Oxygenated Environment Enhances Both Stem Cell Survival and Osteogenic Differentiation

Osteogenesis of mesenchymal stem cells (MSCs) is highly dependent on oxygen supply. We have shown that perfluorotributylamine (PFTBA), a synthetic oxygen carrier, enhances MSC-based bone formation in vivo. Exploring this phenomenon's mechanism, we hypothesize that a transient increase in oxygen levels using PFTBA will affect MSC survival, proliferation, and differentiation, thus increasing bone formation. To test this hypothesis, MSCs overexpressing bone morphogenetic protein 2 were encapsulated in alginate beads that had been supplemented with an emulsion of PFTBA or phosphate-buffered saline. Oxygen measurements showed that supplementation of PFTBA significantly increased the available oxygen level during a 96-h period. PFTBA-containing beads displayed an elevation in cell viability, which was preserved throughout 2 weeks, and a significantly lower ratio of dead cells throughout the experiment. Furthermore, the cells from the control group expressed significantly more hypoxia-related genes such as VEGF,...