Engineering Bone Cell Migration Via Mechanotaxis

通过机械趋向性工程骨细胞迁移

• 批准号: 7083558
• 负责人: Andrew J Putnam
• 金额: $ 6.89万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7083558
• 关键词: bioengineering /biomedical engineering; biomaterial compatibility; biomaterial development /preparation; biomaterial interface interaction; biomechanics; biotechnology; cell adhesion; cell line; cell migration; cell motility; chemotaxis; collagen; craniofacial; extracellular matrix proteins; fibronectins; fluorescent dye /probe; gel; guanine nucleotide binding protein; osteoblasts; photochemistry; polyacrylamide; video microscopy

DESCRIPTION (provided by applicant): A new form of directed cell migration, called mechanotaxis (or durotaxis), in which both speed and directional persistence are influenced by substrate mechanical properties, has been recently described in the literature. Exploiting mechanotaxis therapeutically, in conjunction with chemotaxis and haptotaxis, may represent a new approach to designing biomaterials that provide the appropriate combinations of chemical and mechanical cues to promote the selective migration of osteoblasts (or mesenchymal stem cells) from surrounding healthy tissue into small bony defects. Prior to pursuing craniofacial tissue engineering applications, additional basic science studies addressing the relevance of mechanotaxis for bone, combined with efforts to determine the mechanisms by which cells sense their local mechanical environment to initiate a program of cell motility, are required. This R03 application proposes a set of feasibility studies to determine if a pre-osteoblastic cell line (MC3T3-E1) will migrate via mechanotaxis on model substrates. Specifically, this proposal aims to: 1.) Fabricate polyacrylamide hydrogels with pre-defined mechanical compliance using a photopolymerization process, and to subsequently functionalize these hydrogels with extracellular matrix (ECM) proteins to support MC3T3-E1 adhesion and spreading; 2.) Quantify cell migration speed and directional persistence of MC3T3-E1 cells on ECM-modified hydrogel substrates possessing uniform stiffness, sharp interfaces in stiffness, or gradients in stiffness; and 3.) Determine what role, if any, is played by the Rho GTPases in sensing substrate compliance and regulating the mechanotactic response. Successful completion of these aims will not only provide useful fundamental data regarding cell migration mechanisms, but may also guide future osteoconductive strategies that exploit this mechanotaxis paradigm. Such strategies will be explored in the applicant's future R21 and R01 proposals.

描述（由申请人提供）：一种新形式的定向细胞迁移，称为Mechanotaxis（或Durotaxis），其中最近在文献中描述了速度和方向持久性受底物机械性能的影响。在治疗上剥削机械智能以及趋化性和触觉的结合可能代表了一种设计生物材料的新方法，该方法可提供化学和机械提示的适当组合，以促进骨细胞（或中核干细胞）的选择性迁移，从周围健康组织到小骨质骨质防御。在追求颅面组织工程应用之前，需要进行机械智能与骨骼的相关性的其他基础科学研究，再加上为确定细胞感知其本地机械环境以启动细胞运动程序的机制的努力。该R03应用提出了一组可行性研究，以确定孔稳定细胞系（MC3T3-E1）是否将通过模型底物上的机械触及迁移。具体而言，该提案的目的是：1。）使用光聚合工艺制造具有预定义机械依从性的聚丙烯酰胺水凝胶，然后随后用细胞外基质（ECM）蛋白来使这些水凝胶功能化，以支持MC3T3-E1粘附和扩散； 2.）量化MC3T3-E1细胞在ECM修饰的水凝胶底物上的细胞迁移速度和定向持久性，具有均匀的刚度，刚度清晰的界面或刚度梯度； 3.）确定Rho GTPases在传感底物依从性和调节机械响应方面的作用（如果有的话）。 这些目标的成功完成不仅将提供有关细胞迁移机制的有用基本数据，而且还可以指导利用这种机械范式的未来骨导导策略。 这些策略将在申请人的未来R21和R01提案中进行探讨。