The printer is able to print clusters of the embryonic stem cells delicately enough that they don’t get harmed in the process – this is done by using a series of microvalves.
Dr. Will Shu who participated in the research at Heriot-Watt explains to Humans Invent, “Valve based printing is much more gentle than ink jet printing… we found the printer not only achieved a very high stem cell viability but the cells also maintained their important biological function of pluripotency – the ability of a stem cell to turn into any other type of cell.”
The cells maintained their important biological function of pluripotency
Maintaining the pluripotency of each cell is key because this will allow for stem cells to make any type of organ or tissue and while 3D printing cells has been achieved previously, Dr. Shu’s group is the first to print human embryonic stem cells.
Dr. Shu says, “People have developed different technologies for printing and have been able to print, for example, a dog’s stem cells, taken from the marrow and different sources but those cells cannot be replicated indefinitely outside the body. That means you have to take stem cells every time if you need them. A human embryonic stem cell, however, can replicate indefinitely outside the body.”
By printing the cells, it means they can be placed in the right position in order for them to grow into specific organs. Dr. Shu says, “If you can print these cells 3 dimensionally, it means you can guide the cells to generate 3 dimensional, human, healthy tissue and you can use that tissue as a model system to test its response to drugs.”
For a lot of human diseases it is best to use human tissue to test drugs
Testing drugs on tissue generated from 3D printed human embryonic stem cells is important for two reasons. First of all, it would mean an end to the often- controversial method of drug testing on animals. Secondly, this new type of testing would give more accurate results.
Dr. Shu says, “For a lot of human diseases it is best to use human tissue to test the drugs. It is important to test on human liver tissue for example because a lot of drugs are metabolized in the liver.”
But while the initial plan is to create organs to test drugs the ultimate goal is to be able to create organs that can be transplanted into the body, eliminating the need for organ donors. The stem cells could be taken from the patient him/herself to create the organ so that the body wouldn’t reject this new organ.
In the short term Dr. Shu’s team are working with a stem cell company called Roslin Cellab to create relatively simple tissue such as that of the liver in order to allow for animal-free drug testing.