Performance of various 3D-printed monolith geometries as an alternative to expanded bed adsorption for protein...

Here, we compare the performance of various three-dimensional-printed Monolith Adsorption (PMA) columns designed from a triply periodic minimal surface geometry, the Schoen gyroid. The structures examined had designed hydraulic diameters between 203 and 458 µm and voidages of 40%-60%. We compare column efficiency, porosity, static binding capacity and dynamic binding capacity for various load volumes and flow rates. The results show that all structures allowed efficient passage of yeast cells (>97%) over a wide range of interstitial velocities (191 to 1911 cm/h) while maintaining a low pressure drop (<0.1 MPa). The structure with a voidage of 40% and a hydraulic diameter of 203 µm showed the best performance in all aspects evaluated. Bovine serum albumin (BSA) recoveries for all structures (27%-91% when the loaded volume was 180 mL) were significantly affected by hydraulic diameter, mean channel wall thickness, velocity and voidage. Moreover, biomass addition resulted in a decrease in BSA recovery, which became more obvious at high velocities. However, this did not lead to a dramatic reduction in saturated binding capacity, significant changes in axial dispersion, or blockage of channels and could be compensated for by recirculation of the feed, even at high velocity. PMA thus potentially provides an appealing alternative to Expanded Bed Adsorption, retaining the latter's advantages, while eliminating fluidization issues and minimizing both processing time and buffer consumption.