Targeting Peptide Modification For Promoting The Proliferation Of Endothelial Cells

Dysfunction of vascular endothelium is closely related to the pathogenesis of many complex diseases,especially cardiovascular diseases.In this thesis,endothelial cell specific targeting peptides REDV and CAG were used to design and synthesize the targeting peptide functionalized surface of artificial blood vessels and targeting nanoparticles for condensing therapeutic ZNF580 gene(p ZNF580)and to evaluate their influence on the specific adhesion,proliferation,migration and angiogenesis of endothelial cells(ECs).1.A multifunctional surface of artificial blood vessel with EC-specifically adhesive REDV peptide,hydrophilic HPMA and antimicrobial eugenyl methacrylate were designed and developed.The assays of water contact angle and water uptake,platelet adhesion and surface antibacterial demonstrated that the modified surface had better hydrophilicity,hemocompatibility and antibacterial properties.What's more,the REDV peptide functionalized hydrophilic surface enhanced the selective adhesion and proliferation for human umbilical vein endothelial cells(HUVECs).A biomimetic multifunctional surface with good hemocomatibility,endothelialization and antibacterial properties was synthesiezed by the relatively convenient and practical surface modification method.2.The EC-specific REDV and CAG peptides were grafted onto the biodegradable polyethylenimine-poly(lactide-co-glycolide)-polyethylenimine and polyethyleniminepoly(lactide-co-3(S)-methyl-morpholine-2,5-dione)-polyethylenimine copolymers via the bifunctional poly(ethylene glycol)spacer.Then they self-assembled into positive charged nanoparticles to condense the therapeutic pZNF580 via the electrostatic interactions.The targeting peptide endowed the nanoparticles with EC-selective adhesion.The improved transfection efficiency of nanoparticle/pZNF580 complexes on HUVECs was verified by fluorescence images,ZNF580 protein and mRNA from the cell,protein and transcription aspects.Wound healing and transwell assays demonstrated the enhanced migration of transfected HUVECs.The HUVECs transfected by CAG functionalized nanoparticle/pZNF580 complexes exhibited increased angiogenesis in vitro and in vivo.Besides,the introduction of cell-penetrating peptides and nuclear localization signals into the targeting gene delivery systems raised the cell uptake,endosomal/lysomal escape and nucleus importation of the complexes.In summary,REDV peptide modified hydrophilic artificial vascular grafts could selectively promote the adhesion and proliferation of HUVECs.REDV and CAG peptide functionalized nanoparticles effectively delivered the therapeutic pZNF580 into HUVECs,facilitating the migration,proliferation and angiogenesis of HUVECs.The involvement of cell-penetrating peptides and nuclear localization signals further enhanced the transfection efficiency of HUVECs and accelerated the expression of the encapsulated gene.The thesis provided a new platform for targeting gene therapy,especially for endothelialization and vascularization.All these results showed important implications for the treatment of cardiovascular diseases.