多重手性大分子的合成及多级手性自组装的研究

Although there have been a lot of remarkable achievements in macromolecules self-assembly and organic-inorganic hybrid assembly, it is still very difficult to construct hierarchal chiral nano/micro structures similar as natural organisms' through self-assembly, which is probably because the conformation of traditional chiral molecules are too simple to obtain complex assembly products. In this project, a series of multiple chiral macromolecules are designed based on polypeptide skeletons. They are consist of one hydrophilic polypeptide block with stable α-helix and chiral groups at the end of side chains, and another chiral hydrophobic block or a chiral block with special selective recognition function. These macromolecules are expected to self-assemble to hierarchal chiral structures, or to form ordered chiral phase in microphase separation. In addition, they can also be applied as templates for the preparation of hierarchal chiral macroporous materials and hierarchal chiral metal oxide arrays under the assistance of chiral-patterned substrates, or for bio-inspired self-assembly controlled by complementary DNA strands. Furthermore, some key factors, including the self-assembly mechanism of multiple chiral macromolecules, the law of chirality transfer and amplification and accurate control of hierarchal chiral self-assembly will be thoroughly studied and discussed. The project is expected not only to further uncover the secrets of nature, but also to promote the application of bio-inspired hierarchal chiral materials.

尽管大分子自组装和有机-无机杂化共组装已经取得了令人瞩目的进展，但以自组装法得到类似自然界的多级手性微纳结构目前仍非常困难。这可能是应用的手性分子手性过于单一造成的。本课题设计并合成一系列基于多肽骨架的多重手性大分子，它们包含拥有稳定的α-螺旋和手性侧链端基的亲水多肽嵌段，以及具有特定识别作用或拥有手性的另一嵌段。这些多重手性大分子可以自组装形成多级手性组装体，也可以在微相分离中形成复杂的手性相结构。此外，它们还能够作为模板，结合基板手性诱导作用和DNA单链的特定识别作用制备多级手性大孔材料、多级手性金属氧化物，以及进行手性仿生自组装。在此基础上，本项目将研究多重手性大分子的自组装机理、手性传递和放大的规律以及多级手性组装体的精确调控等科学问题。由此，本课题不但有望进一步揭示自然界的奥秘，还能够为仿生多级手性结构材料的应用奠定基础。

本项目设计合成了三类多重手性大分子，包括：（1）含聚乳酸嵌段的聚L-乳酸-聚二甲基硅氧烷-聚L-乳酸（PLLA-PDMS-PLLA）、聚D-乳酸-聚二甲基硅氧烷-聚D-乳酸（PDLA-PDMS-PDLA）、聚D-乳酸-聚4-乙烯基吡啶-聚氟丙烯酸酯（PDLA-P4VP-PPFA）。（2）基于聚氨基酸骨架的聚（L-赖氨酸-ε-端甲基二缩乙二醇酰胺）-聚谷氨酸苄酯-聚（L-赖氨酸-ε-端甲基二缩乙二醇酰胺）（（PLys(EG)2- PBLG- PLys(EG)2）、聚赖氨酸-聚乙二醇（PLys-PEG）。（3）基于偶氮苯的交替共聚（联萘偶氮苯-六甘醇）P(BpAzo-a-EG6)、梳状聚（3-炔基-4’-甲氧基二甘醇醚偶氮苯）P(o-AAzo-OEG2)。.对上述多重手性大分子的自组装展开研究，包括：（1）PLLA-PDMS-PLLA的结晶诱导组装；PDLA-PDMS-PDLA与 PLLA立构复合结晶诱导组装；PDLA-PDMS-PDLA和PDLA-P4VP-PPFA在PLLA表面立构复合形成疏水层或抗菌层。（2）α-螺旋结构的PLys(EG)2- PBLG- PLys(EG)2的自组装与氧化还原调控；PLys-PEG的电荷复合自组装。（3）P(BpAzo-a-EG6) 和P(o-AAzo-OEG2)的光可逆手性自组装。通过引入结晶、电荷、π-π堆叠等可以精确传递手性的非共价作用，成功制备了多级结构的一维螺旋线状、二维片状组装体，阐明多重手性大分子的自组装机理，获得了表面疏水/抗菌的聚乳酸材料，所得研究成果具有重要理论意义和实用价值。受本项目资助，以通讯作者发表SCI论文12篇，核心及其他期刊3篇，申请中国发明专利3项。培养博士研究生2人（在读），硕士研究生6人。