While extensive research has focused on soluble factors to optimize stem cell culture, conditions such as hypoxia, atmospheric pressure, and the composition and organization of the extracellular matrix are also important drivers of stem cell differentiation and cell function. However, no study to date has systematically analyzed the contribution of these factors in the maintenance and differentiation of stem cells, leading to uncertainty surrounding the extracellular factors that dictate stem cell state.To address this, Xcell Biosciences has developed a novel stem cell culturing platform, the Avatar SystemTM, which allows for tunable control of the microenvironment and uniquely offers customizable settings for oxygen and hydrostatic pressure. In a recent study, Xcell scientists analyzed human pluripotent stem cells to characterize their underlying biology and to demonstrate the utility of the Avatar system. Cells were cultured in minimally supportive media to allow stem cell state to drift. The Avatar system was used to tune environmental conditions and determine the impact of oxygen tension and pressure in guiding stem cell fate.
For this project, scientists reprogrammed primary human dermal fibroblasts via episomal expression of key stemness factors (Sox2, Nanog, and Oct4) while cultured in altered oxygen concentration (1% – 5%) and atmospheric pressure (0 PSI – 5 PSI) using the Avatar system compared to conventional culture methods. Having generated iPSCs, scientists next aimed to assess their pluripotent potential relative to the condition in which reprogramming and subsequent long term culture was performed.
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