The future of treating Type I diabetes could be free of immunosuppression.
Researchers at Cornell University and the University of Alberta, Edmonton, have created a device that’s implantable under the skin and contains thousands of insulin-producing pancreatic cell clusters called islets.
A New Way to Protect Islet Cells
A Dec. 5 report in the Cornell Chronicle explained that in patients with Type I diabetes, the body’s immune system destroys the islets, which prevents the body from getting glucose into muscle and tissue cells. An implantable device — a removable polymer thread developed by Minglin Ma in Cornell’s College of Agriculture and Life Sciences — protects the islets, which secrete insulin and receive nutrients and oxygen.
A 2021 version of that polymer thread controlled blood sugar in mice with diabetes for up to six months.
Then, James Shapiro with the University of Alberta, Edmonton, contacted Ma to discuss the possibility of working together. Shapiro had invented a way to insert islets in channels under the patient’s skin, then applying immunosuppression to protect the islets.
The Cornell announcement quoted Shapiro as saying, “I was intrigued by the virtue of Ma’s approach, as it avoided the need for immunosuppression, and I wondered if we might combine our two innovative strategies to improve cell survival.
“Indeed, it worked.”
Two-Step Implementation
The system devised by Ma and Shapiro is called Subcutaneous Host-Enabled Alginate Thread (SHEATH). Initially, nylon catheters are inserted under the patient’s skin so blood vessels can form around them. That process can take four to six weeks.
Then the catheters are removed, and the islet devices replace them, taking up the same space so the system of blood vessels remain intact.
Ma noted in the announcement that placing the system under the skin can be done as an outpatient procedure and is far less invasive than the typical placement of insulin pumps in the abdomen. The research team hopes that future versions of the systems will last two to five years before needing replacement.
The paper, “Inflammation-Induced Neovascularization of the Subcutaneous Tissue for the Long-Term Survival of Encapsulated Islets Without Immunosuppression,” was published in the Dec. 5 edition of Nature Biomedical Engineering.
