Tissue-engineered vascular graft based on a bioresorbable tubular knit scaffold with flexibility, durability, and suturability for implantation.

ABSTRACT

The tissue-engineered vascular graft (TEVG) is a technology used to recreate a blood vessel by using vascular cells (endothelial cells and smooth muscle cells) and their scaffolds, and is a promising approach as a clinically feasible alternative for small-diameter blood vessel replacement. Since mechanical damage occurs during/after implantation, it needs flexibility and durability to withstand the mechanical damage to be applied. To achieve this, we applied a bioresorbable polyglycolic acid (PGA) fiber-knitted tubular scaffold for vascular endothelial and smooth muscle cell layers. Similar to the native rat aorta, the knitted tubular scaffold (130 µm-thick PGA fiber) exhibited mechanical performance at 150 mN for up to 40% strain for axial stress and at 90 mN for up to 5% strain for circumferential stress. After co-culturing, a vascular barrier comprised of an inner layer of endothelial cells and an outer layer of smooth muscle cells between tubular knits was observed. Up to 93.6% of the co-cultured cells were retained even after bending 50 times, and the suturability to flow liquid without any leakage in various shapes, such as an L-shape or a Y-shape, was acceptable. Taken together, these results support that the PGA tubular knit plays multifunctional roles, such as a porous three-dimensional matrix to attach and grow the vascular cells, and as a flexible and durable scaffold for the suture. Therefore, we suggest that the bioresorbable PGA tubular knit scaffold is a promising scaffold for TEVGs.