A Facile, Versatile, and Highly Efficient Strategy for Peroxynitrite Bioimaging Enabled by Formamide Deformylation

Abstract

Peroxynitrite (ONOO − ) is attracting increasing attention due to its involvement in multiple facets of pathophysiological processes. However, ONOO − bioimaging is still challenging due to (1) the lack of highly specific reaction triggers, (2) the tedious and low-yielding synthesis of current sophisticated probes, and (3) the lack of availability of a versatile chemical strategy. To address these challenges, on the basis of amine formylation/deformylation chemistry, we have developed a novel strategy for ONOO − bioimaging. As proof of principle, we designed, synthesized, and evaluated four novel fluorescent probes equipped with the formamide functionality. Although they feature distinctly different fluorophore classes, all probes can be synthesized in one step in high yields and exhibit particularly specific, highly sensitive, and rapid responses to ONOO − . The bioimaging capability is well demonstrated by successfully visualizing ONOO − fluctuation in live cells and major organs of mice suffering from paraquat poisoning. The proposed strategy has proved to be a facile, versatile, and highly efficient methodology for ONOO − visualization, which will greatly facilitate ONOO − biochemistry and pathophysiology.

Visualization of ONOO– and Viscosity in Drug-Induced Hepatotoxicity with Different Fluorescence Signals by a Sensitive Fluorescent Probe

“…However, extremely short half-life (<10 ms) and nanomolar homeostasis concentration of ONOO – almost precludes its detection in situ under physiological conditions. , Currently, several methods of ONOO – detection have been reported, such as electron spin resonance and liquid chromatography mass spectrometry . In contrast, fluorescence imaging technology not only can greatly improve the efficiency of research in in vitro studies but also can provide a simple, noninvasive, and convenient visual method for real-time tracking in vivo bioimaging. − Therefore, there have emerged a number of fluorescent probes for ONOO – in biological systems mainly based on the protected/deprotected strategy, including the α-keto amide, boronic acid, and formamide-based probes. − …”

Oxygen-Embedded Pentacene Based Near-Infrared Chemiluminescent Nanoprobe for Highly Selective and Sensitive Visualization of Peroxynitrite In Vivo

“…Notably, the negligible effect on the cellular viabilities was observed even under 100 μg/mL, indicating the high biocompatibility of our probe (Figure S13). According to the literature, ONOO – was excessively produced in many inflammation associated with pathological process and diseases. , However, chemiluminescent imaging was rarely explored to detect the formation progress of ONOO – under inflammation environments in vivo . Next, we tested the potential application of NPs-PCP-350 for imaging ONOO – in vivo.…”

“…Peroxynitrite (ONOO – ) as one of the highly reactive oxygen species is the reaction product of nitric oxide with superoxide radical. − ONOO – with a short life (about 10 ms at pH 7.4) can be easily translated into other active secondary radicals such as hydroxyl radical ( • OH), carbonate radicals ( • CO 3 – ), and nitrogen dioxide ( • NO 2 ). , Importantly, ONOO – or those secondary radicals are able to react with many biomolecules, such as lipids, nucleic acids, and proteins, eventually causing cellular apoptosis and contributing to the progression of neurodegenerative disorders, inflammation, immune response, cancers, and other serious diseases. ,− However, due to less availability of powerful detection methods, the biological mechanisms of ONOO – have been not fully illuminated for its involvement in the above pathologic processes until now. , Therefore, a way to real-time and non-invasive detection of ONOO – in vivo with high sensitivity and selectivity is urgently desired to gain crucial insights in exploring the pathological mechanism of ONOO – in related diseases …”

Highly Sensitive Near-Infrared Imaging of Peroxynitrite Fluxes in Inflammation Progress

“…Recently, a near-infrared (NIR, 650–900 nm) fluorescence imaging method featured with deep imaging depth, noninvasive visualization, and high sensitivity has become the cutting-edge method for the study of targets in vivo . − Though a growing body of well-designed fluorescence probes for ONOO – has been raised and some complex roles of ONOO – in cells and living bodies were elucidated, − there are only a handful of NIR fluorescent probes intentionally constructed for the in vivo monitoring of ONOO – content in inflammation progress, which exhibited limited sensitivity and S/N ratio. − Additionally, some organic NIR fluorophores were reported to be easily oxidized by ONOO – due to the strong oxidizing nature of ONOO – , which may result in false-negative signals and inaccurate detection results. − In this scenario, developing an NIR probe for sensitive in vivo detection of ONOO – fluxes in inflammation is still pressing.…”