Endogenous exosome labelling with an amphiphilic NIR-fluorescent probe

Area of Science:

• Biotechnology
• Nanomedicine
• Extracellular Vesicle Research

Background:

• Exosomes are crucial for biological, diagnostic, and medical applications.
• Efficient exosome labeling is needed without altering their inherent properties.
• Current labeling methods can be complex or affect exosome integrity.

Purpose of the Study:

• To develop an endogenous, non-perturbing method for near-infrared (NIR) fluorescently labeling exosomes.
• To validate the integrity and characteristics of labeled exosomes compared to unlabeled ones.
• To demonstrate the utility of NIR-labeled exosomes for visualization and analysis.

Main Methods:

• Utilized an amphiphilic probe for endogenous NIR-fluorescent labeling of exosomes.
• Performed comparative analyses using Nanoparticle Tracking Analysis (NTA), Atomic Force Microscopy (AFM), and flow cytometry.
• Conducted immunoblot analysis and spectroscopic analysis for validation.
• Employed fluorescence imaging to visualize purified NIR-exosomes.

Main Results:

• Successfully achieved NIR-fluorescent labeling of exosomes using an endogenous method.
• Demonstrated high similarity between labeled and unlabeled exosomes via NTA, AFM, flow cytometry, and immunoblotting.
• Confirmed the ability to visualize purified NIR-exosomes using spectroscopic analysis and fluorescence imaging.
• The labeling method avoids immunolabelling or synthetic/chromatographic manipulation.

Conclusions:

• The developed endogenous NIR-fluorescent labeling method is efficient and preserves exosome characteristics.
• This technique offers a valuable tool for studying exosome biology, diagnostics, and therapeutics.
• The method provides a non-invasive approach for visualizing and analyzing exosomes in biological systems.