[Frontiers in Live Bone Imaging Researches. Development of fluorescent pH probe for imaging osteoclast activation]

For the clinical diagnosis of osteoporosis, X-ray CT and biochemical bone metabolism markers, however, there is no method to monitor osteoclast activity in the living system. We have developed the fluorescent probe to monitor osteoclast activity, by the combination of pH sensitive fluorescent dye with bisphosphonate which is delivered to the bone surface by its high affinity to hydroxyl apatite, which is named BAp-E. In vivo mouse imaging of activated osteoclast was successfully demonstrated using two photon excitation laser microscope.