Tailoring of cellular mechanical microenvironments to rescue age-related impairments in bone regeneration

定制细胞机械微环境以挽救与年龄相关的骨再生损伤

• 批准号: 10708034
• 负责人: Elise F Morgan
• 金额: $ 73.31万
• 依托单位: BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-30 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10708034
• 关键词: Address; Age; Aging; Animals; Architecture; Area; Bioreactors; Bone Injury; Bone Matrix; Bone Regeneration; Cell Differentiation process; Cell Proliferation; Cells; Ceramics; Characteristics; Clinical; Clinical Data; Cues; Data; Data Element; Defect; Elements; Fluorescence; Foundations; Gait; Gene Expression; Generations; Heterogeneity; Histology; Immunohistochemistry; Impairment; Implant; In Vitro; Individual; Injury; Knowledge; Laboratory Study; Light; Liquid substance; Marrow; Mechanical Stimulation; Mechanics; Methods; Modeling; Monitor; Mus; Osteoblasts; Osteogenesis; Outcome; Porosity; Printing; Proliferating; Regenerative response; Research Personnel; Risk; Risk Factors; Role; Site; Stimulus; Stromal Cell-Derived Factor 1; Stromal Cells; Techniques; Technology; Testing; Vascularization; Work; age related; aged; analytical tool; bone; bone cell; bone healing; bone repair; bone strength; bone toughness; cell age; cell behavior; design; digital; healing; in vivo; innovation; leptin receptor; manufacture; mechanical load; mechanical signal; mechanical stimulus; microCT; mineralization; novel; osteoblast differentiation; osteogenic; pressure; protein expression; recruit; response; restoration; scaffold; shear stress; skeletal injury; skeletal stem cell; success; tibia; time use; transcriptome sequencing; transcriptomics

Aging impairs both the responsiveness of bone cells to mechanical loading and the success of bone healing following injury. Growing evidence indicates that these two phenomena are related: local mechanical cues present in the cellular microenvironment (“mechanical microenvironment”) regulate numerous aspects of bone healing, including recruitment and osteoblastic differentiation of marrow stromal cells (MSCs). Importantly, studies by multiple groups of investigators have indicated that aged cells remain mechanosensitive, but require higher stimulus magnitudes. Therefore, the focus of this project is on directly manipulating the mechanical microenvironment during bone healing, via customization of the architecture of additively manufactured (AM), osteoinductive, bioceramic scaffolds, in order to identify how the cellular responses to local mechanical cues differ with age. The hypothesis of this work is that tailoring of cellular mechanical microenvironments through advanced AM scaffold design can rescue age-related impairments in bone regeneration. This work builds on preliminary data demonstrating use of an innovative AM method to print mechanically robust ceramic scaffolds of exceptionally tunable architectures with high porosity (>80%) and pore sizes large enough to facilitate vascularization and osteogenesis in vivo. In Aim 1, we will compare the osteogenic responses of young (12-week-old) vs. mature (77-week-old) vs. aged (104-week-old) murine MSCs to the mechanical microenvironment within mechanically loaded scaffolds in vitro. The local mechanical cues present in these scaffolds will be determined using finite element modeling and mechanical testing, and the cellular responses evaluated using a novel combination of techniques including spatial assessment of the progression of osteogenesis at the single-cell level. Aim 2 will leverage these analytical tools as well, and will compare the bone regeneration responses to tailored mechanical microenvironments within scaffolds implanted in young and aged mice. Together, these two aims address an area of high clinical need and will fill critical gaps in knowledge regarding age-related changes in bone mechano- responsiveness during healing. The outcomes of this work will lay the foundation for a new generation of bone repair technologies that can accommodate alterations in cell behavior with aging and harness cell mechano-sensitivity to promote osteogenic differentiation, bone tissue formation, and ultimately, restoration of bone function following injury.

衰老会损害骨细胞对机械负荷的反应性和骨骼的成功 受伤后的愈合。越来越多的证据表明，这两个现象是相关的：局部 细胞微环境（“机械微环境”）中存在的机械提示调节 骨骼愈合的许多方面，包括骨髓的募集和成骨细胞分化 基质细胞（MSC）。重要的是，多组研究人员的研究表明 细胞保持机械敏感性，但需要更高的刺激尺寸。因此，重点 项目正在直接操纵骨骼愈合过程中的机械微环境， 定制添加的制造（AM），骨诱导，生物陶瓷的体系结构 脚手架，以确定细胞对局部机械线索的反应如何随着年龄的增长而不同。 这项工作的假设是通过高级AM量身定制细胞机械微环境 脚手架设计可以挽救与年龄相关的骨骼再生障碍。这项工作以 初步数据，证明了使用创新的AM方法来印刷机械强大的陶瓷 具有高孔隙率（> 80％）的异常可调式体系结构的脚手架，孔径足够大 促进体内血管生成和成骨。在AIM 1中，我们将比较成骨反应 年轻人（12周）与成熟（77周龄）与年龄（104周龄）的鼠MSC 机械微环境在体外机械加载的支架内。当地机械提示 这些支架中存在将使用有限元建模和机械测试确定，以及 使用新颖的技术组合评估的细胞反应，包括空间评估 单细胞水平上成骨的进展。 AIM 2也将利用这些分析工具 并将比较骨再生的反应与定制的机械微环境 植入年轻小鼠和老年小鼠的脚手架。这两个目的共同解决了高临床领域 需求并将填补有关骨骼机械变化的知识的关键空白 - 治愈过程中的反应。这项工作的结果将为新一代奠定基础 骨修复技术可以适应衰老和线束的细胞行为改变 细胞机械敏感性以促进成骨分化，骨组织形成，最终 受伤后骨功能的恢复。