Suedee Roongnapa, Srichana Teerapol, Chuchome Thitima, Kongmark Urairut
Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hatyai, Songkla 90112, Thailand.
J Chromatogr B Analyt Technol Biomed Life Sci. 2004 Nov 25;811(2):191-200. doi: 10.1016/j.jchromb.2004.08.044.
The possibility of introducing multiple recognition in artificial receptors by imprinting polymers, using a mixture of tetracycline (TC) and its degradation products as templates, has been examined. The recognition ability of the resulting molecularly imprinted polymer (MIP), as evaluated by batch rebinding assay, was found to be group-specific to tetracyclines, while the single tetracycline imprinted polymer (MIP-2) prepared using TC free from degradation products as the print molecule showed considerably high selectivity for doxycycline (DC) and modest selectivity for TC and other TC derivatives, oxytetracycline (OTC) and chlortetracycline (CTC). Based on the recognition property of the multiple tetracycline imprinted polymer (MIP-1), the polymer was applied in affinity membrane extraction as a class-selective adsorption phase to remove tetracyclines residues from water. For this purpose, the ground MIP was incorporated in a plasticized poly(vinyl chloride)-membrane by casting method. Affinity separation of the obtained membrane was evaluated for the extraction of tetracycline and its analogs (CTC, OTC or DC) in aqueous solutions by a dialysis method. The membrane exhibited significantly stronger extraction ability towards tetracycline and structurally related compounds than a "blank" membrane having a non-printed polymer (NIP) as the adsorption phase. The result of these membrane extraction studies also indicates that the drug saturating at the receptor sites of MIP (deposited in membrane) faster will also be released into the receptor chamber faster. These affinity membranes were able to extract tetracyclines from water at all pHs, the highest selectivity being shown at pH 7 of the feed solution, which gives the lowest flux of the drug. Moreover, presence of salt in the feed solution increases the release of tetracycline bound in membrane. The results of the present study show that imprinting simultaneous with TC and TC degradation products formed in situ as a mixture template generates the group selectivity towards tetracyclines for the polymeric material. High affinity to a class of tetracycline of the membrane fabricated with this receptor, together with its fast and simple MIP fabrication, provides good possibilities for its application in separation processes of tetracycline antibiotics, which often contaminate the aqueous environment.
以四环素（TC）及其降解产物的混合物为模板，通过聚合物印迹在人工受体中引入多重识别的可能性已得到研究。通过批量再结合试验评估，所得分子印迹聚合物（MIP）的识别能力对四环素类具有基团特异性，而使用不含降解产物的TC作为印迹分子制备的单一四环素印迹聚合物（MIP - 2）对强力霉素（DC）表现出相当高的选择性，对TC和其他TC衍生物土霉素（OTC）和金霉素（CTC）表现出适度的选择性。基于多重四环素印迹聚合物（MIP - 1）的识别特性，该聚合物作为类选择性吸附相应用于亲和膜萃取，以去除水中的四环素残留。为此，通过浇铸法将研磨后的MIP掺入增塑聚氯乙烯膜中。通过透析法评估所得膜对水溶液中四环素及其类似物（CTC、OTC或DC）的亲和分离。与以非印迹聚合物（NIP）作为吸附相的“空白”膜相比，该膜对四环素及结构相关化合物表现出明显更强的萃取能力。这些膜萃取研究的结果还表明，在MIP受体位点（沉积在膜中）饱和更快的药物也会更快释放到受体腔室中。这些亲和膜能够在所有pH值下从水中萃取四环素，在进料溶液pH值为7时表现出最高的选择性，此时药物通量最低。此外，进料溶液中盐的存在会增加膜中结合的四环素的释放。本研究结果表明，以TC和原位形成的TC降解产物的混合物为模板同时进行印迹，可使聚合物材料对四环素类产生基团选择性。用这种受体制造的膜对一类四环素具有高亲和力，以及其快速简单的MIP制备方法，为其在经常污染水环境的四环素抗生素分离过程中的应用提供了良好的可能性。
