Intrinsically Cancer-Mitochondria-Targeted Thermally Activated Delayed Fluorescence Nanoparticles for Two-Photon-Activated Fluorescence Imaging and Photodynamic Therapy

• Published in: ACS applied materials & interfaces Vol. 11; no. 44; pp. 41051 - 41061
• Main Authors: Zhang, Jinfeng, Fang, Fang, Liu, Bin, Tan, Ji-Hua, Chen, Wen-Cheng, Zhu, Zelin, Yuan, Yi, Wan, Yingpeng, Cui, Xiao, Li, Shengliang, Tong, Qing-Xiao, Zhao, Junfang, Meng, Xiang-Min, Lee, Chun-Sing
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06.11.2019
• Subjects: Apoptosis - drug effects; Apoptosis - radiation effects; Cell Line, Tumor; Cell Survival - drug effects; Cell Survival - radiation effects; Fluorescent Dyes - chemistry; Humans; Infrared Rays; Microscopy, Confocal; Microscopy, Fluorescence, Multiphoton; Mitochondria - drug effects; Mitochondria - pathology; Nanoparticles - chemistry; Nanoparticles - toxicity; Neoplasms - drug therapy; Neoplasms - metabolism; Neoplasms - pathology; Photochemotherapy; Photons; Photosensitizing Agents - chemistry; Photosensitizing Agents - pharmacology; Quantum Theory; Singlet Oxygen - metabolism; thermally activated delayed fluorescence (TADF); cancer-mitochondria-targeted; two-photon activated; fluorescence imaging; photodynamic therapy
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.9b14552

A recent breakthrough in the discovery of thermally activated delayed fluorescence (TADF) emitters characterized by small single-triplet energy offsets (ΔE ST) offers a wealth of new opportunities to exploit high-performance metal-free photosensitizers. In this report, two intrinsically cancer-mitochondria-targeted TADF emitters-based nanoparticles (TADF NPs) have been developed for two-photon-activated photodynamic therapy (PDT) and fluorescence imaging. The as-prepared TADF NPs integrate the merits of (1) high 1O2 quantum yield of 52%, (2) sufficient near-infrared light penetration depth due to two-photon activation, and (3) excellent structure-inherent mitochondria-targeting capabilities without extra chemical or physical modifications, inducing remarkable endogenous mitochondria-specific reactive oxygen species production and excellent cancer-cell-killing ability at an ultralow light irradiance. We believe that the development of such intrinsically multifunctional TADF NPs stemming from a single molecule will provide new insights into exploration of novel PDT agents with strong photosensitizing ability for various biomedical applications.