Chemical Modification And Applications Investigation Of Supermacroporous Cryogel

Cryogel has interconnected supermacropores with pore size of several to several hundreds of microns. Ion-exchange supermacroporous cryogel monolithic chromatography is a new method for separation and purification of bioproducts, which is provided with high selectivity and applied to capture and separate target biomolecules directly from unclarified feedstocks or crude cell homogenates at high flow velocities. It permits the solid particulates in the culture fluids to pass through freely without blockage. This technique has potential applications in bioseparation areas.In this paper, novel cation- and anion-exchange cryogels with functional binding groups were prepared by in-situ graft polymerization and their properties were measured. The cation-exchange cryogel with double carboxyl binding groups were developed by exploring the effects of the grafting conditions. Moreover, isolation of ATP from fermentation broth of Saccaromyces cerevisiae was performed by two different anion-exchange cryogels, and isolation of acarbose from fermentation broth of Antinomyces was performed by cation-exchange cryogel.The results showed that the graft polymerization of low and non-water soluble monomer chains with expected functional groups onto the matrix pore surfaces can be performed effectively by transforming them to their salt compounds. In the graft polymerization process of itaconic acid with double carboxyl, grafting conditions, such as concentrations of monomers and initiator, the volume ratio of K₅[Cu（HIO₆）₂] （Cu（III）） to NaOH had influences on the liquid dispersion behaviors, flow resistance, as well as the protein binding capacity of the grafted cryogels. The protein binding capacity increased with the increase of concentration of itaconic acid, graft temperature and graft reaction time hold the line under the present conditions. The protein binding capacity reached the maximum when the volume ratio of Cu（III） to NaOH in the initiator solution was 2:1 （V/V） in the considered situations. Compared with these factors, the concentration of Cu（III） had a relatively weaker influence on the protein binding capacity. The maximum binding capacity of lysozyme was 3.2 mg/mL wet cryogel in these grafted cryogels.The one-step direct separation method of ATP from fermentation broth of Saccharomyces cerevisiae was introduced by anion-exchange chromatography at the high velocities of 5 and 10 cm/min with a novel supermacroporous cryogel. The maximal purity of ATP by the one-step separation method was 98.3% using 0.01 M HCl as running buffer in the N, N-Dimethylaminoethyl methacrylate （DMAEMA） anion-exchange chromatography. In the N, N-Diethylaminoethyl methacrylate （DEAEMA） anion-exchange chromatography, the maximal purity of ATP by the one-step separation method was 97.5% using pure water as running buffer.