Abstract

A pump-free Microfluidic 3d Perfusion Platform for Efficient Generation of Human Stem Cell Derived Hepatocytes

Yi-Chin Toh, Assistant Professor, National University of Singapore

Current microfluidic liver models utilize primary human hepatocytes, which are limited by cell number and batch-to-batch variation. Human stem cell-derived hepatocytes offer an alternative cell source although their efficient differentiation and maturation in a microfluidic platform has not been demonstrated. We have developed a simple and robust microfluidic 3D perfusion platform for the efficient generation of stem cell derived hepatocytes. The device contained a micropillar array to immobilize cells three-dimensionally in a central cell culture compartment flanked by two side perfusion channels. Pump-free constant perfusion flow was achieved by sustained gravity driven flow from two horizontally-orientated media reservoirs placed at differential heights that could be controlled by a 3D printed manifold. We tailored the device for hepatocyte cultures by using computational fluid dynamics simulation to estimate the height difference needed to achieve different perfusion flow rates, which were validated by experimental flow rate measurement using micro-particle image velocimetry. To demonstrate that the pump-free 3D microfluidic perfusion device can support the generation of human stem cell derived hepatocytes, we performed on-chip differentiation of HepaRG cells, a human bipotent stem that can differentiate into hepatocytes and biliary cells, for up to 14 days. The pump-free 3D microfluidic device potentially offers a simple and robust platform to develop highly functional in vitro liver models incorporating human stem cell derived hepatocytes.