AniView Supports Inflammation Imaging Research: An Activatable Dye-Sensitized Lanthanide NanoprobesWith Enhanced NIR-II Luminescence for In VivoInflammation Imaging

New progress has been made in inflammation imaging research.

Professor Yan Zhang’s team at Huazhong University of Science and Technology recently published their latest findings in the internationally recognized journal “Chemistry- A European Journal”.

This study introduces a NIR-IIb-responsive nanoprobe for highly sensitive and specific imaging of hypochlorite (ClO⁻), providing a new noninvasive tool for real-time monitoring of bacterial infection–associated inflammation.

Bacterial infection can trigger acute inflammatory responses, during which neutrophils produce hypochlorite (ClO⁻) via myeloperoxidase-mediated catalysis to eliminate pathogens. However, excessive ClO⁻ production may lead to tissue damage and even septic shock. Therefore, real-time monitoring of ClO⁻ levels is essential for evaluating inflammation severity and therapeutic efficacy. Conventional methods, including iodometry, colorimetry, and chromatography, rely on invasive biopsies and are unsuitable for dynamic in vivo imaging. Although optical imaging techniques enable real-time tracking of physiological processes, most ClO⁻ probes suffer from short emission wavelengths, limited tissue penetration, and low signal-to-background ratios. The second near-infrared window (NIR-II), particularly the NIR-IIb region (1500–1700 nm), offers significantly reduced photon scattering and autofluorescence, enabling deeper tissue penetration and higher imaging resolution. To address these challenges, the authors designed and screened a series of ZW800-based probes coupled to lanthanide nanoparticles (LnNPs) through different bridging atoms (direct linkage, oxygen, or sulfur). Among them, the sulfur-bridged LnNP@ZW800-SC exhibited markedly enhanced NIR-IIb emission at 1523 nm under 808 nm excitation. Leveraging the intrinsic ClO⁻ responsiveness of ZW800-SC and PEG surface modification, the probe achieved highly sensitive and selective imaging of ClO⁻ both in vitro and in an LPS-induced mouse lymphatic inflammation model, demonstrating its potential for noninvasive and dynamic monitoring of bacterial infections.

Experiments using Aniview

In this study, the AniView Phoenix Full-Spectrum In Vivo Imaging System developed by Biolight Biotechnology was used to evaluate the imaging resolution and tracking capability of LnNP@ZW800-SC@PEG.

To assess the imaging resolution of LnNP@ZW800-SC@PEG, a 1% liposome solution was used as an optical tissue phantom. NaYF₄:Nd@DSPE-PEG, with an emission wavelength of 1046 nm, was synthesized as a control probe. As shown in Figure a, NaYF₄:Nd@DSPE-PEG exhibited substantial scattering at depths greater than 3 mm, whereas LnNP@ZW800-SC@PEG maintained clear edge definition even at a depth of 5 mm. Its superior imaging resolution was further validated through hindlimb lymphatic vessel imaging (Figure b).

To investigate probe responsiveness during bacterial infection, an acute inflammation mouse model was established by injecting lipopolysaccharide (LPS) into the lymph nodes, followed by intradermal administration of LnNP@ZW800-SC@PEG into the footpad (Figures c and d). In the control group, fluorescence intensity gradually increased over time and reached its peak at 45 minutes post-injection. The LPS-treated group displayed a similar kinetic profile; however, fluorescence intensity decreased by approximately 50% starting at 45 minutes (Figure e). These results demonstrate that LnNP@ZW800-SC@PEG can effectively track inflammatory status in vivo through ClO⁻-dependent signal modulation.

NIR-II Imaging of Acute Lymph Node Inflammation Using LnNP@ZW800-SC@PEG.

(a) Fluorescence images of NaYF₄:Nd@DSPE-PEG and LnNP@ZW800-SC@PEG in capillary tubes were acquired under 808 nm excitation using 900 nm LP and 1300 nm LP filters, respectively.

(b) Fluorescence images of hindlimb lymphatic vessels following footpad intradermal injection of NaYF₄:Nd@DSPE-PEG (900 nm LP filter) and LnNP@ZW800-SC@PEG (1300 nm LP filter).

(c) Schematic illustration of NIR-II imaging of LPS-induced acute inflammation using the LnNP@ZW800-SC@PEG nanoprobe.

(d) In vivo NIR-II fluorescence images of lymph nodes at different time points after injection of LnNP@ZW800-SC@PEG, along with the corresponding fluorescence intensity measurements.

(e) Quantitative analysis of fluorescence intensity over time derived from panel (d).

DOI：10.1002/chem.70822