Modelling the Development of Tissues In Vitro from Pluripotent Stem Cells

Using the classical embryoid body approach, 3D aggregate cultures facilitate enhanced multi-lineage differentiation of pluripotent stem cells compared to 2D culture. However, such cellular aggregates can become necrotic over prolonged culture in suspension reducing their ability to form complex tissues. We have developed a two-stage 3D culture system whereby stem cells are grown first as aggregates in suspension and then maintained as 3D constructs for extended periods on porous polystyrene scaffolds. Combining 3D culture strategies in this way enhances the formation of complex tissues by providing a suitable microenvironment and sufficient time for developmental processes to occur. Differentiating pluripotent stem cells forming complex tissues in vitro may provide an alternative to the current ‘gold standard’ teratoma formation pluripotency assay. Additionally, the role that morphogens and small molecules play in development can be investigated using this unique culture system, providing a novel approach to study aspects of human embryonic development.