Biodegradation mechanism and rate, biocompatibility, and toxicity for novel Zn-Mg stent materials

新型锌镁支架材料的生物降解机制和速率、生物相容性和毒性

• 批准号: 8957197
• 负责人: Jeremy Goldman
• 金额: $ 44.2万
• 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: 2015-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8957197
• 关键词: Absorbable Implants; Address; Adverse effects; Alloys; Arteries; Behavior; Benchmarking; Biodegradation; Blood; Blood Vessels; Cardiovascular system; Cells; Cereals; Chronic; Coronary; Corrosion; Developed Countries; Diet; Ensure; Environment; Evaluation; Exhibits; Failure; Fibroblasts; Generations; Geometry; Health; Heart Diseases; Human; Hyperplasia; Implant; Iron; Lead; Magnesium; Mechanics; Metabolic Clearance Rate; Metals; Methods; Michigan; Modeling; Mus; Obesity; Oxides; Patients; Penetration; Physiological; Procedures; Property; Rattus; Research; Resistance; Risk; Sampling; Smooth Muscle Myocytes; Stainless Steel; Stents; Tensile Strength; Testing; Time; Toxic effect; Work; Zinc; abdominal aorta; base; biomaterial compatibility; cardiovascular health; cytotoxicity test; design; implantation; improved; in vivo; interest; meetings; novel; programs; scaffold; success

 DESCRIPTION: Heart disease is of great societal interest due to its drastic impact on health in industrialized nations, especially in developed countries where obesity rates are high and the typical diet is not conducive to cardiovascular health. While invasive procedures are not desirable, they are often crucial to ensuring patient survival. The 5 million coronary stents administered world-wide each year remain present in the human artery for the lifetime of the patient. This has resulted in the emergence of several serious side effects. 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 currently pursued in designing such biodegradable stents have met with limited success. 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. Preliminary study suggests that zinc exhibits ideal physiological corrosion behavior for bio absorbable stent application. The viability of a Zn-Mg stent, the corrosion behavior in vivo, and the degradation rate in the vascular environment remain open questions, and are the subjects of the proposed program. The overall feasibility of bio absorbable Zn-Mg stents 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. Zn-Mg alloys will be prepared in order to tailor the material properties to accepted values of tensile strength, elongation to failure, and penetration rate. Our preliminary study has shown that the magnesium addition to zinc increases the mechanical strength. In addition, electro/chemically active Mg additions will lead to tunable rates of bio corrosion. The research will lead to selection and testing of a Zn-Mg alloy that meets the following criteria: i) keep corrosion rates close to the 0.02 mm/year value; ii) have >200 MPa yield strength, and >20% elongation to failure; and iii) exhibit biocompatibility similar to 316L stainless steel, industria standard for stent materials.

 描述：心脏病具有极大的社会兴趣，因为它对工业化国家的健康影响巨大，尤其是在肥胖率很高且典型饮食的发达国家中没有进行心血管健康。尽管侵入性程序并不可取，但它们通常对于确保患者生存至关重要。每年在全球范围内管理的500万个冠状动脉支架在人类动脉中仍然存在于患者的一生中。这导致出现了几种严重的副作用。随着时间的流逝，无害发射的生物吸附金属支架可以最大程度地减少与永久支架相关的正常慢性风险。目前在设计此类可生物降解支架方面追求的MG和FE基合金取得了有限的成功。密歇根理工学院提出的研究旨在首次开发基于Zn的支架的另一种替代行，持续6-9个月 体内。初步研究表明，锌为生物可吸收支架应用表现出理想的生理腐蚀行为。 Zn-MG支架，体内腐蚀行为和血管环境中的降解率的生存能力仍然是空的问题，并且是拟议程序的主题。将评估生物可吸收Zn-mg支架的总体可行性。材料的体内评估生物腐蚀将使用最近开发的巧克力方法完成，其中将带有电线几何形状的样品植入大鼠的伪像壁中。将准备Zn-MG合金以量身定制材料特性 拉伸强度，伸长到失败和穿透率的值。我们的初步研究表明，锌添加的镁增加了机械强度。此外，电/化学活性的MG添加将导致可调的生物腐蚀速率。这项研究将导致符合以下标准的Zn-MG合金的选择和测试：i）保持腐蚀速率接近0.02 mm/年的价值； ii）具有> 200 MPa的屈服强度和> 20％的失败伸长； iii）暴露的生物相容性类似于316L不锈钢，这是支架材料的行业标准。