The Development of Contrast Agents for Photoacoustic Molecular Imaging

Au Photoacoustic molecular imaging (PAI) is a novel biomedical imaging technique that utilize ultrasonic signal as an information carrier. PAI provides optical absorption and dielectric properties relevanted physiology and pathology at the cellular and molecular level through the use of exogenous contrast agents. These contrast agents can generate strong photoacoustic (PA) signal and provide contrast enhancement. In addition, they can be conjugated with molecular probes for targeted early detection and treatment of cancers. Here we review the new exogenous contrast agents in recent years from five types, including dyes, plasmonic nanostructure, various new class nanoparticles and multimodality contrast agents. At last we conduct a further outlook of the application prospects in the field of biomedicine.