A Nanoparticle-Based Approach for the Detection of Extracellular Vesicles

Area of Science:

• Biotechnology
• Nanotechnology
• Biochemistry

Background:

• Extracellular vesicle (EV) analysis is crucial for disease diagnostics but often hindered by complex isolation procedures.
• Developing rapid, efficient methods for EV detection and characterization from bio-fluids is essential.

Purpose of the Study:

• To create a nanoparticle-based time-resolved fluorescence immunoassay (NP-TRFIA) for direct EV analysis from urine and cell culture supernatants.
• To enable characterization of EV surface proteins and glycosylation patterns without prior isolation.

Main Methods:

• Developed NP-TRFIA using biotinylated antibodies for EV capture and Eu3+-chelate or nanoparticle labels for detection.
• Utilized antibodies against tetraspanins and tumor-associated antigens, alongside lectins targeting EV glycans.
• Compared lectin-nanoparticle assays with lectin-chelate assays for signal-to-background ratio.

Main Results:

• Demonstrated specific EV capturing and detection using both antibodies and lectins.
• Achieved 2-10 fold higher signal-to-background ratio with lectin-nanoparticle assays compared to lectin-chelate assays.
• Successfully profiled surface glycosylation of urine-derived EVs and identified differential expression of tumor-associated proteins (e.g., ITGA3, EpCAM) in prostate cancer cell line EVs.

Conclusions:

• NP-TRFIA offers a simplified tool for analyzing and characterizing EVs directly from urine and cell culture supernatants.
• This approach facilitates the identification of disease-specific markers on patient-derived urinary EVs.
• The method supports surface glycosylation profiling and differential expression analysis of EV-associated proteins.