title: Targeted oxygen delivery within hepatic hollow fiber bioreactors via supplementation of hemoglobin-based oxygen carriers.
abstract: Hepatic hollow fiber bioreactors are considered a promising class of bioartificial liver assist device (BLAD). Unfortunately, limited oxygen (O(2)) transport to hepatocytes within this device hinders further development. Hepatocytes in vivo (in the liver sinusoid) experience a wide range of oxygen tensions (pO(2) = 25-70 mmHg), which is important for development of proper differentiated function (zonation). Previously, we observed that bovine red blood cell (bRBC) supplementation of the circulating media stream enhanced oxygenation of cultured C3A hepatoma cells compared to a culture with no O(2) carrier (Gordon, J.; Palmer, A. F. Artif. Cells, BloodSubstitutes, Biotechnol. 2006, 33 (3), 297-306). Despite this success, the cells were not exposed to the desired in vivo O(2) spectrum (Sullivan, J.; Gordon, J.; Palmer, A. Biotechnol. Bioeng. 2006, 93 (2) 306-317). We hypothesize that altering the kinetics of O(2) binding/release to/from hemoglobin-based O(2) carriers (HBOCs) could potentially target O(2) delivery to cell cultures. High P(50) (low O(2) affinity) HBOCs preferentially targeted O(2) delivery at high inlet pO(2) values. Conversely, low P(50) (high O(2) affinity) HBOCs targeted O(2) delivery at low inlet pO(2) values. Additionally, inlet pO(2), flow rate, and HBOC concentration were varied to find optimal bioreactor operating conditions. Our results demonstrate that HBOCs can enhance O(2) delivery to cultured hepatocytes, while exposing them to in vivo-like O(2) tensions, which is critical to create a fully functional BLAD.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Jesse P
authors.initials: JP
authors.lastname: Sullivan
authors.forename: Andre F
authors.initials: AF
authors.lastname: Palmer
mesh_terms: D000818:Animals; D001703:Biophysics / Q000379:methods*; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D002417:Cattle; D045744:Cell Line, Tumor; D003198:Computer Simulation; D004912:Erythrocytes / Q000378:metabolism; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008962:Models, Theoretical; D010100:Oxygen / Q000737:chemistry*; D011312:Pressure; D015657:Respiratory Transport
chemical_list: D006454:Hemoglobins; D010100:Oxygen