Erasable FAP Targeted Spray-On Probe for Fluorescence-Guided Surgery

Area of Science:

• Biomedical Engineering
• Surgical Oncology
• Molecular Imaging

Background:

• Fluorescence-guided surgery (FGS) enhances real-time cancer detection and therapeutic decisions.
• Current fluorescent affinity probes (FAPs) include systemically injected and spray-on types.
• A key challenge in FGS is developing 'turn-off' probes to reduce background noise during iterative procedures.

Purpose of the Study:

• To develop and characterize the first FAP-targeted erasable spray-on probe (ESOP).
• To evaluate the probe's efficacy in sensitive tumor-specific margin visualization.
• To demonstrate the probe's capacity for iterative applications via UV-induced signal erasure.

Main Methods:

• Development of a novel ESOP comprising a rhodamine dye, a photo-responsive triazene linker, and a FAP affinity ligand.
• Application of the ESOP as a spray onto tissue for real-time imaging.
• Erasure of fluorescent signals using a 2-minute UV light pulse for iterative staining.

Main Results:

• The ESOP enabled highly sensitive, tumor-specific margin visualization within minutes of spray application.
• Fluorescent signals were completely erased by UV light, allowing for repeated staining.
• Consistently high tumor-to-background ratios (TBRs) were achieved in iterative applications.

Conclusions:

• FAP-targeted ESOPs are feasible for both cancer and host tissue targeting.
• This technology has the potential to transform next-generation cancer surgeries.
• The development of ESOPs promises to significantly improve patient care through enhanced surgical precision.