PtBA-b-PDMAEMA壳交联胶束的研究-中国材料进展

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Author(s):: Hailong Zhang; Xiaohui Zhang; Jinghua Gong; Shuguang Yang; Jinghong Ma; Jian Xu; (State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China)

摘要:: 通过原子转移自由基聚合（ATRP）制备了聚（丙烯酸叔丁酯-b-甲基丙烯酸二甲胺基乙酯）（PtBA-b-PDMAEMA）两亲性嵌段共聚物，在共溶剂THF溶液中加入选择性溶剂水自组装制备了PtBA-b-PDMAEMA胶束。以1,2-二(2-碘乙氧烷)乙烷（BIEE）为交联剂与PDMAEMA发生交联反应,制备了壳交联胶束（SCL胶束）。通过核磁共振（1H-NMR）、动态光散射（DLS）和透射电镜（TEM）研究了壳交联胶束的结构和形态，并详细探讨了BIEE和PDMAEMA的摩尔比对壳交联结构的影响。发现当[BIEE]/[PDMAEMA]小于0.5时，易发生胶束内交联，形成球形胶束；当其大于0.5时，倾向于形成胶束之间的交联，导致其流体力学直径的增加。另外，还研究了壳交联胶束的pH和温度响应性，发现随着温度和pH的变化，SCL胶束表现出可逆的收缩-伸展性，可以作为药物控制释放的良好载体。

Abstract:: The amphipathic block copolymer poly(t-butyl acrylate)-b-poly(2-dimethylamino)ethyl methacrylate (PtBA-b-PDMAEMA) was synthesized via sequential atom transfer radical polymerization (ATRP), and PtBA-b-PDMAEMA micelles were prepared by adding the selective-solvent water into the cosolvent THF solution. The shell cross-linking micelles (SCL micelle) were obtained by cross-linking PDMAEMA using 1, 2-bis-(2-iodoethoxy) ethane (BIEE) as a cross-linker. The structure and morphology of the SCL micelle were investigated by means of 1H NMR, dynamic light scattering (DLS) and transmission electron microscopy (TEM). The effect of molar ratio of BIEE to PDMAEMA ([BIEE]/[PDMAEMA]) on the cross-linking network structure was investigated in detail. It was found that intra-micelle cross-linking tended to be formed when [BIEE]/[PDMAEMA] ratio was lower than 0.5, and the spherical SCL micelles were obtained. When the ratio was higher than 0.5, inter-micelle cross-linking structure would be obtained, which increased the hydrodynamic diameters of the SCL micelles. In addition, the pH/ thermo-responsive behaviors of the SCL micelles were studied. The SCL micelles showed reversible collapse and stretch with the changes of temperature and pH of the medium, and could be good carriers for drug controlled release system.