Immobilized Cell Culture
The properties of microcarrier beads used for cell immobilization are that they develop charged surfaces, either positive or negative charges, for example, DEAE sephadex (diethyl -aminoethyl type of cross-linked dextran) developed positive charges, polysysteine negative charges, gelatin beads slightly positive or negative charges. The beads require surface coating for adhesion of sufficient number of cells, because energy is required for cell adhesion. In addition glass and ceramic materials are used as good carriers as they contain high surface energy.
In different types of bioreactors different materials such as glass spheres are packed for cell attachment. The materials increase surface area for cultivation of cells en masse. This type of bioreactor is called packed bed bioreactor. For a bioreactor of 100 liter capacity about 50 kg of 3 mm diameter spheres are used. This gives a total surface area of about 20m2.