Assessment of Physical, Mechanical and Biological Properties of Thai Silk Fibroin Vascular Scaffold

Abstract

Silk fibroin has been widely studied and used in biomedical devices such as sutures because of its excellent mechanical properties, biocompatibility and slow degradability. In this study, Thai silk fibroin was applied as the main material for vascular scaffolds. Surface morphology, water absorption, suture retention strength and cell compatibility were investigated. Fibroin (F) films, fibroin/type A gelatin (FA) and fibroin/type B gelatin (FB) scaffolds were compatible with L929 fibroblast cells line. Double-layers vascular scaffolds (approximately 5 mm inner diameter) consist of lyophilized fibroin/gelatin scaffold as the inner layer and air dried silk fibroin scaffold as the outer layer (F/FG scaffold). The inner layer had porous stucture with average pore size 70±18 µm, and the outer layer had smooth surface after observation under a scanning electron microscope. The percentage of water absorption of F/FG scaffolds (116±5%) was significantly higher than that of F scaffolds (90±4%). Suture retention strength of F/FG scaffolds (303±33 gf) examined by using universal testing machine was significantly higher than that of F scaffolds (200±45 gf). Suture retention force of the scaffolds was similar to that of human artery and was higher than the requirement of ANSI/AAMI VP20-1994: the standard of Cardiovascular implant-Vascular graft prostheses.