Silk biomaterials functionalized with recombinant domain V of human perlecan modulate endothelial cell and platelet interactions for vascular applications.

Modulation of endothelial cell and platelet interactions is an essential feature of vascular materials. Silk biomaterials were functionalized with recombinantly expressed domain V of human perlecan, an essential vascular proteoglycan involved in vasculogenesis, angiogenesis and wound healing, using passive adsorption or covalent cross-linking via carbodiimide chemistry. The orientation of domain V on the surface of silk biomaterials was modulated by the immobilization technique and glycosaminoglycan chains played an essential role in the proteoglycan presentation on the material surface. Covalent immobilization supported improved integrin binding site presentation to endothelial cells compared to passive adsorption in the presence of glycosaminoglycan chains, but removal of glycosaminoglycan chains resulted in reduced integrin site availability and thus cell binding. Silk biomaterials covalently functionalized with domain V supported endothelial cell adhesion, spreading and proliferation and were anti-adhesive for platelets, making them promising surfaces for the development of the next-generation vascular grafts.