Three-dimensional Culture of Pancreas Progenitors Differentiated from Mouse Embryonic Stem Cells

Over the last few years the establishment of three-dimensional (3D) cell culture methods allow embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) or stem/progenitor cells to recapitulate many aspects of their differentiation programs and development in vitro. Specifically, ESCs can be coaxed into specific structures resembling in vivo tissues and organs, like eye caps, intestine, forebrain and liver, which termed organoids. The ability of cells to aggregate in this way has been referred as self-organization. With the great potential the organoids hold, they have limitations: they are small and lack mechanical support and vasculature.

In our study we focus on differentiation mouse ESCs to pancreas identity. We developed a robust and efficient differentiation protocol of adherent mouse ESCs to pancreas progenitors, which we aggregated to pancreatic organoids. To supply the mechanical support for the aggregates, we created 3D spatially defined highly porous polymeric scaffolds using a 3D printing technique. Seeding pancreas endothelial cells and mesenchymal support cells on this scaffold, allowed the formation of vessel-like networks inside the entire scaffold. Utilizing the self-organization of the organoids and the scaffold support, we integrate pancreas organoids and vessel-like networks in the polymeric scaffold, mimicking the complex structure of the developing pancreas, which in future will enable the functional maturation upon implantation.

Our study provides a new approach that combines the inherent self-organization of ESCs, engineered vessel networks and mechanical support to better resemble the developing pancreas, which has enormous potential in the fields of regenerative medicine and developmental biology.