Spatio-Temporally Reporting Dose-Dependent Chemotherapy via Uniting Dual-Modal MRI/NIR Imaging.

Unpredictable in vivo therapeutic feedback of hydroxyl radical (. OH) efficiency is the major bottleneck of chemodynamic therapy. Herein, we describe novel Fenton-based nanotheranostics NQ-Cy@Fe&GOD for spatio-temporally reporting intratumor . OH-mediated treatment, which innovatively unites dual-channel near-infrared (NIR) fluorescence and magnetic resonance imaging (MRI) signals. Specifically, MRI signal traces the dose distribution of Fenton-based iron oxide nanoparticles (IONPs) with high-spatial resolution, meanwhile timely fluorescence signal quantifies . OH-mediated therapeutic response with high spatio-temporal resolution. NQ-Cy@Fe&GOD can successfully monitor the intracellular release of IONPs and . OH-induced NQO1 enzyme in living cells and tumor-bearing mice, which makes a breakthrough in conquering the inherent unpredictable obstacles on spatio-temporally reporting chemodynamic therapy, so as to manipulate dose-dependent therapeutic process.

Rational Design of Ratiometric Near-Infrared Aza-BODIPY-Based Fluorescent Probe for in Vivo Imaging of Endogenous Hydrogen Peroxide.

Precise in vivo tracking of hydrogen peroxide is still challenging due to its dynamic complexity and intrinsic background interference. Herein, we describe a rational design strategy to construct asymmetric aza-boron-dipyrromethane derivative (BODIPY)-based ratiometric probes for in vivo tracking H2O2, which are composed of a near-infrared aza-BODIPY core, active targeting group, and H2O2-specific recognition unit. We take advantage of two terminal functionalized conjunctions in the bis-condensed aza-BODIPY by rationally introducing carbonyl group as an electron-deficiency linker for regulating intramolecular charge transfer-induced wavelength shift and by attaching hydrophilic polyethylene glycol-biotin segment as the active targeting moiety. The probe BP5-NB-OB features several striking characteristics: (i) ratiometric near infrared response in both absorption and emission spectra; (ii) active targeting ability (biotin receptor-mediated endocytosis) with excellent biocompatibility; and (iii) in vivo tracking of endogenous H2O2. It was demonstrated that the probe BP5-NB-OB was successfully utilized for tracking endogenous H2O2 in living cells and tumor-bearing mice, providing opportunities to insight into H2O2 related diseases for clinical application.

In vivo ratiometric tracking of endogenous ß-galactosidase activity using an activatable near-infrared fluorescent probe.

Herein, we developed a dual-channel and light-up near-infrared fluorescent probe for ratiometric sensing of ß-galactosidase (ß-gal) activity. The well-designed probe, which shows ratiometric optical response with a significant red-shift (from 575 nm to 730 nm), was successfully applied to detect endogenous ß-gal activity in SKOV-3 cells and tumor-bearing mice.

Near-Infrared Aggregation-Induced Emission-Active Probe Enables in situ and Long-Term Tracking of Endogenous ß-Galactosidase Activity.

High-fidelity tracking of specific enzyme activities is critical for the early diagnosis of diseases such as cancers. However, most of the available fluorescent probes are difficult to obtain in situ information because of tending to facile diffusion or inevitably suffering from aggregation-caused quenching (ACQ) effect. In this work, we developed an elaborated near-infrared (NIR) aggregation-induced emission (AIE)-active fluorescent probe, which is composed of a hydrophobic 2-(2-hydroxyphenyl) benzothiazole (HBT) moiety for extending into the NIR wavelength, and a hydrophilic ß-galactosidase (ß-gal) triggered unit for improving miscibility and guaranteeing its non-emission in aqueous media. This probe is virtually activated by ß-gal, and then specific enzymatic turnover would liberate hydrophobic AIE luminogen (AIEgen) QM-HBT-OH. Simultaneously, brightness NIR fluorescent nanoaggregates are in situ generated as a result of the AIE-active process, making on-site the detection of endogenous ß-gal activity in living cells. By virtue of the NIR AIE-active performance of enzyme-catalyzed nanoaggregates, QM-HBT-ßgal is capable of affording a localizable fluorescence signal and long-term tracking of endogenous ß-gal activity. All results demonstrate that the probe QM-HBT-ßgal has potential to be a powerful molecular tool to evaluate the biological activity of ß-gal, attaining high-fidelity information in preclinical applications.