Work

Experimental study of TPU and SEBS additively manufactured leaflets for novel aortic valve polymer TAVI prosthesis

Year: 2026

Type: article

Abstract: Background and Objective: Transcatheter valve implantation is a cutting-edge technology for high and low risk patients with aortic stenosis. Bioprosthetic valves are limited due to several disadvantages as a long-term durability and structural valve degeneration. Polymeric aortic valve leaflet devices represent state-of-the-art technology to overcome limitations of bioprostheses. Nevertheless, more recent biocompatible and biostable polymers have revealed a significant potential. Additionally, 3D additive manufacturing opens new paths for patient-specific design of biomedical implants. Flexible polymers may not only mimic native aortic valve, but also may improve long-term durability. Polyurethanes and styrene polymers are promising materials for modern polymer valves. Nevertheless, mechanical properties of additive manufactured TPU or SEBS leaflets are not properly studied. Methods: Experimental study of TPU and SEBS samples and aortic valve leaflets for novel aortic valve polymer TAVI prosthesis is presented. Tensile tests and compression tests of three types of FDM-printed samples with various filament alignments (axial alignment, transversal alignment, diagonal alignment) were performed. The results of tests confirmed that longitudinal axial alignment achieve a maximum stress compared to transversal and diagonal directions. Compressive tests of TPU and SEBS 3D-manufactured aortic valve leaflets with digital image correlation technology were performed. Young's modulus and Poisson's ratio were evaluated. Moreover, parameters of constitutive models were found. Results: The TPU tensile specimen exhibits the highest stress/strain values at a speed of 100 mm/min, regardless of the filament alignment pattern. Slightly lower results are observed at a speed of 50 mm/min, which is likely associated with a wide range of plastic deformation. In the case of SEBS, a different pattern is observed: at 500 mm/min, it demonstrates high resistance to fracture, unlike TPU. A comparison of TPU and SEBS specimens at the same speeds and with the same alignment, based on maximum stress values, shows a minimal difference of 4% with the axial alignment at a speed of 50 mm/min; however, when comparing strains, the difference increases to 90%. The results of the compression experiment on aortic valve specimens made of TPU and SEBS at a speed of 30 mm/min showed that TPU force values for is considerably lower (4% of the maximum case), while for SEBS the spread increases to 20% of the maximum case. Conclusion: SEBS aortic valve leaflets were shown to be stiffer than TPU. It can be a step for choice of stiffer/softer leaflets for patient-specific device. The proposed approach can help manufacturers in elaboration and manufacturing of new TAVI polymer devices design made of TPU and SEBS polymers for clinical applications.

Source: Frontiers in Bioengineering and Biotechnology

DOI: 10.3389/fbioe.2026.1959014