Department of Micro-Nano Systems Engineering, Nagoya University, Aichi, Japan.
Exp Hematol. 2013 Aug;41(8):742-8. doi: 10.1016/j.exphem.2013.04.007. Epub 2013 Apr 22.
Induced pluripotent stem cell (iPSC) technology enables us to investigate various potential iPSC-based therapies. Although the safety of iPSC derivation has not been completely validated, anucleate cells, such as platelets or erythrocytes, derived from iPSCs are promising targets. However, the efficiency of in vitro platelet generation from megakaryocytes (MKs) under static culture conditions is lower than is seen in vivo. In this study, we demonstrate the proof of concept by a two-dimensional flow culture system that enabled us to increase platelet yield from human embryonic stem cell or iPSC-derived MKs using a biomimetic artificial blood vessel system. The bioreactor was composed of biodegradable scaffolds with ordered arrays of pores made to mimic in vivo bone marrow through salt leaching. Within the system, two flows in different directions in which the angle between the directions of flow is 60 degrees but not 90 degrees contributed to suitable pressure and shear stress applied to MKs to promote platelet generation. Generated platelets derived from human embryonic stem cells or human induced pluripotent stem cells through the bioreactor with a 60-degree angle revealed intact integrin αIIbβ3 activation after agonist stimulation. Collectively, our findings indicate that two flows in different directions of two-dimensional flow culture may be a feasible system for in vitro generation of platelets from pluripotent stem cells (i.e., iPSC-derived MKs) in numbers sufficient for transfusion therapy.
诱导多能干细胞（iPSC）技术使我们能够研究各种潜在的基于 iPSC 的治疗方法。尽管 iPSC 衍生的安全性尚未完全得到验证，但来自 iPSC 的无核细胞，如血小板或红细胞，是有前途的靶标。然而，在静态培养条件下，巨核细胞（MKs）体外生成血小板的效率低于体内。在这项研究中，我们通过二维流动培养系统证明了这一概念，该系统使用仿生人工血管系统，能够提高人胚胎干细胞或 iPSC 衍生的 MKs 来源的血小板产量。生物反应器由具有通过盐浸出模仿体内骨髓的有序孔阵列的可生物降解支架组成。在该系统中，两个方向相反的流，其流动方向之间的角度为 60 度而不是 90 度，有助于对 MKs 施加适当的压力和剪切应力，以促进血小板生成。通过生物反应器以 60 度角从人胚胎干细胞或人诱导多能干细胞生成的血小板在激动剂刺激后显示出完整的整合素αIIbβ3激活。总之，我们的研究结果表明，二维流动培养中两个方向的两个流可能是一种可行的系统，可用于从多能干细胞（即 iPSC 衍生的 MKs）体外生成足够用于输血治疗的血小板。
