【摘要】 二苯丙氨酸二肽(L-Phe-L-Phe,FF)是引起阿尔兹海默症的A?-多肽成纤维的关键识别序列,具有优异的自组装性能,是制备生物功能性纳米材料的重要组装基元.迄今为止,研究者已制备出多种FF基微纳米结构,但是如何有效地控制自组装材料的形状和尺寸一直都是研究的关键和热点.近年来,本课题组通过改变组装条件以及引入外源小分子等方法来调控FF基肽分子的组装,成功实现了对肽基组装材料的形状、结构和功能的调控.这些研究不仅丰富了FF基肽分子的组装结构,同时也为其他肽基纳米材料的制备和生物功能材料的开发提供了新的策略和重要的实验依据.更多还原

【Abstract】 The self-assembly of biomaterials to form well-ordered hierarchical structures provides great opportunities in biomedical applications. In the past decades, a great many of researches have been focused on self-assembly of peptide molecules owing to their structural simplicity, chemical versatility, biocompatibility, facile synthesis, and widespread applications. Well defined peptide assemblies could be effectively achieved by hydrogen bonding, electrostatic, hydrophobic and ?-? stacking interactions. One well-known and the simplest peptide building block is diphenylalanine(FF), the core recognition motif of the Alzheimer’s ?-amyloid polypeptide. It is a major building block for the preparation of biological functional nanomaterials. So far, researchers have developed a variety of FF-based micro/nanostructures, such as nanotubes, microtubes, microrods, nanowires, and nanovesicles, etc. However, how to effectively control the shape and size of the self-assembled materials has always been the key concern of the research. In recent years, our group has conducted substantial researches on controlled assembly of FF and its derivatives by simply changing the assembly condition(solvents, peptide concentrations, ultrasonic) or introduction of exogenous small molecules(polyoxometalates, sulfonic azobenzenes, aldehydes). For example, our group obtained hexagonal FF microtubes in water and peonylower-like mesocrystal in the organic solvent tetrahydrofuran. When the organic solvent was changed to chloroform or toluene, FF organogels were obtained. Moreover, the structural transition from organogels to flower-like microcrystals were observed by changing the components of solvent. Similarly, upon a change in the peptide concentration, reversible shape transition between self-assembled dipeptide nanotubes and vesicle-like structures is achieved. In view of positive charge of cationic dipeptide, negatively charged small molecules(polyoxometalates and sulfonic azobenzenes) were added into the assembly system and colloidal spheres, urchin-like, flower-like and plate-like structures were obtained, respectively. Apart from non-covalent interactions, our group also exploited covalent Schiff’s reaction between the aldehyde group and the primary amine of peptide in the self-assembly of peptides by introducing aldehyde molecules, yielding peptides nanospheres and crystalline platelet structures. These peptide assemblies with diverse structures were successfully applied in drug delivery, optical waveguiding and SERS substrates. These researches not only enrich the FF-based nanomaterials, but also provide new strategy and important experimental basis for the preparation of other peptides-based nanomaterials and biological function materials. With the development of biology and nanotechnology, especially the establishment of the new assemblies or hybrid systems, higher requirements for the experiment, theory and application of biomolecular self-assembly are put forward. Therefore, further study on the assembly structure, the assembly dynamics and effectively control the assembly of peptides and other biological molecules are highly demanded. At the same time, in order to make the materials not only possess academic research significance, but also ultimately realize the social value, the exploitation of the functionalization and application of the materials will also be the focus of future research issues.更多还原