西罗莫司涂层气管支架的制备及体外药物释放研究

Sirolimus-coated stent for tracheal stenosis and its pharmacokinetics in vitro

目的制备西罗莫司涂层支架及探讨药物涂层支架的体外药物释放过程。方法配制不同浓度比例的西罗莫司/聚乳酸-羟基乙酸共聚物(PLGA),制成浸涂液,将清洗过的裸镍钛合金支架置入浸涂液中;通过扫描电镜观察支架表面的形态、结构和覆膜厚度;用酶放大免疫法测定支架的药物释放量。结果西罗莫司可顺利、均匀地附着于支架表面;西罗莫司/PLGA质量比为1∶10的支架上携带的药物量最多,支架涂层的载药量存在饱和效应。气管涂层支架平均载药量为(80.07±2.26)μg。连续6周的体外药物浓度测定发现,西罗莫司气管支架的药物释放在前10天内呈快速释放过程,此后紧跟一个缓慢释放过程。结论西罗莫司涂层支架具有良好的表面形态学特征,并具有持续有效的药物释放特性,值得进一步研发应用。

Objective To investigate the invitro pharmacokinetics of sirolimus-coated stent for tracheal stenosis.Methods Naked nickel-titanium alloy stent was placed in methylene chloride leaching solution with different ratios of sirolimus/poly（lactic-co-glycolic acid）（PLGA）.The morphology,thickness,and pellicles on the surface of the stent were observed by scanning electronic microscopy.Drug release from the stent were determined by enzyme amplification immunoassay.Results Sirolimus was smoothly and uniformly attached to the stent,with an optimal sirolimus：PLGA coating ratio of 1∶10.Further increased in sirolimus：PLGA ratio did not improve the stent drug loading.A slow release of sirolimus from the stent was observed in the first week,followed by a rapid release and then much slower release process.Conclusion The sirolimus-coated stent has a good surface morphology and a sustained and effective drug release characteristics.Thus,it may be effective in the treatment of tracheal stenosis for further research.