Isolation of extracellular vesicles with multivalent aptamers

Area of Science:

• Biotechnology
• Molecular Biology
• Nanotechnology

Background:

• Extracellular vesicles (EVs) are crucial intercellular communicators involved in disease pathophysiology.
• EV contents are utilized in cancer diagnosis and treatment monitoring, highlighting the need for effective isolation methods.
• Current EV isolation techniques face challenges like low specificity and lengthy procedures, hindering clinical translation.

Purpose of the Study:

• To develop an efficient and specific method for isolating tumor-derived EVs from body fluids.
• To overcome the limitations of existing EV isolation techniques for improved cancer liquid biopsy.
• To facilitate EV-centered research in diseases like acute lymphoblastic leukemia.

Main Methods:

• Utilized a multivalent, long single-stranded aptamer (MA) for EV enrichment and retrieval.
• Anchored biotin-labeled MAs with bound EVs onto streptavidin-coated microspheres.
• Retrieved EVs via DNA aptamer digestion using DNase.

Main Results:

• Isolated approximately 45% of spiked EVs within 40 minutes.
• Achieved 84.7% depletion of albumin contamination.
• Successfully retrieved 93.1% of isolated EVs using DNase in 10 minutes for downstream analysis.

Conclusions:

• The multivalent aptamer method offers efficient and specific isolation of EVs.
• This simple approach can significantly advance EV-centered studies, particularly for acute lymphoblastic leukemia.
• The method shows promise for large-scale clinical implementation of EV-based liquid biopsies.