Towards the Development of 3D-Printed Model of the Human Aorta: Comparison of Mechanical Properties of Biological and Polymeric Materials

The determination of mechanical properties of biological materials is a relevant and interdisciplinary topic of research. In this work we compared the stress–strain relationship of human thoracic aortic wall samples with polymeric 3D printing materials with vessel wall properties. Mechanical tests were performed on a standard test equipment (Instron 3365) in dogbone shaped samples. The physiological modulus of elasticity, the maximum modulus of elasticity, maximum stress and the deformation at the point of maximum stress were determined. The tests showed that mechanical failure consistently occurred in the middle region of the sample. Results of aortic samples obtained from two aortas (ao1 and ao2) showed a physiological elastic modulus of 0.68 ± 0.2 and 0.58 ± 0.4 MPa and maximum elastic modulus of 2.44 ± 0.3 and 2.18 ± 1.1 MPa, for ao1 and ao2, respectively. 3D printed samples of different material composition did not show a tensile stress in the physiological range with elastic modulus and maximum elastic modulus of 0.85 ± 0.04 and 0.95 ± 0.07 MPa, respectively. The results suggest the need of using a combination of materials or microstructures for modeling blood vessel wall mechanical properties.