Fabrication and characterization of a novel compliant small-diameter PET/PU/PCL triad-hybrid vascular graft

Nanomaterial structures are highly contributive in tissue engineering vascular scaffolds (TEVS) due to their ability to mimic the nanoscale dimension of the natural extracellular matrix (ECM) and the existing mechanical match between the native blood vessel and the scaffold as a vascular graft. The aim of this study was to develop and mechanically improve the nanofibrous triad-hybrid scaffolds with different composite ratios of polyethylene terephthalate (PET), polyurethane (PU), and polycaprolactone (PCL). The morphological, biological, mechanical, and biomechanical properties of the neat and hybrid structures were examined using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), tensile strength, compliance, burst pressure, MTT assay, and by implanting the specimens under rat skin to explore the immune system in vivo. The results showed that the fiber diameter and porosity changes in the triad-hybrid electrospun scaffold ranged within 388 ± 88 to 547 ± 89 nm and 56.60 ± 2.06% to 75.00 ± 1.94%, respectively. In addition, the changes in the tensile strength and force in the scaffolds were within the ranges 2.7 ± 0.44 to 5.27 ± 0.83 MPa and 2.68 ± 0.19 to 10.03 ± 0.75 MPa, respectively. Also, the compliance and burst pressure of the structures were reported as 4.05 ± 0.21 to 7.09 ± 0.49 and 1623 ± 329 to 2560 ± 121 mmHg, respectively. According to the MTT assay, high cell viability was observed on the triad-hybrid structures with a high percentage of PET when compared to that of PU. The findings of this research demonstrate that the PET/PU/PCL triad-hybrid vascular scaffold has enough potential to be used in vascular tissue engineering application. (paper)