Exosomes derived from stem cells as an emerging therapeutic strategy for intervertebral disc degeneration

Table 1 Characteristics of three main types of extracellular vesicles

Types of vesicles	Diameter	Markers	Cargos	Density (g/mL)	Origin	Ref.
Exosomes	30-150 nm	CD63, CD81, CD9, HSP70, Flotillin, TSG101, etc.	mRNA, microRNA, lncRNA, circRNA, DNA lipid, protein, etc.	1.13-1.18	Endosomes pathway	[51,74-77]
Microvesicles	50-1000 nm	Integrins, selectins, CD40 ligand	mRNA, microRNA, other non-coding RNA, protein, etc.	1.16-1.19	Plasma membrane; outward budding	[51,75]
Apoptotic bodies	500-2000 nm	Phosphatidylserine, genomic DNA	Nuclear fractions, cell organelles, etc.	1.16-1.28	Plasma membrane	[47,51,78]