Bioengineers at the University of California, San Diego and GlySens Incorporated have developed an implantable glucose sensor and wireless telemetry system that continuously monitors tissue glucose and transmits the information to an external receiver.
The paper, published in the July_28, 2010 issue of the journal Science Translational Medicine, describes the use of this glucose-sensing device as an implant in animals for over one year.
After human clinical trials and FDA approval, the device may be useful to people with diabetes as an alternative to finger sticking and short-term, needle-like glucose sensors that have to be replaced every three to seven days.
“The most important point of this paper is the fact our glucose sensor remains insensitive to tissue encapsulation for over 500 days. That’s a big step from a scientific point of view, and it’s due to the sensor’s unique oxygen detection scheme,” said UC San Diego Bioengineering Professor David Gough, the first author on the paper published in the journal Science Translational Medicine.
Glucose and oxygen from the surrounding tissue diffuse to the sensor, where the enzyme glucose oxidase carries out a chemical reaction in which oxygen is consumed in proportion to how much glucose is present. The remaining oxygen is measured and compared to the baseline oxygen recorded by a nearly identical oxygen reference sensor. The reduced oxygen signal compared to background oxygen signal reflects the glucose concentration. The effects of exercise and changes in local blood flow to the tissues are also largely subtracted out by the differential oxygen sensing system, which includes the pair of sensors side by side in the same device. The implant used in the pig study is about 1.5 inches in diameter, and 5/8 of an inch thick, and could be implanted in a simple outpatient procedure.
“The Science Translational Medicine paper shows our implanted sensors to be successful in animals. You can run the device for a year or more with it constantly working, and recording glucose quite satisfactorily. Now, we are focused on getting the human clinical trials going. We hope to begin the first human trial within in a few months,” said Gough, the bioengineering professor from the UC San Diego Jacobs School of Engineering.
Source: University of California, San Diego, USA