Spinal cord injury (SCI) is a complex pathological process. Based on the encouraging results of preclinical experiments, some stem cell therapies have been translated into clinical practice. Mesenchymal stem cells (MSCs) have become one of the most important seed cells in the treatment of SCI due to their abundant sources, strong proliferation ability and low immunogenicity. However, the survival rate of MSCs transplanted to spinal cord injury is rather low, which hinders its further clinical application. In recent years, hydrogel materials have been widely used in tissue engineering because of their good biocompatibility and biodegradability. The treatment strategy of hydrogel combined with MSCs has made some progress in SCI repair. This review discusses the significance and the existing problems of MSCs in the repair of SCI. It also describes the research progress of hydrogel combined with MSCs in repairing SCI, and prospects its application in clinical research, aiming at providing reference and new ideas for future SCI treatment.
Objective To explore the factors to affect severity of hyperextension injury of the cervical spinal cord (HEICSC). Methods Forty-five patients with HEICSC, 35 males and 10 females, aged 27-67 years old (mean 48.2 years old), were retrospectively analyzed. The disease course was 30 minutes to 16 days. According to modified Frankel grading, there were 6 cases of grade A, 8 cases of grade B, 16 cases of grade C and 15 cases of grade D. Spinal cord injuries (SCI) segments were determined according to SCI plane and high signal change (HSC) in spinal cord on MR images. The whole or large part of HSC segments were supposed to be main injured spinal cord segments (MISCSs) and the staccato or patchy HSC ones were supposed to be common injured spinal cord segments (CISCSs). When the external force acting on head or face suffered was larger, the force produced during high-speed movement or forehead and/or face had severe contused and/or) lacerated wound, the force was defined severe traumatic strength, whereas the reverse was true for sl ight traumatic strength. According to signal magnitude of the cervical discs on T2-weighted MR images, degeneration of cervical discs and cervical vertebras were classified into 5 grades: grade 0-4. Cervical spinal stenosis were graded to 5 grades according to the width of anterior or posterior cerebrospinal fluid layer to spinal cord on T2-weighted MR images and compressed degree of spinal cord on T1-weighted MR images. The influence of traumatic strength, cervical spinal degeneration or cervical spinal stenosis on SCI were explored. Results Among the 45 cases, 12 cases were caused by sl ight traumatic strength, 33 cases were caused by severe one. The cervical spinal cord was injuried more sl ightly and the patients were older in the sl ight traumatic strength cases than in the severe ones (P lt; 0.05). The number of MISCSs were 45 in 40 cases and the 25 segments were located at C3, 4 level. The number of CISCSs were 39 in 21 cases. All the cervical vertebraes of the 45 patients had degenerated. The most were in grade 3 in 22 patients and the severest degenerative segments were mostly located in C5,6 discs in 35 ones. The number of the MISCSs in different degenerative grades of discs was 0 in grade 0, 9 in grade 1, 20 in grade 2, 14 in grade 3, and 2 in grade 4. The ratios of the segment number of injuried spinal cord to the segment number of spinal stenosis in every grade of stenosis were 1/62 in grade 0, 2/11 in grade 1, 27/52 in grade 2, 33/33 in grade 3, 21/22 in grade 4. Conclusion Three main factors including the magnitude of traumatic strength, the degree of instabil ity of cervical vertebrae and the degree of cervical stenosis contribute to development and progress of HEICSC.
