Precise Synergistic Photothermal Therapy Guided by Accurate Temperature-Dependent NIR-II Fluorescence Imaging

Photothermal therapy (PTT) is considered a promising treatment strategy for solid tumors. However, local hyperthermia (over 45 degrees C) during PTT can cause severe side effects in neighboring healthy tissues. PTT with accurate temperature feedback is a compelling strategy to ablate tumors and reduce side effects, but it still faces challenges. Here, a new kind of phototheranostic nanoparticle, namely 17-RF@Ag2Se is developed, enabling in vivo NIR-II fluorescence tracking, PTT and fluorescence nanothermometry as well as synergistic heat-shock protein (HSP) inhibition. Precise PTT with high spatiotemporal resolution is achieved with the help of the designed NIR-II fluorescence imaging-photothermal therapy linkage apparatus. Upon intravenous injection, 17-RF@Ag2Se is specifically accumulated in tumors targeted by the overexpressed integrin alpha v beta 3, which is monitored by NIR-II fluorescence imaging of Ag2Se QDs. Further, the release of HSP inhibitor, tanespimycin (17-AAG), enhances the thermosensitivity of tumor cells. Subsequently, the internal temperature of the tumor is precisely monitored and adjusted during PTT via the temperature-dependent NIR-II fluorescence feedback of Ag2Se QDs and the linkage apparatus calibration, thereby achieving efficient and safe tumor PTT. Also, the results present a new method for accurate temperature monitoring and control in vivo, which can be applied to other biomedical studies. A phototheranostic nanoparticle, 17-RF@Ag2Se, and a NIR-II fluorescence imaging-photothermal therapy linkage apparatus have been developed to achieve high-precision tumor ablation. This approach significantly improves tumor killing efficacy and reduces damage to normal tissues through synergistic photothermal therapy with an HSP90 inhibitor (17-AAG) under the supervision of accurate temperature-dependent NIR-II fluorescence imaging.image