One-Pot Synthesis of Biomimetic Shell Cross-Linked Micelles and Nanocages by ATRP in Alcohol/Water Mixtures
One-Pot Synthesis of Biomimetic Shell Cross-Linked Micelles and Nanocages by ATRP in Alcohol/Water Mixtures
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DOI：
10.1002/anie.201000095
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发表时间：
2010-01-01
影响因子：
16.6
通讯作者：
Lewis, Andrew L.
中科院分区：
文献类型：
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作者：
Sugihara, Shinji;Armes, Steven P.;Lewis, Andrew L.
近年来，合理设计具有独特结构和可控制尺寸的大分子纳米结构变得越来越重要，嵌段共聚物的自组装也引起了相当大的科学兴趣特别是，壳交联（SCL）胶束是一种共价稳定的超分子结构，它结合了胶束、微凝胶、纳米颗粒和树状大分子的理想特性然而，据我们所知，只有一篇报道描述了SCL胶束的一锅合成所谓的“空心纳米笼”可以通过选择性降解和提取成核链，从SCL胶束中获得，留下一个膜状的外壳。[4-7]生物活性成分在纳米笼内的微胶囊化已被评估用于人工细胞的发育。[j]磷酸胆碱基序是细胞膜的重要组成部分。众所周知，基于磷胆碱的聚合物可用于生产具有显著抵抗蛋白质吸附和细菌/细胞粘附的表面，因此可以开发许多生物医学应用在过去的十年中，我们的研究小组已经证明，原子转移自由基聚合（ATRP）[10]可以用于制备低多分散嵌段共聚物，该共聚物基于一种重要的商业上的仿生学单体，即2-（甲基丙烯酰氧基）乙基磷酸胆碱（MPC） [11]在这项研究中，我们利用PMPC链b[12]所表现出的不寻常的不溶性行为，从而开发出一锅合成SCL胶束的第二个例子。此外，我们的合成策略还允许首次一锅合成中空纳米笼，而且不需要对胶束核进行化学降解。方案1和图1描述了一种基于新型ABC三嵌段共聚物的一锅合成SCL胶束的方法，该方法使用ATRP在408C的9:1 iPrOH/water混合物中合成SCL胶束。采用聚环氧乙烷宏观引发剂（PEO）制备了三嵌段共聚物，采用顺序单体加成法先聚合2-（二甲氨基）甲基丙烯酸乙酯（DMA），再聚合MPC。控制聚合过程顺利进行，每个阶段几乎达到完全转化。三嵌段共聚物的组成通过1H NMR谱测定。实际组合物与目标组合物符合较好
Recently, the rational design of well-defined macromolecular nanostructures with unique architectures and controlled dimensions has become increasingly important, with the self-assembly of block copolymers being of considerable scientific interest.[1] In particular, shell cross-linked (SCL) micelles are covalently stabilized supramolecular structures that combine the desirable properties of micelles, microgels, nanoparticles, and dendrimers.[2] However, to the best of our knowledge, there has been only a single report describing the one-pot synthesis of SCL micelles.[3] So-called “hollow nanocages” can be obtained from SCL micelles by selective degradation and extraction of the core-forming chains to leave a membrane-like shell.[4–7] Microencapsulation of biologically active components within such nanocages has been evaluated for the development of artificial cells.[8] The phosphorylcholine motif is a significant component of cell membranes. It is well known that phosphorylcholine-based polymers can be used to produce surfaces which are remarkably resistant to protein adsorption and bacterial/cellular adhesion, therefore allowing many biomedical applications to be developed.[9] Over the last decade our research group has shown that atom transfer radical polymerization (ATRP)[10] can be used to prepare low polydispersity block copolymers based on a commercially important biomimetic monomer, namely 2-(methacryloyloxy) ethyl phosphorylcholine (MPC).[11] In this study we exploit the unusual cononsolvency behavior exhibited by PMPC chains [12] so as to develop only the second example of a one-pot synthesis of SCL micelles. Furthermore, our synthetic strategy also allows the first ever one-pot synthesis of hollow nanocages and, moreover, does not require chemical degradation of the micelle cores. The one-pot synthesis of SCL micelles based on a novel ABC triblock copolymer using ATRP in a 9: 1 iPrOH/water mixture at 408C is described in Scheme 1 and Figure 1. The triblock copolymer was prepared using a poly (ethylene oxide) macroinitiator (PEO), which was used to polymerize first 2-(dimethylamino) ethyl methacrylate (DMA) and then MPC using the sequential monomer addition method. Controlled polymerization proceeded smoothly to reach almost complete conversion at each stage. The triblock copolymer composition was determined by 1H NMR spectroscopy. The actual compositions are in good agreement with the target compositions