Scientists in Australia have created brain-like tissue in the lab using a 3D printer and special bio-ink made from stem cells. The research takes us a step closer to making replacement brain tissue derived from a patient's own skin or blood cells to help treat conditions such as brain injury, Parkinson's disease, epilepsy and schizophrenia. The bio-ink is made of human induced pluripotent stem cells (iPSC), which have the same power as embryonic stem cells to turn into any cell in the body, and possibly form replacement body tissues and even whole organs. The team used 3D printing to make neurones involved in producing GABA and serotonin, as well as support cells called neuroglia, they reported in the journal Advanced Healthcare Material. In the future, they plan to print neurones that produce dopamine.
To make the neurones, researchers used their bio-ink to print layers of a hatched pattern to create a 5 millimetre-sized cube. They then crosslinked the cube into a firm jelly-like substance. Growth factors and nutrients were then fed into the holes of this spongey "scaffold", encouraging the stem cells to grow and turn into neurons and support cells, linking up to form tissue. Waste was also removed via the holes in the scaffold. One of the challenges of using iPSCs is that, like embryonic stem cells, they have the potential to develop into teratomas — disturbing looking tumours that contain more than one type of tissue type (think toenails growing in brain tissue, or teeth growing in ovary tissue). While this is a first step towards 3D printing of whole organs, a whole functioning brain would be a much more complex task.