Second Section of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan.
Ann Biomed Eng. 2012 Sep;40(9):1961-70. doi: 10.1007/s10439-012-0556-x. Epub 2012 Mar 27.
In this report, a balloon-expandable, biodegradable, drug-eluting bifurcation stent (DEBS) that provides a sustainable release of anti-proliferative sirolimus was developed. Biodegradable bifurcation stents, made of polycaprolactone, were first manufactured by injection molding and hot spot welding techniques. Various properties of the fabricated stents, including compression strengths, collapse pressures, and flow pattern in a circulation test, were characterized. The experimental results showed that biodegradable bifurcation stents exhibited comparable mechanical properties with those of metallic stents and superior flow behavior to that of metallic bifurcation stents deployed via the T And small Protrusion approach. Polylactide-polyglycolide (PLGA) copolymer and sirolimus were then dissolved in acetonitrile and coated onto the surface of the stents by a spray coating device. An elution method and a high performance liquid chromatography analysis were utilized to examine the in vitro release characteristics of sirolimus. Biodegradable bifurcation stents released high concentrations of sirolimus for more than 6 weeks, and the total period of drug release could be prolonged by increasing the drug loading of the PLGA/sirolimus coating layers. In addition, the eluted drug could effectively inhibit the proliferation of smooth muscle cells. The developed DEBS in this study may provide a promising strategy for the treatment of cardiovascular bifurcation lesions.
本报告开发了一种球囊扩张、可生物降解、载药分叉支架（DEBS），可提供抗增殖药物西罗莫司的持续释放。首先采用注塑和热点焊接技术制造出由聚己内酯制成的可生物降解的分叉支架。对制造的支架的各种性能，包括压缩强度、塌陷压力以及循环测试中的流动模式进行了表征。实验结果表明，可生物降解的分叉支架具有与金属支架相当的机械性能，并且通过 T 型支架和小突出物方法部署的金属分叉支架具有更好的流动性能。聚乳酸-聚乙醇酸共聚物（PLGA）共聚物和西罗莫司溶解在乙腈中，然后通过喷涂装置涂覆在支架表面。采用洗脱方法和高效液相色谱分析来检查西罗莫司的体外释放特性。可生物降解的分叉支架在超过 6 周的时间内释放出高浓度的西罗莫司，并且通过增加 PLGA/西罗莫司涂层的药物载量可以延长药物释放的总时间。此外，洗脱的药物可以有效抑制平滑肌细胞的增殖。本研究中开发的 DEBS 可能为治疗心血管分叉病变提供了一种有前途的策略。
