温敏荧光嵌段聚合物的制备及其在细胞内的温敏应用研究

In this work, a versatile controlled/living radical polymerization technique, reversible addition-fragmentation chain transfer (RAFT) polymerization method will be studied for the preparation of block copolymer nano-thermometers with good biological compatibility and sensitive temperature response. Meanwhile, these kinds of block copolymer nano-thermometers will be utilized for the intracellular temperature sensing of normal cells and cancer cells. The investigation will include: (1) The hydrophilic chain transfer agents will be designed and synthesized. Then, hydrophilic thermal sensitive monomers and special chain transfer agents will be employed for the RAFT polymerization to obtain the temperature sensing block copolymers with good biological compatibility; (2) The RAFT polymerization method will be employed to regulate the proportion of the block segment and the degree of polymerization for getting the ideal temperature sensing block copolymers; (3) Derivatives of benzofurazan, hemicyanine and rhodamine will be designed and prepared as the fluorescent monomers for the RAFT polymerization of the block copolymers; (4) Temperature variation cellular modal under controlled and chemical induced physiological condition of normal cells and cancer cells will be established. Then the thermal responsive fluorescent block copolymers will be applied for the intracellular temperature sensing. This explorative work will provide sensitive and high efficient strategy for the study of intracellular temperature changing during cell growth, division, metabolism and pathological condition. Moreover, this research will expand the application fields of stimuli-responsive polymer materials in bio-analytical chemistry.

本项研究拟采用可控/活性RAFT聚合法制备生物相容性良好、温度响应灵敏的嵌段聚合物纳米温敏材料，并拟将其应用于正常细胞和癌细胞内的温度变化研究中。研究内容：（1）合成特殊的亲水性链转移剂，并结合采用亲水性良好的温敏单体和RAFT法来合成制备生物相容性良好的嵌段聚合物温敏材料；（2）利用RAFT聚合反应来调控嵌段比及聚合度，合成出性能理想的温敏聚合物并将其制备成新型聚合物纳米温度计；（3）发展苯并呋咱类、半菁类及罗丹明类荧光染料单体实现其在聚合物纳米温敏材料中的RAFT聚合；(4)建立正常细胞和癌细胞的化学刺激条件下温度变化模型，并将该聚合物纳米温度计应用于细胞在正常生理及外界刺激条件下的温度变化研究中。本项研究的探索性较强，若研究结果能取得一定突破，必将为细胞在生长、分裂、代谢及病理条件下温度变化的研究提供灵敏、高效的新方法，同时也将拓展智能响应型聚合物材料在生命分析化学领域中的应用范围。

对细胞内温度变化及相关生物事件开展研究是识别细胞功能和认识生命过程的关键环节。本项研究构建了基于聚合物纳米温度计的活细胞温敏成像分析系统，发展了温敏荧光聚合物纳米材料的制备新方法及细胞温度变化成像分析新技术，探索了药物刺激下细胞内实时在线温度变化研究的新方法；发表SCI论文12篇（7篇IF>5，5篇IF=3-5），获专利授权3项，参加国内外学术会议7次，作分组报告6次。. 具体创新点：① 发展了温敏荧光聚合物纳米材料的制备新方法，构建了将温敏聚合物单元、连接单元及极性响应荧光染料单元相结合的研究策略，实现了一系列聚合物纳米温度计的设计合成；② 发展了聚合物纳米温度计的温度响应性能、亲水性及生物相容性调控新方法；③ 针对细胞内温度研究难点，构建了嵌段型、比率型及靶向型等多功能聚合物纳米温度计，发展了基于聚合物纳米温度计的活细胞内温度变化成像分析系统及分析方法；④ 结合细胞内温度变化模型，发展了药物刺激条件下细胞内温度变化研究的新方法，揭示了因药物刺激会阻断线粒体内的氧化反应及影响离子交换平衡进而改变温度的机理，为细胞内温度变化以及相关生理事件研究提供了新方法。