Interaction of mammalian cell culture broth with adsorbents in expanded bed adsorption of monoclonal antibodies

Compatibility of column inlet and adsorbent designs for processing of corn endosperm extract by expanded bed adsorption

“…Second, interaction of the biomass with the adsorbent base matrix or ligands may interfere with product adsorption and expanded bed hydrodynamic stability. This detrimental phenomenon occurs for a variety of cell/resin combinations (Fernandez-Lahore et al, 2000;Feuser et al, 1999a;1999b;Lin et al, 2001). Most notably, bacterial and yeast cells complex with anion exchange resins, while hybridoma cells do so with cation exchangers.…”

Impact of operating variables on the expanded bed adsorption of Saccharomyces cerevisiae cells using a concanavalin A derivatized perfluorocarbon

“…The relative importance of the parameters characterizing expanded-bed systems for protein recovery such as equilibrium and kinetics of interaction, liquid-and solidphase dispersion, and solid-and liquid-phase mass transport (Thömmes, 1997) are considerably altered where particles of the order of micrometers rather than nanometers are to be separated. The multivalent nature of the interaction between cell surface antigens and immobilized receptors also complicates the picture by enabling adsorbent-adsorbent interactions of the sort that can hinder protein chromatography (Fernandez-Lahore et al, 1999Feuser et al, 1999). Here we try to elucidate how the operating parameters for a particular model system influence the process performance for an expanded-bed cell adsorber.…”

Surface modification of chromatography adsorbents by low temperature low pressure plasma

“…Plasma modification could thus be an 'add on' treatment to already established packed bed and EBA chromatography adsorbent manufacturing processes. 30 Careful optimization of plasma treatment parameters has not been the focus of this work, but is clearly a prerequisite prior to establishing robust methods for large scale preparation of bilayered chromatographic supports with non-adsorptive surfaces. Finally, the extension of low temperature low pressure plasma treatments disclosed here for Q HyperZ, to other beaded chromatographic support materials, and selection of alternative coatings tailored to specific 5 functions (i.e.…”

“…The selectivity of 'surface versus core' modification imparted to Q HyperZ by the various plasma treatments was evaluated in static and dynamic binding studies employing appropriate probes, i.e. 30 plasmid DNA, sonicated calf thymus DNA and bovine serum albumin. In static binding studies performed with adsorbents that had been exposed to plasmas at the 5 g scale (25 g per…”

“…Despite rapid 10 initial successes, the progress of EBA into industry has been slow, and confidence in the technique is waning [25,26]. Perhaps the greatest technical problem affecting EBA is the physical cross-linking of neighbouring adsorbent particles by biomass or large colloidal molecules (especially nucleic acids) present in crude feedstocks, which leads to gross breakdown/collapse of the structure of the expanded bed and consequent loss of 15 chromatographic performance [18,[25][26][27][28][29][30][31][32][33][34]. Attempts to relieve problems of inter-adsorbent particle cross-linking in EBA systems by chemically or mechanically conditioning the crude feedstock prior to application have been at best only partially successful [26,32,33].…”