Growth of insect and plant cells immobilized using electrified liquid jets
In many bio-processing laboratories, major focus has been placed on attempting to find cell culture methods which can increase the concentration of cells and cell products and permit costeffective large-scale production. Methods of animal cell culture have been developed (mainly for mammalian cells) and involve the use of hollow fibers, gel entrapment, ceramic cartridges and microcarriers . It is generally recognized that compared to microbial systems, large-scale mammalian cell suspension culture has been limited, to some extent, by relatively low cell densities. The concentration of extracellular proteins such as monoclonal antibodies and growth factors produced by this method is low and purification from growth media is difficult. The same problems are also encountered in insect culture. Inlow and co-workers , for example, reported maximum insect cell densities of 5.5 x 106 cells/mL in a spinner flask. Hink , working with T. ni cells, obtained maximum polyhedra (AcNPV) concentrations of ca. 2.2 x 108 polyhedra/mL medium at a cell density of 3.8 x 106 cells/mL medium (i.e. ca. 60 polyhedra/cell). Knudson and Tinsley , using S. frugiperda cells, reported 12-40 polyhedra (150-500 IFU)/cell.