Stem cell therapy has come a long way, from the sidelines to a major focus in medical research. In particular, tissue regeneration is an exciting new venture because stem cells have to ability to become and function as any other cell type in the body.
While the benefits of stem cell therapy are clear to see, there were previously some problems in application. While scientists can successfully grow stem cells in a lab dish, once left to their own devices after being transplanted into the body, stem cells often die or find it hard to fuse with surrounding tissue.
The journal Stem Cell Reports publishes findings in this field. One study, led by Molly Shoichet and Derek van der Kooy of the University of Toronto in Canada, came up with a solution. The researchers developed an injectable gel-like material, or “hydrogel,” to protect the growing stem cells. The hydrogel consists of two compounds: methylcellulose and hyaluronan. Methylcellulose forms a gel to hold the stem cells together during delivery to the transplant site, while hyaluronan works to ensure the stem cells survive.
“Through this physical blend of two materials we are getting the best of both worlds,” says Shoichet.
In a new study, the same researchers tested how the hydrogel may benefit stem cell transplantation for nerve cell damage caused by disease or injury.
The study was revolutionary in terms of what it set out to achieve. Firstly, the researchers grew photoreceptors – light-sensitive cells in the eye’s retina that are responsible for vision – from stem cells, before encapsulating them in the hydrogel and injecting them into the eyes of blind mice.
The researchers found that injecting these mice with the hydrogel-encapsulated photoreceptors successfully restored around 15% of their pupillary response, meaning their vision was partially restored.
Encouraged by their success, the team enveloped neural stem and progenitor cells in the hydrogel and injected them into the brains of mice that had brain damage due to recent stroke. Within weeks, the mice demonstrated improvements in motor coordination, according to the researchers.
The next step is to test how the hydrogel-encapsulated neural cells affect rats with stroke injury, noting that rats have larger brains that are more appropriate for behavioral tests.
The study proves that the hydrogel increases the effectiveness of stem cell transplantation. Since the tests were successful in both the eyes and the brain – two separate parts of the nervous system – stem cell therapy has the potential to be used in all organs and systems of the human body.
The research team also says that the hydrogel is safe for human bodies: once the hydrogel has delivered stem cells to the required destination, it dissolves and the body reabsorbs it within a matter of weeks.
Injectable hydrogels have wide-ranging implications. In February, Medical News Today reported on a study published in Nature Communications, in which researchers created an injectable hydrogel made of polymer-containing nanoparticles and cellulose that can deliver multiple drugs over long time periods.
Injectable hydrogels, coupled with stem cell therapy, can be used to combat age-old diseases that we thought were incurable. There are already studies in place detailing how stem cells therapy could one day be used to treat osteoarthritis.
Molly Shoichet and Derek van der Kooy are excited about the doors that their research has opened for medical science. Commenting on their findings, Schoichet says:
“This study goes one step further, showing that the hydrogels do more than just hold stem cells together; they directly promote stem cell survival and integration. This brings stem-cell based therapy closer to reality.”