Three-layer core-shell structure of polypyrrole/polydopamine/poly(l-lactide) nanofibers for wound healing application

Poor wound healing is a very common clinical problem, so far there is no completely satisfactory treatment. Electropsun nanofibrous wound dressings may provide an ideal structure to improve wound healing. Therefore, development of nanofibrous wound dressings with rapid hemostasis, antibacterial and tissue regenerative multi-functions has been a hotspot in the field of skin tissue engineering. In this work, polydopamine (PDA) and polypyrrole (PPy) were uniformly coated onto the surface of poly(l-lactide) (PLLA) nanofibers by in-situ polymerization, forming a novel PPy/PDA/PLLA three-layer core-shell structure. The homogeneously coated PPy and PDA two layers could significantly increase the hydrophilicity, conductivity, near-infrared photothermal antibacterial property, the speed of wound hemostasis, antioxidant capacity and reactive oxygen species (ROS) scavenging capacity, respectively. In addition, PPy/PDA/PLLA nanofibers showed good biocompatibility. Rat wound healing model confirmed that PPy/PDA/PLLA nanofibers could significantly accelerate wound repair in vivo. Thus, this novel nanofibrous wound dressing is a promising candidate for clinical wound healing.