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植入物，这些植入物可以执行其功能，然后溶解在宿主体内，消除当前永久性植入物的有害影响。生物可降解金属具有强度、延展性和可降解性，被认为是制造理想植入物的理想材料。关于生物可降解金属的已发表论文从2005年的不到50篇大幅增加到10年来的2 000多篇。这些金属一直吸引着学术界和工业界的研究人员，因为它们可能会彻底改变医疗产品。未来的趋势是增加生物活性和探索新的临床应用，需要暂时存在的承重植入物。其最新进展之一是将其多孔结构引入骨支架。我是第一个介绍多孔可生物降解金属支架的人，并在《自然》科学报告中报道了多孔铁-聚乳酸-乙醇酸共聚物的新复合材料。** 在过去的6年里，我独立从事生物可降解金属研究，我的长期目标是发展世界公认的新型创新生物材料专业知识，并对其材料-工艺-腐蚀关系有基本的了解。在5年内，我将解决目前的挑战和生物活性生物材料的需求，并探索可生物降解金属的新应用。在一个方向，我将开发新的一类生物活性铁基多孔金属骨支架的应用。多孔铁将成为通过转化涂层技术引入生物活性化合物如Ca-P和Ag离子的骨架。另一个方向是开发新的可生物降解的金属在泌尿外科的新应用。在与泌尿科医生讨论后，我了解到工程学应该发挥作用的地方对坚固的临时输尿管支架的需求尚未得到满足。镁合金和锌合金是制作支架的理想材料，其力学性能比聚合物支架优越上级。这两个方向的工作都是为了通过理解所开发材料的过程-结构-性能关系来产生持久的效果。**我将带来生物活性多孔铁和新型合金的最佳机械和腐蚀性能的有效证据，作为适用于支架和输尿管支架的新技术平台。我将既推进知识，又培养高素质的人才，以获得加拿大科学和工程关键领域的专业知识。招募了四名研究生，并开始了本计划的工作，并取得了一些初步成果。NSERC的支持对他们的继续培养和我们年轻的研究团队的建立起了重要作用。

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.