The NIH sponsored Diabetes Control and Complications Trial clearly demonstrates that near normalization of blood glucose dramatically slows the onset of the devastating complications of diabetes. However the continuous long-term tracking of glucose needed to achieve this tight blood glucose control is not yet available. To this end, this Phase I grant aims to take a previously developed glucose sensor platform and demonstrate an improved subcutaneous glucose sensor in a dog model using controlled release of certain tissue stimulatory factors. Using this approach to modulate the response of cells in the sensor / tissue interface, it is believed that sensor response onset will be accelerated and stability of sensor performance and overall sensor lifetime will be improved. Membranes of controlled release matrices with these stimulatory factors and the necessary coating technologies will be developed and mated to prior membrane technology. Then sensors will be constructed using these membranes, implanted with inclusion of controls without stimulatory factors, performance tested during implant with novel methodology and histologically evaluated upon explant. These studies will set the groundwork for progression to Phase II where optimization in the dog model may lead to feasibility studies incorporating these compounds in sensors in human subjects. PROPOSED COMMERCIAL APPLICATIONS: Implanted medical devices are effectively isolated from body fluids by specialized cells organized into a foreign body capsule. This research proposes a novel method to study and potentially control this cellular behavior permitting better communication of medical implants with surrounding tissue fluid and blood supply. While the focus of this research is on glucose measurement, progress on this problem could make a broad range of measurement and treatment therapies possible.