GOALI/Collaborative Research: Instabilities and Local Strains in Engineered Cartilage Scaffold

该学术与工业合作研究项目（GOALI）将重点研究软骨支架在外部载荷下的力学性能和变形。软多孔支架通常用于促进细胞生长，用于不同组织的修复和再生，包括软骨和骨。这些支架的多孔性有利于细胞生长和营养物质的运输。这种软植入物在植入初期的机械功能主要是由支架来承担施加的载荷并维持其孔隙内细胞的完整性。在软多孔材料中经常遇到的结构不稳定性，既会损害支架的力学功能，也会破坏被包裹的细胞。该研究成果将通过改造工程软骨支架来维持植入功能，防止细胞死亡，从而提高植入手术成功的可能性，从而促进国民健康，改善数百万人的生活质量。此外，该合作项目旨在通过康奈尔大学和约翰霍普金斯大学的暑期拓展项目，吸引来自少数族裔的几名高中生和本科生。本项目将实验、理论和计算相结合，旨在回答以下基本问题：(1)多孔支架的关键微观结构特征如何影响临界屈曲载荷和局部应变分布；(2)母体胶原的力学性能如何影响支架的非线性响应；(3)柔性填充材料的非均匀分布如何影响弹性稳定性的区域和模态。研究计划包括增材制造复杂3D结构的实验，最先进的微尺度变形映射，以及新型软结构复合材料的多尺度模型的开发，这些模型可以捕捉材料非线性力学的各个方面。研究成果和开发的预测工具将在涉及软材料的几个领域产生重大影响，从生物工程和仿生系统到软机器人。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Grant Opportunity for Academic Liaison with Industry (GOALI) collaborative research project will focus on the mechanical properties and deformation of cartilage scaffolds under external loads. Soft porous scaffolds are commonly used to promote cell growth for therapeutic applications in the repair and regeneration of different tissues, including cartilage and bone. The porosity of these scaffolds facilitates cell growth and the transport of nutrients. The mechanical function of such soft implants during the early stage of implantation is dominated by the scaffold that has to carry the applied load and maintain the integrity of cells within its pores. Structural instabilities, often encountered in soft porous materials, can both compromise the mechanical function of the scaffolds as well as damage the encapsulated cells. The research outcomes will advance national health and improve the quality of life for millions of people by transforming engineered cartilage scaffolds in order to maintain implant functionality, prevent cell death, and thus increase the probability of a successful implantation procedure. Furthermore, this collaborative project aims to engage several high-school and undergraduate students from underrepresented minorities through summer outreach programs at Cornell University and Johns Hopkins.This project integrates experimental, theoretical, and computational efforts in order to answer the following fundamental questions: (1) how do key microstructural characteristics of the porous scaffold affect the critical buckling load and the distribution of local strains; (2) how do the mechanical properties of the parent collagen influence the nonlinear response of the scaffolds; (3) how does a non-homogeneous distribution of a compliant filler material affect regions and modes of elastic stability. The research plan involves experiments on additively manufactured complex 3D architectures, state-of-the-art deformation mapping at the microscale, and the development of novel multiscale models of soft architected composites that capture all aspects of the material nonlinear mechanics. The research findings and predictive tools developed will have significant impact in several areas involving soft materials ranging from biological engineering and biomimetic systems to soft robotics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.