Biodegradable ICG-Conjugated Germanium Nanoparticles for In Vivo Near-Infrared Dual-Modality Imaging and Photothermal...

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Medical Imaging

Background:

• Theranostics integrate diagnosis and therapy for real-time tumor monitoring.
• Fluorescence and photoacoustic imaging offer complementary high-resolution, deep-penetration capabilities.
• Biodegradability of theranostic agents is crucial for reducing toxicity and enhancing excretion.

Purpose of the Study:

• To synthesize biocompatible and biodegradable indocyanine green (ICG)-conjugated germanium nanoparticles (GeNPs).
• To investigate the biodistribution and efficacy of ICG-GeNPs in nude mice and 4T1 tumor models.
• To evaluate ICG-GeNPs as theranostic agents for near-infrared (NIR) dual-modality imaging and photothermal therapy.

Main Methods:

• Synthesis of ICG-conjugated GeNPs.
• Intravenous injection of ICG-GeNPs into tumor-bearing mice.
• NIR dual-modality fluorescence and photoacoustic imaging for biodistribution analysis.
• Assessment of in vitro and in vivo toxicity.
• Evaluation of photothermal therapy efficacy.

Main Results:

• ICG-GeNPs exhibited strong NIR absorption and fluorescence with low toxicity.
• Biodistribution studies showed accumulation in liver, spleen, and tumor via the EPR effect.
• Tumor fluorescence signal was significantly enhanced compared to free ICG.
• Photothermal therapy using ICG-GeNPs resulted in significant tumor volume reduction.

Conclusions:

• ICG-GeNPs are promising biodegradable theranostic agents.
• They enable effective in vivo NIR dual-modality imaging.
• They are suitable for photothermal therapy, demonstrating potential for clinical translation.