Vascular Regeneration with Human Pluripotent Stem Cell-derived Vascular Cells and Engineering Approaches

项目摘要 在美国，缺血性心血管疾病是发病率和死亡率的主要原因。尽管 在治疗方面的进展，治疗病情严重的患者仍然远远不是最理想的。最近，细胞 对于那些不需要介入或手术的晚期病例，治疗成为一种有希望的选择。 治疗能够有效地使缺血区重新血运重建。 人多能干细胞(HPSCs)，包括人胚胎干细胞(HESCs)和人 诱导多能干细胞(HiPSCs)是一种很有前途的血管再生候选细胞 它们具有较强的靶细胞分化能力和旁分泌作用。因此，调查人员已经 开发了各种方案来将hPSCs分化为内皮细胞(EC)系细胞。我们已经开发出 一种完全定义的、无异种成分的细胞培养系统，可以产生纯化的功能性内皮细胞 高产量的细胞(ECs)。我们进一步证明了这些hPSC来源的ECs(hPSC-ECs)具有健壮和 体内血管形成活动延长。然而，这种方法的一个警告是，他们的贡献 主要局限于毛细血管水平，无周细胞。实现最佳血运，更稳定、更大 船只也是必要的。在以前的细胞治疗研究中，这一方面几乎没有得到解决。因此， 我们最近也使用一种定义的培养系统来产生人PSC来源的SMC(hPSC-SMC) 观察它们作为血管周细胞和SMC在血管形成中的作用。 细胞治疗的另一个重要障碍是移植细胞的短期存活。要克服 在这个问题上，我们和其他人已经研究了生物工程细胞疗法，并证明了它对 细胞的存活和功能。然而，注射细胞的不均匀和局部分布出现了另一种情况 有问题。最近，我们开发了一种新型的由明胶和聚合物组成的可生物降解的杂化共聚物 庚二酸甘油(PGS)，与海藻酸盐进一步制成微珠形式。我们指的是这个公司-- 聚合物为AlGPM。这种杂化聚合物是可生物降解的，并引起最小的炎症反应。此外， 它的微珠形态促进了包裹的细胞在体内广泛而均匀的分布。 因此，在这项研究中，我们将解决目前细胞治疗缺血的两个未得到满足的需求 血管疾病。首先，我们将使用hPSC-ECs和hPSC-SMCs来诱导不仅Bare的形成 毛细血管，也包括周细胞覆盖的毛细血管和SMC覆盖的小动脉。第二，我们将开发新的 生物材料，可以增强细胞在体内的存活和分布，以最大限度地稳定血管形成和 治疗效果。具体地说，我们将研究这两种细胞类型与 AlGPM水凝胶微球能够发挥最佳的血管再生效果。长期的 这项研究的目标是利用hPSC来源的血管细胞开发临床适用的再生疗法。 与生物工程技术相结合。

Project Summary Ischemic cardiovascular diseases are the leading causes of morbidity and mortality in the USA. Despite advancement in therapeutics, treating patients with severe conditions are still far from optimal. Recently, cell therapy emerged as a promising option for those advanced cases for which no interventional or surgical therapy is able to effectively revascularize the ischemic areas. Human pluripotent stem cells (hPSCs), which include human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), have emerged as a promising candidate for vascular regeneration as they have strong target cell differentiation capacity as well as paracrine effects. Thus, investigators have developed various protocols to differentiate hPSCs into endothelial cell (EC)-lineage cells. We have developed a fully defined, xenogeneic ingredient-free cell culture system that can generate purified functional endothelial cells (ECs) at high yield. We further demonstrated that these hPSC-derived ECs (hPSC-ECs) have robust and prolonged vessel-forming activities in vivo. However, one of the caveats of this approach is that their contribution is mainly restricted to the capillary level without pericytes. For optimal vascularization, more stable and larger vessels are also necessary. In previous cell therapy studies, this aspect was virtually unaddressed. Therefore, we recently generated human PSC-derived SMCs (hPSC-SMCs) by using a defined culture system as well and observed their contribution to vessel formation as vascular pericytes and SMCs. Another important barrier for cell therapy is short-term survival of the transplanted cells. To overcome this problem, we and others have investigated bioengineered cell therapy and demonstrated its effectiveness for cell survival and function. However, uneven and localized distribution of the injected cells emerged as another problem. Recently, we have developed a novel biodegradable hybrid copolymer consisting of gelatin and poly glycerol sebacate (PGS), which was further made into a microbead form with alginate. We refer to this co- polymer as AlGPM. This hybrid polymer is biodegradable and elicits minimal inflammatory responses. Moreover, its microbead form promotes wide and homogeneous distribution of encapsulated cells in vivo. Accordingly, in this study, we will address two unmet needs of the current cell therapy for ischemic vascular disease. First, we will use both hPSC-ECs and hPSC-SMCs to induce formation of not only bare capillaries but also pericyte-covered capillaries and SMC-covered arterioles. Second, we will develop a new biomaterial that can enhance cell survival and distribution in vivo to maximize stable vessel formation and therapeutic effects. Specifically, we will investigate whether a combination of these two cell types with AlGPM hydrogel microbeads is able to exert the optimal effects on vascular regeneration. The long-term goal of this study is to develop clinically applicable regenerative therapy using hPSC-derived vascular cells combined with bioengineering technologies.