MIT researchers have developed a device to keep implanted pancreatic islets oxygenated and alive. The technique involves a replenishable oxygen reservoir and a coating that protects the cells from the immune system. In tests in diabetic rats, the subcutaneous implants kept nearly 90% of the islets alive for up to eight months, and blood glucose levels were within a normal range in most of the treated rats. The technique could provide a long-term treatment option for patients with type 1 diabetes.
Transplanting pancreatic islets is a promising approach for treating type 1 diabetes, as the implanted cells can naturally release insulin in response to blood glucose levels, without the need for repeated insulin injections or regular blood glucose monitoring.
However, the technique has been limited by a few hurdles. One of the major issues is getting enough oxygen to the implanted islets. To date, many implanted islets die due to a lack of oxygen, or because they are attacked by the immune system.
To address this issue, MIT researchers, in collaboration with a company called Beta-O2 Technologies, have developed a device to provide these implanted cells with oxygen. To protect the implanted cells from the immune system, the researchers coated them with a slab of a naturally-occurring polysaccharide called alginate.
The slab contains a membrane that keeps immune cells out, but allows insulin, secreted by the cells in the implant, to enter the bloodstream. The membrane also allows oxygen from a refillable reservoir to permeate the islets, helping to keep them alive. A port implanted under the skin allows the oxygen reservoir to be refilled every day, and the oxygen can travel along a catheter to the islets, which are also implanted under the skin.
In diabetic rats, the implants showed nearly 90% islet survival up to eight months, and most of the treated rats showed normal blood glucose levels over this period. When the researchers removed the implants, blood glucose levels increased again, showing that the treatment had been effective in controlling blood sugar levels. At present, researchers at Beta-O2 Technologies are working on a new version of the implant that will only need to be refilled with oxygen once a week.