Implantable device to produce insulin

There is good news for people suffering from type-1 diabetes as they can soon do away with often tiring constant monitoring of insulin levels in the body.

Researchers have now developed an implantable device that precisely monitors acid build-up in the body for people with diabetes and produces insulin if acidosis becomes a risk.

"We wanted to create a prototype to see whether molecular prostheses could even be used for such fine adjustments to metabolic processes," said Martin Fussenegger from ETH Zurich in Switzerland.

The implantable molecular device is composed of two modules: a sensor that constantly measures blood pH (measure of acidity) and a gene feedback mechanism that produces the necessary amount of insulin.

The researchers constructed both modules from biological components, such as various genes and proteins, and incorporated them into cultivated renal cells.

They then embedded millions of these customised cells in capsules which can be used as implants in the body.

The heart of the implantable molecular device is the pH sensor, which measures the blood's precise acidity and reacts sensitively to minor deviations from the ideal pH value.

If the pH values fall below 7.35, the sensor transmits a signal to trigger the production of insulin.

Such a low pH value is specific for type-1 diabetes.

For humans, normal blood pH values lie between 7.35 and 7.45. By way of comparison, an empty stomach is extremely acidic, with a pH value of 1.5.

The hormone insulin ensures that the normal cells in the body absorb glucose again and switch from fat to sugar as their energy source for metabolism, and the pH value rises again as a result.

The researchers have already tested their invention on mice with type-1 diabetes and related acidosis.

The study appeared online in the journal Molecular Cell.