Study of the Young's modulus and failure strength of binary polymer composite structures based on polyurethane based on stress-strain curve for tissue engineering vascular graft application

.The artery diseases such as the coronary arteries are of the important cardiovascular diseases. The autograft as a common surgical is the main treatment for this problem, but in many patients, the autografts are not. So, due to a large number of requirements, it needs to find suitable replacements for diseases of blood vessels. Tissue engineering at the nanoscale level is a promising approach to the design and fabrication of artificial blood vessels. Nanomaterial structures are highly contributive in tissue engineering vascular scaffolds (TEVS) due to their ability in mimicking the nanoscale dimension of the natural extracellular matrix (ECM) and the existing mechanical match between the native vessel and the scaffold. The aim of this research was developing and mechanically improving nano-fibrous composite scaffolds using blend electrospinning methods with different ratios of the polyethylene terephthalate (PET), polyurethane (PU) and polycaprolactone (PCL). The morphological and mechanical properties all structures were evaluated using SEM, FTIR and tensile properties. The neat and composite structures were completely intact with randomly oriented fibers and without any beads. Results showed that the average fiber diameter, porosity, stress and Young’s modulus changes’ range in composite structures (PCL/PU and PET/PU) obtained 343 ± 94 to 382 ± 83 nm, 58.6 ± 3.12 to 81 ± 1.7 %, 2.66 ± 0.39 to 19.05 ± 3.2 MPa and 3.18 ± 0.09 to 41.4± 3.31 MPa, respectively. The fabricated scaffolds and especially PET/PU structure exhibited suitable mechanical and biological properties and clinical requirements as a small-diameter vascular graft.