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.

关节软骨在关节炎期间广泛退化，导致数百万人疼痛和功能丧失。 对美国人来说。现有的再生治疗方法并不能产生功能性的软骨组织。微压裂 结果纤维软骨形成。镶嵌成形术和其他自体移植手术可能会导致供体部位 发病或愈合接缝。非常需要再生技术，这种技术可以将软骨修复到 函数形式。骨髓间充质干细胞在软骨组织工程中的应用 主要用于无支架高密度细胞接种或低密度细胞接种支架/凝胶。 无支架高密度种植体现了间充质凝聚驱动软骨形成的优点。 然而，颗粒冷凝需要复杂而漫长的生物反应器培养才能获得形式和健壮性。 这是适合植入的。一种脚手架系统，将提供形式、机械坚固性和 微丸的生物诱导性将使微丸能够功能性地输送用于软骨修复的微丸，而不需要花费很长的时间 体外培养时期。这需要一个专门的支架系统，该系统具有连接的大孔网络以 容纳MSC-颗粒，同时在这种大孔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，将在播种时输送MSC颗粒。 该再生模板是通过编织高强度胶原线形成网络来制造的 种植MSC颗粒的大孔通道。值得注意的是，编织的机械 模板在80%的孔容下与软骨的力学相匹配，部分原因是高度仿生的 理想的软骨“拱廊建筑”。此外，电致密胶原线被功能化 用肝素局部缓释软骨诱导型转化生长因子-β-3。据我们所知， 建议的方法是唯一的MSC颗粒递送系统，将生长因子信号与 间充质凝聚以增加软骨产量，所有这些都是在机械功能框架内进行的。 我们的假设是骨髓间充质干细胞-微丸在转化生长因子-β3整合的胶原模板框架内将 结果形成了功能正常的软骨组织。目标1将增加支架的孔连通性，以使颗粒 3D融合。通过修改现有的限制芯块的编织方案来实现这一目的 生长到脚手架的各个通道内。修改后的织造方案将增加可用的 孔隙空间。交联度和胶原线的大小将改变，以抵消 增加支架上的孔洞硬度。第二个目的是改善软骨修复的效果。 肝素介导的转化生长因子-β-3载体将促进编织胶原支架内软骨的形成 胶原线。将具有最佳转化生长因子-β3剂量水平的支架植入兔体内，以获得初步的 洞察支架在体内的性能。该项目将作为R01项目的基础， 将改进和扩大颗粒递送的概念，以在猪动物模型中产生相当大的缺陷。