Flexible and Durable Bioengineered Artificial Blood Vessels

Artificial blood vessels (ABVs) are widely used to treat severe vascular diseases by replacing damaged vessels. Particularly, bioengineered ABVs offer a promising alternative due to their potential to mimic native blood vessel structure and function. However, the mechanical properties of the bioengineered ABVs still need to be improved. To withstand the mechanical stress encountered during or after implantation, bioengineered ABVs are required to possess sufficient flexibility and durability. Herein, we fabricated a knitted tube composed of biodegradable polyglycolic acid (PGA) as a scaffold and co-cultured endothelial cells and smooth muscle cells in a bilayer on it. The porous knitted tubular structure facilitates nutrient and oxygen delivery to three-dimensional co-cultured endothelial and smooth muscle cells. The knitted tubular structure serves to alleviate damage to cultured cells due to its flexibility and stretchability. Remarkably, completed bioengineered ABVs have a bilayer structure with an inner layer of endothelial cells and an outer layer of smooth muscle cells, similar to a real blood vessel. Additionally, the ABVs exhibit flexibility and durability because more than most their cells remain even after cycles of bending.