Study On Protein－Imprinted Soft-wet Gel Polymeric Beads

Molecular imprinting has been shown to be a promising technology for creating highly specific recognition sites within a synthetic polymer. So far it has demonstrated great potential for the specific recognition of small molecules, however, the reports on the imprinting of biological macromolecules such as proteins, whole cells and viruses have been seldom. In this paper, protein-imprinted soft-wet gel polymeric beads (Protein-IPGBs) were prepared. The adsorption and recognition properties of Protein-IPGBs were studies, as well as the imprinting mechanism was discussed.Firstly, Protein-imprinted soft-wet polyacrylamide gel beads were prepared via inverse-phase suspension polymerization with acrylamide and N, N'-methylene diacrylamide as polymerization monomers. The resulted imprinting gel beads had macroporous structure, which was helpful to let the protein pass in and out. The adsorption capacity of BSA-imprinted gel beads was almost four times as much as that of non-imprinted gel beads. The selectivity test of imprinted gel beads showed that imprinted gel beads exhibited good recognition for BSA as compared to the other proteins. We consider the formation of multiple hydrogen bonds and complementary shape between the imprinting cavities and the template proteins are the two factors that lead to the imprinting effect. The effects of protein types, crosslinking degree, reaction temperature and adding amount of template on the adsorption capacity and imprinting efficiency of gel beads were also researched in this part.Further, BSA-imprinted polyacrylamide gel beads were synthesized via inverse-phase seed suspension polymerization, using high-density crosslinked gel beads as core, low-density crosslinked polyacrylamide gel as imprinting shell. The results showed, with adding fewer templates, the adsorption capacity of imprinting gel beads was similar to that prepared by direct entrapment method. The imprinting beads also exhibited quick adsorption rate and improved regeneration property in comparison with those prepared via inverse-phase suspension polymerization.Besides, BSA-IPGBs incorporating functional groups with negative charge were prepared by compolymerzing with methacrylic acid (MAA). The adsorption capacity of IPGBs increased because the carboxyl with charges could enforce interactionbetween the gel beads and BSA. We also found the close of surface Zeta-potential between the templates and the imprinted gel beads could enhance the imprinting effect.