Synthesis and characterization of elastic star shape-memory polymers as self-expandable drug-eluting stents
作者:Liang Xue、Shiyao Dai、Zhi Li
DOI:10.1039/c2jm15918j
日期:——
Elastic shape-memory polymers as self-expendable polymeric drug-eluting stents are developed for the first time, with good mechanical properties, fast self-expansion, and sustained drug release. Novel star block co-polymer PCTOPDs containing hyperbranched poly(ε-caprolactone) (PCL) switching segment and poly(2-oxepane-1,5-dione) (POPD) hard segment were synthesized in high yield and characterized by NMR, GPC, DSC, tensile test and cyclic thermomechanical tensile test. PCTOPD containing 15–27 wt% POPD (PCTOPD-15–27) are found to be non-cytotoxic thermoplastic elastomers (Tm of 39–40 and 120–129 °C, εb of 908–1060%, σm of 12–20 MPa, and E of 60–91 MPa) with good shape-memory properties at 40 °C (Rf of 95–97%, Rr of 97–99%, and shape recovery time of 35 s). The stent made from PCTOPD-27 gives nearly full self-expansion at 37 °C within 45 s. The collapse pressure at a compressive strain of 30% is 1.7 bar. A stent containing 3.0 wt% paclitaxel releases 42% drug linearly in the first 9 days and 67% drug in 30 days with a slower but nearly linear release for the period of 10–30 days. The developed SMP-based drug-eluting stents might be useful in biomedical application such as the treatment of coronary artery disease.
首次开发了作为自膨胀聚合物药物涂层支架的弹性形状记忆聚合物,具有良好的机械性能、快速自膨胀和持续的药物释放。合成了包含超级分支聚(ε-己内酯)(PCL)开关段和聚(2-氧戊烯-1,5-二酮)(POPD)硬段的新型星型嵌段共聚物PCTOPDs,产率高,使用NMR、GPC、DSC、拉伸测试和循环热机械拉伸测试进行表征。含有15-27 wt% POPD的PCTOPD(PCTOPD-15-27)被发现是无细胞毒性的热塑性弹性体(熔点为39-40和120-129 °C,断裂伸长率为908-1060%,抗拉强度为12-20 MPa,弹性模量为60-91 MPa),在40 °C下具有良好的形状记忆性能(恢复率为95-97%,回复率为97-99%,形状恢复时间为35秒)。由PCTOPD-27制成的支架在37 °C下在45秒内几乎完全自膨胀。在30%的压缩应变下,崩溃压力为1.7 bar。含有3.0 wt%紫杉醇的支架在前9天以线性方式释放42%的药物,并在30天内释放67%的药物,10-30天期间释放速度较慢但几乎线性。开发的基于形状记忆聚合物的药物涂层支架可能在生物医学应用中,如冠状动脉疾病的治疗中具有重要作用。