New method to 3D print building blocks of life

Scientists have developed a new 3D printing method capable of producing highly uniform blocks of embryonic stem cells, which could be used as the 'Lego bricks' to build larger structures of tissues, and potentially even micro-organs.
These cells are capable of generating all cell types in the body, the researchers said.
"It was really exciting to see that we could grow embryoid body in such a controlled manner," said lead author Wei Sun, from Drexel University in US.
"The grown embryoid body is uniform and homogenous, and serves as a much better starting point for further tissue growth," Sun said.

The researchers used extrusion-based 3D printing to produce a grid-like 3D structure to grow embryoid body that demonstrated cell viability and rapid self-renewal for 7 days while maintaining high pluripotentcy.
"Two other common methods of printing these cells are either two-dimensional (in a petri dish) or via the 'suspension' method (where a 'stalagmite' of cells is built up by material being dropped via gravity)," said Sun.

"However, these don't show the same cell uniformity and homogenous proliferation," Sun said.
"I think that we've produced a 3D microenvironment which is much more like that found in vivo for growing embryoid body, which explains the higher levels of cell proliferation," he said.

The researchers hope that this technique can be developed to produce embryoid body at a high throughput, providing the basic building blocks for other researchers to perform experiments on tissue regeneration and/or for drug screening studies.
"Our next step is to find out more about how we can vary the size of the embryoid body by changing the printing and structural parameters, and how varying the embryoid body size leads to "manufacture" of different cell types," said Rui Yao, from Tsinghua University in China.
"In the longer term, we'd like to produce controlled heterogeneous embryonic bodies," said Sun.
"This would promote different cell types developing next to each other - which would lead the way for growing micro-organs from scratch within the lab," he added.

The research was published in the journal Biofabrication.