Engineered small-diameter vascular graft with tailored degradation profile transform into a living blood vessel after implantation in a murine model.

Current vascular replacements available on the market often require frequent interventions. In situ tissue engineering (TE), which utilizes biodegradable grafts that transform into autologous vascular tissue at the implantation site, presents a promising solution to these limitations. In this study, electrospun small-diameter scaffolds (2 mm ø) composed of polycaprolactone (PCL) and polydioxanone (PDO), reinforced with a 3D-printed PCL anti-kinking coil, were implanted in a rat abdominal aortic replacement model. Grafts were explanted after 3 and 12 months, and the results were compared with native rat aortic vessels of similar age. The implanted grafts were evaluated for patency, extracellular matrix (ECM) formation, degradation, and remodeling. At 3 months, the grafts were partially resorbed and replaced by vascular neo-tissue due to the degradation of PDO nanofibers. By 12 months, nearly complete graft resorption was observed, with the newly formed vessel exhibiting structural and functional characteristics similar to the native aorta, including elastin deposition, contractile marker expression, and endothelial lining formation. No cases of dilation, rupture, or aneurysmal formation were observed. Patency of the implanted grafts was confirmed by OCT (≈100 %), comparable to native controls. This work employed a small animal model to illustrate the transformation of a synthetic, biodegradable vascular scaffold into a functioning, compliant neo-vessel in a rat aortic replacement.