Microfluidics for Bioartificial Livers- How Semiconductor Technology Can Improve Biomedical Devices

Microfluidics for Bioartificial Livers- How Semiconductor Technology Can Improve Biomedical Devices


Bioartificial Liver (BAL) is a term for medical devices designed to replace natural liver functions. The idea behind the use of artificial livers is to either externally support an injured liver to recovery or bridge a patient with a failing liver to transplantation. Central to all BAL systems is a bioreactor for culturing liver cells. The main function of this reactor is to provide a cell adhesion matrix and supply the necessary nutrient solution. A high cellular oxygen uptake rate combined with low solubility in aqueous media makes oxygen supply to the liver cells the most constraining factor in current reactor designs.
Parallel-plate geometry BALs promise high efficiency for blood detoxification and liver metabolism. These devices can be manufactured in highly parallel fashion using semiconductor technology with dimensions close to those found naturally in the liver. However, due to the specific flow regime at this size-scale oxygen depletion in the medium remains a major problem.
In this seminar I will discuss the current research to overcome transport constraints in parallel-plate BAL devices. Custom oxygen concentration on the channel surface can be generated by adjusting channel geometry and thus prevent cell death along the channel length. After introducing the underlying transport model, I will describe how semiconductor technology is used for the fabrication of a prototype fluidic device. To evaluate the model, oxygen sensors are integrated into the bioreactor and used to measure in-situ dissolved oxygen concentration. Results demonstrating the applicability of the sensors and system scale-up will be shown.