Scaffolds with a Tunable Nonlinear Elastic Region Using a Corrugated Design

Abstract

Elastin is the main component of arteries and is responsible for their high‐elastic high‐strain capacity. The biomechanics of biological tissues typically display a stress–strain curve characterized by a sigmoidal shape that has an initial region with low stress and high strain. Studies aimed at mimicking such biomechanical behavior focus on improving the synthesis of elastin or replicating elastin behavior, which proves to be a continuous challenge. Alternatively, scaffolds' architecture can potentially mimic the sigmoidal stress–strain curve of tissues. Hence, the aim of this study was to replicate the stress–strain curve of a carotid artery using a tailorable corrugated design. Results showed that the corrugated design unfolded during extension without generating significant stress and displayed a sigmoidal stress–strain curve that could be controlled depending on the corrugation features. Editing the amount of fibers resulted in a different Young's modulus, while the amplitude of the fibers and the amount of repeating units influenced the initial nonlinear region of the stress–strain curve. Scaffolds made of poly(ε‐caprolactone) (PCL) and poly(ethylene oxide terephthalate)/poly(butylene terephthalate (PEOT/PBT) were compared to determine the applicability of the design principles to different biodegradable polymers that normally do not have the same biomechanical behavior of soft tissues like arteries. The optimized designs had a similar stress–strain curve within the physiological range as porcine arteries. The corrugated design can serve as a biomimicry approach for vascular grafts or an alternative to vascular stents.

Keywords

• four‐axes additive manufacturing
• mechanical characterizations
• vascular tissue engineering