[Ex vivo platelet production from induced pluripotent stem cells]

Platelet transfusion products derived from induced pluripotent stem cells (iPSCs) have been pursued as a blood donor-independent and genetically manipulative measure to complement or as an alternative to current platelet products. Platelets are enucleate blood cells indispensable for hemostasis. Thus, platelet transfusions have been clinically established to treat patients with severe thrombocytopenia. However, current blood products face issues in the balance of supply and demand, alloimmune responses, and infections and are expected to meet the shortage of donors in aging societies. iPSc-derived platelet products are qualitatively and quantitatively approaching a clinically applicable level, owing to advances and novel findings in expandable megakaryocyte cell lines, turbulence-incorporating bioreactors, and reagents that enable feeder cell-free production and improve platelet quality. Currently, the establishment of guidelines to assure the quality of iPSC-derived blood products for clinical application is in process. Considering the low risk of tumorigenicity and the large demand, ex vivo production of iPSC-derived platelets could lead to iPSC-based regenerative medicine becoming a common clinical practice and the development of a future system in which anyone can safely receive a platelet transfusion in their time of need.