A study on repair of spinal cord injury by neurotrophin-3 sustained-released hydrogel
10.3760/cma.j.cn115530-20250213-00061
- VernacularTitle:神经营养因子-3水凝胶缓释贴片修复脊髓损伤的实验研究
- Author:
Xianzheng GUO
1
;
Haosheng CHEN
;
Zhijian WEI
;
Shiqing FENG
Author Information
1. 山东大学齐鲁医院骨科，济南 250012
- Publication Type:Journal Article
- Keywords:
Chitosan;
Neurotrophin-3;
Spinal cord injury;
Regeneration of nerve
- From:
Chinese Journal of Orthopaedic Trauma
2025;27(10):888-896
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the effect of mesoporous silica (SiO 2) chitosan (CS) hydrogel loaded with neurotrophin-3 (NT-3) on repair of spinal cord injury. Methods:After 2%, 4%, and 6% NT-3/SiO 2 were dissolved in CS solution, they were added into β-glycerophosphate sodium solution for chemical cross-linking to obtain hydrogel patches of different NT-3 loadings. The specific surface area, pore size and pore volume of mesoporous SiO 2 nanoparticles were detected by specific surface area analyzer. The morphology of mesoporous SiO 2 nanoparticles and the pore structure of freeze-dried hydrogel were detected by scanning electron microscopy. Adhesion of the hydrogel was verified by spinal cord tissue. After the NT-3/SiO 2@CS hydrogel was placed in the medium, the concentrations of NT-3 were measured for 1 to 20 days. Neural stem cells (NSCs) were isolated from fetal rats and identified. Cell counting kit 8 (CCK-8) assay was used to detect the proliferation of NSCs treated with different concentrations of hydrogel. Immunofluorescence staining was used to detect the effects of NT-3/SiO 2@CS hydrogel on differentiation of NSCs. Twenty-four 8-week-old C57BL/6JNifdc female mice were randomly divided into a sham operation group (sham), a spinal cord injury group (SCI), a chitosan hydrogel group (CS) and a mesoporous SiO 2-loaded NT-3 hydrogel group (NT-3/SiO 2@CS). In the sham group, the muscle and skin were sutured immediately after laminectomy without spinal cord injury. The CS hydrogel and NT-3/SiO 2@CS hydrogel patches were implanted without treatment after spinal cord injury in the other 3 groups, respectively. Basso Mouse Scale (BMS) was used to evaluate the mice every 7 days for 8 weeks after modeling. The hot and cold board test and Catwalk gait analysis were performed at 8 weeks after surgery. Results:The mesoporous SiO 2 nanoparticles showed typical spherical morphology and a uniform particle size (about 160 nm). The specific surface area, pore volume and pore size of the mesoporous SiO 2 nanoparticles loaded with NT-3 changed from 1,039 m 2/g, 0.726 cm 3/g and 2.754 nm to 779 m 2/g, 0.403 cm 3/g and 1.903 nm, respectively. The hydrogel had a uniform internal microporous structure and good porosity so that it easily adhered to the spinal cord and achieved long-term stable release of NT-3 for at least 20 days. CCK-8 results showed that at 24 hours after the neural stem cells were laid, the cell proliferative activities in the 4%NT-3/SiO 2@CS and 6% NT-3/SiO 2@CS groups were significantly lower than that in the group untreated ( P<0.05). The immunofluorescence staining showed that the fluorescence intensity of glial fibrillary acidic protein (GFAP), the NSC marker in NT-3/SiO 2@CS, insignificantly decreased in the groups with different concentrations of NT-3/SiO 2@CS compared with the group untreated ( P>0.05). The fluorescence intensities of GFAP, MAP2 and GFAP/MAP2 in the NT-3/SiO 2@CS group were significantly higher than those in the other groups ( P<0.05). The BMS scoring for mice showed sham group>NT-3/SiO 2@CS group>SCI group and CS group for 8 weeks of modeling, and the response time of mice to cold and hot stimulations in the NT-3/SiO 2@CS group was significantly shorter than that in the SCI and CS groups. The differences above were statistically significant ( P<0.05). The Catwalk gait analysis showed that the hindlimb footprints in the NT-3/SiO 2@CS group were significantly clearer and more coherent than those in the SCI and CS groups. Conclusions:The sustained-release gel patch based on CS, SiO 2 and NT-3 has a uniform pore structure, good biocompatibility and excellent drug sustained-release effect. It can promote the differentiation of NSCs into neurons, thus contributing to recovery of motor and sensory functions after spinal cord injury.
