Nanoparticles of Chlorin Dimer with Enhanced Absorbance for Photoacoustic Imaging and Phototherapy

Nanoparticle assembled from organic molecules is a versatile platform to integrate various functionalities for theranostics. In this work, nanoparticles are constructed from chlorin dimers that are synthesized by reducing porphyrin molecules. Chlorin dimers can assemble into nanoscale aggregates in the absence of surfactants or other auxiliary agent. The resulting nanoparticles of chlorin dimer exhibit much higher absorbance than the porphyrin counterparts, resulting in enhanced photodynamic and photothermal activity upon irradiation. The forming nanoparticles can be effectively endocytosed by the tumor cells, inducing apoptosis under irradiation. Tumor growth on mice model is inhibited by the photodynamic and photothermal treatment in vivo. Furthermore, this nanoparticle can be used for photoacoustic imaging. It is believed that the integrated imaging and phototherapeutic capability in one nanoparticle is beneficial for future cancer diagnosis, therapy, and molecular imaging.