Tuncel A, Ozdemir A
Hacettepe University, Chemical Engineering Department, Ankara, Turkey.
J Biomater Sci Polym Ed. 2000;11(8):817-31. doi: 10.1163/156856200744039.
A thermosensitive gel matrix was prepared by free radical copolymerization of N-isopropylacrylamide (NIPAM) with a boronic acid-carrying monomer (i.e. 4-vinylphenylboronic acid, VPBA). The synthesis of the gel was performed at 70 degrees C in an alcohol-water mixture, using azobisisobutyronitrile and methylenebisacrylamide as the initiator and the crosslinker, respectively. To produce thermosensitive gels with a higher diol-binding affinity, an amino-containing comonomer, N-[3-(dimethylamino)propyl]methacrylamide (DMAPM) was included in the gel formation recipe. Thermally reversible VPBA-NIPAM and VPBA-DMAPM-NIPAM gels with different swelling properties were obtained by changing the feed concentrations of VPBA and DMAPM. To test the usability of the produced gels as sorbents in nucleotide adsorption, beta-nicotinamide adenine dinucleotide (beta-NAD) was selected as a model biomolecule. Then the adsorption isotherm for beta-NAD was obtained at +4 degrees C in HEPES buffer medium with a pH of 8.5. The support material was in a highly swollen form under these conditions, due to its thermosensitive character. This property was then used to enhance beta-NAD adsorption onto the gel matrix. Equilibrium adsorption capacities up to 70 mg beta-NAD/g dry gel could be achieved with the thermosensitive support prepared with the 12.9 mol% VPBA feed. The gels produced with higher VPBA and DMAPM feed concentrations exhibited higher equilibrium adsorption capacities for beta-NAD.
通过N-异丙基丙烯酰胺（NIPAM）与含硼酸单体（即4-乙烯基苯硼酸，VPBA）的自由基共聚制备了一种热敏凝胶基质。凝胶的合成在70℃下于醇-水混合物中进行，分别使用偶氮二异丁腈和亚甲基双丙烯酰胺作为引发剂和交联剂。为了制备具有更高二醇结合亲和力的热敏凝胶，在凝胶形成配方中加入了含氨基共聚单体N-[3-(二甲氨基)丙基]甲基丙烯酰胺（DMAPM）。通过改变VPBA和DMAPM的进料浓度，获得了具有不同溶胀特性的热可逆VPBA-NIPAM和VPBA-DMAPM-NIPAM凝胶。为了测试所制备凝胶作为核苷酸吸附吸附剂的可用性，选择β-烟酰胺腺嘌呤二核苷酸（β-NAD）作为模型生物分子。然后在+4℃、pH值为8.5的HEPES缓冲介质中获得β-NAD的吸附等温线。由于其热敏特性，在这些条件下支撑材料处于高度溶胀状态。然后利用这一特性增强β-NAD在凝胶基质上的吸附。用12.9 mol% VPBA进料制备的热敏载体对β-NAD的平衡吸附容量可达70 mg β-NAD/g干凝胶。进料浓度较高的VPBA和DMAPM所制备的凝胶对β-NAD表现出更高的平衡吸附容量。
