Commercially Available Media for Flushing Extracorporeal Bioartificial Liver Systems Prior to Connection to the Patient's Circulation: An in vitro Comparative Study in Two and Three Dimensional Porcine Hepatocyte Cultures

Extracorporeal bioartificial liver (BAL) systems based on hepatocytes need to be flushed before clinical application, as hepatocyte culture media are not approved for medical use. Commercially available 0.9% NaCl solution and hemofiltration solution (both supplemented with 10% human albumin) were investigated in vitro to test their potential to wash BAL systems with minimal stress for the cultured hepatocytes. After a 2 hour incubation, the lidocaine metabolising capacity and release of liver enzymes were assessed. As hepatocytes have been cultured in bioreactors in either two or three dimensional cell configurations, we tested the media in respectively hepatocyte monolayers cultures and in our newly developed bioreactor in which hepatocytes reorganise as small hepatocyte aggregates. The three dimensional hepatocyte cultures tolerated both media well, and no significant differences were seen compared with hepatocytes cultured in Williams' E (reference hepatocyte culture medium). The two dimensional hepatocyte cultures tolerated the supplemented hemofiltration solution and the reference medium equally well, but the condition of the porcine hepatocytes monolayer cultures was significantly impaired when incubated with the supplemented physiological saline solution. In conclusion, as a supplemented physiological saline solution may have detrimental effects on the condition of the hepatocytes, the more complex hemofiltration solution (bicarbonate buffered, glucose, essential minerals) was considered the better alternative for flushing bioartificial liver systems.