Improved Biocompatibility and Biodegradation of Zn-based Stent Materials through Surface Nano-Engineering

通过表面纳米工程改善锌基支架材料的生物相容性和生物降解性

• 批准号: 8871928
• 负责人: Jaroslaw W Drelich
• 金额: $ 20.4万
• 依托单位: MICHIGAN TECHNOLOGICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8871928
• 关键词: Alloys; American Heart Association; Arteries; Behavior; Biocompatible; Biodegradation; Blood Vessels; Characteristics; Chronic; Corrosion; Engineering; Environment; Evaluation; Exhibits; Failure; Film; Geometry; Implant; Lead; Lithium; Magic; Metals; Methods; Michigan; Modification; Oxides; Penetration; Physiological; Property; Rare Earth Metals; Rattus; Research; Risk; Sampling; Solutions; Stents; Structure; Surface; Tensile Strength; Testing; Thick; Time; Zinc; base; biomaterial compatibility; design; implant material; implantation; improved; in vivo; meetings; nanoengineering; percutaneous coronary intervention; programs; public health relevance; statistics; success

 DESCRIPTION: Metal stents are commonly used to revascularize occluded arteries. The American Heart Association states that 622,000 percutaneous coronary interventions were performed in 2007 (the most recent period for which statistics have been compiled). A bio absorbable metal stent that harmlessly erodes away over time could minimize the normal chronic risks associated with permanent stents. Mg- and Fe-based alloys are currently pursued in designing such biodegradable stents with a limited success. Only one commercial Mg-based stent called Lekton Magic Stent and developed by Biotronik was recently introduced but it dissolves away too fast and involves rare earth elements, which have unknown biocompatibility. The research proposed at Michigan Tech aims to develop, for the first time, an alternative line of Zn-based stents that last 6-9 months in vivo and contain biocompatible Li. Preliminary study suggests that zinc exhibits ideal physiological corrosion behavior for bio absorbable stent application. The viability of a zinc stent was demonstrated in our preliminary study. The corrosion behavior in vivo for zinc and zinc-lithium with a passive layer of oxide film and its effect on the degradation rate in the vascular environment remain open questions, and are the subjects of the proposed program. The overall feasibility of a bio absorbable zinc and zinc-based stents with engineered surfaces will be evaluated. An in vivo evaluation of materials bio corrosion will be completed utilizing a recently developed arterial implantation method in which a sample with wire geometry is implanted into the arterial wall of a rat. Zinc-lithium alloys will be prepared in order to tailor the material properties to accepted values of tensile strength, elongation to failure, and penetration rate. Oxide films of varying thickness and structure will be formulated on surfaces of both zinc and zinc-lithium alloys using an anodization. The surface engineering of thin oxide films will lead to tunable rates of bio corrosion. The research will lead to selection of surface modification characteristics that meets the following criteria: i) improve hemocompatibility and biocompatibility and zinc-based implant materials; ii) keep corrosion rates below the 0.02 mm/year value in the first 3-4 months; and iii) will not protect metal from accelerated (>0.02 mm/year) biodegradation after 4 months.

 描述：金属支架通常用于闭塞动脉血运重建，2007 年进行了 622,000 例经皮冠状动脉介入治疗（最近一次统计）。随着时间的推移，可生物吸收的金属支架会无害地侵蚀。目前，在设计此类可生物降解支架时，人们一直在追求镁基和铁基合金，以最大限度地减少与永久支架相关的正常慢性风险。最近推出了一种名为 Lekton Magic Stent 的商用镁基支架，由 Biotronik 开发，但它溶解速度太快，并且含有稀土元素，而稀土元素具有未知的生物相容性。密歇根理工大学提出的研究旨在首次开发，锌基支架的替代系列，可在体内持续 6-9 个月，且含有生物相容性锂。初步研究表明，锌对于生物可吸收支架的应用表现出理想的生理腐蚀行为。在我们的初步研究中，具有钝化氧化膜层的锌和锌锂的体内腐蚀行为及其对血管环境中降解率的影响仍然是悬而未决的问题，也是该计划的总体可行性的主题。将利用最近开发的动脉植入方法来评估具有工程表面的生物可​​吸收锌和锌基支架的材料生物腐蚀的体内评估，其中将具有金属丝几何形状的样品植入到动脉壁中。鼠。锌锂合金将 为了使材料性能适应拉伸强度、断裂伸长率和不同厚度和结构的渗透率的可接受值而准备。 使用阳极氧化在锌和锌锂合金表面配制的薄氧化膜的表面工程将导致可调节的生物腐蚀速率。 选择满足以下标准的表面改性特性：i) 改善血液相容性和生物相容性以及锌基植入材料；ii) 在前 3-4 个月内将腐蚀率保持在 0.02 毫米/年以下；以及 iii) 不会；保护金属在 4 个月后免于加速（>0.02 毫米/年）生物降解。