Oxygen Handling Practices for in Vitro Human Pluripotent Stem Cell Cardiomyocyte Differentiation: A Scoping...

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have become a valuable and widely implemented model for cardiovascular research. To obtain hPSC-CMs that resemble the native physiological or pathophysiological phenotype, numerous efforts have been made to optimize hPSC-CM differentiation protocols. The resulting methodologies posed another challenge in the field: variability in differentiation strategies. To improve reproducibility, there is a collective drive towards standardization. This review analyzed 15 years of hPSC-CMs research with a focus on oxygen handling practices during hPSC-CM differentiation. Among the 1722 research articles reviewed, six main approaches were identified whereby differentiation is performed entirely under either hypoxia or normoxia, or with switches between both conditions at specific time points. Remarkably, only 34% and 16% of the articles explicitly reported the oxygen conditions during hPSC culture and CM differentiation, respectively. This indicates that this differentiation parameter appears to be unintentionally underreported. Trend analysis of the accuracy of reporting oxygen handling over the past 15 years revealed that the proportion of articles that do not report oxygen conditions remained constant, at approximately 65% and 35% for hPSC culture and CM differentiation, respectively. On the other hand, among the articles that report conditions or cite published research, there appears to be a convergence towards a selection of the most commonly used protocols.