Agitation increases expansion of cord blood hematopoietic cells and promotes their differentiation into myeloid lineage

Abstract

Mechanical stress caused by agitation is one of the factors that can affect hematopoietic stem cell expansion in suspension bioreactors. Therefore, we have investigated the effects of agitation on umbilical cord blood hematopoietic stem cell (UCB-HSC) growth and differentiation. A comparison was made between various agitation rates (20, 40 and 60 rpm) in spinner-flask and cells cultured in glass petri dish as a static culture. Moreover, the fluid dynamic at various agitation rates of spinner-flask was analyzed to determine shear stress. The spinner-flask contained a rotational moving mixer with glass ball and was kept in tissue culture incubator. To reduce consumption of cytokines, UCB-serum was used which widely decreased the costs. Our results determined that, agitation rate at 40 rpm promoted UCBHSCs expansion and their colony forming potential. Myeloid progenitors were the main type of cells at 40 rpm agitation rate. The results of glucose consumption and lactic acid production were in complete agreement with colony assay and expansion data and indicated the superiority of culture in spinner-flask when agitated at 40 rpm over to other agitation speeds and also static culture. Cell viability and colony count was affected by changing the agitation speed. We assume that changes in cell growth resulted from the effect of shear stress directly on cell viability, and indirectly on signaling pathways that influence the cells to differentiate.

3D models of the hematopoietic stem cell niche under steady-state and active conditions

“…However, also in this context the estimated effective wall shear stresses were around 0.5 Pa 69 . In vitro , effects of fluid dynamics on the expansion of mononuclear cells from UCB (containing HSPCs) in spinner flasks could be observed at shear stresses of ~0.1 Pa 70 . Therefore, it appeared that the shear stress occurring in the present study in the artificial bone marrow analog during perfusion was too small to effectively stimulate cells mechanically.…”

The combined effects of hierarchical scaffolds and mechanical stimuli on ex vivo expansion of haematopoietic stem/progenitor cells

“…Stirred tank, fixed-bed, agitated, and rotating-wall bioreactors have all been used for ex vivo HSPC expansion. Hosseinizand et al [35] used an agitation bioreactor operating at 40 rpm; total cell proliferation was maximal by day 14. However, engraftment capacity was not confirmed, and total cell fold expansion was disappointing ($5-fold) despite long-term incubation (14 days).…”

Recent advances in engineering hydrogels for niche biomimicking and hematopoietic stem cell culturing

“…As microdroplets are formed in these systems, shear forces will change ( Xia et al, 2017 ; Zhan et al, 2022 ). Studies have shown that shear stresses within the hydrogel suspension could reduce the survival of HSCs ( Hosseinizand et al, 2016 ). Mahadik et al (2014) fabricated a microfluidic multicellular gradient hydrogel platform and observed that the viability of MSCs and HSCs was not significantly influenced by flow characteristics.…”