Controlled Release of Basic Fibroblast Growth Factor From Gelatin Hydrogel Sheet Improves Structural and Physiological Properties of Vein Graft in Rat

Abstract

Autologous vein grafts are still widely used, but their long-term patency is suboptimal. The objective of the current study was to determine whether wrapping a vein graft in gelatin hydrogel sheet incorporating basic fibroblast growth factor improves their mechanical and physiological properties. Autologous femoral vein was interposed into the abdominal aorta in rats. The rats were divided into 3 groups: nontreated grafts (group A), grafts wrapped in basic fibroblast growth factor-free gelatin hydrogel sheet (group B), and grafts wrapped in basic fibroblast growth factor-impregnated gelatin hydrogel sheet (group C). On day 1, endothelial desquamation was observed in group A, and the media in groups A and B were disrupted, staining positive in the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. In contrast, the media in group C remained intact and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-negative, associated with activation of MAPK. Graft dilation was significantly inhibited in groups B and C compared with group A, with those in group C showing the smallest degree of neointimal proliferation. At 8 weeks grafts in group C developed neointima with homogeneous elastic laminae, presence of rigid neoadventitia that displayed neovascularity, and the highest blood flow velocity. Wrapping vein grafts in basic fibroblast growth factor-impregnated gelatin hydrogel sheet improved their structural and physiological properties, and might therefore also improve long-term patency.