Nanoporous Silica Materials as Supports for Bioaffinity Separations
Proteomics and biotechnology are increasingly leading to exciting new pharmaceutical therapeutics and refinements in food and beverage products, such as identification of “nutraceuticals”. Such developments create challenges in the separation of bio-molecules, which must be achieved gently and with high selectivity and yield to make the process viable, and can account for the majority of their production cost. For example, the production of many monoclonal antibody based therapeutics being developed to treat cancer and other diseases could be made significantly more economic if higher capacity affinity chromatography supports were available.
A new range of affinity separation supports with high capacity based on templated nanoporous silica materials has been developed to address this need. Templated nanoporous silica materials offer significant benefits as separation supports due to their tunable mesopore sizes, high surface areas and pore volumes, and narrow pore size distributions. Three-dimensionally interconnected “mesocellular foam” (MCF) silica was functionalised with protein A to create an affinity adsorbent for human immunoglobulin G (IgG). The new adsorbent demonstrated high capacity, as predicted from its physicochemical properties, and was able to bind more than two times as much IgG as commercially available controlled pore glass protein A media. The bound IgG could be effectively recovered under standard elution conditions. The results from this model system have demonstrated the potential of templated nanoporous silica materials as supports for high capacity affinity separations.