Application of subcutaneous extracellular matrix to prepare bilayer heparin-coated polycaprolactone/decellularized small-diameter vascular graft for tissue regeneration

In clinical practice, the demand for functional small-diameter vascular grafts continues to increase. In this study, a decellularized aorta artery was inserted into a poly(caprolactone) (PCL) vascular scaffold for self-assembly in-vitro to create a hybrid scaffold. The hybrid scaffold was then implanted subcutaneously into the dorsal flanks and the subcutaneous extracellular matrix was applied for bilayer adhesion. After decellularization, the hybrid scaffold was coated with heparin to prepare a bilayer tissue-engineered vascular graft (BTEVG). The BTEVG exhibited enhanced biomechanical properties compared with those of decellularized tissue. The bilayer scaffold remained patent and displayed no expansion or aneurysm after implantation at 2 months. Endothelial cell formation was observed on the neointimal surface. In the neointimal, decellularized tissue in the inner layer inhibited smooth muscle cells proliferation and neointimal hyperplasia of BTEVG. M2 macrophage cell proliferation in the neointimal may inhibit vascular smooth muscle cell proliferation. Although the PCL-H scaffold demonstrated calcification formation, no calcification was found in the BTEVG. Therefore, BTEVGs can be applied for rapid remodeling of small-diameter blood vessels.