NIR Dye-Conjugated Maltodextrin for Photothermal Therapy of Cancer

Photothermal therapy (PTT) is one of recently emerging anticancer treatment modalities that involve the use of laser and photosensitizers. To fully explore the therapeutic potential of PTT, it is critical to deliver photosensitizers to tumors specifically. Maltodextrin is a hydrophilic polysaccharide consisting of D-glucose units and has been used as a pharmaceutical excipient because of its excellent biocompatibility. IR820 is a derivative of indocyanine green (ICG), a clinically used imaging agent and has potential as a photosensitizer for PTT. However, the clinical translation of IR820 has been limited by its lack of cancer targeting ability and poor stability in physiological environments. In this study, we hypothesized that IR820-conjugated maltodextrin (MDir) preferentially accumulates in tumors and serves as photothermal agents. Combination of MDir and near-infrared (NIR) laser irradiation significantly increased the temperature, leading to photothermal-mediated apoptosis of cancer cells. In a mouse xenograft models, MDir preferentially accumulated in tumors and induced almost complete thermal ablation of tumors upon NIR laser irradiation. Based on its tumor targeting ability, photothermal conversion efficiency and excellent biocompatibility, we anticipate that MDir holds great translational potential as a fluorescence imaging-guided photothermal agent for cancer treatment.