ICF Mechanical Property Optimisation of Magnesium Alloy Wires for Bioresorbable Vascular Scaffolds for the Treatment of Peripheral Arterial Disease

用于治疗外周动脉疾病的生物可吸收血管支架镁合金丝的 ICF 机械性能优化

• 批准号: MR/Z503897/1
• 负责人: David Nash
• 金额: $ 31.15万
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FZ503897%2F1
• 关键词: ICF; Mechanical; Property; Optimisation; Magnesium

This project aims to develop a novel magnesium-lithium-yttrium alloy wire with the optimum mechanical properties required for manufacture of bioresorbable vascular scaffold (BVS) medical devices for the treatment of peripheral artery disease (PAD). Through altering the alloy composition, process temperature and strain rate during wire drawing and forming, this project will investigate how a more favourable microstructure can be generated for optimum mechanical properties with cost effectiveness. The work will be conducted in close collaboration with SME company Lumenology who will apply the knowledge gained into the manufacturing processes of their BVS device.BVS are an emerging technology which address an unmet clinical need for an effective treatment of PAD. There is no consensus on the best treatment approach because open surgery, endovascular interventions, or hybrid strategies all have significant drawbacks. Thus the outlook for patients with PAD is poor, and, without limb amputation in severe cases of PAD, the 5-year mortality rate is as high as 65%.1PAD is mainly caused by atherosclerosis causing narrowing and damage leading to restricted blood flow. Atherosclerosis is generally treated with angioplasty (balloon catheters) and permanent metallic stents. Balloon catheters force open blocked arteries and stents provide structure while the artery heals. Stents are compacted onto balloon catheter delivery systems, fed through the arteries to the blockage and inflated to a larger diameter. Minimisation of the compacted device/balloon system diameter is key to ensure easy delivery and safe expansion.Current stents are effective for treating the coronary arteries, however implementation for long PAD lesions, particularly in arteries below-the-knee (BTK), has been associated with arteries re-occluding early and stent breakages. Temporary BVS devices are a potential solution for the treatment of BTK arteries. A BVS must provide acute structural support equivalent to stents to widen and allow the artery to heal but subsequently be safely absorbed, removing the long-term complications associated with permanent stents.Magnesium alloys are the most promising candidate material for temporary BVS devices because they have appropriate mechanical properties whilst degrading safely, within a suitable timeframe. One limitation of magnesium alloys is that they exhibit relatively poor ductility compared to the materials used in permanent stents. Consequently, current magnesium based BVS devices have larger delivery diameters compared to permanent stents.The mechanical properties of magnesium alloys are strongly influenced by the alloy's microstructure. Benchtop testing demonstrates that Lumenology's current BVS device exhibits impressive mechanical performance. However, during forming, the internal microstructure is significantly deformed, reducing ductility and thus limiting the minimum achievable compaction diameter.This project aims to improve the ductility of magnesium-lithium-yttrium alloy wire by regulating the characteristics of the microstructure through modifying the alloy composition and processing conditions during device manufacture. This will allow the full potential of magnesium alloy wire based BVS devices to be unlocked, opening the door to revolutionising the treatment of PAD.If successful, Lumenology's BVS device with optimised microstructure and mechanical properties will be able to be compacted to smaller diameters making it easier and safer to deliver into diseased arteries. Reduction of the diameter of the device/balloon system will be instrumental in progressing towards a successful first in-human clinical trial. This would allow Lumenology to bring the device to the market to start treating the millions of patients suffering from PAD who currently have limited treatment options and increased risk of death.

该项目旨在开发一种新型的硫镁基金合金线，其生产可吸收可吸收的血管支架（BVS）医疗设备所需的最佳机械性能，用于治疗外围动脉疾病（PAD）。通过改变金属丝图和形成过程中的合金组成，过程温度和应变速率，该项目将研究如何为具有成本效益的最佳机械性能生成更有利的微观结构。这项工作将与中小型企业公司Lumenology密切合作进行，这些知识将应用于其BVS设备的制造过程中。BVS是一种新兴技术，它针对有效治疗PAD的临床需求。最好的治疗方法尚无共识，因为开放手术，血管内干预或混合策略都具有明显的缺点。因此，PAD患者的前景很差，并且在严重的PAD病例中没有肢体截肢的情况下，5年的死亡率高达65％.1pad主要是由于动脉粥样硬化引起的狭窄和损害导致血液流动受限。动脉粥样硬化通常用血管成形术（气球导管）和永久金属支架治疗。动脉愈合时，气球导管强迫开放的动脉和支架提供结构。将支架压实到球囊导管递送系统上，通过动脉馈入堵塞，并膨胀至较大的直径。最小化压实的装置/气球系统直径是确保易于交付和安全扩张的关键。电流支架有效地治疗冠状动脉，但是长垫病变的实施，尤其是在膝盖以下动脉（BTK）中，与动脉重新闭塞的早期和支架相关。临时BVS设备是治疗BTK动脉的潜在解决方案。 BVS必须提供相当于支架的急性结构支撑，以扩大并允许动脉愈合，但随后被安全吸收，消除了与永久支架相关的长期并发症。MagnesiumAlloys是临时BVS设备的最有前途的候选材料，因为它们具有适当的机械性能，同时具有适当的时间范围。镁合金的一个局限性是，与永久支架中使用的材料相比，它们表现出相对较差的延展性。因此，与永久支架相比，当前基于镁的BVS设备的递送直径较大。镁合金的机械性能受合金微结构的强烈影响。台式测试表明，流体学的当前BVS设备表现出令人印象深刻的机械性能。但是，在成型过程中，内部微观结构显着变形，降低了延展性，从而限制了最低可实现的压实直径。该项目旨在通过修饰机构组成和加工条件在设备制造过程中调节微观结构的特性，从而改善镁含镁含量的合金丝的延展性。这将允许解锁镁合金线的BVS设备的全部潜力，从而为彻底改变PAD的处理打开了大门。如果成功的Lumenology的BVS设备具有优化的微结构，并且机械性能将能够将其压实到较小的直径上，从而使其更容易，从而使其更容易地递送到疾病的动物中。设备/气球系统直径的降低将有助于成功的第一次人类临床试验。这将使Lumenology将该设备推向市场，以开始治疗数百万目前患有治疗方案有限和死亡风险增加的PAD患者。