Polymer fibers – strong potential for high productivity downstream processing
Increasing demands for biopharmaceuticals as well as cost constraints and higher titers require high throughput and productivity of downstream processing. High throughput with conventional adsorbents is, however, limited: Conventional packed beds are filled with spherical porous adsorbents particles. Due to the structure of these particles, adsorption is limited by diffusion. Additionally, they have high packing densities and high pressure drops. Therefore, high throughput at high flowrates is not feasible.
Polymeric fibers can serve as chromatography support. Fibers show high capacities and low pressure drops at high flowrates. Furthermore, they have low manufacturing costs and their surface can be modified in a number of varieties. To allow a better understanding of the processes on the fiber-based adsorbents, a mechanistic model was realized using ChromX.
Processes with polymer fibers as adsorbents can now be modelled. A transport-dispersive model in combination with a steric mass action isotherm was utilized. The model had to be calibrated from few column experiments and was successfully applied to simulate tracer, linear gradient elution as well as breakthrough experiments. In this way, all relevant transport and binding mechanisms could be understood, which allowed a better understanding of process and quality.