The bioreactor devices serve as a container for embedded hepatocytes. The module enables mass transfer between patient’s blood and embedded hepatocytes through semi-permeable hollow fibers or membranes. Several types of bioreactors, such as hollow fiber cartridges, and parallel plate dialyzers, have been studied to date. Of these, hollow fiber bioreactors have received the most attention. Generally, hollow-fiver cartridges are used as hemodialyzers in clinical settings for treatment of kidney disease patients. During hemodialysis, blood flows in the lumen side (inside) of the hollow fibers, while dialysate flows into the extracapillary space (area outside the hollow fibers).