胆固醇分子印迹聚合有机凝胶的制备及其选择性吸附研究

PREPARATION OF CHOLESTEROL IMPRINTED POLYMERIZED ORGANOGEL AND SELECTIVITY ADSORPTION ABILITY

以N-十八烷基马来酰胺酸(ODMA)为凝胶剂,在甲基丙烯酸β-羟乙酯、甲基丙烯酸、聚乙二醇二甲基丙烯酸酯和模板分子3-胆固醇酰氧基丙酸(COPA)混合物中自组装形成稳定的超分子有机凝胶,经UV原位光聚合,乙腈提取模板分子制备了胆固醇非共价印迹聚合有机凝胶.吸附实验在水/THF中进行.结果显示胆固醇非共价印迹聚合有机凝胶(MIPO)对胆固醇的吸附量远大于非印迹聚合有机凝胶(NIPO).聚合有机凝胶的吸附表明,在3 h内吸附胆固醇的量(18.9 mg/g)大于豆甾醇(4.5 mg/g)和睾丸激素(3.6 mg/g),表明分子印迹聚合有机凝胶的选择性主要源于孔穴的特异性识别.凝胶剂对吸附的影响表现为随着ODMA的量增加,胆固醇的吸附量先增加后降低,而对豆甾醇和睾丸激素则呈现下降的趋势.当COPA含量过多时,由于干扰印迹孔穴的稳定性,同样使得胆固醇吸附量下降,而对豆甾醇和睾丸激素的吸附基本没有影响.这主要是由于体系网络密度的增加和印迹孔穴更好保持所致.

N-octadecyl maleamic acid（ODMA） as gelator self-assembled in solvent mixture of β-hydroxyethyl methacrylate,methylacrylic acid and polyethylene glycol dimethacrylates-200 in the presence of 3-cholesteryloxycarbonylpropanoic acid（COPA） as template molecule,and turned them into thermally reversible polymerizable organogels.The resultant organogels were subsequently polymerized by in situ UV irradiation.The molecularly-imprinting polymerized organogels were obtained after removal of the template molecules through acetonitrile extracting.The cholesterol molecularly imprinted polymerized organgels（MIPO） showed significantly higher affinity for cholesterol than that for non-imprinted polymerized organgels（NIPO） in water / THF mixture（5 ∶ 6,V /V）.The selectivity experiment indicated that the adsorption amount of MIPO for cholesterol（18.9 mg /g） was higher than that for stigmasterol（4.5 mg /g） and testosterone（3.6 mg /g） within 3 h since the selectivity was based on the specific binding of cholesterol to recognition sites formed in polymers.The adsorption capacity for cholesterol onto MIPO was found to increase and then decrease,but for stigmasterol and testosterone which was decreased with the increase of ODMA in organogel.The higher concentration of COPA in organogel would result the decrease of the adsorption capacity for cholesterol,but the adsorption capacity for stigmasterol and testosterone remained nearly constant.Howevert,hese results could be attributed to the high density of polymer network and stability of imprinted holes.