ObjectiveTo evaluate the effect of the combination of collagen scaffold and brain-derived neurotrophic factor (BDNF) on the repair of transected spinal cord injury in rats.MethodsThirty-two Sprague-Dawley rats were randomly divided into 4 groups: group A (sham operation group), T9, T10 segments of the spinal cord was only exposed; group B, 4-mm T9, T10 segments of the spinal cord were resected; group C, 4-mm T9, T10 segments of the spinal cord were resected and linear ordered collagen scaffolds (LOCS) with corresponding length was transplanted into lesion site; group D, 4-mm T9, T10 segments of the spinal cord were resected and LOCS with collagen binding domain (CBD)-BDNF was transplanted into lesion site. During 3 months after operation, Basso-Beattie-Bresnahan (BBB) locomotor score assessment was performed for each rat once a week. At 3 months after operation, electrophysiological test of motor evoked potential (MEP) was performed for rats in each group. Subsequently, retrograde tracing was performed for each rat by injection of fluorogold (FG) at the L2 spinal cord below the injury level. One week later, brains and spinal cord tissues of rats were collected. Morphological observation was performed to spinal cord tissues after dehydration. The thoracic spinal cords including lesion area were collected and sliced horizontally. Thoracic spinal cords 1 cm above lesion area and lumbar spinal cords 1 cm below lesion area were collected and sliced coronally. Coronal spinal cord tissue sections were observed by the laser confocal scanning microscope and calculated the integral absorbance (IA) value of FG-positive cells. Horizontal tissue sections of thoracic spinal cord underwent immunofluorescence staining to observe the building of transected spinal cord injury model, axonal regeneration in damaged area, and synapse formation of regenerated axons.ResultsDuring 3 months after operation, the BBB scores of groups B, C, and D were significantly lower than those of group A (P<0.05). The BBB scores of group D at 2-12 weeks after operation were significantly higher than those of groups B and C (P<0.05). Electrophysiological tests revealed that there was no MEP in group B; the latencies of MEP in groups C and D were significantly longer than that in group A (P<0.05), and in group C than in group D (P<0.05). Morphological observation of spinal cord tissues showed that the injured area of the spinal cord in group B extended to both two ends, and the lesion site was severely damaged. The morphologies of spinal cord tissues in groups C and D recovered well, and the morphology in group D was closer to normal tissue. Results of retrograde tracing showed that the gray matters of lumbar spinal cords below the lesion area in each group were filled with FG-positive cells; in thoracic spinal cords above lesion sites, theIA value of FG-positive cells in coronal section of spinal cord in group A was significantly larger than those in groups B, C, and D (P<0.05), and in groups C and D than in group B (P<0.05), but no significant difference was found between groups C and D (P>0.05). Immunofluorescence staining results of spinal cord tissue sections selected from dorsal to ventral spinal cord showed transected injured areas of spinal cords which were significantly different from normal tissues. The numbers of NF-positive axons in lesion center of group A were significantly larger than those of groups B, C, and D (P<0.05), and in groups C and D than in group B (P<0.05), and in group D than in group C (P<0.05).ConclusionThe combined therapeutic approach containing LOCS and CBD-BDNF can promote axonal regeneration and recovery of hind limb motor function after transected spinal cord injury in rats.
Objective To explore the therapeutic effect of basic fibroblast growth factor (bFGF) on spinal cord injury (SCI) in rats and the influence of Notch/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Methods A total of 40 10-week-old male Sprague Dawley (SD) rats were selected to establish T10-segment SCI model by a free falling object. Among them, 32 successful models were randomly divided into model group and bFGF group, with 16 in each group. Another 16 SD rats were selected as sham-operation group, with only T10 processes, dura mater, and spinal cord exposed. After modeling, the rats in bFGF group were intraperitoneally injected with 100 μg/kg bFGF (once a day for 28 days), and the rats in model group and sham-operation group were injected with normal saline in the same way. The survival of rats in each group were observed after modeling. Basso-Beattie-Bresnahan (BBB) scores were performed before modeling and at immediate, 14 days, and 28 days after modeling to evaluate the functional recovery of hind limbs. Then, the spinal cord tissue at the site of injury was taken at 28 days and stained with HE, Nissl, and propidium iodide (PI) to observe the pathological changes, neuronal survival (number of Nissl bodies) and apoptosis (number of PI red stained cells) of the spinal cord tissue; immunohistochemical staining and ELISA were used to detect the levels of astrocyte activation markers [glial fibrillary acidic protein (GFAP)] and inflammatory factors [interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), interferon γ (IFN-γ)] in tissues, respectively. Western blot was used to detect the expressions of Notch/STAT3 signaling pathway related proteins [Notch, STAT3, phosphoryl-STAT3 (p-STAT3), bone morphogenetic protein 2 (BMP-2)] in tissues. Results All rats survived until the experiment was completed. At immediate after modeling, the BBB scores in model group and bFGF group significantly decreased when compared to sham-operation group (P<0.05). At 14 and 28 days after modeling, the BBB scores in model group significantly decreased when compared to sham-operation group (P<0.05); the bFGF group showed an increase compared to model group (P<0.05). Compared with before modeling, the BBB scores of model group and bFGF group decreased at immediate after modeling, and gradually increased at 14 and 28 days, the differences between different time points were significant (P<0.05). The structure of spinal cord tissue in sham-operation group was normal; in model group, there were more necrotic lesions in the spinal cord tissue and fewer Nissl bodies with normal structures; the number of necrotic lesions in the spinal cord tissue of the bFGF group significantly reduced compared to the model group, and some normally structured Nissl bodies were visible. Compared with sham-operation group, the number of Nissl bodies in spinal cord tissue significantly decreased, the number of PI red stained cells, GFAP, IL-1β, TNF-α, IFN-γ, Notch, p-STAT3 /STAT3, BMP-2 protein expression levels significantly increased in model group (P<0.05). The above indexes in bFGF group significantly improved when compared with model group (P<0.05). Conclusion bFGF can improve motor function and pathological injury repair of spinal cord tissue in SCI rats, improve neuronal survival, and inhibit neuronal apoptosis, excessive activation of astrocytes in spinal cord tissue and inflammatory response, the mechanism of which may be related to the decreased activity of Notch/STAT3 signaling pathway.
