Functionally Graded Orthopedic Implants via the Slurry Mixing and Dispensing Process

通过浆料混合和分配过程实现功能分级骨科植入物

• 批准号: 1312289
• 负责人: Leon Shaw
• 金额: $ 6.23万
• 依托单位: Illinois Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-10-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1312289&HistoricalAwards=false
• 关键词: Functionally; Graded; Orthopedic; Implants; via

0930365ShawThe materials used for internal fracture fixations and joint replacements are all currently made of metals. However, metallic implants suffer from two shortcomings, one being the poor or non-existent interfacial bonding between the metallic surface and surrounding bone, and the other the higher rigidity of metallic implants than that of natural bone. As a result, the life expectancy of metallic implants is not commensurate with the life expectancy of the recipient, and revision surgery has to be performed every 12-15 years. Surgical revision, however, can be twice as expensive as the primary operation and may lead to significant complications, including infection, deformity, pain, and loss of mobility. This research project is proposed to address these issues.Intellectual Merit: A new family of functionally graded, porous Ti-6Al-4V/apatite implant materials with a hierarchy of engineered microstructures will be investigated and developed through innovative integration of engineering and life science. This new family of orthopedic implants is the first of its kind because they have a Ti-rich core and a hydroxyapatite (HA)-rich surface with a controlled level of micro- and macro-porosity. Together, these carefully designed composition gradients and engineered microstructures will impart to orthopedic implants the excellent corrosion resistance, adequate strength, enhanced mechanical compatibility, and good bioactivity for promoting bone tissue regeneration and fixation of implants. These revolutionary functionally graded orthopedic implants will offer an unparalleled solution to all of the issues faced by the present metallic implants with or without coatings. A novel solid freeform fabrication (SFF) method, termed as the slurry mixing and dispensing (SMD) process for making functionally graded materials (FGMs), has been developed to fabricate such a new family of orthopedic implants. The green orthopedic implants produced from the SMD process will be converted to solid implants using a novel sintering method developed recently in our laboratory. This novel sintering method uses HA nano-rods as the starting powder, and leads to dense HA bodies at sintering temperatures as low as 8500C, which is the lowest temperature ever reported in the literature. We have chosen hip implants as the vehicle to study and demonstrate this new family of orthopedic biomaterials because hip fracture is by far the most devastating type of broken bone and it accounts for about 300,000 hospitalizations every year in U.S. To achieve the research goals, five technical tasks have been identified, and a research team with all of the requisite expertise has been formed. We firmly believe that the synergism of this research team will allow us to successfully conduct this multidisciplinary project and push the frontier of the field of orthopedic biomaterials.Broader Impacts: If successful, this project will have favorable social and economical impacts on society because many patients will benefit from this novel technology. The quality of patient life could be improved greatly. Moreover, a reduction in the need for revision surgery could translate into reduced health care costs. Additionally, the SMD process developed in this study can be applied in the future to fabricate other orthopedic implants (e.g., spinal fixation devices, maxillofacial implants, bone graft materials to fill tumor defects, etc.) and many other FGMs for a wide range of applications such as gradient-index lenses, graded armor materials, bipolar plates for fuel cells, and advanced nanocomposites for aerospace, automobile and tool industries. The broad impacts of this program will also be evident in our strong commitment to education, human resource development and outreach, which will have direct impacts on undergraduate students, graduate students, and middle/high school students. We will work with the Connecticut Pre- Engineering Program (CPEP) to increase the number of underrepresented minorities in engineering, science, and technology. We will host CPEP students during summer to provide the students with hands-on labs related to SMD fabrication and orthopedic implants. Mini-projects will be developed so that CPEP students can conduct these mini-projects in one week with the help from graduate students and PIs. Through this new initiative, we will nurture underrepresented minorities towards positive thinking, increase their interest in science and technology, and motivate them to pursue higher education and become future leaders of the society.

0930365Shaw的材料用于内部断裂固定和关节置换量目前都是由金属制成的。但是，金属植入物遭受了两个缺陷，一种是金属表面和周围骨之间的差或不存在的界面粘合，另一个是金属植入物的刚性高于天然骨骼的刚性。结果，金属植入物的预期寿命与接受者的预期寿命并不相称，并且必须每12 - 15年进行一次修订手术。但是，手术修订可能是主要手术的两倍，可能导致明显的并发症，包括感染，畸形，疼痛和移动性丧失。提出了该研究项目来解决这些问题。智能优点：将通过工程和生命科学的创新整合来调查和开发一个具有工程微观结构层次结构的新型，功能分级的多孔Ti-6AL-4V/APATITE植入物材料。这个新的骨科植入物家族是同类植入物中的第一个家族，因为它们具有富含Ti的核心和一个羟基磷灰石（HA） - 富含微孔和宏观孔隙率的富含羟基磷灰石（HA） - 富含的表面。这些精心设计的成分梯度和工程的微观结构将赋予骨科植入物具有出色的耐腐蚀性，足够的强度，增强的机械兼容性以及良好的生物活性，以促进骨组织再生和植入物的固定。这些革命性的功能分级骨科植入物将为当前具有或没有涂料的金属植入物所面临的所有问题提供无与伦比的解决方案。一种新型的固体自由形式制造（SFF）方法，称为制造功能分级材料（FGM）的浆液混合和分配过程（SMD），以制造这种新的骨科植入物。 SMD工艺产生的绿色骨科植入物将使用最近在我们的实验室中开发的新型烧结方法转化为实心植入物。这种新颖的烧结方法将HA纳米棒用作起始粉末，并在低至8500c的烧结温度下导致浓密的HA体，这是文献中报道的最低温度。我们选择了髋关节植入物作为研究和证明这一新的骨科生物材料家族的工具，因为髋部骨折是迄今为止最具破坏性的骨骼类型，它在美国每年约有300,000个医院来实现研究目标，并确定了五个技术任务，并且已确定了所有必要的研究团队。我们坚信，该研究团队的协同作用将使我们能够成功地进行这项多学科项目，并推动骨科生物材料领域的领域。BROADER的影响：如果成功，该项目将对社会产生有利的社会和经济影响，因为许多患者将从这项新型技术中受益。患者生活的质量可以大大提高。此外，减少对修订手术的需求可能会转化为降低的医疗保健费用。 Additionally, the SMD process developed in this study can be applied in the future to fabricate other orthopedic implants (e.g., spinal fixation devices, maxillofacial implants, bone graft materials to fill tumor defects, etc.) and many other FGMs for a wide range of applications such as gradient-index lenses, graded armor materials, bipolar plates for fuel cells, and advanced nanocomposites for aerospace, automobile和工具行业。 该计划的广泛影响也将在我们对教育，人力资源发展和外展的坚定承诺中显而易见，这将对本科生，研究生和中学生产生直接影响。我们将与康涅狄格州预科计划（CPEP）合作，以增加工程，科学和技术中代表性不足的少数群体的数量。我们将在夏季接待CPEP学生，为学生提供与SMD制造和骨科植入物有关的动手实验室。将开发微型项目，以便CPEP学生可以在研究生和PI的帮助下在一周内进行这些微型项目。通过这项新倡议，我们将培养代表性不足的少数民族，以积极思考，增加对科学和技术的兴趣，并激励他们继续接受高等教育并成为社会的未来领导者。