Computationally Designed 3D Printed Self-Expandable Polymer Stents with Biodegradation Capacity for Minimally Invasive Heart Valve Implantation: A Proof-of-Concept Study

Abstract

The evolution of minimally invasive implantation procedures and the in vivo remodeling potential of decellularized tissue-engineered heart valves require stents with growth capacity to make these techniques available for pediatric patients. By means of computational tools and 3D printing technology, this proof-ofconcept study demonstrates the design and manufacture of a polymer stent with a mechanical performance comparable to that of conventional nitinol stents used for heart valve implantation in animal trials. A commercially available 3D printing polymer was selected, and crush and crimping tests were conducted to validate the results predicted by the computational model. Finally, the degradability of the polymer was assessed via accelerated hydrolysis.

Stent’s Manufacturing Field: Past, Present, and Future Prospects

“…AM refers to processes used to create a 3D object in which layers of material are formed under computer control. The use of this technology for stent manufacture is recent [57][58][59][60][61][62][63][64] and could be a really interesting method to produce stent. Mainly, there are four different AM technologies in the stent field.…”

Additive Manufacturing in Vascular Stent Fabrication

“…Also in 2017, Cabrera et al [40] of Eindhoven University of Technology, Netherlands printed the vascular stent using fused deposition modeling (FDM) technology. The printing device is BakerBot by Replicator, and the printed material is thermoplastic copolyester elastomer (TPC).…”

Multifaceted polymeric materials in three‐dimensional processing (3DP) technologies: Current progress and prospects

“…Biodegradable stents offer the potential to improve long‐term patency rates by providing support for the artery to heal, in addition to potentially remove the risk of late thrombosis and allowing for restoration of natural vasomotion . Polymer stents for minimally invasive heart valve applications have to meet a set of criteria such as sufficient radial force, maintain their position after deployment, and limit plastic deformation to secure initial valve functioning until host body integration . Guerra and Ciurana reported the use of PCL stents with the results showing that the dimensional precision is strongly influenced by printing temperature and flow rate, while the average expansion ratio of 320% and around 22% of recoil ratio showed good radial behavior.…”

“…[129][130][131] Polymer stents for minimally invasive heart valve applications have to meet a set of criteria such as sufficient radial force, maintain their position after deployment, and limit plastic deformation to secure initial valve functioning until host body integration. 132 In pharmaceutics, some polymers have also been used as matrices or carriers in drug administration, especially 3D printed tablets. These include PLA, 138 PVA, 139 polyvinylpyrrolidone, 140 hydroxypropyl methylcellulose acetate succinate, 141 ABS, 142 and poly(ε-caprolactone) (PCL), 143,144 Naturally occurring polymers show better cell affinity and structural similarity to the native tissue environment than those of synthetic materials; thus, they can stimulate cellular behaviors, including migration, proliferation, differentiation, and maturation.…”