Objective To explore the construction of a canine model of vascularized allogeneic spinal cord transplantation (vASCT) and preliminarily evaluate its therapeutic efficacy for spinal cord injury (SCI). Methods Sixteen female Beagle dogs aged 8-12 months were randomly selected, with 8 dogs serving as donors for the harvesting of spinal cord tissue with a vascular pedicle [dorsal intercostal artery (DIA) at the T10 level and accompanying vein]. The remaining 8 dogs underwent a 1.5-cm-length spinal cord defect at the T10 level, followed by transplantation of the donor spinal cord tissue for repair. Polyethylene glycol (PEG) was applied to both ends to spinal cord graft; then, using a random number table method, the dogs were divided into an experimental group (n=4) and a control group (n=4). The experimental group received immunosuppressive intervention with oral tacrolimus [0.1 mg/(kg∙d)] postoperatively, while the control group received no treatment. The operation time and ischemia-reperfusion time of two groups were recorded. The recovery of hind limb function was estimated by Olby score within 2 months after operation; the motor evoked potentials (MEP) was measured through neuroelectrophysiological examination, and the spinal cord integrity was observed through MRI. ResultsThere was no significant difference in the operation time and ischemia-reperfusion time between the two groups (P>0.05). All dogs survived until the completion of the experiment. Within 2 months after operation, all dogs in the control group failed to regain the movement function of hind limbs, and Olby scores were all 0. In the experimental group, the movement and weight-bearing, as well as walking abilities of the hind limbs gradually recovered, and the Olby scores also showed a gradually increasing trend. There was a significant difference between the two groups from 3 to 8 weeks after operation (P<0.05). Neuroelectrophysiological examination indicated that the electrical signals of the experimental group passed through the transplanted area, and the latency was shortened compared to that at 1 month after operation (P<0.05), showing continuous improvement, but the amplitude did not show significant improvement (P>0.05). The control group was unable to detect any MEP changes after operation. MRI examination showed that the transplanted spinal cord in the experimental group survived and had good continuity with normal spinal cord tissue, while no relevant change was observed in the control group. ConclusionThe vASCT model of dogs was successfully constructed. This surgical procedure can restore the continuity of the spinal cord. The combination of tacrolimus anti-immunity is a key factor for the success of transplantation.
