Theranostic Colloidal Nanoparticles of Pyrrolopyrrole Cyanine Derivatives for Simultaneous Near-Infrared Fluorescence Cancer Imaging and Photothermal Therapy

Theranostic agents incorporating diagnostic and therapeutic agents together play crucial roles in clinical cancer treatment. On the one hand, near-infrared (NIR) fluorescence imaging strategies are expected to provide high-resolution real-time structural and molecular information with deep penetration to biological tissues in vivo. On the other hand, photothermal therapy (PTT) offers a highly efficient treatment to cancer with negligible safety concerns. To combine the strengths of both NIR fluorescence imaging and PTT for simultaneous cancer imaging and therapy, we report a type of NIR fluorescent nanoparticles (NPs) composed of pyrrolopyrrole cyanines (PPCys) with a strong absorbance in the NIR optical window. These NPs as effective theranostic agents show strong NIR fluorescence and photothermal effect for simultaneous cancer imaging and therapy at both in vitro and in vivo levels. The in vivo imaging and therapy results in nude mice demonstrate the promising potential of these NIR NPs for preclinical and clinical cancer imaging and therapy applications.