Grow Insulin-Producing Cells Right Under Your Skin

Researchers have found a novel place to load your body with the cells needed to produce lifesaving insulin for blood-sugar regulation in Type 1 diabetics — right under your skin.

In people with Type 1 diabetes, insulin-making cells, located in the pancreas, are damaged and left dysfunctional. Replacing these damaged cells seems a no brainer, as healthy new cells can restore insulin function, but it’s hard to get them in the right place.

But University of Toronto’s Institute of Biomaterials Biomedical Engineering (IBBME) researchers have demonstrated that the space under the skin might be an optimal location for these healthy cells.

“The accessible location of the skin makes . . . transplantation a lot more manageable, especially if the patient responds negatively to the donor cells,” said Alexander Vlahos, the lead author of the study. “The space under the skin has a large area so that it can support many islets [which contain the pancreatic cells], necessary for this approach.”

Previous research has focused on other sites such as the abdominal cavity and in the liver, but they haven’t fared well. They wound up being hostile environments that can possibly damage the new cells, resulting in a loss of function.

Vlahos pursued the idea of transplanting cells under the skin because the current method of implanting into the liver requires too many donor cells, due to the possibility of destruction to the cells. Skin presents “fewer hazards than other transplantation sites,” Vlahos confirmed.

As for the pancreas itself as a vehicle for these cells, “pancreatic islets are scattered throughout the pancreas in between other pancreatic cells that secrete digestive enzymes,” said Vlahos. “This makes it impractical to try to deliver islets to the pancreas: you would most likely be delivering it to a region of the pancreas that is secreting these enzymes.” The enzymes could destroy the new cells.

In his tests, Vlahos injected healthy pancreatic islets under the skin and found that normal blood sugar levels could be restored within 21 days, provided he created blood vessels at the same time. To test their functionality, the transplant cells were removed, and glucose levels returned to diabetic levels.

“Pancreatic islets comprise approximately one percent of the pancreas, but require 15 to 20 percent of the blood flow to the organ,” said Vlahos. “We needed to ensure adequate blood flow to the islets in order for this to work.”

Proper blood flow is therefore essential. “The next phase of our research will involve engineering the blood vessel network first and then injecting fewer islets into the already vascularized tissue,” said Michael Sefton, a senior researcher of the study a professor in the Department of Chemical Engineering Applied Chemistry at IBBME. “A well-vascularized environment will allow more of the cells to survive and function within the host, reducing the need for multiple donors per patient.”

The report was published in Proceedings of the National Academy of Sciences journal.