Murine model of implantable glucose sensors: a novel model for glucose sensor development

Although implantable glucose sensors have existed for over 30 years, their function deteriorates in hours to days, in large part as a result of tissue responses to the implanted sensor (i.e., acute and chronic inflammation, fibrosis, and vessel regression). Little is known about the mediators and mechanisms that control these tissue responses to implantable glucose sensors. In the present study, we developed and validated a murine model for implantable glucose sensors, which suitably parallel sensor function in humans. Using special care in implantation and implant retaining techniques, we demonstrated that (1) sensor function deteriorates rapidly within days post-implantation and (2) loss of glucose sensor function correlated with tissue reactions at the sites of sensor implantation, especially in the vicinity of the glucose oxidase-based working electrode. These studies establish a murine model that can be used to evaluate implantable glucose sensors in vivo. This model should provide the foundation for future studies to understand the factors and mechanisms that control sensor function in vivo.