Controllable Self-Assembly And Drug Delivery Of Small Heptapeptide Biomolecules

There are many nature macromolecules consist of small molecules, such as proteins, sugars, etc. Due to simple structures, extensive sources and remarkable functions, their applications have been expanded to the fields of material science, environmental science and energy science. However, they are always difficult to be used directly. Therefore, it is important to seek the method to functionalize and utilize the small biomolecules efficiently. Molecular self-assembly may be the key.Among the small molecules, small molecular peptides which can self-assemble into nanostructure receive much attention in the fields of chemical synthesis and polymer materials all the time. Moreover, small molecular peptides have been regarded as ideal biomaterials in biomaterials, tissue engineering and drug release for their unique functions, novel self-assembly shapes and excellent biocompatibility.In this thesis, small molecular peptides were chose as model molecules. Through the way of self-assembly, different adjusting methods of self-assembly had been designed and the regulation mechanism of self-assembling was analyzed in order to obtain the peptide nanomaterials with controlled structures and their potential applications.The main research can be summarized as follows:(1) Different surfaces were used to regulate the7AAP aelf-assembly. It had been found that7AAP could self-assemble into a core-branched nanostructure in H2O. The resulting pre-assemblies further assembled into different structures on the nylon membranes, nitrocellulose membranes and polytetrafluoroethylene hydrophilic membranes. Our results reveal that the interface can regulate the behavior of7AAP self-assembly.(2) A novel kind of self-assembling peptide with UV-responsive properties was tested. The result showed that after light irradiation, the morphology of the7AAP changed significantly and the degree of influence depends on the UV dose, but the structure of7AAP doesn’t change, which suggested that the UV light could affect the applications of the new biomaterial.(3) Chitosan (cs) was proposed as a stabilizer for preparing Fmoc-7AAP/CS hybrid hydrogel. Results demonstrated that the hybrid hydrogel had much higher stability compared to Fmoc-7AAP hydrogel alone, which might be caused by-OH groups, branched chains and the high water-absorption capacity of the CS. Moreover, ketoprofen was chosen to study the release behavior. The sustained and controlled drug release from this hybrid hydrogel was achieved by varying the concentrations of CS and aging time.