Preparation Of Gold Glyconanoparticles And Research On Their Interaction With Concanavalin A

Glyconanoparticle is an important bioactive particle.It can enhance the ability of specific recognition proteins through multivalent interaction.So that it has important application value in the fields of glycoscience and biomedical.Gold nanoparticles have many advantages such as small size,large specific surface area and so on,which make it have unique optical,thermal and catalytic properties.Sugar is carbohydrate.It is not only the main energy source of human life,but also has important function in cellular activity,including cell proliferation,cell recognition,signal transduction and pathogen infection.In particular,the study of the specific recognition of sugar and protein on the cell surface(CPIs)is helpful to understand the process of tumor formation and metastasis.In this thesis,in order to explore the interaction between sugar and protein,three kinds of glyconanoparticles were prepared.By the surface plasmon resonance characteristics of gold nanoparticles and colorimetric analysis method,the specific binding force of glyconanoparticles and concanavalin A was analyzed qualitatively.The surface dissociation constants of gyconanoparticles and ConA was calculated quantitatively by turbidimetric method.The binding strength of different kinds of sugar and protein was compared.Finally,we explored the target recognition ability of glyconanoparticles to cancer cells by biological experiments.The main contents of this thesis include:(1)Firstly,two kinds of gold nanoparticles with uniform particle size and good dispersion were prepared by crystal seed growth method.The size of gold nanoparticles can be controlled by changing the amount of seeds.The effects of reaction parameters such as the amount of AgNO3,AA and CTAB on the absorption peak of gold nanorods were investigated.Then the FeCl3 etching method was used to dynamically adjust the morphology of gold nanorods at room temperature.The etching reaction takes place at the tip of the gold nanorods,the oxidation products were obtained by investigating the reaction mechanism.The effects of the concentration of etchant,etching time,CTAB concentration and reaction temperature on the reaction rate were investigated.Compared with the seed growth method,the etching method is more convenient and faster to obtain the gold nanoparticles with different morphology.(2)The gold nanoparticles coated with three kinds of sugar were prepared by covalent coupling and gold nanoparticles catalysis.The samples were characterized by TEM,Zeta potential and FTIR spectra,and the results showed that the sugar molecules were successfully connect to the surface of gold nanoparticles.The effects of the reaction temperature and the concentration of the added sugar on the SPR absorption peak were investigated.In addition,the stability of gold nanoparticles in different salt solution and pH solution was alsoinvestigated,the results showed that the particles did not gather in a complex environment,and the stability of gold nanoparticles was improved by glycosylation.MTT method was used to test the cytotoxicity in vitro,the results showed that the glyconanoparticles were not toxic to the cells,and they were safe to the organism,glycosylation enhanced the biocompatibility of gold nanoparticles.(3)ConA was selected as the model protein to evaluate the bioactivity of three kinds of glyconanoparticles.Through the characterization of UV-vis,TEM,DLS,the binding ability between three kinds of glyconanoparticles and protein was qualitatively analyzed.It was found that the interaction between Glc-AuNPs and ConA was the strongest.Taking Glc-AuNPs as an example,the relationship between the binding strength and the density of sugar coated,the protein concentration was discussed.In addition,we also explored the specific recognition ability of glyconanoparticles,the surface dissociation constant(Kd)of glyconanoparticles and ConA was calculated quantitatively,the calculated results are consistent with the qualitative analysis.Finally,using the photothermal effect of gold nanoparticles and MTT method,the cytotoxicity in vitro was detected.It is proved that the glyconanoparticles have the function of target recognition.This nanocomposite has broad application prospects in the treatment of diseases in the future.