CAREER: Engineering Functional Muscle-Tendon Structures using Scaffold-Free Cell-Based Directed Assembly and Theoretical Modeling

这份综合的研究和教育事业建议的重点是了解纤维网络结构在整体组织功能中的作用，从而建立结构-功能关系。在PI的无支架方法中，细胞生长和产生自己的细胞外基质的自然能力被利用，使用几何约束，形成功能单一的纤维。这种自下而上的方法将被用来创建和调整纤维，这些纤维将作为肌肉-肌腱结构的构建块，在这种结构中，可以指定为纤维级别的精度。这些肌肉-肌腱结构的力学特性，与基于纤维的理论建模相结合，将为建立结构-功能关系提供所需的洞察力。该方法的关键创新是：(1)通过定向细胞生长形成单个纤维的无支架工程和力学评估，(2)建立精确的纤维水平的功能性肌肉-肌腱结构。这代表着组织工程学方法的根本性转变；这是创造功能性肌肉-肌腱单位所必需的，在这种单位中，肌肉和肌腱纤维结构决定了结构的生理和生物力学功能。这项研究计划将利用无支架方法来设计肌肉和肌腱纤维，通过使用几何约束来指导成肌细胞和成纤维细胞的生长：(1)对环境刺激对肌肉和肌腱中细胞生长和纤维形成的影响有一个基本的了解。(2)确定了优化肌肉和肌腱纤维性能的生物反应器参数集(S)。(3)采用理论建模和实验相结合的方法，表征了纤维和卷曲几何形状对卷曲工程肌腱纤维粘弹性低载荷和破坏性能的影响。(4)在理论建模模拟的指导下，创建具有纤维级结构保真度的功能性肌肉-肌腱结构，以达到所需的力学性能。(5)建立工程化肌肉-肌腱结构的结构-功能关系；包括每个组织的贡献，以及肌肉-肌腱界面的兼容性。这项研究将得到研究生、本科生和K-12学术水平的综合教育项目的补充，既包括在伦斯勒理工学院内部，也作为教育外展。最新的研究成果和方法将被纳入目前由PI教授或联合教授的3门研究生/本科生混合课程中，并将为生物医学工程实验室课程的细胞与组织工程轨道开发相关的5周实验室实验。获得的组织工程知识将被整合到PI正在进行的本科生(BIR研讨会)和K-12(设计您的未来日)扩展研讨会中。此外，PI还将把为期一周的生物材料模块引入夏季美国材料学会“材料日营”，通过一系列互动的动手实验来建立软组织中存在的胶原蛋白网络的结构-功能关系。

0954990CorrThis integrated research and education CAREER proposal is focused to understand the role of fiber network architecture on overall tissue function, and thus establish the structure-function relationship. In the PI's scaffold-free approach, the natural ability of cells to grow and create their own extracellular matrix is harnessed, using geometric constraint, to form functional single fibers. This bottom-up approach will be utilized to create and tune fibers that will serve as building blocks for muscle-tendon structures, in which the architecture can be specified to fiber-level precision. The mechanical characterization of these muscle-tendon structures, when coupled with fiber-based theoretical modeling, will provide insight required to establish the structure-function relationship.The key novelties to this approach are: (1) scaffold-free engineering and mechanical evaluation of single fibers formed by directed cell growth, and (2) building functional muscle-tendon structures to precise fiber-level architecture. This represents a fundamental shift in tissue engineering approach; one necessary to create functional muscle-tendon units in which both muscle and tendon fiber architecture dictate the physiological and biomechanical function of the structure. This research program will utilize a scaffold-free approach to engineer muscle and tendon fibers by directing the growth of myoblasts and fibroblasts using geometric constraints to: (1) develop a fundamental understanding of the influence of environmental stimuli on cellular growth and fiber formation, in both muscle and tendon. (2) determine set(s) of bioreactor parameters for optimal muscle and tendon fiber performance(3) characterize the influence of fiber and crimp geometry on crimped engineered tendon fibers viscoelastic low-load and failure properties, using theoretical modeling and experimentation. (4) create functional muscle-tendon structures with fiber-level architectural fidelity to achieve the desired mechanical performance, as guided by theoretical modeling simulations.(5) establish the structure-function relationship for engineered muscle-tendon structures; including the contributions of each tissue, and compatibility at the muscle-tendon interface.The research will be complemented by integrated educational projects at the graduate, undergraduate and K-12 academic levels, both within Rensselaer Polytechnic Institute and as educational outreach. The latest research findings and methods will be incorporated into 3 graduate/undergraduate hybrid courses currently taught or co-taught by the PI, and a related 5-week lab experiment will be developed for the Cell & Tissue Engineering track of the Biomedical Engineering Laboratory course. Tissue engineering knowledge gained will be integrated into the PI's ongoing undergraduate (BIR Workshop) and K-12 (Design Your Future Day) outreach seminars. Furthermore, the PI will introduce a week-long biomaterials module into the summer American Society of Materials "Materials Day Camp", using an interactive series of hands-on experiments to establish the structure-function relationship of collagen networks present in soft tissues.