镁基支架是下一代完全可降解血管支架的有希望的候选者。最新进展包括基于Magmaris®WE43的药物洗脱支架的CE批准。然而,到目前为止,长期(植入1年以上)体内降解和降解产物引起的生理效应尚不清楚。在这项研究中,在裸露的Mg-Nd-Zn-Zr之后进行了20个月的观察(缩写。JDBM)支架原型植入新西兰大白兔颈总动脉,评价其安全性,功效,尤其是降解行为。还研究了主要第二相Mg12Nd的降解。结果表明,JDBM裸支架具有良好的安全性和有效性,在28天内完全重新内皮化。JDBM支架支柱在4个月内大部分被降解产物原位替换。重要的发现是降解产物的体积和Ca浓度长期下降,消除临床医生对血管钙化的担忧。此外,尽管植入1个月后Nd和Zr在脾脏和肝脏中突然增加,但由于未检测到任何主要器官的持续富集,因此支架中的合金元素Mg和Zn可以安全代谢。总的来说,长期体内结果显示JDBM支架的快速再内皮化和降解产物的长期安全性,表明其作为完全可降解血管支架骨干的巨大潜力。
镁基支架是下一代完全可降解支架的有希望的候选者,特别是在最近推出了同类产品(Magmaris)之后。然而,关于镁基支架及其降解产物的长期降解和代谢机制的基本问题仍然没有答案。我们将我们的专利Mg-Nd-Zn-Zr裸支架植入家兔颈总动脉,并进行了20个月的观察。我们发现含Ca的降解产物可以在体内进一步降解。所有合金元素在兔的主要器官中没有连续富集。这些发现在一定程度上消除了临床医生对镁合金支架植入后血管钙化和元素富集的担忧。
Mg-based stent is a promising candidate of the next generation fully degradable vascular stents. The latest progress includes the CE approval of the Magmaris ® WE43 based drug eluting stent. However, so far, the long term (more than 1 year implantation) in vivo degradation and the physiological effects caused by the degradation products were still unclear. In this
study, a 20 month observation was carried out after the bare Mg-Nd-Zn-Zr (abbr. JDBM) stent prototype was implanted into the common carotid artery of New Zealand white rabbit in order to evaluate its safety, efficacy and especially degradation behavior. The degradation of the main second phase Mg12Nd was also studied. Results showed that the bare JDBM stent had good safety and efficacy with a complete re-endothelialization within 28 days. The JDBM stent struts were mostly replaced in situ by degradation products in 4 month. The important finding was that the volume and Ca concentration of the degradation products decreased in the long term, eliminating the clinicians\' concern of possible vessel calcification. In addition, the alloying elements Mg and Zn in the stent could be safely metabolized as continuous enrichment in any of the main organs were not detected although Nd and Zr showed an abrupt increase in spleen and liver after 1 month implantation. Collectively, the long term in vivo results showed the rapid re-endothelialization of JDBM stent and the long term safety of the degradation products, indicating its great potential as the backbone of the fully degradable vascular stent.
Mg-based stent is a promising candidate of the next generation fully degradable stents, especially after the recent market launch of one of its kind (Magmaris). However the fundamental question about the long term degradation and metabolic mechanism of Mg-based stent and its degradation products remain unanswered. We implanted our patented Mg-Nd-Zn-Zr bare stent into the common carotid artery of rabbits and conducted a 20 months observation. We found that the Ca containing degradation products could be further degraded in vivo. All the alloying elements showed no continuous enrichment in the main organs of rabbits. These findings eliminate the clinicians\' concern of possible vessel calcification and element enrichment after the implantation of Mg alloy based stents to some extent.