Evaluation of endothelialization in the center part of graft using 3cm vascular grafts implanted in the abdominal aortae of the rat.

Abstract

In order to develop small-diameter vascular grafts, it is necessary to evaluate endothelialization, especially, in the center part at early stage. For implantation of vascular grafts of 1cm in length to abdominal aortae of rat, endothelial cells can be formed easily by stretching anastomosis. We evaluated the endothelialization in the center part of vascular grafts by implanting vascular grafts using transgenic (TG) silk fibroin (SF) of 3cm in length. Vascular grafts were prepared 1.5mm in diameter and 1 and 3cm in length using wild type (WT) SF and TG SF by braiding structure, respectively. The grafts were removed after 2weeks or 3months and evaluated pathologically. Endothelialization was not confirmed totally after 3months of implantation. However, endothelialization in the center part of grafts was significantly higher in TG SF than in WT SF. No significant difference was found regarding tissue infiltration and internal diameter. The TG SF revealed migration of the endothelial cells into the center part of the vessels at the early stage. Also, tissue infiltration and remodeling is expected using SF. The 3cm length vascular grafts can be evaluated as a new experimental system.