(99m)Tc-labelled gold nanoparticles capped with HYNIC-peptide/mannose for sentinel lymph node detection

Area of Science:

• Nanotechnology
• Radiopharmaceutical Science
• Oncology

Background:

• Sentinel lymph node detection (SLND) is crucial for cancer staging.
• Current SLND methods face limitations in specificity and retention.
• Development of targeted radiopharmaceuticals can improve SLND accuracy.

Purpose of the Study:

• To prepare a multifunctional system of technetium-99m-labelled gold nanoparticles conjugated to HYNIC-GGC/mannose.
• To evaluate the biological behavior of this system as a potential radiopharmaceutical for SLND.

Main Methods:

• Synthesis and characterization of HYNIC-GGC-AuNP-mannose nanoconjugates.
• Technetium-99m labeling and radiochemical purity assessment.
• In vitro mannose receptor binding studies and in vivo biodistribution in Wistar rats using micro-SPECT/CT.

Main Results:

• Successful functionalization of gold nanoparticles with HYNIC-GGC and mannose.
• High radiochemical purity (>95%) of the (99m)Tc-AuNP-mannose conjugate.
• Specific binding to mannose receptors and significant, retained uptake in the first lymph node (popliteal) after administration, with minimal off-target accumulation.

Conclusions:

• The (99m)Tc-AuNP-mannose conjugate demonstrates excellent retention in the sentinel lymph node for up to 24 hours.
• This target-specific radionanoconjugate shows promise for SLND applications within conventional protocols.