Technetium-Radiolabeled Mannose-Functionalized Gold Nanoparticles as Nanoprobes for Sentinel Lymph Node Detection

Area of Science:

• Nanomedicine
• Radiochemistry
• Biomedical Imaging

Background:

• Gold nanoparticles (AuNPs) are valuable nanomaterials for developing radiolabeled nanoprobes for single-photon emission computed tomography (SPECT) imaging.
• Functionalized AuNPs can enhance radioactive signaling for improved lymphatic mapping in sentinel nodes.

Purpose of the Study:

• To describe an alternative method for functionalizing commercial AuNPs with mannose.
• To develop and evaluate ^99mTc-radiolabeled AuNPs-mannose as a SPECT contrast agent for lymphatic mapping.

Main Methods:

• Chemical derivatization of AuNPs with lipoic acid and biofunctionalization with mannose.
• Radiolabeling using the thiolate hydrazinonicotinamide-glycine-glycine-cysteine (HYNIC) molecule for ^99mTc.
• Physicochemical characterization (UV-Vis, DLS, FTIR, TEM) and stability assessment.
• In vivo testing in a rat sentinel lymph node model using microSPECT/CT imaging.

Main Results:

• Successful physicochemical characterization and stability assessment of the AuNPs-mannose system.
• Achieved efficient ^99mTc radiolabeling with high purity.
• SPECT/CT imaging demonstrated that ^99mTc-AuNPs-mannose effectively tracks and accumulates in lymph nodes.
• Performance was comparable to the clinical standard, ^99mTc-Sulfur colloid.

Conclusions:

• The developed ^99mTc-AuNPs-mannose nanoprobes are stable and suitable for SPECT imaging.
• These nanoprobes show potential as a SPECT contrast agent for lymphatic mapping.
• The findings support the use of AuNPs-mannose for sentinel lymph node detection.