Summary

Physical forces regulate stem cell differentiation in-vivo, however few simple and precise methods exist to better understand this biology in-vitro. Here we describe the use of a novel bioreactor that enables addition of physical force in the form of elevated atmospheric pressure during reprogramming of human fibroblasts and culture of human induced pluripotent stem cell (iPSC) and neural stem cell (NSC) lines. We demonstrate that elevated atmospheric pressure and hypoxia can positively regulate reprogramming of human fibroblasts to iPSCs across multiple donors. Prolonged culture of iPSCs in elevated atmospheric pressure (+ 2 PSI) and 15% oxygen exhibited progressive differentiation with concomitant metabolic and epigenetic gene expression changes. Furthermore, elevated atmospheric pressure positively regulates differentiation of iPSCs to neural-ectodermal and hematopoietic lineages when combined with appropriate soluble factors and oxygen concentration. In summary, these results demonstrate the significance of applied atmospheric pressure for stem cell applications and warrants further investigation.