标题: 以萘二甲醯亚胺为基础之自组装奈米结构及 其发光特性
Napthalimide-based Self-assembled Nanostructures and Their Luminescence Characteristics
作者: 黄钰棠
林欣杰
Huang, Yu-Tang
Lin, Hsin Chieh
材料科学与工程学系奈米科技硕博士班
关键字: 自组装胜肽奈米管柱;聚集诱导发光;萘二甲醯亚胺衍生物;Self-assembled peptide nanotubes;Aggregation-induced emmisiom;Napthalimide derivatives
公开日期: 2016
摘要: 近年来,透过胜肽分子自组装形成奈米结构之新型材料成为蓬勃发展的热门研究题材。迄今为止,在胜肽奈米管柱的研究中,多数以双胜肽为基底的奈米管柱被广为探讨,乃因其合成成本低,制备方法简易且稳定性高,应用端广泛。于本研究中我们导入一系列低分子量短链的双肽胜肽分子,探讨其自组装结构以及基本物理特性。研究主题分成两个部分进行,各别为调控奈米结构形貌表现和观察分子聚集导致的发光表现。
在第一部分的研究主题中,设计具有聚集诱导发光特性之萘二甲醯亚胺(NI)连接双肽的组合,第一个胺基酸为苯丙胺酸,提供部分疏水作用力,改变第二个胺基酸,使整个系统具有不同程度的双亲性,合成的材料为NI-FA、NI-FD、NI-FE和NI-FS,对以上材料进行不同浓度、酸硷与时间变异的研究,NI-FD与NI-FE于特定条件下并无特定奈米结构形成;而NI-FA及NI-FS除了可在中性条件下,可分别形成大小为104 nm ± 3 nm 与118 nm ± 6 nm的大型胜肽奈米管柱外,在一定的浓度与酸硷值范围内,也都为奈米管柱的表现。与NI-FS相较下,NI-FA可于短时间内、极硷且浓度高的环境依旧为成形的奈米管柱,形貌稳定性较高,在所观察的环境中无任何奈米结构共存的现象,形貌一致性高,管柱尺寸较小。此外,我们也推论其形成管柱机制较目前文献上更为完备,此机制的理解,有助于小分子自组装胜肽奈米管柱的探讨与发展。另外,NI-FA与NI-FS于人类纤维母细胞(WS1)的细胞存活度测试表现良好,预期两者于生物应用上具相当的应用价值及发展潜力。
在第二部分的研究主题,探讨萘二甲醯亚胺(NI)在4号位置连接上不同环数的环烷基作为推电子基团,依环烷尺寸小到大分别是5RNI、6RNI、7RNI和8RNI,并连接相同的短链胜肽分子(FDD)之萤光特性表现。材料分别为5RNI-FDD、6RNI-FDD、7RNI-FDD和8RNI-FDD,透过许多光学测试的结果,显示只有6RNI-FDD表现出聚集诱导发光的特性,推测在六环的萘二甲醯亚胺系统(6RNI)中,位于4号位置的六环环胺与萘二甲醯亚胺(NI)的苯环平面结构可能存有较大的旋转角度,故只有6RNI-FDD表现出聚集诱导发光的特性,其余三者的萤光表现皆为聚集导致粹灭。并以成胶条件下做细胞培养,6RNI-FDD于子宫颈癌细胞(HeLa)及前列腺癌细胞(PC3)之细胞存活率与其他三者衍生物相较下,皆有生物相容性最高的表现,推测具有生物显影应用的潜力。
In recent years, self-assembled peptide nanostructures have become a popular research field in material science. To date, dipeptide-based nanotubes were widely discussed because of low cost, easy preparation, high stability and diverse applications. In this study, we introduce a series of low-molecular-weight short dipeptide molecules to explore the self-assembled structure and their (photo)physical properties. There are two topics in this thesis, the first topic is to modulate the nanostructure morphology, and the other one is to study the properties of aggregation-induce emission.
In the first topic, we design four 1,8-Naphthalimide (NI)/dipeptide conjugates. The first amino acid at the N-terminus of the peptide is phenylaniline, providing part of hydrophobicity and different tail peptides with various amphiphilics. They are NI-FA, NI-FD, NI-FE and NI-FS. We studied these materials with different concentrations, pH value and time evolution. We found the self-assembled nanostructure of NI-FD and NI-FE formed no specific nanostructures under certain conditions, while NI-FA and NI-FS appear large-scale well-defined peptide nanotubes with the width of 104 nm ± 3 nm and 118 nm ± 6 nm, respectively. The self-assembled structures of NI-FA and NI-FS are also nanotubes in a range of pH values and concentrations. In comparison of NI-FS and NI-FA, NI-FA can form nanotubes in shorter time and extreme pH environments, pointing to higher stability of morphology. There is no coexistence of nanostructures possessing higher uniformity of morphology and smaller size. Besides, we studied the formation of nanotubes is more detail than that in the literature. Thus, it is beneficial to the development of small molecular of self-assembled peptide nanotubes. Furthermore, we also observed NI-FA and NI-FS possess excellent cell-compatibility toward WS1 cell line. As a result, we recognized both of them are new type of nanotube-based biomaterials.
In the second part of the research, we demonstrated a series of 1,8-Naphthalimide (NI) derivatives through combining different cyclic amine groups as donating electronic groups, then conjugate the same peptide sequences FDD in N terminus. They are 5RNI-FDD、6RNI-FDD、7RNI-FDD and 8RNI-FDD. Only 6RNI-FDD showed AIE effect through many photophysical studies. We speculated that there is the larger dihedral angle existed between NI and the six-membered ring at 4 position of NI. Additionally, we found 6RNI-FDD holds better cell-compatibility toward HeLa and PC3 cells via MTT assay that is very promising in application on bio-imaging.
URI: http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070351606
http://hdl.handle.net/11536/139379
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