Long-term surveillance of zinc implant in murine artery: Surprisingly steady biocorrosion rate.
Long-term surveillance of zinc implant in murine artery: Surprisingly steady biocorrosion rate.
复制标题
DOI：
10.1016/j.actbio.2017.05.045
复制
发表时间：
2017-08
影响因子：
9.7
通讯作者：
Goldman J
中科院分区：
文献类型：
--
作者：
Drelich AJ;Zhao S;Guillory RJ 2nd;Drelich JW;Goldman J
将金属锌植入大鼠腹主动脉长达6个月，已被证明可降解，同时避免了通常与血管植入物再狭窄相关的反应。然而，关于锌植入物最终是通过产生稳定的腐蚀产物还是通过细胞介导的纤维包裹过程防止关键反应物和产物在金属表面扩散而最终钝化的主要问题仍然存在。在这里，我们进行了临床相关的长期活体研究，以表征晚期锌种植体的生物腐蚀行为和产品，以解决这些关键问题。我们发现，植入小鼠动脉的锌丝在植入后至少20个月内表现出稳定的腐蚀，没有局部毒性，尽管钝化腐蚀产物的稳定积累和金属丝的纤维状包裹。尽管纤维包裹不能防止种植体的持续腐蚀，但这可能与植入后10至20个月观察到的慢性炎症减轻有关。X射线元素分析和红外光谱分析证实，锌种植体周围腐蚀产物的主要成分是氧化锌、碳酸锌和磷酸锌。这些产物符合从生理溶液的Pourbai图和体外电化学阻抗测试得出的稳定相。这一结果支持了早期的预测，即锌支架可以成功地生物整合到动脉环境中，并在大约1-2年的时间内安全地降解。
Metallic zinc implanted into the abdominal aorta of rats out to 6 months has been demonstrated to degrade while avoiding responses commonly associated with the restenosis of vascular implants. However, major questions remain regarding whether a zinc implant would ultimately passivate through the production of stable corrosion products or via a cell mediated fibrous encapsulation process that prevents the diffusion of critical reactants and products at the metal surface. Here, we have conducted clinically relevant long term in vivo studies in order to characterize late stage zinc implant biocorrosion behavior and products to address these critical questions. We found that zinc wires implanted in the murine artery exhibit steady corrosion without local toxicity for up to at least 20 months post-implantation, despite a steady buildup of passivating corrosion products and intense fibrous encapsulation of the wire. Although fibrous encapsulation was not able to prevent continued implant corrosion, it may be related to the reduced chronic inflammation observed between 10 and 20 months post-implantation. X-ray elemental and infrared spectroscopy analyses confirmed zinc oxide, zinc carbonate, and zinc phosphate as the main components of corrosion products surrounding the Zn implant. These products coincide with stable phases concluded from Pourbaix diagrams of a physiological solution and in vitro electrochemical impedance tests. The results support earlier predictions that zinc stents could become successfully bio-integrated into the arterial environment and safely degrade within a time frame of approximately 1 – 2 years.