Hypoxia-activated probe for NIR fluorescence and photoacoustic dual-mode tumor imaging

Abstract

Construction of tumor microenvironment responsive probe with more than one imaging modality, in particular toward hypoxia of solid tumors, is an appealing yet significantly challenging task. In this work, we designed a hypoxia-activated probe TBTO (Triphenylamine-Benzothiadiazole-Triphenylamine derivative featuring four diethylamino N-Oxide groups) for in vivo imaging. TBTO could undergo bioreduction in a hypoxic microenvironment to yield compound TBT sharing both near-infrared (NIR) aggregation-induced emission and strong twisted intramolecular charge transfer features, which endows the probe with excellent performance in NIR fluorescence and photoacoustic dual-mode tumor imaging. This study offers useful insights into designing a new generation agent for clinical cancer diagnosis.

Targeted contrast agents and activatable probes for photoacoustic imaging of cancer

“…Several design strategies have been employed to develop PA probes to visualize tumor hypoxia. 183,208,310–323…”

NIR-I Dye-Based Probe: A New Window for Bimodal Tumor Theranostics

“…Li and his co-workers rationally synthesized a hypoxia-activable probe TBTO which could undergo bioreduction in a hypoxic microenvironment and be converted to an AIE-active product TBT. In vitro and in vivo assessments revealed the FI/PAI ability of TBT ( Figure 12 ) ( Li M. et al, 2021 ). Additionally, Liu et al designed two new AIEgens DPMD and TPMD with a cross-shaped D-A structure.…”

“…(E) In vivo PA images of the tumor site in the mice after tail intravenous injection with TBTO NPs (200 μl, 1 mg/ml) or saline (200 μl) as the control. Reproduced with permission from Li M. et al (2021) . Copyright 2021, Cell Press.…”

Aggregation‐Induced Emission‐Based Platforms for the Treatment of Bacteria, Fungi, and Viruses

“…[ 68 ] Figure listed some typical AIE PTAs. [ 41,66–73 ] It should be emphasized that if the energy of excited electrons is decayed by the nonradiative pathway, the fluorescence of the PTAs which is induced by radiative energy decay should be relatively weak. Therefore, the AIE PTAs with strong photothermal conversion efficiency are always accompanied by weak fluorescence.…”