Bladder Acellular Matrix Graft Reinforced Silk Fibroin Composite Scaffolds Loaded VEGF with Aligned Electrospun Fibers in Multiple Layers

Bombyx mori silk is of great interest to people for its outstanding mechanical and biological properties. However, the traditional electrospun regenerated silk fibroin (RSF) scaffolds from aqueous solution were weak and had limited applications. This study was to fabricate reinforced scaffolds with well-aligned RSF fibers electrospun on a layer of native extracellular matrix, bladder acellular matrix graft (BAMG). The silk fibroin fibers were well-aligned as a grill in multiple layers. Both the BAMG and the grill structure significantly improved the tensile properties and suture retention of the composite scaffolds, which can be sutured well with tissue during implantation. In vitro assay indicates that the scaffolds had a good biocompatibility. Porcine iliac endothelial cells (PIECs) attached and proliferated well on the vascular endothelial growth factor (VEGF) loaded scaffolds compared with those without VEGF. Moreover, the grill-like structure guides PIECs well along the aligned fiber.