NIR Dyes for Enhanced Analyte Sensing In Vivo

Continuous monitoring of body chemistries for metabolic monitoring, monitoring concentration of biothreats, early detection of sickness, and stress monitoring has the potential to enhance warrior performance. Currently available sensors are inaccurate and have short lifetimes, primarily due to the body"s foreign body response (FBR) to implanted materials. PROFUSA"s tissue-integrating sensor platform was shown to overcome the FBR during long-term animal studies in a recently completed DARPA seedling project. Changes in lifetime and intensity of luminescent sensing nanospheres within the sensor reflect fluctuating analyte concentrations, and are monitored optically through the skin. Therefore, efficient light propagation through the skin is critical, necessitating stable dyes in the optical window of the skin. In this Phase I STTR, PROFUSA proposes to synthesize a stable luminescent dye with excitation and emission spectra in the NIR optical window of the skin to replace current dyes that are either prone to photobleaching or fall outside the optical window of the skin. The NIR dye will be incorporated into a functional glucose assay contained in PROFUSA"s proprietary scaffold and tested in vitro. Synthesis of the proposed dye will enable a platform in which many other molecules may be monitored though exchange of the recognition element (e.g. lactate).