Development and screening of epoxy-spacer-phage cryogels for affinity chromatography: Enhancing the binding capacity

Organized cryogel composites with 3D hierarchical porosity as an extraction adsorbent for nucleosides

Macroscopic monoliths are highly desirable in many fields of application. Herein, well organized organic-inorganic cryogel composite with a three-dimensional hierarchical meso- and macroporous structure are presented, which were produced by in situ copolymerization of mesoporous multifunctional silica (size: 1-20 μm; pore: 2-20 nm mostly) and monomers (hydroxyethyl methacrylate and diallyldimethylammonium chloride) in water below the freezing point. This copolymerization method effectively adjusted the macropores of the basic cryogel, and the nanosilica was more homogeneously dispersed in the basic cryogel. The specific surface area of the cryogel composite was increased 17 times versus than that of the basic cryogel. The abundant meso- and macroporous pores on the cryogel composite provided sufficient reactive sites favorable for the efficient mass transport of target compounds. When the cryogel composite, as solid phase extraction adsorbent, was coupled with high-performance liquid chromatography, an analytical tool, the nucleosides were quantified with good selectivity, lower detection limits (0.9-1.3 ng/mL) and satisfactory recoveries of greater than 80% from spiked human serum.

Preparation and characterization of large-format macroporous cryogel disks for use in affinity chromatography and biotechnological applications

We have prepared and evaluated larger format phage-bound epoxy-cryogel columns in order to increase the yield of bound target. Freezing thermograms showed that larger column formats (2.5-5 cm diameter) are not usable due to irregular polymerization phenomena. Preparing thin disks of 0.5 cm height with similar diameter proved to be an excellent alternative. Disks could be stacked and run in a chromatographic setup. In this way, we could increase the matrix volume, ligand-binding capacity, and finally the yield of bound target. By increasing the column volume about sevenfold, we observed a 12-fold increase of ligand density and a sevenfold increase in the yield of protein recovery in a column where phages were attached without spacer and a 10- to 34-fold increase in a spacer column, depending on the spacer used.