Encapsulated Islets for Type 1 Diabetes Patients

Implanting encapsulated beta cells may be beneficial…. 

Transplantation of insulin-producing islets from deceased donors has helped to restore the function of insulin to some degree in patients with type 1 diabetes. However, as with most transplantations, there are two main limiting factors that impede its usefulness in those with diabetes. The first is the fact that there is a limited supply of donated islets, which come from deceased donors; the second is the necessity to induce immune-system suppression. With regards to the latter, the use of immunosuppressants to prevent rejection of the transplanted cells can take a toll on the body and are a life-long requirement.

Beta cell encapsulation is a highly probable resolution to these limitations. In a recent study, researchers implanted encapsulated beta cells into a 63 year old man with type 1 diabetes. The beta cells used were from a deceased donor and were encapsulated in a specially designed chamber that was composed of a combination of alginate and other materials which was supplied with oxygen in order to sustain survival of the cells.

The 63 year old patient had had type 1 diabetes for 54 years and displayed no signs of residual beta cell function. The researchers implanted the encapsulated beta cells and evaluated the patient after 10 months. Upon their evaluation, two significant results were noted. The first was that the patient showed modest increases in C-peptide which indicated that the implanted cells were producing insulin on their own. The second finding was that the patient’s immune system did not show any signs of attacking or destroying the implanted cells. This lack of attack indicates that the device used for encapsulation provided successful protection of the beta cells during the trial period.

Although the results from this study look encouraging for the future of encapsulated beta cell implantation, there are a few points to bear in mind. This study involved only a single patient who still required self-injected insulin and monitoring of blood glucose levels. Furthermore, the study was for a short period of time. However, the results observed are the first of its kind showing that encapsulated beta cells can be successfully implanted into a patient with type 1 diabetes in order to provide insulin-producing function while avoiding the need of immunosuppressants.

Practice Pearls:

• Implantation of encapsulated beta cells shows promise of providing insulin-producing function.
• Beta cells shown to survive encapsulation with a combination of materials and oxygen.
• Need for immunosuppressants may be avoided with proper encapsulation device that prevents the immune system from attacking the beta cells.

PNAS, Published online October 2013