Preparation And Characterization Of Co-modified Fiber Membrane Surface Of REDV Peptide And Smart Gene Delivery System

Small-caliber artificial vascular grafts are vital significant for the treatment of vascular diseases,but their clinical applications are limited due to high thrombogenicity.In recent years,rapid endothelialization on the inner surface of vascular grafts is a promising approach to prevent thrombosis and improve the long-term patency rate of vascular grafts.The main bottleneck of rapid endothelialization is that the inner surface of vascular grafts is difficult to adhere endothelial cells(ECs)and has weak capability of promoting the proliferation and migration of ECs.In this study,a small-caliber artificial vascular graft based on poly(lactic acid-cocaprolactone)and gelatin was designed and prepared via electrospinning technology.The surface of graft was co-modified by ECs selective adhesion polypeptide Arg-GluAsp-Val(REDV)and enzyme-responsive gene delivery system.First,biotin functionalized amphiphilic cationic copolymer m PEG-b-PLMD-g-PEI-PEG-Biotin was synthesized,which was further used to load ZNF580 plasmid(p ZNF580)to form gene complexes.Subsequently,gene complexes were connected to the surface via the GPQGIWGQ-C peptide linker featured as matrix metalloproteinase-responsive cleavage using biotin-avidin strong interactions for constructing an enzyme-responsive gene delivery system.This enzymatic release–functionalized gene delivery surface was safe and relatively stable in blood environment.Research results showed that REDV peptide on co-modification surface could selectively adhere ECs.Subsequently,the overexpressed matrix metalloproteinase by ECs could specifically cleave GPQGIWGQ-C peptide linker.And finally,gene complexes were intelligently and enzymatically released from graft surface,and thereby efficiently transfecting ECs.These processes promoted the proliferation and migration of ECs,and finally achieved in situ rapid endothelialization of graft surface.Cell experiments confirmed that m PEG-b-PLMD-g-PEI-PEG-Biotin/p ZNF580 gene complexes were low cytotoxicity and effectively transfection on ECs.Besides,the modified surface of gene complexes was triggered by ECs and mediated effective delivery of p ZNF580 into the nucleus of ECs,which effectively enhanced the proliferation and migration of ECs,and improved in vitro tube-formation.The animal experiment of rat abdominal aorta blood vessel transplantation proved that the comodified surface of vascular grafts accelerated the formation of endothelial layer in vivo,which mainly benefited from the synergistic effect of REDV and enzymetriggered gene transfection.This thesis provides a new avenue for the rapid endothelialization of blood-contacting medical devices,and is of great significance for the research of of vascular diseases treatment.