Developing a high-throughput platform to direct adipogenic and osteogenic differentiation in adipose-derived stem cells.

The popular reductionist approach towards stem cell differentiation has identified an array of factors that can induce lineage-specific differentiation. Whether these variables direct differentiation in a multivariable setting in the same way as a single-variable setting is a question of interest. Polyacrylamide hydrogels of specific stiffness were microcontact printed with fibronectin in specific shapes and sizes to construct 54 different extracellular matrix types of defined stiffness, shape, and area. Three media types were also used to investigate the effect of both biomechanical and biochemical inducers of differentiation on adipose-derived stem cells. Stiffness was found to be a significant regulator of both adipogenic (3 kPa) and osteogenic (35 kPa) differentiation across all conditions. Biochemically induced osteogenic differentiation occurred as well as increased osteogenesis on larger extracellular matrix areas (above 5,000 μm2 ). The absence of clear trends for all variables demonstrates the atypical expression patterns that arise when variables that may work competitively or synergistically are considered together in a single, high-throughput system.