is a typical chronic wound wherein healing the local tissue is difficult due to lack of blood vessels and tissue necrosis caused by the long-term accumulation of free radicals. Near-field electrospinning (NFES) is an innovative technology used to produce micro-nano-scaled, controllable sequencing fibers. In this study, we constructed a novel wound dressing based on the NFES polycaprolactone (PCL) fiber network and modified gelatin with methacrylic anhydride (GelMA) hydrogel to promote angiogenesis and the re-epithelialization of diabetic wounds. An angiogenic and antioxidant drug named deferoxamine (DFO) was encapsulated in a GelMA hydrogel to achieve a slow-release effect that is more suitable for chronic wounds. The cell adhesion experiment showed that the cells could attach to the fibers in the dressing group having a network of PCL fibers on the surface and grow along the direction of the fibers, which in turn, effectively regulates cell behavior from the physical structure. Additionally, the large pore size (~ 500 μm) of the network allowed the cells to penetrate the pores and enter the surface of the hydrogel without being blocked out. Besides, the composite dressing had a notable effect on angiogenesis. Furthermore, antioxidation experiments confirmed that the DFO-loaded hydrogel exhibited antioxidant activity. Experimental animal models of diabetes showed that rats treated with the PCL-GelMA-DFO (PGD) hydrogel had faster ability of hemostasis, scab formation, and wound healing. In conclusion, the PGD hydrogel effectively promoted the repair of chronic wounds.

Electrospinning is a popular and effective method of producing porous nanofibers with a large surface area, superior physical and chemical properties, and a controllable pore size. Owing to these properties, electrospun nanofibers can mimic the extracellular matrix and some human tissue structures, based on the fiber configuration. Consequently, the application of electrospun nanofibers as biomaterials, varying from two-dimensional (2D) wound dressings to three-dimensional (3D) tissue engineering scaffolds, has increased rapidly in recent years. Nanofibers can either be uniform fiber strands or coaxial drug carriers, and their overall structure varies from random mesh-like mats to aligned or gradient scaffolds. In addition, the pore size of the fibers can be adjusted or the fibers can be loaded with disparate medicines to provide different functions. This review discusses the various structures and applications of 2D fiber mats and 3D nanofibrous scaffolds made up of different one-dimensional (1D) fibers in tissue engineering. In particular, we focus on the improvements made in recent years, especially in the fields of wound healing, angiogenesis, and tissue regeneration.