Cu2+-attached pumice particles embedded composite cryogels for protein purification.

In this study, chromatographic performance of Cu2+-attached pumice particles embedded to monolithic cryogels (Cu2+-APPsEMC) for human serum albumin (HSA) was investigated. Monolithic composite cryogels were prepared by means of polymerization of gel-forming precursors at sub-zero temperatures. The chemical composition of pumice and surface of composite cryogels were determined by X-ray fluorescence spectrometer and scanning electron microscopy, respectively. The highest adsorption capacity (549.5 mg/g pumice) of cryogels was achieved at phosphate buffer of pH 8.0 with initial HSA solution of 3 mg/ml. SDS-PAGE analysis was performed for the samples studied on human serum to determine HSA adsorption/desorption performance of cryogel qualitatively.

Investigation of lysozyme adsorption performance of Cu(2+)-attached PHEMA beads embedded cryogel membranes.

For the purification of large molecules, cryogels are an alternative stationary phase to particle based media. But, due to the drawbacks of cryogels (i.e., low surface area) and particle sorbents (i.e., pressure drop in fixed beds), in recent years, the use of hybrid cryogels has greatly increased. In this study, a novel hybrid cryogel column was synthesized for the purification of lysozyme from aqueous solutions and hen egg white (HEW). Firstly, poly(2-hydroxyethyl methacrylate) beads (2µm size) were prepared, and after iminodiacetic acid (IDA) immobilization, Cu(2+) ions were attached via the IDA chelating groups. These arranged Cu(2+)-attached PHEMA beads (Cu(2+)-ABs) were located into PHEMA based cryogel in order to prepare Cu(2+)-ABs embedded supermacroporous hybrid cryogel (Cu(2+)-ABsEHC) column. The specific surface area of the hybrid cryogel was found as 95m(2)/g by using BET. The amount of IDA on beads was found as 875µmol IDA/g. It was approached to the optimum adsorption levels at initial lysozyme concentration of 4mg/mL and pH8.0 as 874.9mg/g beads. The purity of lysozyme adsorbed from HEW was studied by SDS-PAGE with a purity of 86.4%. It is demonstrated that this column is a potential separation medium for purification of lysozyme from HEW.