Applications for stem cells were once considered ‘futuristic.’ But today’s research is ushering in a new era in which these cells are a source of great hope for use in regenerative medicine, as well as in the development of new drugs to prevent and treat illnesses including diabetes, Parkinson’s disease, spinal cord injury and macular degeneration.
Dr. Ian Rogers, an Associate Scientist at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital, is on the forefront of creating stem-cell based treatments for diabetes. He and his colleagues are using stem cells to create natural replacements for essential cells in the pancreas that are destroyed by the illness, specifically in Type 1 diabetes.
For the past five years, Dr. Rogers has been focused on developing the regenerative capacity of umbilical cord and adult stem cells for clinical use, and so making them a part of the future standard of care. His latest project involves developing induced pluripotent stem cells—which have the ability to develop into many different types of cells—from umbilical cord blood cells. Increasing the regenerative capacity of cord blood cells would extend their healing power beyond the blood diseases for which they are used currently.
“For the treatment of diabetes, we can differentiate stem cells into the critical cells of the pancreas that, in healthy people, measure blood sugar and produce the amount of insulin required to process it,” says Dr. Rogers. “These specialized cells would then be implanted in people with diabetes to reactivate the natural process.”
At this stage, Dr. Rogers’ team is building a pancreas out of a surgical sponge, in effect a three-dimensional structure seeded with insulin-producing islet cells. Ideally, the pancreas would be grown in the lab and then placed under the skin of a person with Type 1 diabetes to restore their insulin production.
This is a highly sophisticated procedure, says Dr. Rogers. The most advanced research project in his lab is much simpler: regenerating blood vessels so people with Type 2 diabetes who have damaged fingers and toes, (resulting from peripheral vascular disease) can avoid amputation.
So far the pancreatic stem cell technique has been studied in mice with promising results, although trials in humans are several years away. Lab studies have demonstrated that mice with a damaged pancreas can regulate their blood glucose levels within normal ranges with the transplanted cells. Coaxing the stem cells to develop into functional islets is not efficient enough to start clinical trials, but Dr. Rogers’ group is now working to fix this problem.
He notes that stem cell transplants always carry the risk of rejection or possible tumour formation. To make the procedure safe, Dr. Rogers’ lab is working to place the cells into porous bags that will allow the exchange of molecules between the cells and the body, but prevent the cells from escaping. This will also allow a physician to top up or replace the cells if they stop working.
“The cells have shown no adverse side effects, so we are hopeful of their future benefit in people with diabetes,” says Dr. Rogers. He notes that if the procedure works, a patient’s cell implants would require replacements every few years in an outpatient procedure, to counteract the body’s natural immune response that slowly destroys them. “We envision using the stem cells to augment insulin injections,” says Dr. Rogers. “At first, we expect the cells to reduce the number of injections a patient requires. Eventually, as the procedure of generating islets becomes more efficient, we anticipate the patient will be able to go for months or even years without having to inject insulin.”
“There is considerable excitement of the potential for stem cell research but, ultimately, its value will only be realized if it can be applied to real medical needs,” notes Dr. Jim Woodgett, Director of Research at the Lunenfeld. “Dr. Rogers, like many other scientists, is very much focused on using this technology to benefit patients.”