Turbulence Activates Platelet Biogenesis to Enable Clinical Scale Ex Vivo Production

Abstract

The ex vivo generation of platelets from human-induced pluripotent cells (hiPSCs) is expected to compensate donor-dependent transfusion systems. However, manufacturing the clinically required number of platelets remains unachieved due to the low platelet release from hiPSC-derived megakaryocytes (hiPSC-MKs). Here, we report turbulence as a physical regulator in thrombopoiesis in vivo and its application to turbulence-controllable bioreactors. The identification of turbulent energy as a determinant parameter allowed scale-up to 8 L for the generation of 100 billion-order platelets from hiPSC-MKs, which satisfies clinical requirements. Turbulent flow promoted the release from megakaryocytes of IGFBP2, MIF, and Nardilysin to facilitate platelet shedding. hiPSC-platelets showed properties of bona fide human platelets, including circulation and hemostasis capacities upon transfusion in two animal models. This study provides a concept in which a coordinated physico-chemical mechanism promotes platelet biogenesis and an innovative strategy for ex vivo platelet manufacturing.

Human‐induced pluripotent stem cell‐derived blood products: state of the art and future directions

“…The combination of turbulence, shear and SR-1 still allowed a reasonable increase in platelet shedding, up to~70-80 pro-platelets/MK [54]. The addition of these factors in shear conditions, with low/absent turbulence, improved platelet production [54]. In these turbulence cultures, the enhanced release of IGFBP2, macrophage migration inhibitory factor and nardilysin was reported (using imMKCLs) to positively affect platelet shedding [54].…”

“…Although high percentages of CD41a are obtained by multiple groups (50-99%), only the inducible cMYC, BMI1 and BCL-XL imMKCLs model achieved almost complete CD42b positivity (98-99.8%; others 30-60%) [11,27,54,55,[57][58][59]62]. Different cell-surface markers correspond to MK maturation, among which are CD41a and CD42.…”

“…One of these factors is presumably shear stress, which leads to increased thrombocyte production [73]. The combination of turbulence, shear and SR-1 still allowed a reasonable increase in platelet shedding, up to~70-80 pro-platelets/MK [54]. The combination of turbulence, shear and SR-1 still allowed a reasonable increase in platelet shedding, up to~70-80 pro-platelets/MK [54].…”

“…Pro-platelet production can be even increased further with a collagen-based scaffold in a flow bioreactor system to 29 platelets/MK [56]. In these turbulence cultures, the enhanced release of IGFBP2, macrophage migration inhibitory factor and nardilysin was reported (using imMKCLs) to positively affect platelet shedding [54]. With these improvements, for the first time, an iPSCderived thrombocyte transfusion unit (~1 9 10 11 ) was produced in an 8L bioreactor (three different iPSC clones, range~0.5-1.3 9 10 11 ).…”

Whirling Platelets Away for Transfusion

“…For reasons elegantly reviewed elsewhere, the generation of clinically relevant numbers of platelets ex vivo has represented one of the major obstacles to platelet manufacturing (Lambert et al, 2013). In this issue of Cell, Ito et al address this obstacle by identifying novel physical and molecular factors which enable large-scale ex vivo platelet production from imMKCL (Ito et al, 2018). …”