Stem cells have the potential to help us understand and treat a range of diseases and injuries — from vision loss to cancers. For instance, a Japanese man in his 60s was recently treated for vision loss due to macular degeneration using stem cells donated by another person. And many other clinical trials involving stem cells are underway.
However, there is still a lot to learn about stem cells and many barriers to overcome before most potential treatments can be realized. One such barrier is how to grow large quantities of stem cells while maintaining their unique properties. Now, Stanford researchers have developed a new gel in which they can grow massive numbers of neural stem cells in less space.
Stem cells are unspecialized cells that can self-renew and develop into many different types of cells in the body. Researchers hope that neural stem cells — that differentiate into neurons and glia cells in the nervous system — can be used to treat spinal cord injuries, Parkinson's disease, Huntington's disease and other nervous system disorders.
As recently reported in Nature Materials, the Stanford team engineered a new polymer-based gel optimized for neural stem cells, which allows them to grow in three dimensions instead of two.
“For a 3-D culture, we need only a 4-inch-by-4-inch plot of lab space, or about 16 square inches. A 2-D culture requires a plot of four feet by four feet, or about 16 square feet,” said the study's first author Chris Madl, PhD, a postdoctoral researcher in microbiology and immunology, in a recent Stanford news release. In addition to taking 100-times less lab space, the new 3-D process also demands less energy and nutrients to grow the cells, he said.
A key to the development was the realization that neural stem cells need to chemically or physically remodel their surrounding environment to maintain their ability to differentiate into other cells. The researchers discovered this by creating and testing a family of gels with varying stiffness and remodeling susceptibilities. The authors explained in the paper, “Whereas cells cultured in 2-D are unrestricted and free to spread, cells within nanoporous 3-D hydrogels require matrix remodeling to spread, migrate, and proliferate.”
Surprisingly, they also discovered that the neural stem cells weren’t sensitive to the stiffness of the gel, unlike most other stem cells.
These new findings have given the leader of the research group new hope for future stem cell therapies. Sarah Heilshorn, PhD, associate professor of materials science and engineering, said in the release, “There’s this convergence of biological knowledge and engineering principles in stem cell research that has me hopeful we might finally actually solve big problems.”
Previously: “Home away from home”: Artificial muscle fibers keep lab-grown stem cells happy, How Stanford researchers are engineering materials that mimic those found in our own bodies and Diabetes hampers activity of bone stem cells, Stanford researchers find
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