Researchers from the Massachusetts Institute of Technology (MIT) have worked with Beta-O2 Technologies to develop an implantable device, which could help insulin-producing cells live longer after transplant and improve treatment of type 1 diabetes.
The partnership has tested an implantable device, which renders islet cells with their own supply of oxygen through chamber that can be refilled every 24 hours, helping to improve treatment of type 1 diabetes.
Islet cells are pancreatic cells, which are responsible for producing insulin when blood glucose concentration increases.
MIT professor of chemical engineering and study senior author Clark Colton said: “The benefits of this approach are: you keep the islets alive to perform their function, you don’t need as much tissue, and you reduce the ability of the implants to provoke an immune response.”
Tests of the implants in rats demonstrated that around 90% of the islets stayed viable for several months, and most of the rats continued to have normal blood glucose levels across the process.
The destruction of pancreas’ islet cells by the patient’s own immune system results in type 1 diabetes.
To offer protection for the transplanted cells, researchers are working on the development of implants that can encapsulate islets in a material such as a polymer.
Islets are encapsulated in a slab of alginate in the device tested by the researchers. Alginate is a polysaccharide produced by algae, which is having about 600μ thickness.
A membrane on one side of slab excludes immune cells and large proteins, and allows to pass insulin, nutrients, and oxygen.
With about 5mm thick, the gas chamber below the chamber carries atmospheric gases such as nitrogen and carbon dioxide, as well as oxygen.
Oxygen flows from the chamber over the semipermeable membrane, and into the islets engrafted in the alginate slab. The oxygen partial pressure continually drops, as it diffuses through the slab.
Researchers determined that they require to start with an oxygen partial pressure of 500 mm Hg in the gas chamber to assure that that the partial pressure remains at least 50 mm Hg for 24 hours
After 24 hours, the oxygen will be refilled through a port, in which a device implanted under the skin and connected to a catheter that leads to the encapsulated islets.
Researchers demonstrated that around 90% of the islets survived the entire transplant period, which ranged from 11 weeks to eight months, in tests in diabetic mice without immunosuppression.
Image: Illustration showing pancreatic islets and oxygen molecules. Photo: courtesy of Christine Daniloff/MIT.