温敏环糊精构筑智能聚合物

By combining the concepts of cyclodextrin chemistry and smart materials, cyclodextrin-based stimuli-responsive polymers should have shown promising applications in various areas. It remains a great challenge to prepare the novel stimuli-responsive polymers, especially thermo-responsive polymers, based on cyclodextrin derivitives, and investigate the relationships between the inclusion ability of cyclodextrins and the smart behavior. Recently, we reported oligoethylene glycols (OEG)-modified cyclodextrins (CDs) show characteristic thermoresponsive behavior, with phase transition temperatures tunable in the range of room temperature to 60 oC via the ring size of CD and chain length of OEGs. Herein, in present proposal we propose strategies to synthesize a novel kind of stimuli-responsive polymers from these CD derivitives via the covalent or non-covalent linkage. This research plan includes two parts. First, we aim to synthesize linear thermo-responsive polymers which carry OEG-modified CD moieties in each repeating unit by using "macromonomer route". The inclusion ability of CD units, thermo-responsive behavior together with their interrelationship and mutual acting mechanism will be investigated intensively. Second, we intend to construct the CD-based supramolecular polymers by the intermolecular (self-) inclusion complexation of OEG-modified CDs (the host) appended with a dye as the guest moiety. The formation of supramolecular polymers and its dependence on the external conditions, such as concentration, temperature, pH and external guests will be examined. We expect the implementation of the above project will not only enrich and expand the traditional cyclodextrin research fields, but also provide a general strategy for fabrication of a novel class of stimuli-responsive CD polymers, which would have fascinating applications in drug delivery, controlled release and sensors.

环糊精构筑的智能聚合物，结合了环糊精的超分子化学特性，同时兼具智能聚合物的环境响应性，在制备新型智能聚合物、拓展环糊精超分子化学等方面具有重要研究价值及应用前景。前期研究发现，齐聚烷氧醚改性的环糊精表现出优异的温度敏感行为，其相转变温度可以通过改变环的尺寸大小或烷氧醚链长在室温到60 oC之间得以很好调控。本课题拟在此工作基础上，采用烷氧醚改性的温敏环糊精衍生物为构筑基元，通过共价或超分子的链接方式，构筑一系列新型环糊精智能聚合物。深入研究共价型环糊精聚合物的包络行为、温敏特性以及两者之间的相互关系。详细探讨超分子聚合物的形成过程及其对浓度、温度、pH以及外加客体分子等的刺激响应性。进一步开展此类智能聚合物在药物控制释放、传感器等不同方面的应用基础研究。期望通过本课题的成功实施，不仅能开发一类新型环糊精类智能材料，同时拓展环糊精的智能化途径及其应用领域。

智能环糊精兼具有环糊精超分子及环境刺激响应性质，近年来受到高度重视。本项目围绕温敏环糊精核心，通过共价或超分子方式，构筑了一系列功能化环糊精小分子和聚合物，并深入研究了温敏行为对超分子形成与解离的控制过程。取得的重要结果包括：（1）采用大单体路线首次制备了结构规整的温敏环糊精聚合物，并发现其主客体包络行为可通过温敏相变得以“开”/“关”控制；（2）基于温敏环糊精可逆包络与释放特性，通过与各种偶氮和奈环类染料配对复合，灵活地构筑了一系列超分子型温敏比色/荧光探针；（3）温敏环糊精可作为载体有效地控制所接枝甲基红染料的可逆质子化过程；（4）苯磺酰胺修饰温敏环糊精能可逆地识别碳酸酐酶，从而有效调控其生物催化活性；（5）首次以温敏环糊精为配体制备了温敏金纳米颗粒，实现了其在水相中可逆聚集与分散的控制；（6）采用硫醇-烯烃点击反应高效制备了含硫醚的烷氧醚化环糊精，赋予其温敏和氧化还原双重响应性质；（7）将温敏相变诱导超分子解络合规律应用到温敏多肽聚合物体系，实现了对邻苯二酚类物质的可逆包络与释放。本项目的实施大大拓展了智能环糊精这一特色研究方向，丰富了环糊精超分子化学，使其在智能材料、传感器和酶识别等领域展示良好的应用前景。