A Simple Benchtop Filtration Method to Isolate Small Extracellular Vesicles from Human Mesenchymal Stem Cells.

Area of Science:

• Biotechnology
• Cell Biology
• Regenerative Medicine

Background:

• Ultracentrifugation is the standard for small extracellular vesicles (sEVs) isolation but suffers from low yield and poor subtype separation.
• Developing efficient and scalable methods for sEV isolation is crucial for their therapeutic and diagnostic applications.

Purpose of the Study:

• To develop and validate a simple benchtop filtration method for isolating human umbilical cord-derived MSC small extracellular vesicles (hUC-MSC-sEVs).
• To characterize the isolated hUC-MSC-sEVs and compare the method's efficiency with traditional techniques.

Main Methods:

• Isolation of hUC-MSC-sEVs using a novel ultrafiltration technique from conditioned medium.
• Characterization of isolated sEVs via nanoparticle tracking analysis (NTA), BCA protein assay, western blot, and transmission electron microscopy (TEM).

Main Results:

• The filtration method successfully isolated hUC-MSC-sEVs with a size range of 30-200 nm.
• High particle concentration (7.75 × 10^10 particles/mL) and protein concentration (80 µg/mL) were achieved.
• Characterization confirmed the presence of exosomal markers (CD9, CD81, TSG101) and morphology consistent with sEVs, meeting MISEV 2018 guidelines.

Conclusions:

• The developed filtration method provides an efficient and scalable approach for isolating hUC-MSC-sEVs.
• This method overcomes limitations of ultracentrifugation, offering improved yield and purity for sEV isolation.
• The isolated hUC-MSC-sEVs are suitable for further research and potential therapeutic applications.