Tumor-Targeting Near-Infrared Dimeric Heptamethine Cyanine Photosensitizers with An Aromatic Diphenol linker for Imaging-Guided Cancer Phototherapy.

Phototherapy was considered as a promising alternative to conventional tumor treatments due to its noninvasive modality and effective therapeutic effect. However, designing a photosensitizer with satisfactory therapeutic effect and high security remains a considerable challenge. Herein, we develop a series of dimeric heptamethine cyanine photosensitizers with an aromatic diphenol linker at the meso position to improve the photothermal conversion efficiency (PCE). Thanks to the extended conjugate system and high steric hindrance, the screened 26NA-NIR and 44BP-NIR exhibit high PCE (about 35%), bright near-infrared (NIR) fluorescence, excellent ROS generation capability, and improved photostability. Furthermore, their outstanding performance on imaging-guided PDT-PTT synergistic therapy is demonstrated by in vivo and in vitro experiments. In conclusion, this study designs a series of dimeric heptamethine cyanine photosensitizers and presents two compounds for potential clinical applications. The strategy provides a new method to design NIR photosensitizers for imaging-guided cancer treatment. This article is protected by copyright. All rights reserved.