Overview:
We propose to utilize 3D printing to design and develop a novel RV-PA conduit that increases its size via tailored self-unfolding triggered by flow and time so that fewer complications as well as surgeries are required to maintain and develop normal pulmonary blood flow from infancy to adulthood. It is envisioned that 3D printing will also allow for improved precision in patient customization and on-demand design changes to enable better functionality.
– We are developing 3D printing processes (fused deposition modeling) to 3D print shape-changing RV-PA conduits with FDA-approved materials such as Thermoplastic Polyurethane (TPU).
We anticipate that self- unfolding mechanisms and associated shape changes will result in operation of the conduits over longer periods of infant and child growth into adulthood.
In the R21 phase, we will design, fabrication, surface modification, and in-vitro testing of self-unfolding RV- PA conduits. We will first conduct printing parameter studies for 3D printing of FDA-approved materials for fabrication of RV-PA conduits with variable dimensions.
Simultaneously, we will utilize numerical simulations to determine design parameters that allow size changes and validate these using in-vitro tests for functionality and bio-compatibility.
In the R33 phase, we will upgrade our 3D printer and refine the RV-PA conduits to enable printing with better resolution and with fluoro-polymer inks to eliminate the need for surface modification. Finally, we will validate in- vivo operation using comprehensive hemodynamic evaluations and post-mortem gross-histological evaluation in a sheep model. We will analyze extracellular matrix formation, characterize endothelial cell function and white blood cell activation, and quantify immunohistochemistry for inflammation analysis.
– We are developing thermo-responsive inks for direct ink writing (DIW) to 3D print RV-PA conduits that can change their shape with varying temperatures.
