Atomically Precise Fluorescent Gold Nanocluster as a Barrier-Permeable and Brain-Specific Imaging Probe

Area of Science:

• Nanomaterials Science
• Biomedical Imaging
• Neuroscience

Background:

• Photonic nanomaterials are vital for optical brain imaging, aiding early diagnosis of brain disorders.
• The blood-brain barrier (BBB) restricts the passage of most substances into the brain, posing a challenge for imaging agents.

Purpose of the Study:

• To develop a targeted nanomaterial capable of crossing the BBB for enhanced optical brain imaging.
• To evaluate the efficacy of L-dopa-conjugated gold clusters (Dop@LAuC) in penetrating the BBB.

Main Methods:

• Synthesis of gold clusters (LAuC) and conjugation with Levodopa to form Dop@LAuC.
• In vitro assessment of Dop@LAuC and LAuC penetration across a BBB model using brain endothelial cells.
• In vivo optical imaging in mice to confirm BBB crossing and assess barrier integrity.

Main Results:

• Dop@LAuC demonstrated significantly enhanced BBB penetration (50% in 3 hours) compared to unconjugated LAuC (10% in 3 hours) in vitro.
• In vivo imaging confirmed that Dop@LAuC effectively crosses the BBB without compromising its integrity.
• The nanomaterial emits in the near-infrared (NIR) spectrum, suitable for real-time optical imaging.

Conclusions:

• Levodopa conjugation enhances the ability of gold clusters to cross the blood-brain barrier.
• Dop@LAuC represents a promising tool for targeted optical brain imaging and early disease diagnosis.
• This approach offers a potential strategy to overcome BBB limitations in neuroimaging.