BME.07 Perfusion Channel Creation through 3D Printed Micropatterned Gelatin Scaffold for Cholangiocyte Seeding

• Jameel Carey
• Huthaifah Khan
• Hari Shankar Manoj Vineetha
• Janet Quiroz
• Kemuel Roberts

Liver disease results in nearly 2 million deaths worldwide, with cirrhosis alone the 11th most common cause of death globally. Including progressive liver failure and cancers, the family of liver diseases account for almost 3.5 percent of all global deaths, with liver-related complications deeply affecting the larger percentage of the population afflicted with diabetes of any variety. As such, there is a comprehensive need for better, more accurate liver models which can help develop lifesaving drugs, as current animal-based models do not fully emulate the human response. One promising approach is the use of a 3D-printed micropatterned scaffold into which relevant cells will be implanted to generate a liver-like functional environment, requiring the integration of hepatocytes, vascular tissue, and – most importantly for this project – biliary compartments. Our objective was to implement the latter of the three – to design a method of reliably producing a channel of specific dimensions within the crosslinked gelatin scaffold interposing two micropatterned regions, through which media could be perfused at an appropriate rate and cholangiocytes seeded to form hepatic structures. On the basis of this, the team iterated through various approaches before settling on our current method, which involves the use of a device consisting of a platform for the gelatin to be 3D-printed, and a rail-mounted puncturing segment into which a standard-gauge needle could be loaded. Following puncturing, the entire device can be left stably in the crosslinking fluid, and media perfusion can occur smoothly by directly connecting tubing to the outer side of the attached needle. In order to ensure the device is autoclavable for sterile cell work and heavy enough to remain stationary in the crosslinking fluid, the team also iterated through several materials for the CAD modelling, including PLA plastic, non-medical grade resin, and finally aluminium. To test the functionality, our verification testing involved performing a full printing-puncturing-crosslinking cycle, followed by imaging under a microscope to test the size and uniformity of the channel, and a perfusion test with blue dye-stained water where flow rate, shear stress, media throughput and spread through the gel were measured. The results demonstrated that while we had to pick a different standard gauge in order to ensure a smoother flow profile, the channel production itself was extremely uniform and maintained the structural integrity of the gelatin scaffold reliably.