Function of an Implanted Tissue Glucose Sensor for More than 1 Year in Animals

Abstract

An implantable sensor capable of long-term monitoring of tissue glucose concentrations by wireless telemetry has been developed for eventual application in people with diabetes. In a recent trial, the sensor-telemetry system functioned continuously while implanted in subcutaneous tissues of two pigs for a total of 222 days and 520 days respectively, with each animal in both non-diabetic and diabetic states. The sensor detects glucose via an enzyme electrode principle that is based on differential electrochemical oxygen detection, which reduces the sensitivity of the sensor to encapsulation by the body, variations in local microvascular perfusion, limited availability of tissue oxygen, and inactivation of the enzymes. After an initial two-week stabilization period, the implanted sensors maintained stability of calibration for extended periods. The lag between blood and tissue glucose concentrations was 11.8 ± 5.7 minutes and 6.5 ± 13.3 minutes respectively, for rising and falling blood glucose challenges (mean ± SD). The lag was determined mainly by glucose mass transfer in the tissues, rather than the intrinsic response of the sensor, and showed no systematic change over implant test periods. These results represent a milestone in the translation of the sensor system to human applications.

Clinical Use of Continuous Glucose Monitoring in Pediatrics

“…Alternately, long-term implantable CGMs may also have a role in pediatrics in the future, although more research is required. 64,65 As the burden of wearing CGM decreases and accuracy increases, we anticipate CGM becoming an indispensable tool that succeeds the finger stick in a multitude of pediatric clinical settings.…”

Remote System for Monitoring Animal Models With Single-Metabolite Bio-Nano-Sensors

“…This work was supported in part by the i-IronIC project, a grant from the Swiss Nano-Tera Initiative, and the Swiss National Science Foundation (NSF) under Project Sinergia CRSII2_127547/1 and Project Sino-Swiss IZLCZ2 123967. The associate editor coordinating the review of this paper and approving it for publication was Dr. Anna Grazia Mignani S. Carrara, L. Bolomey, C. Boero and up to one year in pigs [7]. The next step will be the extension of the technology to other relevant metabolites like, for example, glutamate and ATP.…”

Optical properties of hydrogels filled with dispersed nanoparticles

“…Polymeric materials with specific stimuli responsive behavior are widely used for medical and biotechnological applications [1][2][3][4]. In particular, polymeric hydrogel systems have attracted great interest due to their soft and flexible consistency and their ability to absorb large amounts of water, keeping at the same time their three-dimensional stability [5,6].…”