Table 1 Studies on the treatment of SCI with exosomes derived from MSCs

Huang et al. [65]

Epidural Fat-MSCs

SD rats

60–130 nm

Intravenous injection (IV)

Alleviate cell death, attenuate tissue damage, and improve neurological recovery

Inhibit NLRP3 inflammation

Pasquale et al. [66]

hUCMSCs

SD rats

–

IV

anti-inflammatory and anti-scarring activity

Decrease the expression of pro-inflammatory cytokines and reduce astrogliosis and scarring.

Huang et al. [67]

BMSCs

SD rats

20–130 nm

IV

Attenuate cellular apoptosis and inflammation. Promote angiogenesis

Attenuate Bax expression and upregulate Bcl-2 expression. Upregulate pro-inflammatory cytokines and downregulate anti-inflammatory cytokines.

Lu et al. [68]

BMSCs

SD rats

–

IV

Attenuate neuronal cell death and Improve motor recovery

Increases BSCB pericyte coverage and decreases BSCB permeability. Inhibit pericyte migration via the NF-κB p65 pathway.

Liu et al. [69]

BMSCs

SD rats

20–150 nm

IV

Attenuate neuronal cell apoptosis and lesion size. Suppressed glial scar formation and inflammation. Promote axonal regeneration.

Suppress the activation of A1 neurotoxic reactive astrocytes. Reduce TNF-α, IL-1β, and IL-6.

Wang et al. [70]

BMSCs

SD rats

30–150 nm

IV

Reduce SCI-induced A1 astrocytes

Inhibit the nuclear translocation of NF-κB p65.

Yu et al. [71]

BMSCs

SD rats

–

IV

Accelerate the motor function and promote neuronal regeneration. Alleviate histopathological damage.

MiR-29b regulate proteins involved in neuronal regeneration, such as NF200, GAP-43, and GFAP.

Zhou et al. [72]

BMSCs

Wistar rats

40–160 nm

IV

Improve functional recovery and attenuate lesion size and apoptosis

MiR-21-5p downregulate expression of the pro-apoptotic target gene FasL.

Ji et al. [73]

BMSCs

SD rats

30–100 nm

IV

Attenuate the protective effects of obese rat MSC-derived exosomes against SCI

Insulin resistance decreased miR-21 expression in MSCs. Overexpression of miR-21 in obese rat MSCs restored the protective effects.

Xu et al. [74]

hMSCs PC12 cells

SD rats

–

IV

Suppresses the apoptosis of neuron cells and improve functional recovery

MiR-21 and miR-19b derived from the exosomes of hMSCs regulated the apoptosis and differentiation of neuron cells by regulating PTEN expression

Kang et al. [75]

–

SD rats

40–110 nm

IV

MiR-21 facilitate post-SCI recovery and suppress neuron cell death

MiR-21 inhibit the expression of PTEN/PDCD4. MiR-21/PTEN/PDCD4 signaling pathways increased cell viability and inhibited cell death in vitro

Sun et al. [76]

hUCMSCs

C57BL/6 mice

70 nm

IV

Promote locomotor functional recovery and reduce inflammation

Downregulate the inflammatory cytokines, such as TNF-α, MIP-1α, IL-6 and IFN-γ and trigger the macrophage Polarization from M1 to M2 phenotype

Li et al. [77]

BMSCs

SD rats

–

IV

Improved functional recovery, Reduced the lesion volume, Preserved neurons.

MiR-133b activate ERK1/2, STAT3, and CREB. Inhibit RhoA expression.

Li et al. [78]

BMSCs

Wistar rats

–

–

Improve locomotor functional recovery and inhibit neuronal apoptosis.

Activate the Wnt/β-catenin signaling pathway.

Zhao et al. [79]

BMSCs

Wistar rats

20–130 nm

IV

Improve functional recovery and reduce SCI-Induced complement activation.

Inhibit complement mRNA synthesis and release and inhibit activation of NF-κB signaling by binding to microglia cells.

Huang et al. [80]

BMSCs

SD rats

30–120 nm

IV

Improved functional recovery and reduced the lesion volume.

Promote angiogenesis and neurogenesis.

Yuan et al .[81]

BMSCs

SD rats

–

IV

Improved functional recovery and the axonal regeneration. Decreased the injury volume, retained the neuronal cells,

MiR-126 activates ERK1/2, STAT3 and CREB while inhibiting the expression of RhoA.

Gu et al. [82]

BMSCs

SD rats

30–150 nm

IV

Improve the recovery of motor function. Reduce neuronal apoptosis.

The expression of proapoptotic protein caspase-3 is decreased while the antiapoptotic protein Bcl-2 is upregulated, BMSC-exosomes induces activation of autophagy after SCI.