Abstract

A Novel Vertical Flow Bioreactor for Perfusion Culture

Liang Zhu, Student, National University Of Singapore

Our lab was the first of its kind to prove mechanical compaction may enhance hepatic function and polarity. In order to achieve high throughput and control, the working prototype was optimized to provide a promising platform for drug testing purposes. Perfusion cultures of hepatocytes have been widely used in various applications, including bioartificial liver (BAL), therapeutic development, tissue engineering and drug toxicology testing.1–3 Our previous lab publication was the first of its kind to experimentally prove that mechanical compaction may enhance hepatic function and polarity.4 In order to make a scalable and controllable system based on the findings, a vertical flow bioreactor integrated with a membrane as a shear stress filter is reported here. The design may be scaled up from a single or double well design, to a maximum 24-well plate. The micro pores on the shear stress filter membrane may build up pressure in the cell culture chamber to generate compaction on the hepatocytes, which is controllable by a syringe pump. The bioreactor adopts an open-cap design for an easy harvest of cells for imaging and assays, while the large culture area accommodates enough cell number per data point to facilitate drug testing applications. In our working prototype, the perfusion condition was optimized on primary rat hepatocytes for an improved hepatic function. It was shown that the albumin and urea production when cultured with 0.1mL/hr flow rate was higher than those under 0.036mL/hr and 0.011mL/hr perfusion or static culture. The morphology of 0.1mL/hr was found to keep more cuboidal shape than other flow rates. In conclusion, the novel vertical flow bioreactor provides a scalable in vitro culture system to enhance hepatocyte function over conventional static culture and may be a promising platform for drug testing purposes.