Experimental Study On Folate-conjugated Chitosan Nanoparticles As Targeting VEGF SiRNA Plasmid Carriers For Anti-breast Cancer

Chitosan is not only a natural high molecular cationic substance,but also it have an excellent biocompatibility.It becomes the focus of attention during the field of biomedical materials,but chitosan targeting is weak,and due to its low transfection limite its application.For these shortcomings,the article modified chitosan by using folic acid molecules targeting functional groups which is introduced in chitosan.This study is of great significance to the treatment of neoplastic diseases and provides a clue for folate-conjugated chitosan as a gene carrier.Firstly,the study purified raw chitosan.Molecular weight is determined by viscosity method,and degree of deacetylation is determined by acid-base titration.Then, we use homogeneous synthetic method to folic acid conjugated chitosan and ionic crosslinking method to synthesize preparation of folate-conjugated chitosan (FA-CTS) nanoparticles.Folate-conjugated chitosan characterized namely particle size is measured by UV,IR,zeta particle size analyzer,and the rate of folate folate-conjugated chitosan nanoparticles is calculated.NIH-3T3cells toxicity is analyzed by SPSS software. Secondly,the synthetsis method of folate-conjugated chitosan siRNA (FA-CTS-siRNA) nanoparticlesis the complex coacervation,then we research drug loading and sustained release.The result of DNA electrophoresis research prove the folate-conjugated chitosan protective effect of genes.Zeta particle size analyzer provs the FA-CTS-siRNA nanoparticle surface with the amount of charge.The surface morphology is observed by transmission electron microscopy. Finally, the FA-CTS-siRNA nanoparticles are labeled with a fluorescent to detect the transfection efficiency.The inhibition rate of folate-conjugated chitosan nanoparticles which transfect the VEGF siRNA gene into MCF-3cells is researched by MTT assay.Using Western Blot, RT-PCR, ELIS A ways detect of folate-conjugated chitosan gene nanoparticles on the VEGF siRNA protein and VEGF gene expression in MCF-7cells. And apoptosis rate is researched by Annexin V-FITC/PI double staining in MCF-7cells.