GOALI: Tuning Degradation Properties of Metallic Implants through Polymeric Coatings and Surface Texture

目标：通过聚合物涂层和表面纹理调整金属植入物的降解性能

• 批准号: 1538727
• 负责人: Ryan Toomey
• 金额: $ 42.59万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1538727&HistoricalAwards=false
• 关键词: GOALI; Tuning; Degradation; Properties; Metallic

There are approximately 1.5 million arthroscopic procedures (interference screws, suture anchors) per year in the United States. However, the current generation of biodegradable orthopedic implants have not fully met expectations. Compared to commonly available metallic or polymeric implants, magnesium alloys combine the advantages of both into one material. Magnesium screws, for instance, can be made self-tapping and smaller in size than polymer screws, minimizing injury to the surrounding bone upon implantation. Yet, they are also degradable, opening up the possibility of fully bioresorbable metals. That said, the major limitation of magnesium is that its rate of degradation is too rapid for most clinical applications. This Grant Opportunity for Academic Liaison with Industry (GOALI) research project will investigate how thin barrier coatings on magnesium can be used to extend degradation time frames, which will usher in the next generation of fully degradable implants with fixation properties similar to currently available metals without the need for subsequent surgeries. As part of the overall effort, a concurrent and integrated educational program also is designed to train students and prepare them for the unique challenges presented by implantable materials. A collaboration with ConMed Corporation will offer tight integration between PhD scholarship and industrial skills in order to more thoroughly prepare students for jobs after graduation. The research will be broadly distributed into both classroom instruction and to middle and high school studentsIn this research project, biodegradable polymer coatings will be investigated to control the bioabsorption of magnesium implants delineating the interrelationships between coating process variables, coating composition, mechanical properties and life-cycle performance. Results will be benchmarked against currently available bioresorbable materials. By varying the composition and molecular weight of the polymer coating as well as changing the crystallinity and the thickness of the coating through processing conditions, it is hypothesized that water availability can be controlled in order to customize bioabsorption profiles of the implant. Lines of research that will be addressed include the following 1: How is water availability at the magnesium surface controlled by a degradable polymer coating? 2: What are the events of early pre-osteoblasts attachment followed by their subsequent proliferation and maturation into bone forming cells on polymer-coated magnesium model implants? 3; How does roughness of the magnesium surface affect the biodegradation of magnesium/polymer materials? The answers to these questions will enable predictions of degradation behavior over time to guide the design of future devices.

在美国，每年大约有150万例关节镜手术（干涉螺钉、缝合锚）。然而，目前这一代可生物降解的骨科植入物并没有完全达到预期的效果。与常用的金属或聚合物植入物相比，镁合金将两者的优点结合在一起。例如，镁螺丝可以自攻，尺寸比聚合物螺丝更小，在植入时对周围骨骼的伤害最小。然而，它们也是可降解的，开启了完全生物可吸收金属的可能性。也就是说，镁的主要限制是它的降解速度对于大多数临床应用来说太快了。这项学术与工业联络资助项目（GOALI）将研究如何使用镁的薄屏障涂层来延长降解时间框架，这将带来下一代完全可降解的植入物，其固定性能与目前可用的金属相似，而无需后续手术。作为整体努力的一部分，一个同步的综合教育项目也被设计用来训练学生，并为他们应对植入式材料带来的独特挑战做好准备。与ConMed公司的合作将提供博士奖学金和工业技能的紧密结合，以便更彻底地为学生毕业后的工作做好准备。该研究将广泛应用于课堂教学和初高中学生。在本研究项目中，将研究可生物降解聚合物涂层来控制镁植入物的生物吸收，描述涂层工艺变量、涂层成分、力学性能和生命周期性能之间的相互关系。结果将以目前可用的生物可吸收材料为基准。通过改变聚合物涂层的组成和分子量，以及通过加工条件改变涂层的结晶度和厚度，假设可以控制水的可用性，以定制植入物的生物吸收谱。将解决的研究方向包括以下1：可降解聚合物涂层如何控制镁表面的水利用率？2：在聚合物包覆镁模型植入物上，早期成骨前细胞附着以及随后的增殖和成熟为成骨细胞的过程是什么？3;镁表面的粗糙度如何影响镁/聚合物材料的生物降解？这些问题的答案将使随着时间的推移退化行为的预测能够指导未来设备的设计。