UK extends 3D printing to human embryonic stem cells for the first time

According to the website of the Physicists' Organization, Heriot-Watt University in the UK and a stem cell technology company have collaborated to develop a vacuum valve-based three-dimensional (3D) printing technology, which for the first time extends 3D printing to human embryonic stem cells. This breakthrough makes it possible to use human embryonic stem cells to "build" human tissues and organs for transplantation. The printed structure can also be used for drug testing to accelerate the improvement of the testing process. The relevant paper was published in the journal "Biomanufacturing" published on February 5.

　　In recent years, 3D printing has gradually developed into the field of biomanufacturing. Jason King, business development manager of Roslin Cerabo Stem Cell Technology, said: "Usually, laboratory cultured cells grow in two dimensions, and only a few cells can be printed in three dimensions. Human stem cells are too sensitive to be controlled in this way. We are the first in the world to print and culture human embryonic stem cells."

　　The key issues in the printing process are controllability and reducing damage, so as to ensure the developmental capacity and normal function of cells and tissues. Human embryonic stem cells come from the "stem cell line" produced in the early embryonic stage. They have no clear development direction and can differentiate into any type of cell in the human body. The research team has developed a vacuum valve cell printer. The cells are loaded into two separate containers of the printer and then printed uniformly on a plate according to a pre-programmed program. The printer fully considers the sensitivity and fragility of human embryonic stem cells and can print highly active cells.

　　After human embryonic stem cells are printed, they undergo a number of tests, such as testing their activity to see if they can still differentiate into different types of cells; testing the printing density, characteristic properties and distribution of the cells to evaluate the accuracy of the printing method.

　　"We found that this vacuum valve printing method is gentle enough to maintain the developmental capacity of stem cells and can accurately print spheres of the same size. More importantly, the printed human embryonic stem cells maintain their pluripotency and can differentiate into other types of cells." Will Wenmiao Shu (transliteration), a co-author of the paper and Heriot-Watt University in the UK, said: "This method uses air pressure to print cells. The air pressure can be controlled by switching micro vacuum tubes. The number of ejected cells can be precisely controlled by changing the nozzle diameter, inlet air pressure or the time the vacuum tube is opened."

　　Shu also pointed out that by printing 3D structures generated by human embryonic stem cells, we can create more accurate human tissue models, which is very useful for drug development and toxicity testing. Because most drug development targets human diseases, it makes more sense to use human tissues for experiments.

　　“This is a scientific advance that we hope will have great long-term value by providing reliable drugs without having to test them on animals, providing organs for transplantation without the need for donations, and eliminating the problems of organ rejection and immunosuppression,” King said.