Preparation and evaluation of polymer-coated adsorbents for the expanded bed recovery of protein products from particulate feedstocks

Use of PAT principles for the open‐loop control of laboratory and pilot‐scale chromatography columns

“…15 It should be noted that the use of expanded beds for recovering and purifying biological products is limited at present by the lack of appropriate resin particles and despite recent advancements in this field, such as pellicular adsorbents which offer the potential for high uptake and desorption rates, issues of adsorbent aggregation (leading to the collapse of beds) and fouling by cells, cell debris, proteins and nucleic acids still need to be resolved. 16 Although washing steps can be used to eliminate impurities, these can be time-consuming and require large volumes of buffer and furthermore, validation of resincleaning protocols can be challenging and expensive. 16 For these reasons, EBA has not been widely adopted at industrial scale, although the viability of the method has been demonstrated for a wide range of feedstocks, including bacterial, yeast and mammalian cell cultures as well as milk sources.…”

In situ modification of chromatography adsorbents using cold atmospheric pressure plasmas

“…This is because these species are often as large as, or larger than, the pores of most conventional chromatographic media; thus their adsorption is confined to the exterior surface of the adsorbent, resulting in exceptionally low target binding capacities per unit volume. [8][9][10][11] New types of beaded chromatography adsorbents featuring two or more distinct functional regions spatially separated from one another within the same support bead have been the subject of a handful of research reports since 2002; 5,[12][13][14][15][16][17] the most promising of these describing the manufacture and testing of bi-layered bi-functional supports comprising ion exchange (IEC) functionalized cores surmounted by outer size excluding (SEC) layers. 5,[13][14][15] The main attraction of the bi-layered SEC-IEC support architecture ( Fig.…”

Surface modification of chromatography adsorbents by low temperature low pressure plasma

“…The present study concerns the simplest multi-layered multi-functional support design one can envisage, 30 namely one featuring just two differently functionalised layers -an inert outer size excluding layer and inner ion exchange functionalised core. The benefits of bi-layered size exclusion chromatography -ion exchange chromatography (SEC-IEC) beaded support designs have been clearly demonstrated in the context of 'nanoplex' purification [7,8], fluidised bed separation of organic acids [9,10] and expanded bed adsorption of proteins [11,12]. The important findings from these studies, inherent flaws in the methods employed thus far to manufacture bi-layered SEC-IEC hybrids, and identification of a simple and effective solution 5…”

“…The polyacrylic acid layer was penetrable by small molecules 5 such as the target, shikimic acid, but not to proteins, and repelled much larger negatively [10]. Most 25 recently, Jahanshahi and co-workers [12] applied similar methods to laminate commercial (STREAMLINE DEAE, CM HyperZ) and prototype expanded bed support materials with 2% agarose. These authors made similar claims concerning the benefits of their shielded adsorbents, namely reduction in fouling/inter-particle cross-linking and improved bed stability in a crude particulate containing feedstock (20% w/v yeast homogenate), plus several more, 30 such as improved washing efficiency, reduced buffer consumption, shorter operating cycle times, improved purity and clarity of eluted target proteins.…”

“…Although Jahanshahi et al [12] employed a more sophisticated three phase emulsification manufacturing process than that described by Viloria-Cols and co-workers [10], much thicker agarose coats were cast in their work. Layer thickness was greatest on smaller core particles.…”