Engineering Bone Cell Migration Via Mechanotaxis

通过机械趋向性工程骨细胞迁移

• 批准号: 6983606
• 负责人: Andrew J Putnam
• 金额: $ 7.11万
• 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/6983606
• 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）：最近在文献中描述了一种新形式的定向细胞迁移，称为机械趋向性（或杜罗趋向性），其中速度和方向持久性均受到基质机械性能的影响。在治疗上利用机械趋化性，结合趋化性和趋触性，可能代表了一种设计生物材料的新方法，该生物材料提供化学和机械线索的适当组合，以促进成骨细胞（或间充质干细胞）从周围健康组织选择性迁移到小的骨缺损中。在追求颅面组织工程应用之前，需要进行额外的基础科学研究来解决骨机械趋向性的相关性，并结合确定细胞感知其局部机械环境以启动细胞运动程序的机制。该 R03 申请提出了一系列可行性研究，以确定前成骨细胞系 (MC3T3-E1) 是否会通过模型基质上的机械趋向性进行迁移。具体来说，该提案旨在： 1.) 使用光聚合过程制造具有预定义机械顺应性的聚丙烯酰胺水凝胶，并随后使用细胞外基质（ECM）蛋白对这些水凝胶进行功能化，以支持 MC3T3-E1 粘附和扩散； 2.) 量化 MC3T3-E1 细胞在 ECM 修饰的水凝胶基底上的细胞迁移速度和定向持久性，该水凝胶基底具有均匀的刚度、尖锐的刚度界面或刚度梯度； 3.) 确定 Rho GTPases 在感应底物顺应性和调节机械趋化反应方面发挥什么作用（如果有的话）。 成功完成这些目标不仅将提供有关细胞迁移机制的有用基础数据，而且还可能指导未来利用这种趋力范式的骨传导策略。 申请人将在未来的 R21 和 R01 提案中探讨此类策略。