可降解血管支架材料的表面性能及生物相容性

Biodegradable vascular stent materials: surface properties and biocompatibility

背景:临床治疗多种心血管疾病的过程中,可降解支架植入治疗是一种常用的手段,相应的支架应该具备良好的表面性能和生物相容性。目的:观察可降解血管支架材料的表面性能,并对其生物相容性进行分析。方法:制备人工血浆,对可降解镁合金支架进行浸泡,利用电镜扫描观察材料表面的腐蚀情况。制备材料浸提液,进行细胞毒性实验,观察浸提液培养人脐静脉内皮细胞的毒性反应级别。进行血小板黏附实验和溶血率测试,检测材料的细胞相容性和血液相容性。结果与结论:人工血浆中浸泡10 d后对材料进行电镜扫描和观察,可以观察到在材料表面形成了一层均匀分布的腐蚀层。在对材料进行吹干的过程中,腐蚀层出现裂纹。对腐蚀产物进行清洗之后观察,材料腐蚀表面主要为呈均匀分布的腐蚀坑点。细胞毒性实验中,阳性对照组中细胞无吸光度值,几乎全部死亡。材料浸提液组中不同人脐静脉内皮细胞培养时间,反应级别均为0或1级。经黏附实验,电镜扫描可以发现在材料表面血小板大多呈圆盘状,一些血小板发生形变,伸出伪足,未出现血小板聚集现象。经溶血率测试,材料的溶血率为3.15%。对国家医疗器械生物学评价标准进行比较,符合溶血率小于5%的要求。结果表明,可降解镁合金血管支架材料具有良好的耐腐蚀性能,且具有良好的细胞形容性和血液相容性,可以满足临床应用的需求。

BACKGROUND： Biodegradable stent implantation is a commonly used method in the clinical treatment of a variety of cardiovascular diseases. Importantly, the corresponding stent should have good surface properties and biocompatibility. OBJECTIVE： To observe the surface properties of the biodegradable vascular stent material, and to analyze its biocompatibility. METHODS： Artificial plasma was prepared for soaking the biodegradable magnesium alloy stent, and the corrosion of the material was observed by scanning electron microscope. Stent extraction solution was prepared and cytotoxicity test was carried out to observe the toxicity level of human umbilical vein endothelial cells cultured in the culture medium. Platelet adhesion test and hemolysis test ware performed to detect cell and blood compatibility of the material. RESULTS AND CONCLUSION： After the 10-day immersion in artificial plasma, the material was scanned and a uniform corrosion layer was found on the surface of the material. During the drying of the material, some cracks appeared on the corrosion layer. After the corrosion products were removed, there were corrosion pits uniformly distributed on the corrosion surface of the material. In the cytotoxicity test, there were no absorbance values in the positive control group, and almost all of the cells died. After cultured in the material extraction, the toxicity level of human umbilical vein endothelial cells was graded 0 or 1. In the adhesion test, platelets on the stent surface were mostly disk-shaped under scanning electron microscope some of which were deformed and extended pseudopodia, but no platelet aggregation occurred. The hemolysis rate of the material was 3.15%, in accordance with the requirement of the hemolytic rate 〈 5%. These experimental results show that the biodegradable magnesium alloy stent material has good corrosion resistance and good cell and blood compatibility, which can meet the demand of clinical application.