Quantification of Desiccated Extracellular Vesicles by Quartz Crystal Microbalance

Area of Science:

• Biotechnology
• Biosensing
• Nanotechnology

Background:

• Accurate quantification of extracellular vesicles (EVs) is essential for understanding their role in cell-to-cell signaling, disease modeling, and drug development.
• Current methods for EV quantification are limited and often require large sample volumes.
• The precise number of EVs in cell culture media is influenced by cell status, highlighting the need for reliable quantification techniques.

Purpose of the Study:

• To introduce and validate the use of quartz crystal microbalance (QCM) as a biosensor for quantifying extracellular vesicles (EVs).
• To assess the sensitivity and resolution limits of QCM for EV detection.
• To explore novel sample preparation and analysis patterns for EV quantification using QCM.

Main Methods:

• Application of quartz crystal microbalance (QCM) as a biosensor.
• Quantification of desiccated extracellular vesicles (EVs) on a quartz crystal surface after solvent evaporation.
• Measurement of resonant frequency shifts in the quartz crystal to determine EV quantity.
• Analysis of EV distribution patterns post-drying.

Main Results:

• QCM biosensors successfully quantified extracellular vesicle (EV) quantities up to 6 × 10⁷, adhering to Sauerbrey's relation.
• The developed biosensor demonstrated a resolution limit, distinguishing samples with as few as 2.7 × 10⁵ EVs.
• A distinct ring-shaped deposition pattern of EVs was observed and characterized after sample drying on the quartz crystal.

Conclusions:

• Quartz crystal microbalance (QCM) technology provides a highly sensitive and cost-effective method for extracellular vesicle (EV) quantification.
• QCM requires only small sample volumes, offering an advantage over existing EV quantification approaches.
• This QCM-based biosensor holds significant potential for advancing research in cell signaling, disease diagnostics, and therapeutic development involving EVs.