Evaluating the Potential of Human Induced Pluripotent Stem Cells (hiPSC) For Cartilage Repair

骨关节炎是一种与软骨和关节功能障碍有关的衰弱性疾病， 严重影响患者生活质量的创伤或衰老，导致每年的 大约150亿美元用于美国的医疗保健。软骨再生本来就是低效的 并且仍然是未满足的医疗需求，其增加了关节炎发展的倾向， 条件用于修复局灶性软骨缺损的基于细胞的治疗方法已经利用 自体成体软骨细胞或成体间充质干细胞（MSC），但成功有限 这是由于产生劣质纤维软骨和细胞缺乏。丰富的自体来源 因此，像人类诱导多能干细胞（hiPSC）一样， 软骨此外，从人iPSC产生发育上“更年轻”的软骨细胞 类似于新生或幼年软骨细胞， 比成人软骨细胞更有潜力。因此，这项研究的目的是产生 来自同一健康或OA供体的iPSC和MSC，并比较它们在软骨形成中的潜力 体外再生和大鼠模型中的骨软骨缺损。为此，一名少校 这一进展将是产生无足迹的人iPSC，即不使用病毒载体 永久整合到基因组中。使用合成mRNA将允许产生安全的 和临床相关的hiPSC。此外，我们最近开发了一种有效的方法， 引导人iPSC（hiPSC）向软骨细胞（或软骨祖细胞）分化 使用短暂暴露于一系列生长因子。我们将定义分子和功能 hiPSC和hMSC衍生的软骨细胞的特征与其功能相关 能力的其次，我们将优化仿生水凝胶支架的成熟和 移植人iPSC和hMSC衍生的软骨细胞。第三， 人iPSC-和hMSC-衍生的软骨细胞修复局灶性软骨缺损将在 手术诱导的骨软骨缺损大鼠模型沿着长期安全性研究， 小鼠总的来说，这些研究将有助于评估和提供一个机械的理解， 基于hiPSC的细胞疗法是否上级基于hMSC的疗法， 成功完成可以为进一步开发临床适用的iPSC提供动力- 局部软骨损伤的基础治疗。

Osteoarthritis is a debilitating condition associated with cartilage and joint dysfunction caused by trauma or aging that severely affects patients' quality of life resulting in a yearly burden of approximately 15 billion dollars on US healthcare. Cartilage regeneration is inherently inefficient and remains an unmet medical need that increases the propensity for development of arthritic conditions. Cell-based therapeutic approaches for repairing focal cartilage defects have utilized autologous adult chondrocytes or adult mesenchymal stem cells (MSC) but with limited success due to generation of inferior fibrocartilage and paucity of cells. An abundant autologous source like human induced pluripotent stem cells (hiPSC) is therefore attractive for engineering cartilage. Additionally, generation of developmentally `younger' chondrocytes from human iPSC akin to the neonatal or juvenile chondrocytes are expected to possess a higher regeneration potential than adult chondrocytes. The aim of this research proposal is therefore to generate iPSC and MSC from the same healthy or OA donor and comparing their potential for cartilage regeneration in vitro and in an osteochondral defect in a rat model. Towards this end, a major advance will be the generation of footprint-free human iPSC i.e. without the use of viral vectors that permanently integrate into the genome. Use of synthetic mRNA will allow generation of safe and clinically relevant hiPSC. Additionally, we have recently developed an efficient methodology to direct human iPSC (hiPSC) differentiation towards chondrocytes (or chondroprogenitor cells) using transient exposure to a series of growth factors. We will define molecular and functional characteristics of hiPSC- and hMSC-derived chondrocytes to relate with their functional capabilities. Secondly, we will optimize a biomimetic hydrogel scaffold for the maturation and implantation of human iPSC- and hMSC-derived chondrocytes. Thirdly, the potential of the human iPSC- and hMSC-derived chondrocytes to repair a focal cartilage defect will be tested in a rat model of surgically induced osteochondral defect along with long-term safety studies in mice. Collectively, these studies will help evaluate and provide a mechanistic understanding of whether a hiPSC-based cellular therapy will be superior to hMSC-based therapy and successful completion can provide the impetus to further develop a clinically applicable iPSC- based therapy for focal cartilage injury.