Preparation And Research On Host-gust Complex Intelligent Photoresponsive Hydrogel

As a sort of very important soft material, hydrogel has been widely applied in many different areas. In recent years, more and more attentions have been paid to the researches about hydrogels. Supramolecular hydrogel based on cyclodextrin is a new research area in recent years. Besides the basic properties of normal hydrogel, such as biocompatibility, high water content, drug loading etc., it also has the intelligence according to specific self-assembly and molecular recognition, such as photo-responsive, thermo-responsive, pH-responsive etc. As a result, it pays a significant promoting to the research and application of traditional hydrogel, which could meet the requirements of different areas. It is widely acknowledged that poly-peptide hydrogel with excellent biocompatibility and biodegradability has been widely applied in the biomedical materials, such as drug/gene release carrier and scaffold for tissue engineering.Recently, the report about the research on polypeptide based host-gust complex intelligent responsive hydrogel containing good biocompatibility and intelligent response is very few. This has dramatically limited the application of supramolecular intelligent hydrogel in the biopharmaceutical areas. Therefore, a new type of host-guest complex photoresponsive intelligent hydrogel based on polypeptide was prepared in this paper, which is of great importance in the area of biomedical materials.The first part of this paper is the synthesis and analysis of Me-G2-Azo. Firstly, Me-Gi-OH is prepared from the TEG and other starting materials, and then Me-G2-COOH is obtained Me-Gi-OH reacting with MGi-Ts. Secondly, with azobenzene group is prepared through reduction reactions and substitution reactions, and its structures and properties arecharacterized through1H NMR. The self-assembly properties of Me-G2-Azo is explored and characterized through DLS, UV-vis and TEM. The second part is the synthesis and research of host-guest complex intelligent hydrogel. Firstly, PELG with pendant groups of azide is synthesized through ring-opening polymerization of NCA and azide reaction. Secondly, the prepared PNIPAM with acetylene group and cyclodextrin functional molecules with acetylene group are grafted to PELG through click reaction, and PELG-g-(PNIPAM/β-CD) is successfully preoared. Lastly, two quite different host-guest complex intelligent hydrogels are prepared:the polypeptide based host-guest complex intelligent hydrogel and ternary system intelligent hydrogel. The formation mechanism of two different host-guest complex intelligent hydrogels are explored through1H NMR,TEM and senior rotary rheometer. This two types of host-guest complex intelligent hydrogel have a potential application value in intelligent control drug release and other fields.