Human galactosylated membrane bioreactor for the long-term maintenance of liver specific functions

In recent years the use of polymeric membranes as substrate for cell culture is growing for their characteristics of stability, biocompatibility and selectivity [1,2]. The improvement of liver cell-membrane interactions can be achieved by surface modification with defined molecules that can mimic the external cell environment. Membrane surfaces functionalised through plasma enhanced chemical vapor deposition (PE-CVD) and subsequent immobilisation of biomolecules could elicit specific cellular responses in terms of adhesion, growth and cellular functionalities [3]. Galactose-conjugated surfaces have been proposed as alternatives for hepatocyte cultures due to specific interactions between the galactose moiety and the asyaloglycoprotein receptor present on hepatocyte cytoplasmatic membrane. In this paper we explored the ability of galactosylated Polyethersulfon (PES) membrane bioreactor to support the long-term maintenance of liver specific functions of human hepatocytes. The stability of the coating and the effective immobilization of galactose on PES membrane was investigated and characterised. We also studied the effect of the interleukin 6 (IL-6), as mediator of inflammatory response, on metabolism of the hepatocyte cultured in the bioreactor, in order to investigate the production of acute phase proteins, such as albumin, fetuin and C reactive protein (CRP) as negative and positive proteins of acute phase.