Plastic Pancreas Holds Promise as Diabetes Treatment

WASHINGTON — A plastic pancreas that kept diabetic laboratory animals healthy for months with automatic doses of insulin holds promise for a permanent treatment of diabetes, researchers say in a new study.

Shaped like a hockey puck but slightly smaller, the two-ounce artificial pancreas houses transplanted insulin-producing cells. A unique membrane protects the cells from rejection by the immune system while allowing insulin to merge with the bloodstream.

A report on the experiments was being published today in the journal Science.

Dr. William L. Chick of BioHybrid Technologies Inc. of Shrewsbury, Mass., a co-developer of the device, said if future tests with humans prove that the technique works, the plastic pancreas could eliminate the daily routine of insulin injections now endured by millions of diabetes patients.

“It’s a giant first step toward what is essentially a permanent pancreas transplant without the need for immune suppression drugs,” said Dr. Richard Kahn, the chief scientist for the American Diabetes Assn. “It’s exciting research that holds a great promise.”

Chick said the heart of the device is the membrane, a plastic material that he said is “selectively permeable.”

The membrane lines a hollow coil inside the artificial pancreas. On one side of the membrane, insulin-producing cells, called islets, are implanted. Blood from the body circulates through the coil on the other side of the membrane.

Chick said the membrane allows small molecules from the blood to pass through and nourish the islet cells. The islets, in turn, produce insulin that penetrates the membrane to join the blood.

However, the membrane blocks large immune system cells, such as lymphocytes, that normally would attack any implanted tissue. In this way, the islets are protected against rejection by the body.

In the lab experiments, dogs were turned into diabetics by the surgical removal of their pancreas glands. Two artificial pancreas devices were then implanted in each dog and researchers monitored the animals’ insulin levels.

Chick said that one dog has lived eight months with the device, three for six months and still others for shorter periods.