Cartilage Repair by Condensed Mesenchymal Stem Cell Delivery via Collagen Fabric

通过胶原蛋白织物输送浓缩间充质干细胞来修复软骨

• 批准号: 9441710
• 负责人: Ozan Akkus
• 金额: $ 20.92万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9441710
• 关键词: Allografting; American; Animal Model; Architecture; Arthritis; Autologous; Autologous Transplantation; Bioreactors; Cartilage; Cell Density; Cell fusion; Cells; Chondrocytes; Chondrogenesis; Collagen; Complex; Contralateral; Cues; Defect; Diagnosis; Distal; Dose; Face; Family suidae; Femur; Fibrocartilages; Formulation; Foundations; Gel; Growth; Growth Factor; Harvest; Health; Heparin; Histology; Implant; In Vitro; Individual; Inferior; Joints; Knee; Marrow; Mechanics; Mediating; Mesenchymal; Mesenchymal Stem Cells; Morbidity - disease rate; Natural regeneration; Oryctolagus cuniculus; Outcome; Output; Pain; Patients; Pattern; Performance; Pharmaceutical Preparations; Physical condensation; Porosity; Procedures; Replacement Arthroplasty; Resort; Scheme; Seeds; Shapes; Site; System; Technology; Textiles; Time; Tissue Engineering; Tissues; Weight-Bearing state; articular cartilage; cartilage degradation; cartilage repair; crosslink; density; healing; implantation; improved; in vivo; innovation; insight; loss of function; mechanical properties; osteochondral tissue; regenerative; repaired; scaffold; scale up; social; success; transforming growth factor beta3

Articular cartilage degenerates extensively during arthritis, causing pain and loss of function to millions of Americans. Existing regenerative treatments do not result in a functional cartilage tissue. Microfracturing results in fibrocartilage formation. Mosaicplasty and other autograft procedures may result in donor site morbidity or healing seams. There is a great need for regenerative technologies which will repair cartilage to a functional form. Tissue engineering of cartilage using marrow derived mesenchymal stem cells (MSCs) have mainly focused on scaffold-free high density cell seeding or scaffolds/gels seeded with cells at lower density. Scaffold-free high density seeding presents the merit of mesenchymal condensation driven chondrogenesis. However, pellet condensation requires complex and lengthy bioreactor culture to attain a form and robustness that is suitable for implantation. A scaffold system that would provide the form, mechanical robustness and bioinductivity to the pellets would enable functional delivery of pellets for cartilage repair without lengthy in vitro culture periods. This requires a specialized scaffold system that has a connected macroporous network to accommodate MSC-pellets while having sufficient strength at the face of such macroporosity. We propose a fully load-bearing bioinductive regenerative template that will deliver MSC-pellets at the time of seeding. The regenerative template is fabricated by weaving high-strength collagen threads to form a network of macroporous channels within which MSC pellets are seeded. Remarkably, the mechanics of the woven template matches the mechanics of cartilage at 80% pore volume due in part to biomimicry of the highly desired `arcade architecture' of cartilage. Furthermore, electrocompacted collagen threads are functionalized with heparin for sustained delivery of chondroinductive TGF-β3 locally. To the best of our knowledge, the proposed approach is the only MSC pellet delivery system that synergizes growth factor cues with mesenchymal condensation to increase chondrogenic output, all in a mechanically functional framework. Our hypothesis is MSC-pellet delivery within the framework of TGF-β3 integrated collagen template will result in a functional cartilage tissue. Aim 1 will increase pore connectivity of the scaffold to enable pellet fusion in 3D. The aim will be attained by modifying the existing weaving scheme which confines pellet growth to within individual channels of the scaffold. The modified weaving scheme will increase available pore space. The degree of crosslinking and the collagen thread size will be varied to offset the effects of increased porosity on scaffold stiffness. Second Aim will improve repair outcome on cartilage repair. Chondrogenesis in woven collagen scaffolds will be enhanced by heparin mediated TGF-β3 delivery from collagen threads. Scaffolds with optimal TGF-β3 dose level will be implanted in rabbits to obtain preliminary insight into the scaffold performance in vivo. The project will serve as a foundation of a R01 project that would refine and scale-up the pellet delivery concept to sizeable defects in a porcine animal model.

关节软骨退化广泛在关节炎，造成疼痛和丧失功能，以百万计 美国人。现有的再生治疗不会产生功能性软骨组织。微骨折 导致纤维软骨形成。镶嵌成形术和其他自体移植手术可能导致供体部位 发病率或愈合缝。有一个很大的需要再生技术，将修复软骨， 函数形式利用骨髓间充质干细胞（MSCs）进行软骨组织工程， 主要集中于无支架的高密度细胞接种或以较低密度接种细胞的支架/凝胶。 无支架高密度接种呈现出间充质凝聚驱动软骨形成的优点。 然而，沉淀冷凝需要复杂和漫长的生物反应器培养，以获得形状和稳健性 适合于植入。一种支架系统，该支架系统将提供形状、机械坚固性和 对丸粒的生物诱导性将使得用于软骨修复的丸粒的功能性递送成为可能， 离体培养期。这需要一个专门的支架系统，该系统具有连接的大孔网络， 容纳MSC颗粒，同时在这种大孔隙的表面具有足够的强度。我们提出了一个 完全承载的生物诱导再生模板，其将在接种时递送MSC-颗粒。 再生模板是通过编织高强度胶原蛋白线以形成一个网状结构来制造的。 大孔通道，MSC颗粒被接种在该大孔通道内。值得注意的是， 模板在80%孔体积下与软骨力学相匹配，部分原因是高度生物模拟。 理想的软骨“拱廊结构”。此外，电压实的胶原线被功能化， 与肝素一起用于局部持续递送软骨诱导性TGF-β3。据我们所知， 提出的方法是唯一的MSC颗粒输送系统，协同生长因子线索， 间充质冷凝以增加软骨生成输出，所有这些都在机械功能框架中。 我们的假设是在TGF-β3整合的胶原模板的框架内的MSC颗粒递送将 形成功能性软骨组织。目的1将增加支架的孔连通性，以使颗粒能够形成。 3D融合通过改变现有的织制方案， 生长到支架的单个通道内。修改后的编织方案将增加可用的 孔隙空间交联度和胶原线尺寸将变化以抵消 增加支架刚度的孔隙率。第二个目标将改善软骨修复的修复结果。 编织胶原支架中的软骨形成将通过肝素介导的TGF-β3从 胶原线将具有最佳TGF-β3剂量水平的支架植入家兔体内， 深入了解支架在体内的性能。该项目将作为R 01项目的基础， 将改进和按比例放大颗粒递送概念，以在猪动物模型中获得相当大的缺陷。