Fabrication and Characterization of Electrospun Bi-Hybrid PU/PET Scaffolds for Small-Diameter Vascular Grafts Applications.

In spite of advances have been made during the past decades, the problems associated with small-diameter vascular grafts, including low patency and compliance mismatch and in consequence of that thrombosis, aneurysm and intimal hyperplasia are still challenges. To address these problems, net polyurethane (PU) and poly (ethylene terephthalate) (PET) polymers and hybrid PU/PET were electrospun to create three different types of small-diameter vascular scaffolds due to their unique physicochemical characteristics: PU, PET, and novel hybrid PU/PET scaffolds. The results show that the PU and PET composite can improve the mechanical properties of the tissue-engineered vascular scaffolds in the range of the native vessels where the non-cytotoxicity characteristic of these well-known polymers is still immutable. The compliance and stiffness factor of the fabricated hybrid scaffolds were 4.468 ± 0.177 and 22.718 ± 0.896%/0.01 mmHg, respectively, which were significantly different with that of the net PU and PET electrospun scaffolds. Other properties such as ultimate tensile stress (UTS) (3.56 ± 1.21 MPa) were also in good accordance with the native vessels. Furthermore, FT-IR analysis testified the presence of both PU and PET in the hybrid scaffolds. Overall, we were able to fabricate a hybrid scaffold as a small-diameter vascular graft that mechanically matched the gold standard of blood vessel substitution.