3D-PRINTED SUPERELASTIC LATTICE-BASED STRUCTURES FOR LOAD-BEARING BIOMEDICAL APPLICATIONS

用于承载生物医学应用的 3D 打印超弹性晶格结构

• 批准号: RGPIN-2020-05800
• 负责人: Brailovski, Vladimir
• 金额: $ 2.84万
• 依托单位: École de technologie supérieure
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=740837
• 关键词: 3D; PRINTED; SUPERELASTIC; LATTICE; BASED

The proposed research program aims at developing lattice-based implants with enhanced biomechanical compatibility and geometric conformity, by bridging the fields of biomechanics, mechanical design, materials science and technology. The application focus of this research program is intervertebral cages, since these devices play a significant role in the quality of life of patients with spinal disorders, and none of the currently available designs offers a satisfying solution. The applicant suggests that superelastic lattice-based implants with enhanced biomechanical and geometrical compatibilities will improve the outcome of implantation by optimizing the load sharing capacity of such devices and facilitating their installation. The development and ex vivo validation of a new generation of orthopedic implants constitute the main innovative aspects of this research. In order to mimic the behavior of surrounding bone, and maintain the mechanical strength of an implant, while providing adequate pore size for bone ingrowth, the project starts with the structural optimization and modeling of different lattice structure candidates. Next, these structures will be 3D-printed from a superelastic shape memory alloy and subjected to static and fatigue mechanical testing in order to establish scaling relations between the functional properties of cellular structures and their bulk material equivalents. To avoid the trial-and-error approach when optimizing these structures, their superelastic behavior will be simulated using a multi-scale numerical modeling approach, and the numerical results will be compared with the experimental observations. Next, intervertebral cage prototypes will be designed and tested to simulate physiological movements of the spine: compression, flexion/extension and axial rotation. Prototype cages will be retro-engineered to fit the intervertebral spaces in two typical locations (cervical and lumbar), using CT files obtained from patients. Finally, in the perspective of just-in-time implant delivery to the operation room, a technologically reliable and economically viable workflow will be developed. The body of knowledge created during this research will be directly transposable from intervertebral cages (application focus of this program) to other load-bearing personalized implant applications, namely, endoprostheses for the replacement of critical bone defects following bone tumors or invasive soft tissue sarcomas. Furthermore, a better understanding of the impact of the 3D printing technology on the service properties, especially with respect to fatigue, will be widely applicable, and will not be limited exclusively to shape memory alloys and the medical domain. Finally, the proposed program will contribute to the multidisciplinary (biomechanics, mechanical design, materials science, metallurgy) training of highly qualified personnel and attract top-level local and foreign students to ETS.

拟议的研究计划旨在通过连接生物力学、机械设计、材料科学和技术领域，开发具有增强生物力学兼容性和几何一致性的基于晶格的植入物。该研究项目的应用重点是椎间融合器，因为这些装置对脊柱疾病患者的生活质量起着重要作用，而目前可用的设计都没有提供令人满意的解决方案。申请人建议，具有增强的生物力学和几何兼容性的基于超弹性晶格的植入物将通过优化此类装置的负载共享能力并促进其安装来改善植入的结果。新一代骨科植入物的开发和离体验证构成了本研究的主要创新方面。为了模仿周围骨骼的行为，保持植入物的机械强度，同时为骨骼向内生长提供足够的孔径，该项目从不同晶格结构候选物的结构优化和建模开始。接下来，这些结构将由超弹性形状记忆合金进行 3D 打印，并进行静态和疲劳机械测试，以便建立蜂窝结构的功能特性与其等效块体材料之间的比例关系。为了避免在优化这些结构时采用试错法，将使用多尺度数值建模方法来模拟它们的超弹性行为，并将数值结果与实验观察结果进行比较。 接下来，将设计和测试椎间融合器原型，以模拟脊柱的生理运动：压缩、屈曲/伸展和轴向旋转。原型笼将使用从患者获得的 CT 文件进行逆向设计，以适应两个典型位置（颈椎和腰椎）的椎间隙。最后，从及时将种植体输送到手术室的角度来看，将开发出技术可靠且经济可行的工作流程。 这项研究期间创建的知识体系将直接从椎间融合器（该计划的应用重点）转移到其他承重个性化植入物应用，即用于替代骨肿瘤或侵袭性软组织肉瘤后严重骨缺损的内置假体。此外，更好地了解3D打印技术对使用性能（尤其是疲劳方面）的影响将得到广泛应用，而不仅仅局限于形状记忆合金和医疗领域。最后，拟议的项目将有助于多学科（生物力学、机械设计、材料科学、冶金）高素质人才的培养，并吸引顶尖的本地和外国学生到 ETS 就读。