What kind of cells do you use in your research?
In my research we mainly use human cells. We grow these cells from human stem cells, which can be isolated from small biopsies, or obtained from iPS cells. An iPS cell (induced pluripotent stem cell) is so to speak reprogrammed, and can therefore become any type of cell. In theory, we can let these stem cells become any type of cell. We distinguish between hard and soft materials, depending on the tissue of interest. For hard materials we focus on bone cells, for soft materials these are pancreatic cells. Besides that, with our laboratory working also at the Veterinary Clinic of Utrecht University, we sometimes use stem cells from horses, which also suffer from similar bone and joint diseases as humans.
How do you make an organ from these cells?
For printing, we use a mixture of stem cells in a hydrogel. This hydrogel is a polymer rich in water, which forms 3D structures to home cells, also known as a scaffold, and can for example harden under the action of visible light. Then, theoretically, the cells can continue to grow in the scaffold and actually form tissues that we then study for regenerative medicine.
What is the greatest challenge in your research?
Maturation, or the development from stem cell to tissue-specific cell, is very complex. The cells have to form a new network of cells in the scaffold. The cells then have to communicate with each other. Moreover, in bones, for example, you have various tissues that together form a larger structure. The outside is hard, and the inside consists of softer tissues (the bone marrow), which makes it even more complicated.