In a paper published today, scientists reveal a new 3D bioprinting method for producing highly uniform ‘blocks’ of embryonic stem cells (ESCs), which have the capacity to differentiate into any cell type in the body. These blocks could be used as ‘lego bricks’ to build large-scale tissue structures for stem cell regulation and expansion, regenerative medicine, drug screening studies, and potentially even for the construction of micro-organs.
The study, carried out by researchers at Tsinghua University in Beijing and Drexel University in Philidelphia, represents the first time ESCs have been 3D printed into a 3D cell-laden hydrogel construct, producing uniform, pluripotent (able to generate almost any cell in the body), high-throughput and size-controllable embryoid bodies, with a 90% survival rate.
“It was really exciting to see that we could grow embryoid body in such a controlled manner,” said Wei Sun, a lead author on the paper. “The grown embryoid body is uniform and homogenous, and serves as a much better starting point for further tissue growth.”
In the paper, the researchers explain that because of their capacity for self-renewal and differentiation into nearly all cell types, ESCs hold great promise as an in vitro model system for studies in early embryonic development, and are also an important source for applications in diagnostics, therapeutics, and drug screening. However, previous methods for printing these cells, either via 2D creation in a petri-dish, or via a ‘suspension’ method, resulted in non-uniform ESCs. They found that reconstructing a 3D cell micro-environment, much like that found in vivo, would be critical to directing stem cell fate and generating uniform cell sources with high levels of proliferation for tissue engineering and other biomedical applications.