Fabrication of a bionic asymmetric wettable Cu-doped chitosan-laponite-PCL wound dressing with rapid healing and antibacterial effect

Asymmetrical dressings, which are composed of a compact top layer and a porous bottom layer, are commonly used to mimic the characteristics and structure of the epidermis and dermis layers, and overcome the flaws of traditional dressings such as wound dryness and bacterial penetration. Herein, a bio-inspired double-layer asymmetric wettable wound dressing was prepared by low-temperature 3D printing coupled with electrospinning technology. The hydrophobic top layer of poly(caprolactone)(PCL) film produced by electrospinning was used to simulate the compact and air-permeable epidermis. The hydrophilic bottom layer of the dressing, a scaffold composed of chitosan and copper ions doped Laponite (Cu@CS-Lap) was used to kill bacteria and speed up wound healing. Additionally, the composite dressings also showed excellent cytocompatibility and antibacterial properties in vitro experiments. The migratory area of Cu-doped group human umbilical vein endothelial cells increased by about 48.19% compared to the control group, as revealed by the results of the cell scratch experiment. Furthermore, in vivo experiments in rats showed that wound closure at the 0.5Cu@CS5-PCL dressing reached 98.24% after 12 days, indicating the enormous potential of asymmetric double dressings in boosting wound healing.