Nitric Oxide and a Conditioned Medium Affect the Hematopoietic Development in a Microfluidic Mouse Embryonic Stem Cell/OP9 Co-Cultivation System

A microfluidic co-culture system, consisting of mouse embryonic stem cells (mESCs)/OP9 cells, was evaluated as a platform for studying hematopoietic differentiation mechanisms in vitro. mESC differentiation into blood cells was achieved in a microchannel that had the minimum size necessary to culture cells. The number of generated blood cells increased or decreased based on the nitric oxide (NO) donor or inhibitor used. Conditioned medium from OP9 cell cultures also promoted an increase in the number of blood cells. The number of generated blood cells under normal medium flow conditions was lower than that observed under the static condition. However, when using a conditioned medium, the number of generated blood cells under flow conditions was the same as that observed under the static condition. We conclude that secreted molecules from OP9 cells have a large influence on the differentiation of mESCs into blood cells. This is the first report of a microfluidic mESC/OP9 co-culture system that can contribute to highly detailed hematopoietic research studies by mimicking the cellular environment.