两亲性可降解导电聚合物及其可注射水凝胶的制备与性能研究

Degradable and electrically conducting polymers with the unique properties of being electrically conducting and degradable are used as bioactive scaffolds for tissue engineering. Most of the exsiting degradable conduting polymers dissolve in common organic solvent. However, this could lead to environmental problem and toxicity, especially when used in vivo. In this proposal, on the basis of our previous work on design and synthesis of degradable conduting polymers with different architecture, we will synthesize two kinds of amphiphilic ABC type triblock and ABCBA type multiblock copolymers, where A, B and C represent poly(ethylene glycol), aliphatic polyester and aniline oliogomers, respectively. These rod-coil block copolymers would self-assemble in water due to their amphiphilic nature. These micelles will transform into injectable hydrogles with increasing the polymer concentration in aqueous solution. The effect of composition, structure, block length, oxidation state of aniline oligomer on the self-assembly behavior will be discussed. The optimized condition for the transition and the properties of the injectable hydrogels will be studied. The cytotoxicity of these materials will also be investigated. These conductive degradable injectable hydrogels as scafolds have great petential application in neural, bone and cardic regeneration where electroactiviety is needed. This will lead to new possibilities of applications of degradable conducting polymers in tissue engineering.

生物可降解导电聚合物作为生物活性支架材料在再生医学中具有重要的应用价值。然而目前报道的可降解导电高分子材料不具有两亲性质，一般只能溶解在有机溶剂中，不利于环境保护和严重阻碍在人体内的应用。为此，在我们合成不同大分子构造的可降解导电聚合物的前期研究基础上，本项目拟合成两类两亲性的可降解导电高分子材料-ABC型和ABCBA型两亲性可降解导电共聚物(A:苯胺寡聚物嵌段；B:脂肪族聚酯可降解嵌段；C:聚乙二醇亲水性嵌段)。这些两亲性导电嵌段聚合物在水溶液中自组装形成胶束；胶束浓度增大形成导电性生物降解可注射水凝胶。本项目拟研究聚合物组成、结构、嵌段大小、苯胺氧化态等对自组装行为的影响，以及导电可注射水凝胶的形成条件及性能，并测定其细胞毒性，为可注射水凝胶作为可注射导电组织工程支架在神经、骨骼、心脏等电信号刺激敏感的组织修复中的应用奠定基础，最终将为可降解导电聚合物在组织工程中的应用提供新的途径。