A flat-drawn silk fibre membrane based composite antibacterial and conductive wound dressing

Natural silk possesses excellent biocompatibility and biodegradability, which makes it a promising material of medical dressings. However, the silk is mainly obtained by simply removing sericin from silkworm cocoons and thus the prepared dressing shows limited mechanical strength and poor breathability. Flat-drawing, a novel technique in sericulture, enables the production of high-strength flat-drawn silk fibre membranes. In this study, a silk/polyaniline/silver nanoparticles (Silk/PANI/AgNPs) composite dressing was prepared by in-situ polymerization and in-situ photoreduction method using the degummed flat-drawn silk fibre membrane as the framework. The introduction of polyaniline not only improved the conductivity of the silk membrane from insulation to slightly higher than that of human skin, but also served as a reducible site for the in-situ photoreduction synthesis of silver nanoparticles (AgNPs) to provide excellent antibacterial properties and ensure the biocompatibility. The obtained dressing has a mechanical strength of 1.881 MPa and a conductivity of 0.029 S/cm. The in vivo experiment on a full-thickness skin defect model in New Zealand rabbit demonstrates that the dressings can effectively promote wound healing due to its good air permeability, water absorption, conductivity, and antibacterial properties. Our study offers a new strategy for the development of functional dressings based on flat-drawn silk membranes.