| Percutaneous coronary interventional (PCI)as the main interventional therapies of coronary artery disease has induced the restenosis of blood vessel, which has restricted its development. The planting of stent in blood vessel can decrease the restenosis incidence rate, but that also brings the in-stent restenosis (ISR). Now the emergence of drug-eluting stents has reduced the incidence of ISR. The drug coated on stents can inhibit or breakdown DNA synthesis in cell, which can inhibit the neoinerma hyperplasy and affect the cell proliferation. Studies shows that rapid endothelium of stents may be an available method to inhibit ISR, which can make injuried vessel wall reendothelialization quickly. However, the adhesion, proliferation and resource of cells planted on the stent are the unsolved questions in the endothelialization process of stents. Recent studies show that endothelial progenitor cells (EPCs) are a cell population that has the capacity to circulate, proliferate, and differentiate into mature endothelial cells, and EPCs has been identified as a key factor for re-endothelialization.The EPCs capture stents have been developed using immobilized antibodies targeted at EPCs surface antigens. Antibody-coated stent planted into vessel to capture EPCs in circulating blood and to keep them on stent and to make stent endotheliazation depends on the adhesion, proliferation of EPC on antibody coating.Now the studies on stent surface endothelialum focus on the resource of cell, the time of endothelium and the anti-restenosis capability. In this study, EPCs from SD rat were isolated by density gradient centrifugation with Percoll solution. And immunofluorescence, immunocytochemistry and flow cytometry were used to identify EPCs. EPCs adhesion force on different substrates was detected by use of single micropipette aspiration technique. The effect of shear stress on adhesion of EPCs to substrates (anti-VEGFR2, anti-CD34 and anti-CD133) by parallel plate flow Chamber technique at multi-cell level. The proliferation of EPCs treated with sophorcarpidine solution was assayed with MTT assay, and the cell cycle was detected with flow cytometer (FCM). At last, the EPCs capture ability was valued.Results showed that the high purity EPCs was obtained by density gradient centrifugation with Percoll solution, and EPCs were VEGFR2+CD34+CD133+ cells. The adhesion force of EPCs and endothelial cells on different substrates depended on concentration of gelatin, anti-VEGFR2, anti-CD34 and anti-CD133. The adhesion characters of EPCs on the four substrate materials were better than that of ECs. And the same time, the adhesion force of EPCs to antibody CD133 was the strongest among the four substrate materials. The study on the effect of shear stress on EPCs showed that the proliferation rate and reservation rate on anti-CD133 coating have great difference to compare with other substrates (anti-VEGFR2 and anti-CD34). And the NO expression of EPCs was increased with the treatment of shear stress. Sophorcarpidine increased EPCs adhesive activity at concentration 100μg/ml. With the increase of Sophorcarpidine concentration, the apoptosis rate decreased with significant difference (P<0.05). However, cytotoxicity was seen at higher sophorcarpidine concentration (150μg/ml). The minimum apoptosis rate was (1.87±1.682) % at concentration 100μg/ml. The ability of capturing EPCs of CD133 antibody coating was stronger than that of CD34 antibody coating.In a word, these findings in this study may offer the researchers the inspiration to realize the endothelialization of stent surface, and be the reference for the research of endothelialization of artificial heart valve and artificial vascular.
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