This Small Business Innovation Research Phase I Project involves the development of a diabetic small animal model for in vivo testing of a minimally invasive glucose sensor. Diabetes is an increasingly common lifelong disease and is associated with many complications. It is responsible for an estimated 10-15% of all health care expenditures. Effective treatment has been shown to prevent or delay many of the associated complications. The most common current treatments include diet, exercise, and self-monitoring of blood glucose (SMBG). An improvement to the current SMBG method would enable and encourage patients to monitor their glucose levels more closely and thus improve the the general health and quality of life of the diabetic population. This technology is based on a small optical sensor implant that is fluorescent and detectable through the skin. In order to bring this novel glucose sensor closer to clinical trials, animal efficacy trials must be performed. The diabetic, immune reconstituted nude rat model will be developed to test the in vivo performance of the glucose sensor. Data will be collected to demonstrate that the sensor measures glucose changes in insulin and glucose tolerance tests. The life-time and biocompatibility of the sensor will also be studied. An improvement to the current method of measuring glucose levels would enable and encourage diabetic patients to measure glucose levels more frequently at home. An advance in glucose measurement technology would greatly impact the diabetes market. A large commercial market currently exists for innovative improvements to the current fingerstick method, such as the minimally invasive glucose sensor described in this proposal.