ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

(Wanless, 1999). This low value could bring the hepatocytes to the required standard of
viability and function. In vitro, hepatocytes showed performance over a range of inlet
oxygen partial pressure from 75 to 380 mmHg, and being problematical with lower and
higher inlet oxygen partial pressure.
The results indicated that a silicone rubber membrane of Dm of 16x10 -5 is the best choice
for the outer membrane to ensure cells are oxygenated. The model predicted that the cells
in the annulus could be oxygenated similar to those found the native liver even at high cell
density (figure 7.9, 7.10a and 7.11a). Previous experimental studies showed that the
hepatocytes become functionally impaired below 2 mmHg. At Vmax=100nmol/(cm 3 s) and
silicone rubber of Dm=16x10 -7 (figure 7.11b), the model predicted values of PO2 in the cell
compartment less than 1mmHg over the entire axial length for pG of 40-150mmHg. When
Vmax was 25nmol/(cm 3 s), the results showed (for Dm=16x10 -7 ) the annulus PO2
decreasing from 6, 4.2 and 3.5 mmHg at entryto 1.2, 0.5 and 0.3 (PG = 150, 70, 40 mmHg,
respectively) and remains constant for the next 50% axial length. This decrease in the
annulus PO2 may be caused by initial increase in the cells OCR whereas plasma enters the
annulus for detoxification.
7. CONCULOSION
FIF bioreactor for hepatocytes was developed. This bioreactor has a separate integral
oxygenation in the outermost compartment by the creation of a third space namely
compartment C. This integral oxygenation compartment can easily oxygenate the cells in
the annulus to levels higher than 2 mmHg; ensuring that the cells are functional and viable.
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