Fabrication of injectable hydrogels from silk fibroin and angiogenic peptides for vascular growth and tissue regeneration

Development of new biomaterials which can structurally and functionally mimic natural cell environments is one major goal of tissue engineering. Recently, self-assembling peptides are attractive candidates to prepare biomimetic cellular niches, because their nanoscale network and biomechanical properties are similar to those of the natural extracellular matrix (ECM). Here, we describe the generation of a new bioactive hydrogel composed of silk fibroin (SF) and a self-assembling peptide NapFFSVVYGLR for tissue engineering. As a consequence of the cooperative assembling of silk fibroin and NapFFSVVYGLR and the functional role of the SVVYGLR epitope from the osteopontin protein, a bioactive hydrogel (e.g., SV-SF) is afforded, which exhibits good gel stabilities and high capacities to induce endothelial cell adhesion, growth and migration. After implantation into the defect area of mouse skin, the SV-SF hydrogel can promote vascularization and epidermization for epidermal repair, by stimulating collagen deposition and expression of angiogenesis-related genes/proteins. Altogether, these results suggest that the bioactive hydrogel can work as a promising material for vascular regeneration and wound healing applications.