Activatable Near-Infrared Fluorescence Imaging Using PEGylated Bacteriochlorin-Based Chlorin and BODIPY-Dyads as...

Area of Science:

• Biomedical imaging
• Organic chemistry
• Fluorescence spectroscopy

Background:

• Near-infrared (NIR) fluorescent probes offer advantages for in vivo imaging, including deeper tissue penetration and lower autofluorescence.
• Activatable probes enhance target specificity by activating only upon binding, improving signal-to-background ratios.
• Limited availability of activatable NIR probes hinders their widespread application.

Purpose of the Study:

• To develop novel activatable NIR fluorophores based on bacteriochlorin.
• To create energy-transfer dyads incorporating chlorin-bacteriochlorin and boron-dipyrromethene (BODIPY)-bacteriochlorin structures.
• To address aggregation issues in targeted bacteriochlorin probes by incorporating polyethylene glycol (PEG) chains.

Main Methods:

• Synthesis of chlorin-bacteriochlorin and BODIPY-bacteriochlorin energy-transfer dyads.
• Characterization of fluorophore properties, including excitation and emission spectra.
• PEGylation of bacteriochlorin-based probes to improve hydrophilicity and prevent aggregation.

Main Results:

• Developed two novel types of activatable NIR fluorophores with multiple narrow excitation bands and strong NIR emission.
• Demonstrated that PEGylation improves hydrophilicity without negatively impacting probe pharmacokinetics.
• Successfully created PEGylated bacteriochlorin-based probes, overcoming previous aggregation limitations.

Conclusions:

• The novel PEGylated bacteriochlorin-based activatable fluorophores show significant potential for targeted in vivo imaging.
• These probes can function as multicolor NIR fluorescent agents, enhancing diagnostic capabilities.
• The developed probes address key limitations of existing NIR imaging agents, paving the way for advanced biomedical applications.