背景:冠状动脉内置入药物涂层支架显著解决了支架内再狭窄,但是,支架内晚期及超晚期血栓带来新的难题加快支架内皮化,预防血栓形成成为研究的关键。目的:观察内皮细胞在经刻蚀并构建仿生的生物活性表面,整合细胞外基质成分的金属钛表面的生长情况。设计、时间及地点:对比观察,于2007-08/2009-01在西南交通大学先进材料与技术教育部重点实验室完成。材料:成年杂交犬6只,体质量15—20kg,纯钛(99.997%)为西安宝鸡有色金属有限公司产品,切割成5mm×5mm×2mm圆片试样。方法:在已刻蚀的钛表面通过自组装技术构建胶原-肝素-血管内皮生长因子-内皮祖细胞膜蛋白抗体为组分的多层膜作为涂层组;未涂层的钛为未涂层组。成年杂交犬6只,涂层组样品置入右侧股动脉,未涂层组置入左侧股动脉内,获得2h,15d,3个月的样品。主要观察指标:乳酸脱氢酶实验测定黏附血小板的数量;酶联免疫法测定GMP-140以检测黏附血小板激活程度;扫描电镜观察黏附血小板的形貌;采用SysmexCA-600凝血仪测定活化部分凝血活酶时间及凝血酶原时间。扫描电镜观察植入物在不同时间点,内皮细胞在其表面的生长;免疫荧光法观察置入2h的试片表面分化成熟的内皮细胞,其血管内皮生长因子受体2的表达。结果:①乳酸脱氢酶实验显示涂层样片的乳酸脱氢酶值比未涂层显著减少,说明涂层钛可以减少血小板的黏附(P〈0.05)。②黏附血小板激活程度的定量分析结果显示在涂层上黏附血小板P-选择素的表达显著小于未涂层上的表达(P〈0.05)。③扫描电镜可见涂层钛表面黏附血小板形貌的变形程度小于未涂层钛。④涂层的活化部分凝血活酶时间和凝血酶原时间分别是(134.2±13.3),(34.2±5.7)s;未涂层的活化部分凝血活酶时间和凝血酶原时间分别是(44.9±2.3),(17.3±2.4)s,?
BACKGROUND: Coronary artery drug-eluting stent implantation significantly resolves the in-stent restenosis. However, the late and very late in-stent thrombosis makes new problems. Accelerating stent endothelialization to prevent thrombosis is the key in related study. OBJECTIVE: To observe the growth and propagation of vascular endothelial cells (ECs) on the surface of intravascular stent material. DESIGN, TIME AND SETTING: Comparative observation was performed at the Key Laboratory of Advancad Materials Technology, Ministry of Education, Southwest Jiaotong University from August 2007 to January 2009. MATERIALS: Atotal of 6 adult hybrid dogs, weighing 15-20 kg, were used. Pure titanium (99.97%) was purchased from Xi'an Baoji Non-ferrous Metals, and cut into round samples, 5min×5mm×2mm. METHODS: The multilayer of collagen/heparin/vascular growth factor (VEGF)-endothelial progenitor cell membrane protein anti-cluster of differentiation 34(CD34) was constructed by a layer-by-layer self-assembly (LbL)on the surface of'litanium testing slice as coated group. Uncoated group was the bare Titanium testing slice. In 6 adult hybrid dogs, the coated group samples were inserted into the dght femoral artery, the uncoated group samples were inserted into the left femoral artery. The samples of 2 hours, 15 days and 3 months were harvested. MAIN OUTCOME MEASURES: Lactate dehydrogenase(LDH) experiment determined the number of platelet adhesion. Enzyme-linked immunosorbent assay was used to detect the degree of platelet-activating on adhesion. The morphology of adhesive platelet was tested by scanning electron microscope (SEM). Activated partial thromboplastin time (aPTT) and Prothrombin time (PT) tests were measured on Sysmex CA-600 Blood Coagulation Analyzer. SEM evaluated the growth on the surface of implant testing titanium slice at different time points. The expression of vascular endothelial growth factor receptor-2 (VEGF-R2) of maturation EC on the surface of testing