Small-Diameter Vessels Reconstruction Using Cell Tissue-Engineering Graft Based on the Polycaprolactone

Polycaprolactone (PCL) is widely applied for the construction of small-diameter tissue-engineered vascular grafts (TEGs) due to its biomechanical properties, slow degradation, and good biocompatibility. In the present study the TEG based on a tubular scaffold seeded with smooth muscle aortic cells (SMCs) in a rat abdominal aorta replacement model was tested. Polyester tubular scaffolds were generated by thermally induced phase separation and seeded with rat SMCs. To track the implanted SMCs in vivo, cells were labeled with superparamagnetic iron oxide nanoparticles (SPIONs). Histological evaluation of the migration of autologous endothelial cells (ECs) and formation of the endothelial lining was performed 4, 8, and 12 weeks after graft interposition. TEG demonstrated a high patency rate without any complications at the end of the 12-week period. The migration of ECs into the lumen of the implanted TEG and formation of the cell monolayer were already present at 4 weeks, as confirmed by histological analysis. The architecture of both neointima and neoadventitia were similar to those of the native vessel. SPION-labeled SMCs were detected throughout the TEG, indicating the role of these cells in the endothelization of scaffolds. The SMC-seeded scaffolds demonstrated improved patency and biointegrative properties when compared to the acellular grafts.