Bioactive silk fibroin scaffold with nanoarchitecture for wound healing

Scarless skin regeneration for full-thickness wounds remains a challenge in skin tissue engineering. The surprising scar-free repair function of fetal skin has inspired that the ideal wound dressing can be designed by recapitulating the biophysical and biochemical properties. However, there is no more powerful effective scaffold put into practice due to their mismatched structures and inappropriate components. Here, a novel bioactive scaffold was detailly designed by mimicking extracellular matrix from its chemical components and biophysical nanostructures. Through introduction of hyaluronic acid (HA) and natural silk fibroin nanofibers (SNFs), the silk fibroin (SF)-based scaffolds with higher porosity (~92.5 %), water-uptake ratio (~96 %) and swelling ratio (~90 %) were facilely prepared by lyophilization. In vitro, human umbilical vein endothelial cells (HUVECs) were seeded in the scaffold with nanostructures. The results showed better cytocompatibility of the scaffolds to support cell spread, proliferation and differentiation. In vivo, effect of the scaffolds on full-thickness skin defects of the nude mouse demonstrated that the SNFs incorporated scaffolds could not only accelerated wound healing (up to 98.2 ± 0.5 % within 4 weeks) but also can regulate collagen arrangement by nanofibers as a template to inhibit the scar forming. This study provides a useful strategy for exploring bioactive SF-based scaffolds by natural SNFs decoration for novel wound dressing and artificial skin.