Tri-layer gradient fibre-aligned electrospun composite: Accelerating skin wound healing

s The structure and topography of the scaffold material play an essential role in the skin wound healing process, and aligned nanofibers can guide cell growth and proliferation to some extent. It has been demonstrated that the optimal scaffold fabrication method for wound healing is to generate three-dimensional scaffolds composed of nanoscale fibers. Inspired by the structure and function of skin, composite aligned electrospun dressings with fiber gradient changes are prepared by continuous spinning through changing the relevant parameters of the electrospinning process, thereby creating a wettability gradient change to mimic the skin's hydrophilic-hydrophobic transition. This design efficiently manages exudates from the wound site and maintains humidity balance. The hydrophilic inner layer (A100) absorbs wound exudates and maintains a moist environment in the wound. The A300 layer, with its appropriate porosity, ensures nutrient and gas exchange at the wound site, providing an ideal microenvironment for cell growth. The outermost layer, A500, is a mechanical barrier to prevent bacterial invasion, wound infection, and over-hydration. In vitro experiments have verified that the dressing exhibits good biocompatibility and mechanical properties, while in vivo experiments have confirmed that the dressing promotes wound healing, collagen deposition, angiogenesis, hair follicle regeneration, and reduces fibrosis at the wound site. Additionally, it improves scar formation to a certain extent.