The Synthesis And Research Of Biological Activity Of Gold Nanoparticles

Recently,tumor incidence and mortality are rising,but the methods of radiotherapy and chemotherapy are difficult to treat the radical tumor,absolutely,and the recurrence rate is high.To solve the key problem,we should discover and determine the effective drug targets,and develop target-oriented anti-tumor drugs.Therefore,the research of drug with low toxicity,high targeting,strong selection,low drug resistance has become an important new treatment to treat tumors.Gold nanoparticles are currently one of the most widely studied nanomaterials,due to their unique optical properties,favourable chemical stability and biocompatibility.Amino acids are essential components of the organism.Therefore,the amino acid derivatives with the novel structure are designed and synthesized,which are conjugated with the molecule of cell membrane fluorescent probe.And the targeting effect of the cell membrane fluorescent probe is realized by using these novel amino acids.Polyamines are simple linear polycations that can be detected in all living organisms,and are used to transport the synthetic polyamine derivatives to the internal of cells,and use its characteristics to inhibit the growth of tumor cells and play a role in targeting.Cholic acid(LCA)can be used to treat deficiency of bile acid,gallstones,liver disease.Some bile acids and their vinegar derivatives have a certain anti-virus,anti-fungal activity.And part of the bile acid have also the potential to targeted therapy the liver disease and reduce cholesterol levels.Based on the application of gold nanoparticles in the modified nano-gold in fluorescence imaging and drug delivery,in this paper,we mainly carried out the following two aspects:Firstly,we bind the amino acid-polyamine derivatives on the surface of gold nanoparticles so that these gold nanoparticles can specifically recognize the cell membrane and produce the water-soluble AuNP with green fluorescence or red fluorescence(MPA-R-4C-X).And then we subjected MTT assay for their biological activities.The results show that these nano-gold complex were used in the presence of three cells(HepG2,SMMC-7721,QSG-7701,MCF-7 and HCT-116 cells).The toxicity of nano-gold complex in various cells is small.The results show that amino acid-polyamine derivatives modified nano-gold can enter the cells and fluorescence imaging,and mainly distributed in the cell membrane,indicating that it can be as a potential cell membrane fluorescent probe.Secondly,we synthesized the gold nanoparticles modified by chitosan acid and lithopic acid derivatives.And the modified gold nanoparticles characterized by TEM.The results show that the size distribution of nano-gold was uniform(?15 nm),and has a better water solubility.We choose four kinds of cells(HepG2,SMMC-7721,QSG-7701 and MCF-7)to research the toxicity of modified gold nanoparticles by MTT assay.The results show that these AuNPs have higher inhibition rate on hepatocellular carcinoma cells compared with other cancer cells.Then we used laser confocal,flow cytometry and molecular devices,to research way of the cancer cell death.And a series of experiments found that drug delivery system can enter the cells,and can induce liver cancer cell death through the pathways of apoptosis.In this study,a new drug carrier with good performance was obtained,and this provided evidence for new drug delivery system.