Design, Preparation, and Performance of a Novel Bilayer Tissue-Engineered Small-Diameter Vascular Graft

In clinical practice, the need for small-diameter vascular grafts continues to increase. Decellularized xenografts are commonly used for vascular reconstructive procedures. Here, porcine coronary arteries are decellularized, which destroys the extracellular matrix structure, leading to the decrease of vascular strength and the increase of vascular permeability. A bilayer tissue-engineered vascular graft (BTEV) is fabricated by electrospinning poly(l-lactide-co-carprolactone)/gelatin outside of the decellularized vessels and functionalized by immobilizing heparin, which increases the biomechanical strength and anticoagulant activity of decellularized vessels. The biosafety and efficacy of the heparin-modified BTEVs (HBTEVs) are verified by implanting in rat models. HBTEVs remain patent and display no expansion or aneurism. After 4 weeks of implantation, a cell monolayer in the internal surface and a dense middle layer have formed, and the mechanical properties of regenerated vessels are similar to those of rat abdominal aorta. Therefore, HBTEVs can be used for rapid remodeling of small-diameter blood vessels.