Generation of mesenchymal stem-like cells for producing extracellular vesicles

Table 1 Preclinical studies on the therapeutic effect of human extracellular vesicles derived from mesenchymal stem-like cells

Animal	Disease model	Methods for generating mesenchymal stem-like cells (iMSCs)	Extracellular vesicle preparation		Route, time, and dose	Main outcome	Ref.
			Production	Isolation
Mice	Hindlimb ischemia	Culture of iPSCs with DMEM with FBS (10%) and L-Glutamine (2 mmol) for 14 d (P1) followed by subsequent passaging (up to P4)	Culture with MesenGro® at 80% confluency for 48 h	UC followed by purification by concentration (Amicon®) and additional UC using sucrose (30%) density	Four injections of iMSC-exosome (200 µg) into the quadriceps muscle after 24 h of femoral artery excision	Decrease of ischemic injury with the increase of vessel density and blood perfusion	[54]
Rat	Dorsal skin wound	Same as ref[54] but not clear of the cell passages	Culture with MesenGro® at 80% confluency for 48 h	UC followed by purification by concentration with filter (100 kDa MWCO)	Four injections of iMSC-exosome (160 µg) around the wound sites	(1) Reduction of scar width, with an accelerated epithelialization and increased collagen maturity; (2) Enhanced vessel formation and maturation	[55]
Rat	Partial hepatic ischemia (60 min)	Same as ref[54] but not clear of the passaging time	Same as ref[55]	Same as ref[55]	iMSC-exosome (600 µg) was injected via inferior vena cava right after reperfusion	(1) Reduction in hepatocyte necrosis and sinusoidal congestion; (2) Reduced serum level of TNF-α, IL-6, and HMGB 1; (3) Reduced level of apoptotic markers (caspase-3, glutathione peroxidase, superoxide dismutase)	[57]
Mice	Partial hepatic ischemia (60 min)	Same as ref[55]	Same as ref[55] except that DMEM was used for exosome production	ExoQuik® precipitation	iMSC-exosome (2.5 × 1012 particles) were injected via the inferior vena cava right after declamping	(1) Reduction in ALT, AST, and hepatocyte necrosis; (2) Reduced sinusoidal congestion with lower pathology score	[58]
Rat	Osteoporosis induced by ovariectomy	Same as ref[55]	Same as ref[55] except that MGro-500® was used for exosome production	Same as ref[55]	Transplantation of β-TCP scaffolds lyophilized with iMSC-exosomes (100 or 200 µg) into the scalp incision	Increase in the bone regeneration and vessel formation as shown by micro-CT, microfil perfusion, and morphological and IHC analyses	[59]
Rat	Steriod-induced osteonecrosis of femoral head	Same as ref[54]	Same as ref[55]	Same as ref[55]	100 μL of iMSC-exosome (1 × 1010/mL or 1 × 1011/mL) was I.V. injected before each methylprednisolone injection (once per week for 3 wk)	Inhibition of bone loss and increase of vessel density in the femoral head as shown by micro-CT	[60]
Mice	Collagenase-induced osteoarthritis	Same as ref[55]	Same as ref[55]	UC followed by purification by concentration with filter (100 kDa MWCO) for two repeats	Intra-articular injection of 8 μL iMSC-exosome (1.0 × 1010/ml) for three times (7, 14, 21 d after induction) and analyzed at day 28	Reduction in the osteonecrotic change as shown by the pathology of macro-morphology (tibial plateus), histology, and IHC	[61]

ALT: Alanine aminotransferase; AST: Aspartate transaminase; β-TCP: Beta-tricalcium phosphate; DMEM: Dulbecco's modified Eagle medium; FBS: Fetal bovine serum; HMGB1: High mobility group box 1; IHC: Immunohistochemistry; iPSCs: Induced pluripotent stem cells; Micro-CT: micro-computed tomography; MWCO: Molecular weight cut-off; UC: Ultracentrifugation; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-α; iMSC: Induced mesenchymal stem cell.