Novel Highly Regenerative and Scalable Progenitor Cell Exosomes for Treating Peripheral Artery Disease

摘要 外周动脉疾病（PAD）与四肢血管阻塞相关，导致间歇性 跛行、缺血性溃疡、休息时腿部疼痛和截肢。在美国，大约有650万人 外周动脉疾病（PAD）， 影响12-20%的60岁以上人群 .目前的细胞疗法， 由于移植细胞存活率差和不充分，恢复肢体灌注仅显示出中等益处。 促血管生成的线索因此，迫切需要PAD疗法的替代治疗。最近， 使用间充质干细胞（MSC）衍生的外泌体的疗法已被认为是有前途的无细胞免疫疗法。 治疗各种疾病，包括PAD。然而，MSC是异质的并且不能很好地扩展，因此， 限制了它们作为用于商业规模开发和临床应用的外来体的可靠来源的有用性。 应用程序.我们之前已经证明，我们的高度再生，专有的 处于早期发育状态的PureStem®祖细胞产生高度血管生成的外泌体。 因此，我们建议通过使用WAX的高度可扩展性来克服当前外泌体生产的限制。 PureStem®人多能干细胞衍生的细胞系作为同种异体PAD治疗的来源。一个关键的理由 使用外泌体的另一个优点是它们具有低免疫原性，这意味着它们不太可能引起不期望的免疫原性。 它们是非复制性的，这避免了与细胞疗法相关的许多风险。 由于外泌体介导细胞间通讯，我们可以使用PureStem，而不是管理细胞， 血管生成外泌体在PAD的鼠模型中改善肢体血管再生和血液灌注。此外，委员会认为， 外泌体的生产可能更具成本效益，使用和储存也更方便。 这项STTR I期提案的目标是证明外泌体改善肿瘤的治疗可行性。 小鼠后肢缺血模型中的血管生成功能。首先，我们将建立两个引导血管生成的外泌体， 生产细胞系，并通过基于以下因素评估细胞系，在体外生产GMP相容的PureStem®外泌体 外泌体输出、外泌体血管生成活性以及外泌体可扩展性和稳定性。然后我们将测试这两个 在后肢缺血小鼠模型中选择PureStem外泌体系，以验证它们在 vivo.在我们完善的PAD动物模型中使用来自可扩展的实验室的外来体的体内可行性证据 PureStem细胞系将为进一步的临床前开发和IND铺平道路，从而使研究成为可能。 前瞻性STTR II期。总之，我们预计PureStem外泌体的治疗潜力， 提供一种创新的、具有成本效益的和方便的“现成的”再生干细胞衍生疗法， 垫.

ABSTRACT Peripheral artery disease (PAD) is associated with vascular obstructions in the extremities, leading to intermittent claudication, ischemic ulcers, leg pain at rest, and amputation. In the US, approximately 6.5 million people have peripheral artery disease (PAD), affecting 12-20% of people over 60 years of age . Current cell therapies to restore limb perfusion have shown only moderate benefits due to poor transplant cell survival and inadequate pro-angiogenic cues. Therefore, there is a critical need for alternative treatments for PAD therapy. Recently, therapy using mesenchymal stem cell (MSCs)-derived exosomes has been recognized as a promising, cell-free treatment in various diseases, including PAD. However, MSCs are heterogeneous and do not scale well, thus, limiting their usefulness as a reliable source of exosomes for commercial scale development and clinical application. We at AgeX Therapeutics have previously shown that our highly regenerative, proprietary PureStem® progenitor cells, which are at an early developmental state, produce highly angiogenic exosomes. Thus, we propose to overcome the current exosome production limitations by using AgeX’s highly scalable PureStem® human pluripotent stem cell-derived cell lines as a source of allogeneic PAD therapy. A key rationale for using exosomes is that they have low immunogenicity, which means they are not likely to cause undesirable immune responses, and they are non-replicative, which obviates many of the risks associated with cell therapy. Since exosomes mediate intercellular communication, instead of administering cells, we can use PureStem angiogenic exosomes in a murine model of PAD to improve limb revascularization and blood perfusion. Moreover, exosomes are likely to be more cost-effective to produce and more convenient to use and store. The goal of this STTR Phase I proposal is to demonstrate the therapeutic feasibility of exosomes to improve angiogenic function in a mouse hindlimb ischemia model. First, we will establish two lead angiogenic exosome production cell lines and produce GMP-compatible PureStem® exosomes in vitro by assessing lines based on exosome output, exosome angiogenic activity, and exosome scalability and stability. We will then test the two selected PureStem exosome lines in a hindlimb ischemia mouse model to validate their therapeutic efficacy in vivo. Evidence of in vivo feasibility in our well-established PAD animal model using exosomes from a scalable PureStem cell line will pave the way for further preclinical development and IND, thus enabling studies for a prospective STTR Phase II. Taken together, we anticipate the therapeutic potential for PureStem exosomes to provide an innovative, cost-effective, and convenient “off-the-shelf” regenerative stem cell-derived therapy for PAD.