MICROCARRIER TECHNOLOGY, PRESENT STATUS AND PERSPECTIVE

Only a decade after Van Wezel introduced the first product made in mic rocarrier cultures on industrial scale at economically acceptable cost s, namely Inactivated Polio Vaccine (IPV), interest was taken in this revolutionary type of cell growth system. The basic idea was to develo p a culture system with equal potentials for control of environmental culture conditions and scaling up as the systems used in industrial mi crobiology. Although initially only positively-charged beads were used it soon became clear that negatively-charged or amphoteric materials such as proteins or amino acids polymerized to the surface were equall y useful. Eventually numerous different types of microcarrier were dev eloped. The second generation of microcarriers consisted of macroporou s beads providing increased surface area for cell attachment and growt h by external and interior space. Such microcarriers offer great poten tial for high cell densities and enhanced productivity for certain pro duction systems, especially recombinant CHO-cells. These carriers, whi ch not only provide possibilities for anchorage-dependent cells but al so for cells growing suspension, can be used in homogeneous bioreactor s as well as in fluidized or fixed-bed systems. Despite considerable i nvestments and research on the development and improvement of microcar riers one question is still open: is microcarrier technology still in its infancy or is it full-grown and is the basic idea realized? In thi s paper a general overview will be given of the present state of micro carrier technology and also of its perspectives.