A Proximity-Induced pH-Responsive DNA Switch for Reversible Capture and Release of Extracellular Vesicles

Area of Science:

• Biotechnology
• Molecular Biology
• Nanotechnology

Background:

• Extracellular vesicles (EVs) are crucial in biological processes but challenging to isolate due to their size and density.
• Current isolation methods often compromise EV integrity, hindering clinical applications like cancer diagnosis and monitoring.

Purpose of the Study:

• To develop a novel, mild, and efficient method for isolating intact extracellular vesicles (EVs).
• To enable reversible EV capture and release using a proximity-induced pH-responsive DNA switch (PPS).

Main Methods:

• A proximity-induced pH-responsive DNA switch (PPS) utilizing dual-aptamer probes (targeting EpCAM and CD63) for EV capture.
• Hoogsteen triplex formation at pH 6.5 for EV binding to magnetic beads.
• Reversible EV release at neutral pH (7.4) without chemical denaturants.

Main Results:

• Achieved high EV purification efficiency (79.4% in PBS, 72.6% in biological matrices) within 1 hour.
• Demonstrated preservation of EV structural integrity and bioactivity through wound-healing and cellular uptake assays.
• Modular aptamer design allows for adaptation to various EV subpopulations with reduced cost and complexity.

Conclusions:

• The PPS strategy offers a robust, nondestructive method for high-purity EV isolation.
• This technique preserves EV integrity and bioactivity, supporting applications in disease diagnosis and drug delivery.
• The PPS method shows significant potential for advancing EV-related research and clinical translation.