In a new study from the University of Wisconsin–Madison, scientists now have a clearer path toward the practical use of human stem cell treatments. Both induced and embryonic stem cells can form into any tissue in the body. For nearly 20 years since stem cells were discovered, there have been many complications on the road to medical applications. Researchers are using a simple synthetic material that stem cells can grow on without previous problems of reproducibility. The results of the study were reported in Nature Biomedical Engineering.
New Substrates to Grow Stem Cells & Assemble Tissue
Responding to chemical signals, stem cells can grow into specialized cells that form muscle, blood vessel, or brain tissue. Researchers developed a material called a substrate to which the stem cells are anchored. The substrate is made of proteins from mouse tumors. The most complex of these substrates is called Matrigel containing over 1500 proteins. Matrigel is very powerful and is used to grow cells and assemble body tissues. Being a complex material to work with, there are substantial problems with reproducibility of the cells as well as harboring pathogens.
The researchers have developed and patented two new substrates. The first one will be used to raise stem cells for a multitude of applications including regenerative medicine. The second substrate will be used as a test bed for growing arteries in the lab to evaluating drug toxicity. Many drugs cannot be administered to pregnant women as the growing fetus has developing arteries and the new toxicity tests may serve as a solution as to which drugs may be safe. Growing arteries in the lab can also be used to test vascular toxicity to the many environmental chemicals. One more application is to find drugs that inhibit blood vessel growth which may be used to starve cancer tumors.
From Lab Experiments to Functional Tissue
As the stem cells convert into specialized cells, the goal is to improve the chemistry of the substrate material. The team used robots to fill arrays of over 100 materials. A process was developed to test each array for its validity and its ability to bond with the stem cells. The robot can process hundreds of substrate materials per week.
A spinoff of the research project called Stem Pharm has started to commercialize the patents to sell to pharmaceutical companies and research institutes. According to William Murphy the co-founder of the company, their experimental vascular screening creation has already been successfully tested.
One of the hurdles to overcome is to find a better substrate for growing stem cells. These cells are super flexible and it is only a matter of time before the full potential of stem cells are realized. The team has proven that simple materials can be effective in nurturing stem cells. The next step is to improve stem cell development so that functional tissues can be made for patients.
