Boronic acid-functionalized HEMA-based gels for nucleotide adsorption

A gel matrix that could be used as a sorbent for the specific adsorption of nucleotides was prepared by the radical copolymerization of 2-hydroxyethylmethacrylate (HEMA) with a relatively new boronic acid-functionalized monomer (4-vinylphenylboronic acid, VPBA). The synthesis of a gel could be achieved at a reasonably low temperature (+4 degrees C) by using potassium persulfate and tetramethylethylenediamine as the redox system and methylenebisacrylamide (MBA) as the crosslinker. To increase the diol binding affinity of boronic acid-carrying gels, two different amine-containing monomers [N-3-(dimethylamino)propylmethacrylamide DMAPM and 2-(dimethylamino)ethylmethacrylate, DMAEM) were also included in the gel-formation recipe. Then HEMA-VPBA-DMAPM and HEMA-VPBA-DMAEM terpolymer gels were obtained. The boronic acid-functionalized gel matrices with different swelling properties were produced by changing the feed concentrations of VPBA and of the amine-containing monomers (DMAPM and DMAEM). To test the usability of produced gels as a sorbent in the nucleotide adsorption, p-nicotinamide adenine dinucleotide (P-NAD) was selected as a model compound. The results of adsorption experiments indicated that the beta-NAD adsorption capacity of HEMA-based gels increased with increasing VPBA feed concentration. Equilibrium adsorption capacities up to 33 mg beta-NAD/g dry gel could be achieved with the DMAPM-containing boronic acid-functionalized HEMA-based gels. An increase in the feed concentration of DMAPM resulted in an increase in the beta-NAD adsorption capacity of gels, while a decrease was observed with an increasing feed concentration of the other amine-containing monomer (DMAEM). (C) 2000 John Wiley & Sons, Inc.