Alginate-encapsulated human hepatoma C3A cells for use in a bioartificial liver device - the hybrid-MDS

Purpose: The aim of this study was to encapsulate C3A cells into alginate microcapsules with an average diameter of <= 100 mu m, thus enabling them to be recirculated in a bioartificial liver device based on MDS (Microsphere-based Detoxification System) technology. The microcapsules have to be permeable for essential proteins such as albumin. Methods: C3A cells were encapsulated using alginate. The resulting alginate beads were coated with poly(diallyldimethylammoniumchloride) (pDADMAC) and poly(sodium-p-styrenesulfonate) (pSS). Their mechanical stability was tested by recirculation of the microcapsule suspension, while their permeability was determined by reverse-size exclusion chromatography and by the use of a confocal laser microscope. The metabolic activities of encapsulated C3A cells were compared to freely growing adherent C3A cells in static cultivation models. The metabolic functionality of encapsulated C3A cells in static conditions was compared to encapsulated C3A cells in a dynamic model. Results: The mean diameter of the resulting microcapsules was 86 mu mu m. Our experiments show that these microcapsules were permeable for albumin and the high flow rate of 600 ml/min in a dynamic model has no influence on the survival and the metabolic activities of the encapsulated cells during the tested time of 24 hours. Conclusions: Alginate microcapsules containing C3A cells can be used to produce albumin and growth factors in a bioartificial or hybrid liver support system. Thanks to their small diameter, the microcapsules in suspension can be recirculated in the MDS. (Int J Artif Organs 2009; 32: 769-78)