Development of Thermoplastic Polyurethane Scaffolds for Vascular Tissue Engineering

Abstract Objective: The development of small-diameter vascular grafts remains an unresolved challenge in regenerative medicine due to the mechanical mismatch between commercial prostheses and native tissues, which leads to intimal hyperplasia and thrombosis. The aim of this work was to fabricate tubular scaffolds from thermoplastic polyurethane and to perform a comprehensive evaluation of their morphology, mechanical properties, leak-tightness, and cytocompatibility. Methods: Tubular scaffolds were fabricated by electrospinning using a rotating collector. Morphology was assessed via scanning electron microscopy (SEM). Mechanical properties were evaluated by tensile testing, and leak-tightness was tested using a hydrostatic pressure setup. Cytocompatibility was assessed using EA.hy926 cells: cytotoxicity was measured after 72 h, while cell adhesion and morphology were analyzed after 15 days of static culture and after 15 and 30 days of culture in a bioreactor. Results: SEM analysis revealed randomly oriented fibers with an average diameter of 0.97 ± 0.35 µm. Mechanical testing showed a Young’s modulus in the range of 0.8–1.2 MPa, comparable to native arteries (0.1–1 MPa), and elongation at break up to 500%. Leak-tightness was confirmed at pressures up to 220 mmHg. Cytotoxicity assessment on EA.hy926 cells showed cell viability exceeding 84% after 72 h. After 15 days of culture, cells formed a dense endothelial layer on the scaffolds, and after 30 days in the bioreactor, cell infiltration into the porous structure was observed. Conclusion: The obtained results indicate the promising potential of the developed thermoplastic polyurethane scaffolds for use as next-generation vascular implants..