Near-Infrared Dye-Conjugated Amphiphilic Hyaluronic Acid Derivatives as a Dual Contrast Agent for In Vivo Optical and Photoacoustic Tumor Imaging

Amphiphilic
hyaluronic acid (HA) derivatives bearing hydrophobic
indocyanine green dye derivatives and hydrophilic poly­(ethylene glycol)
were synthesized through the use of condensation and copper-catalyzed
click cyclization reactions. The amphiphilic HA derivatives dissolved
in water and formed self-assemblies in which the near-infrared dyes
were tightly packed and arranged to form dimers or H-aggregates. By
irradiating an aqueous solution of HA derivatives with near-infrared
light, photoacoustic signals were detected along with fluorescence
emission. Self-assemblies consisting of HA derivatives could smoothly
accumulate in tumor tissues by passive tumor targeting. By utilizing
HA derivatives as a contrast agent, tumor sites were clearly visualized
by optical imaging as well as by photoacoustic tomography.