title: Bilayered vascular grafts based on silk proteins.
abstract: A major block in the development of small diameter vascular grafts is achieving suitable blood vessel regeneration while minimizing the risk of thrombosis, intimal hyperplasia, suture retention, and mechanical failure. Silk-based tubular vessels for tissue engineering have been prepared by molding, dipping, electrospinning, or gel spinning, however, further studies are needed to improve the mechanical and blood compatibility properties. In the present study a bilayered vascular graft based on silk fibroin (SF) was developed. The graft was composed of an inner silk fiber-reinforced SF tube containing heparin and a highly porous SF external layer. Compared with previously fabricated SF tubes the fiber-reinforcement provided a comparable or higher mechanical strength, burst pressure, and suture retention strength, as well as mechanical compliance, to saphenous veins for vascular grafts. Heparin release was sustained for at least 1 month, affording blood compatibility to the grafts. The outer layer of the grafts prepared through lyophilization had a highly porous structure in which the macropore walls were composed of nanofibers similar to extracellular matrix, which offered an excellent environment for cell growth. In vitro studies showed good cytocompatibility and hemocompatibility.
authors.affiliation: National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, People's Republic of China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Liu
authors.forename: Chaofei
authors.initials: C
authors.lastname: Dong
authors.forename: Guozhong
authors.initials: G
authors.lastname: Lu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lu
authors.forename: Zhanxiong
authors.initials: Z
authors.lastname: Li
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.forename: Hesun
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000648:ultrastructure; D001807:Blood Vessel Prosthesis; D012831:Bombyx / Q000737:chemistry; D002138:Calibration; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005349:Fibroins / Q000494:pharmacology*; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008297:Male; D008422:Materials Testing; D010973:Platelet Adhesiveness / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D017550:Spectroscopy, Fourier Transform Infrared; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure; D013718:Tensile Strength / Q000187:drug effects; D054457:Tissue Scaffolds / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D006493:Heparin; D005349:Fibroins
keywords: Bilayer; Compatibility; Mechanical properties; Silk; Vascular grafts