An effective strategy based on electrostatic interaction for the simultaneous sequential purification and isolation...

Area of Science:

• Biomaterials Science
• Nanotechnology
• Biochemistry

Background:

• Exosomes are crucial biomarkers for disease diagnosis, but their isolation from biological fluids like serum and urine is often hindered by protein contamination.
• Existing methods such as ultracentrifugation are time-consuming and may not effectively remove all contaminants.

Purpose of the Study:

• To develop a novel material-based strategy for the simultaneous purification and isolation of exosomes from serum and urine.
• To enhance the efficiency of exosome isolation by effectively removing protein contaminants.
• To provide a faster and more cost-effective alternative to traditional exosome isolation techniques.

Main Methods:

• A dual nanoparticle system, polyacrylic acid (PAA)-coated anionic nanoparticles and polyethyleneimine (PEI)-functionalized cationic nanoparticles (Fe3O4@PAA and Fe3O4@PEI), was employed.
• The strategy leverages electrostatic and hydrophobic interactions to remove contaminant proteins and capture/release exosomes.
• The PAA-PEI strategy was applied to serum and urine samples, followed by downstream proteomics analysis and comparison with ultracentrifugation (UC).

Main Results:

• The PAA-PEI strategy achieved high exosome recovery (>95%) from serum with 87% protein contaminant removal.
• For urinary exosomes, the PAA-PEI strategy demonstrated 98.6% contaminant removal efficiency, yielding a higher exosome concentration than UC.
• Proteomics analysis identified more urinary exosomal proteins (124) using the PAA-PEI strategy compared to UC (92).

Conclusions:

• The PAA-PEI strategy is highly effective for exosome capture and significantly mitigates protein contamination interference.
• This method offers a faster (1 hour vs. 3 hours for UC) and more efficient approach for exosome isolation from complex biological samples.
• The developed strategy presents a promising candidate for early disease discovery and diagnosis, highlighting the importance of addressing protein interference in isolation methods.