All humans start out from a single cell which then divides to eventually form the embryo. Depending on the signals sent by their adjacent cells, these divided cells are then developed or differentiated into specific tissues or organs.
In regenerative medicine, controlling that differentiation in the lab is crucial as stem cells could be differentiated to allow for the growing of organs in vitro and replace damaged adult cells, particularly those with very limited abilities to replicate, such as the brain or heart.
One common approach scientists adopt when differentiating stem cells is by using chemical stimulators. While this method is very efficient to make one single type of cells, it lacks the ability to reproduce the complexity of living organisms, where several cell types coexist and collaborate to form an organ.
Alternatively, inspired by the natural process of cell development, another method involves the packing of stem cells into small cellular aggregates, or spheres called embryoid bodies. Similar to real embryos, the cell-cell interaction in embryoid bodies is the main driver of differentiation. From the production of these embryoid bodies, it was found that parameters such as cell numbers, size, and