Development of small-diameter vascular graft made from silk

Bombyx mori silk fibroin (SF) fiber is a well-known excellent fiber for textile. However, the SF fiber has also a long history of use in sutures. There are large demands for surgical revascularization of small-diameter (less than 6 mm in diameter) vascular grafts, but no available artificial grafts at present Thus the SF was used as artificial blood vessel material. The grafts with 1.5 mm in inner diameter and 10 mm in length, were implanted into rat abdominal aorta by us and proved to be excellent grafts with remarkably high patency (ca. 85%. n = 27 at 12 months) after grafting with remodeling. Endothelial cells and smooth muscle cells migrated into the SF graft early after implantation, and became organized into an endothelium and a media-like smooth muscle layer. Several attempts of the preparation of SF grafts and the animal implantation experiments are described together with the scope of the future works about the development of the small-diameter SF vascular grafts.