Ligament engineering; Effect of gene induction and cyclic stretch

韧带工程；

• 批准号: 7544573
• 负责人: Robyn Shaffer
• 金额: $ 3.01万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-30 至 2011-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7544573
• 关键词: Affect; Animal Model; Architecture; Biocompatible; Biocompatible Materials; Caliber; Cell Differentiation process; Cells; Characteristics; Clinical; Condition; Deposition; Development; Embryonic Development; Engineering; Epidemic; Extracellular Matrix; Extracellular Matrix Proteins; Fiber; Fibroblasts; Future; Gene Expression; Genetic Engineering; Goals; Immune response; Individual; Injury; Knee; Knee Injuries; Length; Ligaments; Limb structure; Localized; Mechanics; Mesenchymal Stem Cells; Methods; Modality; Musculoskeletal; Natural regeneration; Numbers; Obesity; Outcome; Patients; Phenotype; Physical activity; Physiological; Polymers; Population; Protein Overexpression; Quality of life; Recruitment Activity; Research Proposals; Signaling Molecule; Site; Source; Sports; Standards of Weights and Measures; Stem cells; Stretching; Sum; Techniques; Tendon structure; Testing; Tissue Engineering; Tissues; Training; United States; Urea; Work; base; gene induction; in vivo; nanofiber; novel; reconstruction; repaired; response; scaffold; scleraxis; transcription factor

DESCRIPTION (provided by applicant): The focus of this research proposal is the development of a tissue engineered ligament graft for ACL regeneration. Currently, ACL injuries are the most common knee injury in the United States. As the population places more emphasis on physical activity to combat the obesity epidemic and the level of intensity in individual sports increases, the number of ACL injuries is likely to rise. Current reconstruction strategies are not sufficient for successful long-term clinical outcomes and a new method to repair the ACL-deficient knee is needed. An ACL reconstruction that results in an increased quality of life for the patient may be possible through tissue engineering techniques. Our cell-based approach utilizes mesenchymal stem cells (MSCs), a progenitor cell source suitable for musculoskeletal tissue engineering strategies. By directing lineage commitment of MSCs, a suitable tissue can be formed. We propose to engineer ligament tissue by combining three techniques: electrospun fiber meshes, mechanical stretch and scleraxis-expresssing MSCs. We hypothesize that the fiber architecture of the biomaterial, namely fiber orientation and diameter, will affect MSC response to mechancial stretch and the subsequent development of extracellular matrix. Further, we postulate that MSCs with constitutive overexpression of the ligament/tendon transcription factor, scleraxis, will act synergistically with electrospun biomaterials to promote ligament tissue development. Therefore, we propose two specific aims: (1) To determine the effect of fiber architecture under mechanical stretch on ligament tissue formation. (2) To determine the potential of scleraxis-modified mesenchymal stem cells (MSCs) cultured on electrospun polymers on the formation of ligament tissue. Stem cell differentiation to ligament tissue phenotype will be characterized by gene expression and extracellular matrix protein deposition. The long term goal of this project is an engineered ligament capable of integration and regeneration once implated at the site of injury. The studies outlined in this proposal will generate a platform for developing functional ligaments using a multidimensional approach involving polymeric biomaterial architecture and mechanical stretch as well as genetic engineering.

描述（由申请人提供）：本研究计划的重点是开发用于 ACL 再生的组织工程韧带移植物。目前，ACL 损伤是美国最常见的膝部损伤。随着人们更加重视身体活动以对抗肥胖流行，以及个人运动强度的增加，ACL 损伤的数量可能会增加。目前的重建策略不足以获得成功的长期临床结果，需要一种新的方法来修复 ACL 缺陷的膝盖。通过组织工程技术可以实现 ACL 重建，从而提高患者的生活质量。我们基于细胞的方法利用间充质干细胞（MSC），这是一种适合肌肉骨骼组织工程策略的祖细胞来源。通过指导间充质干细胞的谱系定型，可以形成合适的组织。我们建议通过结合三种技术来设计韧带组织：电纺纤维网、机械拉伸和巩膜表达间充质干细胞。我们假设生物材料的纤维结构，即纤维方向和直径，将影响​​ MSC 对机械拉伸的反应以及细胞外基质的后续发育。此外，我们假设韧带/肌腱转录因子 scleraxis 组成型过度表达的 MSC 将与电纺生物材料协同作用，促进韧带组织发育。因此，我们提出两个具体目标：（1）确定机械拉伸下纤维结构对韧带组织形成的影响。 (2) 确定在电纺聚合物上培养的经巩膜修饰的间充质干细胞（MSC）对韧带组织形成的潜力。干细胞分化为韧带组织表型的特征是基因表达和细胞外基质蛋白沉积。该项目的长期目标是设计出一种工程韧带，一旦植入受伤部位即可整合和再生。该提案中概述的研究将生成一个平台，使用涉及聚合生物材料结构、机械拉伸以及基因工程的多维方法来开发功能韧带。