The present study was to investigate the effects of infusing remifentanil-poly-caprolactone (REM-PCL) through the abdominal aorta on spinal cord ischemia reperfusion injury (SCIRI). The model of SCIRI was created by clamping the infrarenal aortic in thirty-six New Zealand white rabbits, which were randomly divided into sham group (group S), control group (group C), and REM-PCL group (group R) with 12 rabbits in each one. The spinal cord microcirculatory blood flow (SCMBF) and blood flow rate (BFR) were monitored before ischemia, 15 min, 30 min, 60 min and 120 min after reperfusion, respectively. Neurologic Function was evaluated before ischemia, 6h, 12h and 24h after reperfusion. The concentration of serum neuron-specific enolase (NSE), interleukin-lβ (IL-lβ) and interleukin-8 (IL-8) were monitored before ischemia, 45 min after ischemia, 30 min, 60 min, 6 h, 12 h and 24 h after reperfusion. The abnormal rate of motor neuron of spinal cord tissues and the level of superoxide dismutase (SOD), reactive oxygen species (ROS), glutathione peroxidase (GSH-PX), malondialdehyde (MDA), total anti-oxidation capacity (T-AOC) and mitochondrial swelling degree (MSD) in neural mitochondria were determined before ischemia, 45 min after clamping, 60 min and 120 min after reperfusion. As a result, the neural mitochondrial SOD, GSH-PX and T-AOC decreased while ROS, MDA, MSD, IL-lβ, IL-8 and NSE distinctly increased after clamping of the abdominal aorta as compared to the value before ischemia in group C (P < 0.01). Neurologic function scores recovered more rapidly in group R than those in group C during reperfusion (P < 0.01). The neural mitochondrial SOD, GSH-PX and T-AOC were distinctly higher while ROS, MDA, MSD, IL-lβ, IL-8 and NSE were distinctly lower in group R than those in group C (P < 0.01). The abnormal rate of motor neuron was significantly higher in group C during reperfusion than that in group R (P < 0.01). It has been shown that the intra-aortic REM-PCL infusion can alleviate SCIRI by inhibiting inflammatory response and improving mitochondrial anti-oxidation capacity.
ObjectiveTo evaluate whether long frozen elephant trunk (FET) increases the risk of spinal cord injury in patients with acute type A aortic dissection.MethodsFrom 2018 to 2019, 172 patients with acute type A aortic dissection were treated in Guangdong Provincial People’s Hospital. They were divided into two groups according to the length of FET: patients treated with stents of 100 mm in length were enrolled into a short FET group, and those with stents of 150 mm in length into a long FET group. There were 124 patients in the short FET group, including 108 (87.1%) males and 16 (12.9%) females with a mean age of 51.8±7.9 years. There were 48 patients in the long FET group, including 44 (91.7%) males and 4 (8.3%) females with a mean age of 50.6±9.7 years. The clinical data and prognosis of the patients were analyzed.ResultsThe mean distal stent graft was at the level of T 8.5±0.7 in the long FET group, and at the level of T 6.8±0.6 in the short FET group (P=0.001). Sixteen patients died after operation in the two groups, including 13 (10.5%) in the short FET group and 3 (6.2%) in the long FET group (P=0.561). There were 7 patients of spinal cord injury in the two groups, including 6 (4.8%) in the short FET group and 1 (2.2%) in the long FET group (P=0.675). There was no statistical difference in other complications between the two groups. The follow-up time was 16.7 (1-30) months. During the follow-up, 2 patients died in the long FET group and 5 died in the short FET group. No new spinal cord injury or distal reintervention occurred during the follow-up.ConclusionLong FET does not increase the incidence of spinal cord injury in patients with acute type A aortic dissection.
The capacity of embryonic spinal cord tissue in the repair of injured structure of spinal cord has been noted for years. In order to investigate the embryonic spinal cord graft in the repair of motor function of injured spinal cord, the embryonic spinal cord tissue was transplanted to the hemisection cavity in spinal cord in adult rat. One hundred adult Wistar Rats were used to simulate the hemisectional injury of spinal cord by drilling 2-3 mm cavity in lumbar enlargement. Sixty rats were treated with rat embryonic spinal cord tissue grafting while the other forty were chosen as control. The outcome was evaluated according the combined behavioural score (CBS) and motor evoked potential (MEP) in the 1, 2, 4 and 12 weeks. The grafting group was superior to the control as assessed by CBS (P lt; 0.05), especially within 4 weeks. (P lt; 0.01). The restoration of the latent peak of early wave(P1, N1) was better in the grafting group, too. This suggested that embryonic spinal cord graft could improve the recovery of motor function of injured spinal cord in adult rat. The effect of the embryonic spinal cord tissue graft might be concerned with its secretion of several kinds of neurotrophic factors, nerve growth factor, nerve transmitted factor, or adjustment of hormone.
