Method could boost diabetes therapy

Transplants of insulin-producing tissue, called islets, have helped some people with type I diabetes control their blood sugar and get healthier. But there’s a critical shortage of transplantable islets, which are clumps of pancreatic tissue containing insulin-producing beta cells.

Now researchers have developed a new laboratory method of growing islets that produce more beta cells, potentially allowing physicians to spread transplantable cells among more patients. Islets are obtained from a cadaver and then usually cultured in the lab before being given to a patient with diabetes.

Unlike islets grown in a liquid culture, those grown in a matrix made of the two proteins fibrinogen and thrombin clump together and grow into three-dimensional shapes, says Gillian Beattie of the Scripps Whittier Diabetes Institute at the University of California, San Diego.

Matrix cultures produce three times as much insulin as liquid cultures do and contain three times as many beta cells. Once transplanted into mice, the islets grown in the matrix give rise to larger grafts richer in insulin than grafts arising from liquid-grown islets, Beattie and her team reported in San Francisco in mid-June at the meeting of the American Diabetes Association.

The new findings will be “easy to translate clinically,” Beattie says. However, she adds, the procedure is likely to be expensive and ultimately will be replaced by other methods that are less dependent on the supply of human pancreatic tissue.