Ultrabright NIR-II Nanoparticles for High-Resolution In Vivo Imaging: From Systemic Vasculature Visualization to...

Area of Science:

• Biomedical Engineering
• Materials Science
• Organic Chemistry

Background:

• Highly emissive fluorescence probes are essential for accurate disease diagnosis.
• Organic dyes in the near-infrared-II (NIR-II) spectrum often suffer from low quantum yield, limiting their diagnostic utility.
• Aggregation-induced emission (AIE) offers a strategy to enhance fluorescence properties.

Purpose of the Study:

• To design and synthesize a novel aggregation-induced emission (AIE) luminogen, TPE-Hexoxyl, for bright NIR-II fluorescence imaging.
• To engineer NIR-II nanoparticles from TPE-Hexoxyl with improved quantum yield and stability.
• To evaluate the diagnostic potential of these nanoparticles in preclinical models.

Main Methods:

• Strategic molecular design of TPE-Hexoxyl to suppress π-π stacking and intramolecular charge transfer.
• Fabrication of NIR-II nanoparticles from TPE-Hexoxyl.
• In vitro characterization of nanoparticle stability and photophysical properties (absolute Φ_PL = 0.9%).
• In vivo imaging studies in mouse models for vasculature, lymphatic networks, tumor detection, and inflammatory disease mapping.

Main Results:

• Engineered NIR-II nanoparticles with exceptionally high photoluminescence quantum yield (Φ_PL = 0.9%), among the brightest reported organic probes.
• Demonstrated excellent colloidal stability and photostability of the TPE-Hexoxyl nanoparticles in vitro.
• Achieved high-resolution, dynamic in vivo imaging of systemic vasculature, cerebral microvasculature, and lymphatic systems.
• Showcased superior sensitivity in detecting tumor lesions and precise mapping of inflammatory regions in disease models.

Conclusions:

• TPE-Hexoxyl nanoparticles represent a significant advancement in bright organic NIR-II fluorophores.
• The developed nanoparticles demonstrate transformative potential for clinical pathological diagnostics, including tumor and inflammatory disease visualization.
• This work provides a molecular design paradigm for creating high-performance organic NIR-II fluorophores for advanced biomedical applications.