Abstract

Rigor and Reproducibility of Extracellular Vesicles: A Nanoscale Perspective

Shivani Sharma, Associate Director, University of California, Los Angeles

Interest in extracellular vesicles (EVs) in biomedical field is rapidly expanding and has raised high hopes towards novel diagnostics and therapeutics. Current biophysical analysis of EVs typically encompass particle density and size distribution determinations using various techniques. However, variabilities in EV isolation methods, and the structural complexity of these biological-nanoparticles (sub-100nm) necessitate more rigorous nanoscale biophysical characterization of single EVs to facilitate more reliable and comparable EV-based assays. Combing scanning probe, super-resolution optical and electron microscopy, our findings demonstrate the effectiveness of orthogonal high-resolution biophysical-biomechanical characteristics of single EVs, not discernable via particle size distributions and counts alone. The assessment of key structural-mechanical parameters identified as morphology, Rms roughness, Young’s modulus, and co-existent non-vesicles within EV isolates, collectively termed ‘EV-nano-metrics’ provides a promising complementary approach towards advanced understanding of the complexity and heterogeneity of EV isolates, with broad implications for enhancing the reliability and reproducibility of EV-analytes  in research and clinical use.