Development and validation of novel bioactive biodegradable metals for high performance biomaterials

生物医学设备行业的梦想是为患者和临床医生提供新一代的植入物，这些植入物可以发挥其功能，然后在宿主体内溶解，消除目前永久性植入物的有害影响。生物可降解金属兼具强度、延展性和可降解性，被视为制造这些梦寐以求的植入物的理想材料。关于生物可降解金属的论文从2005年的不到50篇增加到10年来的2000多篇。这些金属一直吸引着学术界和工业界的研究人员，因为它们有可能彻底改变医疗产品。未来的趋势是增加生物活性和探索新的临床应用，这些应用需要临时存在的承重植入物。其最新发展之一是引入多孔结构的骨支架。我是最早介绍多孔可生物降解金属支架的人之一，并在《自然科学报告》上报道了多孔铁聚（乳酸-羟基乙酸）的新型复合材料。******在过去的6年里，我独立从事生物可降解金属的研究，我确定了我的长期目标，即在对材料-过程-腐蚀关系有基本了解的情况下，在新型创新生物材料方面发展世界公认的专业知识。在5年内，我将解决当前对生物活性生物材料的挑战和需求，并探索生物可降解金属的新应用。一方面，我将针对骨支架的应用开发一类新的生物活性铁基多孔金属。多孔铁将成为通过转化涂层技术结合Ca-P和Ag离子等生物活性化合物的骨干。另一个方向是开发新型生物可降解金属，以期在泌尿外科领域有新的应用。在与泌尿科医生讨论后，我了解到目前对强大的临时输尿管支架的需求尚未得到满足，而工程技术应该发挥作用。镁合金和锌合金是制作支架的理想材料，其机械性能优于聚合物支架。这两个方向的工作都是为了通过了解所开发材料的工艺-结构-性能关系而产生持久的影响。******我将带来生物活性多孔铁和新型合金作为新技术平台的最佳力学和腐蚀性能的有效证据，分别适用于支架和输尿管支架。我将推进知识和培养高素质的人才，为加拿大在科学和工程的关键领域获得专业知识。招收了四名研究生，并开始了该项目计划的工作，并取得了一些初步成果。国家科学研究委员会的支持对他们的继续培训和我们年轻研究小组的建立起了重要的作用。

The dream of biomedical device industries is to provide patients and clinicians with a new generation of implants that can perform its function then dissolve in the host body, eliminating the harmful effects of current permanent implants. Biodegradable metals, having the combination of strength, ductility and degradability, have been viewed as the ideal materials for making those dreamed implants. Published works on biodegradable metals have been significantly increasing from less than 50 papers in 2005 to more than 2,000 over 10 years. These metals have been attracting researchers in academia and industries alike as they can potentially revolutionize the medical products. The future trend goes toward adding bioactivities and exploring new clinical applications that require a temporary presence of load bearing implants. One of the latest development is the introduction of its porous structure for bone scaffolds. I am among the first to introduce porous biodegradable metal scaffolds with the works on new composites of porous iron-poly(lactic-co-glycolic acid) as reported in Nature's Scientific Reports. ******Having worked independently in biodegradable metals research in the past 6 years, I defined my long-term objective to develop world-recognized expertise in novel innovative biomaterials with fundamental understanding of their material-process-corrosion relationship. Within 5 years, I will address the current challenge and need for bioactive biomaterials and explore new applications of biodegradable metals. At one direction, I will develop new class of bioactive iron-based porous metals in view of bone scaffold applications. The porous iron will be the backbone for incorporating bioactive compounds like Ca-P and Ag ions via conversion coating technique. Another direction is on developing novel biodegradable metals in view of new application in urology. Having discussed with urologists, I understood there is an unfulfilled need for strong temporary ureteral stents where engineering should take the role. Magnesium and zinc alloys are the ideal materials to make the stent with superior mechanical property than that made of polymers. The works in both directions are intended to make a lasting effect by understanding process-structure-property relationship of the developed materials.******I will bring valid evidence of the optimum mechanical and corrosion properties of bioactive porous iron and novel alloys as new technological platform applicable to scaffold and ureteral stents, respectively. I will both advance knowledge and train high qualified personnel to acquire expertise in the key areas of science and engineering for Canada. Four graduate students were recruited and have been initiating works planned in this program with some preliminary results. The support from NSERC plays an important role to the continuation of their training and the establishment of our young research group.