Table 2.

Challenges of PDNVs extraction and purification methods.

Method	Guideline	Advantage	Challenge
Ultracentrifugation	Size and density	Simple separating Large sample processing Preserving integrity	Time-consuming Requiring specialized equipment Damaging particles
Dialysis	Removing small molecule impurities	Removing small impurities effectively	Relatively time-intensive Lower efficiency
Size-exclusion chromatography	Size	High purity of isolated PDNVs Shorter Processing time Preserves EV integrity and biological activity	High cost Limited sample volume
Immunoaffinity capture-based technique	Selective enrichment using specific covalent or affinity magnetic beads	Higher extraction purity Higher yield Suitable for large diluted samples	Longer processing time Longer processing time Higher extraction cost
Differential ultrafiltration	Size	Allowing handling of larger sample volumes	Limited by particle size Affected recovery rate