涂层工艺对聚碳酸亚乙酯载药涂层性能和体外释放动力学的影响

Effect of Preparation Methods on Property and Drug Release Kinetics of Sirolimus Loaded Poly(ethylene carbonate) Coatings

为了考察不同涂层工艺对冠脉支架涂层的影响,分别采用手动浸涂和自动超声喷涂法在316L不锈钢冠脉支架基体表面制备含雷帕霉素的聚碳酸亚乙酯(PEC)涂层。首先对PEC进行了凝胶渗透色谱(GPC)、差示扫描量热(DSC)以及拉伸实验测试,初步证明其物理化学性质适合作支架可降解涂层材料。然后用扫描电子显微镜(SEM)、原子力显微镜(AFM)、接触角测定仪、球囊扩张法等对涂层表面的形貌、亲水性以及涂层和支架基体的结合力进行分析,并在PBS(pH=7.4)模拟体液中测试上述两种工艺方法制备的药物洗脱支架体外药物释放动力学曲线。结果表明,上述两种方法制备的药物涂层在微观结构、亲水性以及与支架的结合力方面存在一定差异,药物释放速率和释放趋势也有所不同,超声喷涂法制备的药物洗脱支架释放速率和释放趋势较稳定。

To understand the effect of preparation methods on stent coating, sirolimus loaded poly（ethylene carbonate） coatings were prepared on the surfaces of 316L stainless steel substrates by manual dipping method and au- tomatic ultrasonic spraying method respectively. Firstly, PEC was analyzed by gel permeation chromatography （GPC）, differential scanning calorimetry （DSC） and strain-stress test, and the initial results demonstrate that PEC is suitable to be as stent biodegradable coating material. Then the microstructure and hydrophilicity of the drug loaded coatingPs surfaces were analyzed by scanning electron microscopy （SEM）, atomic force microscopy （AFM） and con- tact angle meter. Further the bonding strength between coating and substrate was tested through balloon dilation. In vitro drug release kinetics curves were experimented in PBS finally. The results show some differences in mean rough- ness, hydrophilicity and the bonding strength. In vitro drug release behavior of drug eluting stent prepared by auto- matic ultrasonic spraying method is more stable than that prepared by manual dipping method.