Development of a novel small diameter vascular graft based on an electrospun blend PET/PU scaffold: from fabrication to structural, mechanical, and in vitro evaluation

The development of small-diameter vascular grafts (SDVGs) remains a significant challenge and unsolved problem due to issues with compliance mismatch, thrombosis, and graft failure. This study explores electrospun blended scaffolds made from polyethylene terephthalate (PET) and polyurethane (PU), both Food and Drug Administration (FDA)-approved polymers, as potential candidates for small-diameter vascular applications. Nanofibrous scaffolds composed of blended PET and PU were fabricated using the electrospinning method. The morphological and chemical properties of the scaffolds were characterized by FE-SEM, porosity measurement, FTIR, and DSC. Comprehensive mechanical evaluations, including tensile strength, burst pressure, and compliance, were performed. Biocompatibility was assessed by examining cellular adhesion, proliferation, and viability on the scaffolds. For in vivo evaluation, the electrospun scaffolds were subcutaneously implanted in rats. The PET/PU blended scaffolds exhibited excellent physicochemical compatibility, with mechanical properties within the range of native small-diameter blood vessels (SDBVs). Burst pressure and compliance evaluations demonstrated the ability of the PET/PU blend to mitigate the compliance mismatch commonly observed in synthetic grafts. Additionally, the scaffolds supported strong human cell adhesion, proliferation, and high cell viability, indicating good biocompatibility. No signs of necrosis, calcification, severe fibrosis, inflammation, or foreign body granulomatous reaction were observed following subcutaneous implantation of the scaffolds. Electrospun PET/PU scaffolds offer promising mechanical and biocompatible properties for SDVGs applications. The ability to address compliance mismatch, combined with excellent cellular support, positions these scaffolds as a strong candidate for clinical use. However, further preclinical and clinical studies are necessary to validate their long-term safety, performance, and commercial viability.