Gold Nanocluster Extracellular Vesicle Supraparticles: Self-Assembled Nanostructures for Three-Dimensional Uptake...

Area of Science:

• Biotechnology
• Cell Biology
• Nanotechnology

Background:

• Extracellular vesicles (EVs) are crucial for intercellular communication.
• Imaging EVs within cells is challenging due to low contrast.
• Understanding EV fate after cellular uptake is vital for therapeutic applications.

Purpose of the Study:

• To develop a high-resolution imaging strategy for extracellular vesicles (EVs).
• To visualize the cellular uptake and intracellular fate of EVs.
• To explore the potential of gold nanocluster (AuNC)-labeled EVs for cellular delivery.

Main Methods:

• Self-assembly of EVs with hydrophobic gold nanoclusters (AuNCs) into supraparticles.
• High-resolution imaging using focused ion beam-scanning electron microscopy (FIB-SEM).
• Elemental analysis using dark-field scanning transmission electron microscopy energy-dispersive X-ray spectroscopy (DF-STEM EDX).

Main Results:

• AuNC-EV supraparticles enabled clear visualization of EV reuptake in breast cancer cells.
• The entire process from endocytosis to lysosomal degradation was tracked.
• Gold presence was confirmed in EVs and lysosomes within cellular compartments.

Conclusions:

• AuNC-EV supraparticles offer a robust labeling strategy for high-resolution EV imaging.
• This method facilitates in vitro tracking of EV cellular uptake and fate.
• The approach holds promise for EV-based imaging and AuNCs' cellular delivery.