LAUSR

ABSTRACT Multimodal imaging‐guided synergistic combination therapy has shown great potential for cancer treatment. However, the nanocarrier‐based theranostic systems suffer from batch‐to‐batch variation, complexity of multicomponent, poor drug loading, and carrier‐related toxicity issues. To address these issues, herein we developed a novel carrier‐free theranostic system with nanoscale characteristics for near‐infrared fluorescence (NIRF) and photoacoustic (PA) dual‐modal imaging‐guided synergistic chemo‐photothermal therapy (PTT). Indocyanine green (ICG) and epirubicin (EPI) could co‐self‐assemble into small molecular nanoparticles (NPs) in aqueous solution without any molecular precursor or excipient via collaborative interactions (electrostatic, &pgr;–&pgr; stacking, and hydrophobic interactions). The exceptionally high dual‐drug loading (˜ 92 wt%) ICG‐EPI NPs showed good physiological stability, preferable photothermal response, excellent NIRF/PA imaging properties, pH‐/photo‐responsive drug release behavior, and promoted cellular endocytosis compared with free ICG or EPI. Importantly, the ICG‐EPI NPs showed excellent tumor targeting ability with high spatial resolution and deep penetration via in vivo NIRF/PA dual‐modal imaging. Moreover, in comparison with individual chemotherapy or PTT, the combinational chemo‐PTT therapy of ICG‐EPI NPs with NIR laser irradiation synergistically induced apoptosis and death of cancer cells in vitro, and showed synergistic chemo‐PTT efficiency in vivo as evidenced by highly efficient tumor ablation. Furthermore, the ICG‐EPI NPs exhibited inappreciable toxicity. This co‐self‐assembly of both FDA‐approved agents provides a safe and “Molecular economical” strategy in the rational design of multifunctional nano‐theranostic systems for real‐time self‐monitoring intracellular drug delivery and targeting multimodal imaging‐guided synergistic combination therapy.