Table 3.

The Comparison Between Secretomes and Extracellular Vesicles

	Secretomes	EVs
Origin	Soluble factors secreted by stem cells into a conditioned medium.3	Naturally released stem cell vesicles in secretomes.55
Contents	Many bioactive molecules, including EVs.3	Many bioactive molecules, particularly Exo, MVs, and ABs.36,56,57
Size	Not quantifiable in terms of physical size.	Exosomes: 30–150 nm Ectosomes/ Microvesicles: 50–500 nm Apoptotic bodies: 1000–50004
Advantages	The generation process is less challenging.3	More advantageous in their biological function due to their small size, great stability, low cytotoxicity, immunogenicity, and target specificity (especially exosomes).35
Limitations	Products are highly heterogeneous due to the difficulty of purifying the specific therapeutic components.54	Technical challenges in isolation and purification.54