Radiolabeled γ-polyglutamic acid complex as a nano-platform for sentinel lymph node imaging.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Molecular Imaging

Background:

• Sentinel lymph node (LN) detection is crucial for cancer staging.
• Developing safe and effective molecular imaging probes is essential for early detection.

Purpose of the Study:

• To establish a safe and biocompatible nano-platform for molecular imaging.
• To evaluate the effectiveness of a novel indium-111-labeled complex for sentinel LN imaging.

Main Methods:

• A ternary anionic complex (DTPA-G4/PEI/γ-PGA) was synthesized and labeled with indium-111.
• Cytotoxicity and erythrocyte agglutination were assessed.
• In vitro cellular uptake by macrophage cells was evaluated.
• In vivo biodistribution and sentinel LN visualization using SPECT were performed in rats.

Main Results:

• The anionic (111)In-DTPA-G4/PEI/γ-PGA exhibited low cytotoxicity and minimal erythrocyte agglutination, indicating high biocompatibility.
• (111)In-DTPA-G4/PEI/γ-PGA showed significant uptake by macrophage cells via phagocytosis and a γ-PGA-specific pathway.
• In vivo studies demonstrated higher accumulation of (111)In-DTPA-G4/PEI/γ-PGA in sentinel LNs compared to the cationic counterpart.
• SPECT imaging clearly visualized the sentinel LNs using the developed nano-platform.

Conclusions:

• The developed anionic nano-platform (111)In-DTPA-G4/PEI/γ-PGA is safe and biocompatible.
• This nano-platform is effective for molecular imaging of sentinel lymph nodes.
• It holds potential for future clinical applications in cancer diagnostics.