[unreadable] There is a growing need in the medical imaging sciences to better detect and characterize abnormal tissue and disease processes. Optical imaging in the near-infrared spectrum offers the possibility to employ fluorescently-tagged reporter probes to obtain specific molecular information about a particular disease state. VisEn Medical, Inc is pioneering the development of a novel optical molecular imaging technology platform that enables imaging of molecular activity in animals and in humans. This proprietary technology platform is based on near-infrared activatible optical probes that become activated only when they come in contact with the specific enzymes that they are designed to target. Importantly, VisEn's probes can be modified to image a wide number of specific enzyme targets. The primary goal of this SBIR grant is to develop an optical molecular probe for detecting MMP-13 activity in vivo. We have chosen to develop an imaging probe targeted to MMP-13 enzyme as it is known to be associated with many different disease states including cancer and arthritis. The specific aims of this grant proposal are summarized below. [unreadable] [unreadable] Aim #1 Design and synthesize several MMP-13 optical molecular imaging probes for in vitro testing and characterization. [unreadable] Aim #2 Characterize each of the synthesized probes with regards to their in vitro physicochemical and biological properties, including MMP-13 selectivity. [unreadable] Aim #3 Perform in vivo imaging experiments to demonstrate the ability of the MMP-13 probes to image MMP-13 activity in animal tumors models in real time and noninvasively. [unreadable] [unreadable] Thus, the specific aims of this proposal represent the first steps towards the development of a clinical agent to image molecular profiles of cancer in vivo. [unreadable] [unreadable]