Gold Nanoparticles for Brain Tumor Imaging: A Systematic Review

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Oncology

Background:

• Accurate demarcation of malignant brain tumors is crucial for complete surgical resection and improved patient survival.
• Current contrast agents like gadolinium (Gd) have limitations in depicting precise tumor margins.
• Gold nanoparticles (GNPs) offer unique properties and biocompatibility for enhanced brain tumor diagnosis.

Purpose of the Study:

• To review the application of gold nanoparticles (GNPs) for in vitro and in vivo brain tumor diagnosis.
• To assess the potential of GNPs as diagnostic probes for improving brain tumor imaging and surgical planning.

Main Methods:

• A comprehensive PubMed search was conducted using keywords 'gold,' 'NP,' and 'brain tumor.'
• Eligibility assessment of retrieved studies was performed independently by two reviewers.
• Data extracted included study model, GNP characteristics (shape, size, coating), BBB penetration strategies, imaging modalities, and therapeutic conjugations.

Main Results:

• Sixteen studies published between 2011 and 2017 were included; no human studies were found.
• Most in vivo studies utilized rodent models with spherical GNPs (20-120 nm), often coated with polyethylene glycol (PEG).
• Enhanced blood-brain barrier (BBB) penetration was achieved via surface modification or external energy; MRI and Raman scattering were common imaging modalities.

Conclusions:

• Experimental evidence suggests GNPs are versatile, persistent, and safe contrast agents for multimodality brain tumor imaging.
• GNPs can improve pre-, intra-, and post-operative microscopic precision, enhancing tumor edge visualization.
• Diagnostic GNPs hold potential as theranostic nanoparticles, combining diagnostic and therapeutic capabilities.