3D printed polymers that mimic the mechanical properties of atherosclerotic blood vessels for training models: the advantageous degradation induced by UV radiation and hydrolysis.

Abstract

Background: Atherosclerosis is a chronic disease characterized by the narrowing and hardening of arteries that may induce serious complications and even sudden death. Percutaneous angioplasty is performed as the main treatment of atherosclerotic-based cardiovascular diseases, which are the leading cause of mortality worldwide. Patient-specific physical models of these vascular conditions would greatly assist percutaneous angioplasty medical training and planning. Such models must be composed of materials that accurately replicate the properties of tissues. However, this mimicking can be challenging due to the complexity and composition of atherosclerotic vasculature. As additive manufacturing allows the production of complex and personalized structures, it provides great potential for manufacturing those models. The application of additive manufacturing in this context is often associated with high production costs, mainly related to material synthesis. Commercial materials could break this limitation, but they are still misaddressed.

Methods: Therefore, this work intends to explore the use of three different commercial UV-curable resins to mimic the several types of atherosclerotic vessels. They were manufactured by vat photopolymerisation process, specifically the stereolithography (SLA) technology to mimic atherosclerotic vessels. The mechanical performance of materials and the influence of immersion in phosphate buffered saline (PBS) solution and irradiation with UV light, during different times, were evaluated. Dynamic tensile tests were conducted to study the fatigue resistance of materials under physiological loads.

Results: The results showed that immersion in PBS solution enhanced the dynamic mechano-stability. Likewise, irradiation with UV-C light was pointed out as an interesting strategy to adjust the hardness of materials, with the advantage of being a fast and low-cost approach.

Conclusion: Comparisons with the literature supported that all used materials are suitable for mimicking the mechanical properties of atherosclerotic vessels, specifically when previously immersed in physiological-simulated fluids, such as PBS.