Enhanced Oxygen Delivery to Primary Hepatocytes within a Hollow Fiber Bioreactor Facilitated via Hemoglobin-Based Oxygen Carriers

Abstract

The production of a fully functional bioartificial liver assist device (BLAD) would greatly enhance available treatment options for patients suffering from acute liver failure. Currently, inadequate oxygen provision to hepatocytes seeded within hollow fiber bioreactors hampers development of a viable hollow fiber-based BLAD. Experimentally, oxygen provision to primary rat hepatocytes cultured within hollow fiber bioreactors was measured, it was observed that supplementation with an oxygen carrier (bovine red blood cells at approximately 2% human hematocrit) did not significantly improve oxygenation compared to the absence of an oxygen carrier. Therefore, an oxygen transport model of an individual hollow fiber within the bioreactor was developed and simulated (up to approximately 10% human hematocrit) to more fully examine the effect of oxygen carrier supplementation on oxygenation within the bioreactor. The modeling analysis, supported via the experimental results, was utilized to predict optimal bioreactor operating conditions for the delivery of in vivo-like oxygen gradients to cultured hepatocytes in clinically relevant settings.

Perfluorocarbon facilitated O2 transport in a hepatic hollow fiber bioreactor

“…The transport of O 2 is then limited by the O 2 demand of the hepatoma cells, thus, the O 2 flux cannot infinitely increase but instead reaches a plateau at a relatively higher pO 2,in . Previous studies on O 2 transport in HF bioreactors showed that supplementation of hemoglobin-based oxygen carriers (HBOCs) in the cell culture media greatly enhanced O 2 transport through the HF membrane (Sullivan and Palmer, 2006;Sullivan et al, 2007). For HBOCs with varying O 2 affinity, the O 2 flux rises sharply with increasing pO 2,in and reaches a plateau at pO 2,in ¼ $60 mm Hg in a HF with the same dimensions and hepatocyte cell density used in this work (Chen and Palmer, 2009).…”

Hemoglobin Regulates the Metabolic, Synthetic, Detoxification, and Biotransformation Functions of Hepatoma Cells Cultured in a Hollow Fiber Bioreactor

“…This has been demonstrated by extensive simulation work conducted in our lab. [19][20][21][22] Recent experimental studies also showed that supplementation of bovine red blood cells (bRBCs) into the circulating cell culture medium improved O 2 transport to cultured C3A cells in a HF bioreactor. 23,24 In the presence of bRBCs, the molar ratio of lactate production to glucose consumption of hepatoma cells was remarkably reduced, while albumin synthesis increased substantially, which indicates highly efficient cellular metabolism and synthetic function.…”

A theoretical method to improve and optimize the design of bioartificial livers

“…In designing a HF-BAL, three main constraints exist on the system: (i) the cartridge must contain a cell loading of 10-40% of the liver's mass (Sullivan et al, 2007) or approximately to 10-40 billion cells for an average adult; (ii) the hollow fibers must supply the cells with adequate nutrition: oxygen is generally considered to be the main limiting nutrient in hollow fiber bioreactor (HFBR) applications (Piret and Cooney 1991); (iii) the device is limited in the range of blood/plasma flow rates that can be supplied; this is generally between 100 and 300 mL/min due to technical and rheological constraints (Pless and Sauer 2005).…”