Design and assembly of solid-phases for the effective recovery of nanoparticulate bioproducts in fluidised bed contactors

Practical recovery of nanoparticulate bioproducts from suspension feedstocks has been studied in batch, fixed bed and fluidised bed adsorptive contactors. The performance of five discrete configurations of adsorbent solid phase has been critically evaluated in the anion exchange recovery of mg quantities of BSA nanoparticles. These have served as surrogate size mimics of less easily sourced viral and plasmid gene therapy vectors, characterised by high value and a shortage of supply in quantities sufficient for research and development. Performance parameters of binding capacity, efficacy of washing, desorption efficiency and total cycle time were strongly influenced by the external and internal topographies of solid phases, together with the localised concentrations of interacting chemical ligands which modulate adsorption. In respect of a full operational recovery cycle, porous adsorbents developed for refined chromatographic fractionation of macromolecules, appear less suited overall than solid, non-porous particles, or solid particles coated with a shallow pellicle of active adsorbent material. Such findings have been confirmed in a detailed demonstration of the recovery of plasmid DNA (7.8 Kb) from chemical lysates of Escherichia coli.