Co-administration of human adipose-derived stem cells and low-level laser to alleviate neuropathic pain after experimental spinal cord injury

BACKGROUND: Evidence has suggested that human adipose-derived stem cells (hADSCs) and low-level laser has neuroprotective effects on spinal cord injury (SCI). Therefore, the combined effect of the hADSCs and laser on neuregeneration and neuropathic pain after SCI was investigated. METHODS: Forty-eight adult male Wistar rats with 200–250 g weight were used. Thirty minutes after compression, injury with laser was irritated, and 1 week following SCI, about 1 × 10(6) cells were transplanted into the spinal cord. Motor function and neuropathic pain were assessed weekly. Molecular and histological studies were done at the end of the fourth week. RESULTS: The combined application of hADSCs and laser has significantly improved motor function recovery (p = 0.0001), hyperalgesia (p < 0.05), and allodynia (p < 0.05). GDNF mRNA expression was significantly increased in hADSCs and laser+hADSC-treated animals (p < 0.001). Finally, co-administration of hADSCs and laser has enhanced the number of axons around cavity more than other treatments (p < 0.001). CONCLUSIONS: The results showed that the combination of laser and ADSCs could significantly improve the motor function and alleviate SCI-induced allodynia and hyperalgesia. Therefore, using a combination of laser and hADSCs in future experimental and translational clinical studies is suggested.