ObjectiveTo explore the effectiveness of functional reconstruction of hand grasp and pinch by tendon transfers in patients with cervical spinal cord injury.MethodsBetween July 2013 and January 2016, tendon transfer surgery were performed in 21 patients (41 hands) with cervical spinal injury that motion level was located at C6 to reconstruct hand grasp and pinch function. There were 18 males and 3 females with a mean age of 42.3 years (range, 17-65 years). Nineteen patients were with complete spinal cord injury [American Spinal Injury Association (ASIA) grading A], 1 patient was with central cord syndrome whose bilateral hands were completely paralyzed and lower limbs were normal (ASIA grading D), and 1 patient was with cervical spondylotic myelopathy (AISA grading D). The time from injury to hospitalization was 12-22 months (mean, 16.8 months). According to the International classification of surgery of the hand in tetraplegia (ICSHT), there were 6 cases of grade O3, 10 of grade O4, 3 of grade OCu5, and 2 of grade O5. The surgery was divided into two stages with an interval of 6-11 months. At the first stage, grip function was reconstructed in all patients by transfering the extensor carpi radialis longus from radialis side to palmar side through subcutaneous tunnel, and braided and sutured with the flexor pollicis longus and flexor digitorum profundus. At the second stage, the lateral pinch function of the thumb and index finger was reconstructed by braiding and suturing the radial half of the extensor carpi ulnaris (the patients graded as ICSHT O3) or pronator tere (the patients graded above ICSHT O3) with extensor pollicis longus and abductor pollicis longus. The grasp force, the thumb and index finger lateral pinch force, and the maximum fingertips distance between the thumb and index finger were measured at preoperation and at different time points after operation. The modified Lamb and Chan questionnaire, based upon the activities of daily living, was used to evaluate the hand function of all patients at 6 months after sencond stage surgery.ResultsThere was 1 patient with elbow skin lesion, 1 patient with wrist stiffness; both of them recovered after corresponding treatment. All the 21 patients were followed up 15-32 months (mean, 19.6 months) without wound infection, tendon adhesion, tendon rupture, and other complications. The grasp forces of all patients were significantly improved at 4 weeks, 3 months, 6 months, and 1 year after the first stage surgery when compared with preoperative value (P<0.05); and no significant difference was found between different time points after operation (P>0.05). The thumb and index finger lateral pinch force and the maximum fingertips distance between the thumb and index finger of all patients were also significantly improved at 4 weeks, 3 months, 6 months, and 1 year after the second stage surgery when compared with preoperative values (P<0.05); and no significant difference was found between different time points after operation (P>0.05). And there was no significant difference of above indexes between the patients graded as ICSHT O3 and above ICSHT O3 (P>0.05). The functional outcome was good in 19 cases, fair in 1 case, and poor in 1 case according to modified Lamb and Chan questionnaire at 6 months after second stage surgery.ConclusionTendon transfer can significantly improve the hand function and the quality of life of the patients with complete cervical spinal cord injury.
Objective To explore the related factors of upper urinary tract deterioration (UUTD) in spinal cord injury patients using intermittent catheterization (IC-SCI) in the community. Methods Patients with spinal cord injury in the Chinese community were selected for investigation between August 3 and August 31, 2020. The included patients were divided into UUTD group and non-UUTD group. The basic information, intermittent catheterization practices, and urinary complications were compared between the two groups. Logistic regression was used to analyze the risk factors contributing to UUTD. Results A total of 431 patients were surveyed. Among them, there were 310 males and 121 females, 246 cases in the non-UUTD group and 185 cases in the UUTD group. There were statistically significant differences in the disease duration, gender, etiology, urinary incontinence, urinary tract infection, bladder calculi and nephrolithiasis between the two groups (P<0.05); there was no statistically significant difference in the other indicators between the two groups (P>0.05). The results of logistic regression analysis showed that urinary tract infection [odds ratio (OR)=3.229, 95% confidence interval (CI) (1.706, 6.110), P<0.001], nephrolithiasis [OR=4.846, 95%CI (2.617, 8.973), P<0.001], and urinary incontinence [OR=2.345, 95%CI (1.116, 4.925), P=0.024] were risk factors for UUTD. Conclusion Urinary tract infection, nephrolithiasis and urinary incontinence are independent risk factors for UUTD in community-based IC-SCI patients and deserve attention for preventive strategies.