Development of HLA engineered universal vascular grafts from human iPSCs

对于以下患者来说，获得容易获得的小直径(2-4 mm)血管移植物是一个未得到满足的需求 外周动脉损伤或外周动脉粥样硬化。尽管假体或自体移植物可能是 为此目的，假体移植物中感染或血栓形成的潜在风险以及有限的 因疾病、既往使用或大小不匹配而导致的患者亚组中自体血管的可用性 受伤的船只限制了它们的应用。脱细胞组织工程血管移植(TEVGs) 人类诱导多能干细胞(HiPSCs)为自体或合成移植物提供了一种很有前途的替代方法。 这些HiPSC-TEVGs可以由血管平滑肌细胞(VSMCs)和内皮细胞构建 (ECS)源自HiPSCs，以前已被证明具有与天然材料相当的机械性能 临床搭桥手术中使用的血管。与其他血管移植物相比，HiPSC-TEVGs具有几个优点， 值得注意的是，HiPSCs能够自我更新并分化为体内几乎所有类型的细胞，这使得 可补充来源，从中派生VSMC以可重复地创建TEVG。关键是，HiPSC-TEVGs可以 用于解决容易获得的小直径外周动脉血管移植物尚未满足的需求 损伤或动脉粥样硬化，通过脱细胞继而内皮化的TEVG。而脱细胞 TEVGs可以直接实施为较大直径的血管移植物，而小直径移植物需要 防止血管内血栓形成的血管内皮细胞。这一事实进一步增加了HiPSC技术的价值 由于低免疫原性ECs的成功衍生，“普遍的”ECs用于此目的。低免疫原性 HiPSCs是通过调节人类白细胞抗原(HLAs)的表达而产生的，以避免 被宿主免疫系统破坏，同时为小直径移植物提供健康的内皮。创作 以及生物材料和细胞相互作用的研究，这些生物材料和细胞具有机械健壮、免疫原性低、 内皮化的HiPSC-TEVGs构成了这一提议的基础，在这里的成功将增加经济和 通过增强短期存储能力和达到扩展的产品的实际影响 耐心的人群。为了追求这一点，将对低免疫原性进行广泛的验证和表征， 通用EC差异化，为移植物工程生产功能和机械性能坚固的ECs。 脱细胞、低免疫原性内皮化的HiPSC-TEVGs也将被生成，并具有生物相容性 将评估血小板-和全血-管腔表面的相互作用。此外，体内免疫兼容性和 将在人源化的大鼠主动脉间置移植物中评估通用HiPSC-TEVGs的治疗效果 模特。从这项提案中收集到的信息将证明普遍的 HiPSC-TEVG技术，为未来非人类灵长类动物，并最终临床应用铺平了道路 这些移植物适用于外周动脉损伤或动脉粥样硬化的患者。

Access to readily available small diameter (2-4 mm) vascular grafts presents an unmet need to patients following peripheral arterial injury or peripheral arterial atherosclerosis. Although prosthetic or autologous grafts could be utilized for this purpose, the potential risk of infection or thrombus formation in prosthetic grafts and the limited autologous vessel availability in a subset of patients arising from disease, prior utilization, or size mismatch to the injured vessel restricts their application. Acellular tissue engineered vascular grafts (TEVGs) derived from human induced pluripotent stem cells (hiPSCs) provide a promising alternative to autologous or synthetic grafts. These hiPSC-TEVGs can be constructed from vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) derived from hiPSCs and have previously been shown to have mechanical properties comparable to native vessels used in clinical bypass surgeries. hiPSC-TEVGs offer several advantages over other vascular grafts, notably the ability for hiPSCs to self-renew and differentiate into almost every cell type in the body allows for a replenishable source from which to derive VSMCs to reproducibly create TEVGs. Critically, hiPSC-TEVGs could be utilized to address the unmet needs of readily available small diameter vascular grafts for peripheral arterial injury or atherosclerosis through decellularization followed by endothelialization of the TEVG. Whereas acellular TEVGs could directly be implemented as larger diameter vascular grafts, small diameter grafts require an endothelium to prevent thrombosis in the vessel. This fact further increases the value of the hiPSC technology due to the successful derivation of hypoimmunogenic, “universal” ECs for this purpose. Hypoimmunogenic hiPSCs are created through modulating the expression of human leukocyte antigens (HLAs) so as to avoid destruction by the host immune system, while providing a healthy endothelium to small diameter grafts. Creation and investigation of the biomaterial and cellular interactions of mechanically robust, hypoimmunogenic, endothelialized hiPSC-TEVGs forms the basis of this proposal, and success here will increase the economic and practical impact of the product through enhancing short term storage capability and reaching an expansive patient populace. In pursuit of this, expansive validation and characterization will be done on hypoimmunogenic, universal EC differentiation to produce functionally and mechanically robust ECs for graft engineering. Decellularized, hypoimmunogenic endothelialized hiPSC-TEVGs will also be generated and biocompatibility of platelet- and whole blood-luminal surface interactions will be assessed. Further, in vivo immunocompatibility and therapeutic efficacy of universal hiPSC-TEVGs will be evaluated in a humanized rat aortic interposition graft model. Information gleaned from this proposal will demonstrate the diversity and practicality of the universal hiPSC-TEVG technology, and pave the way for future non-human primate, and ultimately clinical utilization of these grafts for patients with peripheral arterial injury or atherosclerosis.