2023, Vol. 27 ›› Issue (6): 890-896

Collagen/silk fibroin scaffold combined with neural stem cells in the treatment of traumatic spinal cord injury

Li Xiaoyin1, Yang Xiaoqing2, Chen Shulian1, Li Zhengchao1, Wang Ziqi1, Song Zhen1, Zhu Daren1, Chen Xuyi1   

Abstract: BACKGROUND: With the increasing number of traffic accidents, fall injuries, and sports injuries,   traumatic spinal cord injury has become the primary disease that threatens spinal cord health.
OBJECTIVE: To investigate the efficacy of collagen/silk fibroin scaffold combined with neural stem cells in the treatment of traumatic spinal cord injury.
METHODS:   (1) Collagen and silk fibroin raw materials were extracted separately and mixed in a mass ratio of 2:4. Collagen/silk fibroin scaffold was prepared by vacuum freeze-drying. Passage 3 GFP mouse neural stem cells were seeded on collagen/silk fibroin scaffolds. Neural stem cell growth was observed under light microscope and scanning electron microscope. (2) Totally 40 adult SD rats were randomly divided into five groups (n=8 per group). The normal group did not receive any treatment. In the model group, a T10 segment spinal cord defect model was established. In the stem cell group, neural stem cells were injected into the spinal cord defect. Collagen/silk fibroin scaffolds were implanted at the spinal cord defect site in the scaffold group. Collagen/silk fibroin scaffolds seeded with neural stem cells were implanted at the spinal cord defect site of the combination group. Open field test BBB score and slope test were performed every week after operation. Evoked potential detection, hematoxylin-eosin staining and immunofluorescence staining were conducted to evaluate the recovery of traumatic spinal cord injury rats.
RESULTS AND CONCLUSION: (1) Optical microscopy and scanning electron microscopy showed that the collagen/silk fibroin scaffolds were favorable for the adhesion, extension and differentiation of neural stem cells. (2) Open field test BBB score and slope test results demonstrated that the motor function of the rats in each spinal cord injury group recovered to different degrees with the prolongation of time. The speed and degree of motor function recovery of the rats in each treatment group were better than those in the model group, and the motor function recovery of the rats in the combination group was the best. At 8 weeks after operation, the detection results of latency and amplitude of motor evoked potentials and somatosensory evoked potentials of rats in each treatment group were better than those in the model group after spinal cord injury (P < 0.05). The detection results of the combination group were better than those of the stem cell group and the scaffold group (P < 0.05). At 8 weeks after operation, hematoxylin-eosin staining demonstrated that the repair effect of the injured spinal cord in the model group was the worst and the repair effect of the combination group was the best. Immunofluorescence staining exhibited that the number of neurofilament protein-positive cells at the spinal cord injury site of the rats in the model group was the least, and the number of neurofilament protein-positive cells in each treatment group was more than that in the model group, among which the number of the combination group was the most. (3) Collagen/silk fibroin scaffold combined with neural stem cells has a certain effect on the improvement of the function of both lower limbs and the repair of spinal cord tissue in rats with traumatic spinal cord injury.
Key words: biological tissue engineering, collagen, silk fibroin, neural stem cell, traumatic spinal cord injury, rat, diffusion tensor imaging, animal model