A scalable method for the culture of cells in a fluidised bed bioreactor is disclosed wherein hepatocytes or other cells are encapsulated in alginate or an alternative matrix in the presence of bead density or buoyancy modifying additives such as glass beads. The encapsulation comprises seeding a matrix forming agent with cells, adding the density modifiers, streaming the mixture through a nozzle and cutting the stream into beads for polymerisation (e.g. JetCutter bead extrusion technology). Alginate encapsulated HepG2 cells comprising glass particles such that the beads are weighted to be buoyant in an upward current in human plasma are disclosed. Also disclosed is a chamber for a bio-artificial liver configured for perfusive culture and cryopreservation.
