Nanoparticles for bioimaging in regenerative medicine

Hydrogen peroxide is a major reactive oxygen species (ROS) and plays a fundamental role as a second messenger in normal cellular signal transduction. The overexpression of hydrogen peroxide has been implicated in inflammatory responses and numerous life-threatening diseases. Therefore, hydrogen peroxide has great potential as a diagnostic biomarker of inflammatory response. Inflammation is considered one of the most important host reactions to implanted biomaterials, and therefore how implanted biomaterials influence inflammation is of central important in determining the outcome of scaffold-based regenerative medicine. Imaging of hydrogen peroxide in cells and tissues has been performed by using optical probes that can react with hydrogen peroxide with high sensitivity and specificity and emit light. Optical imaging allows us to watch the behavior of target biological molecules in real time, providing temporal and spatial information on biological molecules in cells and tissues. The development of optical probes for molecular imaging of hydrogen peroxide is now a very active research area. This review has special emphasis on the design, detection mechanism, and performance of fluorescent and luminescent probes for hydrogen peroxide.