等离子体处理脱细胞血管支架的血液相容性

Blood compatibility of decellularized vascular scaffolds by plasma initiated surface modification

背景:由于脱细胞方法去除了血管内表面的内皮细胞层,容易引发血栓形成,因此有必要对脱细胞支架表面进行改性处理。目的:观察兔腹主动脉脱细胞支架等离子体处理后血液相容性的改变。设计、时间及地点:血管支架的血液相容性实验,2007-12/2008-05在南京大学医学院附属鼓楼医院实验室完成。材料:新西兰大白兔24只由鼓楼医院实验动物中心提供;富含血小板血浆由南京血液中心提供。方法:新西兰大白兔盐酸氯胺酮麻醉后,仰位固定,腹部正中切口,仔细游离腹主动脉,直径约2mm。阻断血流后,剪下一段腹主动脉长约20mm,肝素生理盐水冲洗,再用Tris缓冲生理盐水冲洗,酶解方法制备兔腹主动脉脱细胞支架,利用等离子体处理引发脱细胞支架表面改性。主要观察指标:通过光镜观察兔腹主动脉脱细胞支架等离子体处理前后结构的变化;电镜观察处理前后支架表面形态的改变;通过表面接触角仪测定两组支架表面的亲水性;血小板黏附实验观察处理前后支架表面血液相容性。结果:兔腹主动脉脱细胞处理后,光镜和电镜检测见血管壁保留胶原纤维和弹力纤维,未见明显细胞残留;兔腹主动脉脱细胞支架等离子体处理前后光镜检测未见明显异常,电镜检测见脱细胞支架表面呈沟槽样,沟槽间表面光滑,经等离子体处理后表面仍呈沟槽样,但沟槽间表面粗糙;兔腹主动脉脱细胞支架经等离子体处理后接触角明显减小(P<0.01);血小板黏附实验中,脱细胞血管组见多量血小板黏附,而等离子体处理脱细胞支架组有相对较少血小板黏附。结论:兔腹主动脉脱细胞支架通过等离子体处理后,具有良好的亲水性和抗凝血性。

BACKGROUND： In decellularizative procedures, endothelium layer is removed, which leads to thrombosis, accordingly, it is necessary to modify the decellularized vascular scaffolds. OBJECTIVE： To investigate the effects of plasma initiated surface modification in improving the blood compatibility of decellularized vascular scaffolds of rabbits abdominal aortal. DESIGN, TIME AND SETTING： The test of blood compatibility with vascular scaffolds was performed at the Affiliated Drum Tower Hospital of Nanjing University Medical School between December 2007 and May 2008. MATERIALS： Twenty-four New Zealand rabbits were supplied by experimental animal center of Drum Tower Hospital. The platelet rich plasma was provided by Nanjing Blood Center. METHODS： New Zealand rabbits were anesthetized with ketamine, fixed on back and longitudinally cut in abdominal region, infused aortic 2 mm. After basllar artery was blocked, 20 mm abdominal aorta were obtained and washed with heparin-saline followed by Tns buffered saline. Decellularized vascular scaffolds of rabbits abdominal aortal were obtained by enzymolysis and underwent surface modification with plasma initiation technique. MAIN OUTCOME MEASURES： Light microscopy and scanning electron microscopy （SEM） was used to observe the morphological features of decellularized vascular scaffolds before and after plasma initiated, hydrophilia of scaffolds were calculated with water contact angle. The blood compatibility of modified decellularized vascular scaffolds surface was assayed by platelet adhesion test. RESULTS： Light microscopy showed that there were no cells remained in vascular walls after enzymolysis and no significant difference in morphological features before and after modified. SEM showed groove-like surface morphology in the control group and smooth between grooves. In the treated group, SEM also showed groove-like surface morphology, but rough between grooves. The water contact angle in the treated group was obvious smaller than that of the control group （P 〈 0.01 ）. The platelet adhesion test showed that the number of adhering platelets was less on the surface of the modified decelluladzed vascular scaffolds than on the surface of un-modified decellularized vascular scaffolds. CONCLUSION： Plasma modified decellularized vascular scaffolds possess excellent hydrophilia as well as blood anticoagulant activity.