Improves Endothelialization Of Acellular Bovine Jugular Vein Conduit Modified By RGD: A Experimental Study

Part 1Objective: To investigate a method of using ammonialow-temperature plasma treatment immobilizing GRGDSPK (Gly-Arg-Gly-Asp-Ser-Pro-Lys) peptide on acellular bovine jugular veinconduit(BJV) and investigate the feasibility and effect.Methods: Acellular bovine jugular vein matrix was obtained bychemical decellularization and dye-mediated photooxidation (DMP)technique, then treated with freeze-drying process. The methods wereachieved modifying the GRGDSPK peptide on the surface of acellularbovine jugular vein conduit by ammonia plasma-induced in sitepolymerization and physical absorbtion process. The condition ofammonia low-temperature plasma treatment was 50w and 2rain. Thechanges of surface physical and chemical characteristics of acellularbovine jugular vein conduit was analysis by x-ray photoelectronspectroscopy(XPS) and confocal laser scanning microscopy(LCSM);endothelial cell culture experiment were used to evaluate tissuecompatibility of RGD modified BJV; the mechanics performance was also evaluated by tensile force equipment.Results: After ammonia low-temperature plasma treatment, thesurface some polar groups such as carbon-oxygen functionalities andnitrogen functionalities were successfully introduced to the surface ofbovine jugular vein conduit. After immerged into GRGDSPKpeptide(0.22mg/ml) solution, the surface some polar groups sharplydecreased; compared with the group of physical absorbtion, usingammonia low-temperature plasma treatment immobilizing GRGDSPKpeptide on the surface of BJV could effectively resist the fluid sheafingforce in vitro; endothelial cell culture experiment confirmed ammonialow-temperature plasma treatment immobilizing GRGDSPK peptide onthe surface of BJV could significantly improve the cell affinition ofacellular bovine jugular vein matrix. Compared with acellular bovinejugular vein, only one index of mechanics performance was found hadsignificant decreased in the group with ammonia plasma treatment andRGD modification.Conclusion: As a convenient method, ammonia low-temperatureplasma treatment can realized immobilizing RGD peptide on the surfaceof acellular bovine jugular vein conduit; the cell affinition of acellularbovine jugular vein can be improved by this method. But, the treatment offreeze-drying process had some negative influence on the the mechanicsperformance of BJV. Part 2Objective: To investigate whether RGD modified aceUular bovinejugular vein grafts could promot endothelium growth in vivo.Methods: According to the principle of matching, after processedwith ammonia low-temperature plasma treatment immobilizing RGD,acellular bovine jugular vein were sutured into 3.1 ram-diameter vasculargrafts. Health SD rat, weight 350-380g, were chosed as experimentalanimals. Experimental animals were divided into PR-BJV group (graftstreated with plasma process and RGD modification, n=24) and BJV group(had nothing surface treatment, n=24) seif-made vascular prothesis wereimplanted into the inferior vena cave(IVC) of rats based on matched-pairsprinciple. The vein grafts were harvested at 3 d, 1 w, 2 w, 3 w afterimplantation. The patency and mural thrombus of grafts were evaluated;the thickness of neointima was measured and analysised by gross andlight microscopy observation; scanning electron microscope (SEM) wereused to evaluate neoendothelial cells on grafts surface.Imunohistochemical method withâ…§factors antibody was also used to evaluat endothelialization.Results: Except 3 d, the patent of implanted vascular gaffs inPR-BJV group all exceeded the grafts in BJV group; Gross and lightmicroscope discover the thinness neointima comprising a lots of cell onthe surface PR-BJV group at 3d; moreover, the neointima increased veryslow with the elapse of time; the surface of PR-BJV group also littlethrombosis emerge. There were only seldom thrombosis on the surface ofBJV group at 3d; but, the neointima and thrombosis were significantlybuildup from 7d after vascular implantation. SEM andimunohistochemical methods confirmed that there were endothelial celladhereing on the surface of PR-BJV group grafts at 7d. The completelyendothelial cell line forming on the surface of PR-BJV group at 14d; andneointima hyperplasia and thrombosis was relieved by this reason.conversely, there were only little endothelial cell creeping fromanastomotic stoma at 21d and poor endothelial cell line on the surface inBJV group.Conclusion: Owing to the histocompatiability being improved withplasma treated and RGD modification, acellular bovine jugular veingrafts can promot cndothelium growth of rat in vivo.