152 Three-Dimensional Printing Bespoke Polycaprolactone Tracheal Splint for Treatment of Tracheomalacia

Abstract

Abstract Aim Tracheomalacia can be a fatal airway disease with limited treatment options. Three-dimensional (3D) printing has led to various patient-specific tracheal stents and splints. However, these are limited by mismatched stiffness and resulting granulation tissue formation and fibrosis. We aimed to develop a non-toxic and biodegradable polycaprolactone expandable tracheal splint by 3D printing. By fine-tuning mechanical properties, we hypothesised that the splint would match the native trachea and accommodate tracheal growth in tracheomalacia patients. Method We designed splints consisting of concave topological patterns with varying angles and aspect ratios. Fabrication occurred using polycaprolactone filaments in a 3D fuse deposition modelling printer. Uniaxial tensile studies were performed on splints to assess Young’s Modulus, Toughness, Ultimate strain, Strength, and Poisson ratio. Splints displaying optimal mechanical properties were tested for human lung fibroblast cell viability, proliferation, and morphology. Results On a mechanical testing rig, uniaxial tensile studies confirmed that splint designs with smaller angles and negative Poisson ratios of up to strains of 25%, better mimicked mechanical properties of native human trachea, accommodating tracheal growth. In vitro studies using these tracheal splints demonstrated successful human lung cell proliferation with low cell toxicity. Conclusions This study characterised 3D printed bespoke tracheal splints with various 2D structures, showing mechanical properties that match the native trachea. However, in vivo studies investigating cellular interactions on our splint must be performed to further evaluate the ability for endogenous tissue formation.