MeKo Laser Material Processing e.K, Sarstedt, Germany.
CVPath Institute, Inc., Gaithersburg, Maryland, USA.
J Biomed Mater Res B Appl Biomater. 2021 Sep;109(9):1292-1302. doi: 10.1002/jbm.b.34790. Epub 2021 Jan 1.
The novel Resoloy® rare earth magnesium alloy was developed for bioresorbable vascular implant application, as an alternative to the WE43 used in Biotronik's Magmaris scaffold, which received CE approval in 2016. Initially, the Magmaris showed very promising preclinical and clinical results, but the formation of an unexpected conversion product and a too fast loss of integrity has proven to be a flaw. The safety and efficacy of Resoloy, which is intended to be bioresorbed without any remnants, has been investigated in an in vitro degradation study and a porcine coronary animal model. Four different groups of scaffolds composed of Resoloy (Res) as the backbone material and additionally equipped with a fluoride passivation layer (Res-F), a polyester topcoat (Res-P), or a duplex layer composed of a fluoride passivation layer and a polymeric topcoat (Res-PF) were compared to a Magmaris scaffold in an in vitro degradation test. Preclinical safety and efficacy of Res-F and Res-PF were subsequently evaluated in a coronary porcine model for 12 and 28 days. Scanning electron microscope, quantitative coronary angiography, micro-computed tomography, histopathology, and histomorphometry analyses were conducted to evaluate preclinical parameters and degradation behavior of the scaffolds. Res-PF with a duplex layer shows the slowest degradation and the longest supporting force of all test groups. The in vitro data are confirmed by the results of the in vivo study, in which Res-PF exhibited a longer supporting force than Res-F, but also caused higher neointima formation. Both studied groups showed excellent biocompatibility. A starter colonization of the strut area with cells during bioresorption was observed. The in vitro degradation test shows that a combination of MgF passivation and a PLLA topcoat on a Resoloy magnesium backbone (Res-PF) leads to a much slower degradation and a longer support time than a Magmaris control group. In a preclinical study, the safety and efficacy of this duplex layer could be demonstrated. The beginning colonization of the degraded strut area by macrophages can be seen as clear indications that the resorption of the intermediate degradation product takes a different course than that of the Magmaris scaffold.
新型 Resoloy®稀土镁合金是为生物可吸收血管植入物应用而开发的，可作为 2016 年获得 CE 批准的 Biotronik 的 Magmaris 支架中使用的 WE43 的替代品。最初，Magmaris 显示出非常有前景的临床前和临床结果，但形成了意想不到的转化产物和过快的完整性丧失已被证明是一个缺陷。旨在无任何残留物的情况下被生物吸收的 Resoloy 的安全性和有效性已在体外降解研究和猪冠状动脉动物模型中进行了研究。在体外降解试验中，将由 Resoloy（Res）作为骨干材料并另外配备氟化物钝化层（Res-F）、聚酯面漆（Res-P）或由氟化物钝化层和聚合物面漆组成的双层（Res-PF）的四个不同支架组与 Magmaris 支架进行了比较。随后，在冠状动脉猪模型中对 Res-F 和 Res-PF 进行了 12 和 28 天的临床前安全性和疗效评估。扫描电子显微镜、定量冠状动脉造影、微计算机断层扫描、组织病理学和组织形态计量学分析用于评估支架的临床前参数和降解行为。所有测试组中，具有双层的 Res-PF 显示出最慢的降解速度和最长的支撑力。体外数据得到体内研究结果的证实，其中 Res-PF 表现出比 Res-F 更长的支撑力，但也导致更高的新生内膜形成。两个研究组均表现出良好的生物相容性。在生物吸收过程中观察到细胞在支架区域的起始定植。体外降解试验表明，MgF 钝化和 PLLA 面漆在 Resoloy 镁骨架上的组合（Res-PF）导致比 Magmaris 对照组更慢的降解和更长的支撑时间。在临床前研究中，证明了这种双层的安全性和有效性。可以看到巨噬细胞对降解支架区域的起始定植，这清楚地表明中间降解产物的吸收过程与 Magmaris 支架不同。
