Guillory Roger J, Bowen Patrick K, Hopkins Sean P, Shearier Emily R, Earley Elisha J, Gillette Amani A, Aghion Eli, Bocks Martin, Drelich Jaroslaw W, Goldman Jeremy
Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
Division of Pediatric Cardiology, University of Michigan Congenital Heart Center, Ann Arbor, Michigan 48109, United States.
ACS Biomater Sci Eng. 2016 Dec 12;2(12):2355-2364. doi: 10.1021/acsbiomaterials.6b00591. Epub 2016 Nov 23.
There has been considerable recent interest to develop a feasible bioresorbable stent (BRS) metal. Although zinc and its alloys have many potential advantages, the inflammatory response has not been carefully examined. Using a modified wire implantation model, we characterize the inflammatory response elicited by zinc at high purity (4N) [99.99%], special high grade (SHG)[∼99.7%], and alloyed with 1 wt % (Zn-1Al), 3% (Zn-3Al), and 5.5% (Zn-5Al) aluminum. We found that inflammatory cells were able to penetrate the thick and porous corrosion layer that quickly formed around SHG, Zn-1Al, Zn-3Al, and Zn-5Al implants. In contrast, a delayed entrance of inflammatory cells into the corrosion layer around 4N zinc due to a significantly lower corrosion rate was associated with greater fibrous encapsulation, appearance of necrotic regions, and increased macrophage labeling. Interestingly, cell viability at the interface decreased from SHG, to Zn-1Al, and then Zn-3Al, a trend associated with an increased CD68 and CD11b labeling and capsule thickness. Potentially, the shift to intergranular corrosion due to the aluminum addition increased the activity of macrophages. We conclude that the ability of macrophages to penetrate and remain viable within the corrosion layer may be of fundamental importance for eliciting biocompatible inflammatory responses around corrodible metals.
最近，人们对开发一种可行的生物可吸收支架（BRS）金属产生了浓厚兴趣。尽管锌及其合金具有许多潜在优势，但炎症反应尚未得到仔细研究。我们使用改良的金属丝植入模型，对高纯度（4N）[99.99%]、特级高纯度（SHG）[约99.7%]以及与1 wt%（Zn-1Al）、3%（Zn-3Al）和5.5%（Zn-5Al）铝合金化的锌引发的炎症反应进行了表征。我们发现，炎症细胞能够穿透在SHG、Zn-1Al、Zn-3Al和Zn-5Al植入物周围迅速形成的厚而多孔的腐蚀层。相比之下，由于腐蚀速率显著降低，炎症细胞进入4N锌周围腐蚀层的时间延迟，这与更严重的纤维包裹、坏死区域的出现以及巨噬细胞标记增加有关。有趣的是，界面处的细胞活力从SHG到Zn-1Al再到Zn-3Al逐渐降低，这一趋势与CD68和CD11b标记以及包膜厚度的增加有关。潜在地，由于添加铝导致的晶间腐蚀转变增加了巨噬细胞的活性。我们得出结论，巨噬细胞穿透腐蚀层并在其中保持活力的能力可能对于引发可腐蚀金属周围的生物相容性炎症反应至关重要。
