VEGF-shRNA Loading Multi-functional Self-assembled Nanoparticles For Anti-tumor Targeted Therapy

Vascular endothelial growth factor(VEGF)plays an important role in promoting the proliferation of vascular endothelial cells,increasing vascular permeability,promoting the formation of vascular support and inhibiting the apoptosis of tumor cells.Therefore,VEGF plays an important role in the formation of tumor blood vessels which is a key factor in tumorigenesis,tumor growth,invasion and metastasis.The discovery of genes related to the development of tumors and the elucidation of these related genes to the regulation of tumor development have laid the foundation for the tumor intervention and treatment by using gene drugs.And the discovery of various gene therapy technologies including RNAi,providing great hope for the effective treatment of the tumor in recent years.However,there are many obstacles in the process of clinical tumor therapy using siRNA and other drugs,including how to avoid rapid degradation or removal of gene drugs by the renal and reticuloendothelial system after systemic administration,how to achieve the enrichment of drugs in tumor tissue,how to achieve drug-specific recognition of tumor cells and how to achieve efficient transfection and the release from the lysosome.In this study,a multifunctional self-assembled nanoparticle system was used for tumor targeting siRNA delivery and tumor therapy studies.The system consists of CD-PEI,Ad-PAMAM,functional peptide modified Ad-PEG and other molecular modules.The modules are self-assembled into nanoparticles by the recognition and binding of Ad and CD.And these nanoparticles have high loading capacity of gene drugs through the charge interaction.To accomplish this objective,we firstly synthesized CD-PEI,Ad-PAMAM and Ad-PEG modified by target peptide GE11 and trans-peptide GALA(Ad-PEG-GE11,Ad-PEG-GALA).Then,we constructed a self-assembled nanoparticle system(GE11/GALA-DNA@SNPs)using these modules and plasmid DNA(VEGF-shRNA expression vector).We investigated and characterized the physicochemical properties,stability and cytotoxicity of these self-assembled nanoparticles.Furthermore,we evaluated the cell transfection effect of GE11/GALA-DNA@SNPs and its RNAi effect.Finally,we constructed a model of A549 lung cancer subcutaneous tumor for GE11/GALA-VEGF-shRNA@SNPs-mediated tumor RNAi therapy.The results showed that our GE11/GALA-VEGF-shRNA@SNPs could effectively load the VEGF-shRNA gene,and had good stability and low cytotoxicity.The functionalization of target peptides and transmembrane peptides on the surface of self-assembled nanoparticles can significantly improve the cell-specific recognition and gene delivery capacity of the carrier system.In vivo antitumor experiments showed that compared with the control group,the GE11/GALA-VEGF-shRNA@SNPs could reduce the expression of VEGF in the tumor tissue more efficiently,thus reducing the formation of tumor neovascularization and finally inhibiting the growth of tumors.Throughout the treatment phase of the study,the multifunctional gene drug-loaded self-assembled nanoparticle system did not show acute and chronic toxicity to mice.In summary,our multifunctional self-assembled nanoparticle drug delivery system resulted in better therapeutic effect and reduced systemic toxicity,which reveals its potential for tumor targeted gene drug delivery and therapy.