Isolation of bacterial extracellular vesicles from raw samples using a portable microstructured electrochemical...

Area of Science:

• Microbiology
• Nanotechnology
• Immunology

Background:

• Bacterial extracellular vesicles (EVs) are crucial for microbial communication and host interactions.
• Conventional isolation methods like ultracentrifugation (UC) are time-consuming and prone to contamination.
• Improved methods are needed for efficient and pure bacterial EV isolation.

Purpose of the Study:

• To evaluate a novel portable microstructured electrochemical device (PMED) for rapid and selective bacterial EV isolation.
• To compare the purity and characteristics of EVs isolated by PMED versus UC.
• To assess the immunomodulatory effects of device-isolated EVs.

Main Methods:

• Immunoaffinity capture and voltage-triggered release using a PMED.
• Isolation of EVs from Escherichia coli (E. coli) and Lactobacillus fermentum (Lb. fermentum) cultures and spiked urine samples.
• Characterization using nanoparticle tracking analysis (NTA), dynamic light scattering (DLS), and Western blot.
• Functional assays measuring Toll-like receptor (TLR) activation.

Main Results:

• The PMED successfully isolated bacterial EVs from various samples with superior purity compared to UC.
• NTA, DLS, and Western blot confirmed enhanced selectivity and reduced contaminants in device-isolated EVs.
• Device-isolated Lb. fermentum EVs selectively activated TLR4, indicating a refined immunomodulatory profile.

Conclusions:

• The PMED provides a rapid, selective, and efficient method for bacterial EV isolation.
• This technology has significant potential for developing EV-based diagnostics, such as for urinary tract infections.
• The PMED facilitates deeper study into bacterial communication and immune regulation via EVs.