Objective: To investigate the neuroprotective effect of conducting hydrogel loaded with tetramethylpyrazine sustained-release microparticles (hereinafter referred to as "TGTP hydrogel") on spinal cord injury rats.
Methods: Forty-eight adult female Sprague Dawley rats were randomly divided into 4 groups: sham operation group (group A), model group (group B), conductive hydrogel group (group C), and TGTP hydrogel group (group D), with 12 rats in each group. Only laminectomy was performed in group A, and complete spinal cord transection was performed in groups B, C, and D. Basso-Bettie-Bresnahan (BBB) score was used to evaluate the recovery of hind limb motor function of each group before modeling and at 1, 3, 7, 14, and 28 days after modeling, respectively. At 28 days after modeling, the rats were sacrificed for luxol fast blue (LFB) staining to detect myelin regeneration. Nissl staining was used to detect the survival of neurons. Immunohistochemical staining was used to evaluate the expression of inflammation-related factors [nuclear factor кB (NF-кB), tumor necrosis factor α (TNF-α), and interleukin 10 (IL-10)]. Immunofluorescence staining and Western blot were used to evaluate the expression of neurofilament 200 (NF200).
Rseults: BBB scores of group A were significantly better than those of the other three groups at all time points after modeling (P<0.05); at 14 and 28 days after modeling, there was no significant difference in BBB scores between groups C and D (P>0.05), but the BBB score of group D was significantly better than that of group B (P<0.05). LFB staining and Nissl staining showed that the structure of neurons and myelin in group A was intact, and the myelin integrity and survival number of neurons in group D were significantly better than those in groups B and C. Immunohistochemical staining showed that the absorbency (A) value of NF-кB and TNF-α in group A were significantly lower than those in groups B and C (P<0.05), the A value of IL-10 was significantly higher than that in the other three groups (P<0.05); the A value of NF-κB in group D was significantly lower than that in groups B and C, the A value of TNF-α in group D was significantly lower than that in group B, while the A value of IL-10 in group D was significantly higher than that in group B (P<0.05). Immunofluorescence staining showed that the structure of neurons and nerve fibers in group A was clear and the fluorescence intensity was high. The fluorescence intensity of NF200 in group D was higher than that in groups B and C, and some nerve fibers could be seen. Western blot analysis showed that the relative expression of NF200 in group A was the highest, and the relative expression of NF200 in group D was significantly higher than that in groups B and C (P<0.05).
Conclusion: The TGTP hydrogel can effectively promote the recovery of motor function in rats with spinal cord injury, and its mechanism may be related to the regulation of inflammatory response.
目的: 探讨携载川芎嗪缓释微粒导电水凝胶（以下简称“TGTP水凝胶”）对脊髓损伤大鼠的神经保护作用。.
方法: 将48只成年雌性SD大鼠随机分为4组，假手术组（A组）、模型组（B组）、导电水凝胶组（C组）、TGTP水凝胶组（D组），每组12只。A组仅行椎板切除术，B～D组均制备脊髓完全横断大鼠模型。分别于造模前及造模后1、3、7、14、28 d采用BBB评分评估各组大鼠后肢运动功能恢复情况。造模后28 d处死动物取材行劳克坚牢蓝（luxol fast blue，LFB）染色检测髓鞘再生情况；Nissl染色检测神经元存活情况；免疫组织化学染色评估炎症相关因子（NF-кB、TNF-α、IL-10）表达情况；免疫荧光染色和Western blot评估神经丝蛋白200（neurofilament 200，NF200）表达。.
结果: 造模后各时间点A组BBB评分均优于其余3组（P<0.05）；14、28 d C、D组BBB评分差异无统计学意义（P>0.05），但D组BBB评分明显优于B组（P<0.05）。LFB染色与Nissl染色示，A组神经元及髓鞘结构完整，D组髓鞘完整性与神经元存活数量均明显优于B、C组。免疫组织化学染色示，A组NF-κB、TNF-α吸光度（A）值明显低于B、C组（P<0.05），IL-10 A值明显高于其余3组（P<0.05）；D组NF-κB A值明显低于B、C组，TNF-α A值明显低于B组，IL-10 A值明显高于B组，差异均有统计学意义（P<0.05）。免疫荧光染色示，A组神经元及神经纤维结构清晰，荧光强度高；D组较B、C组NF200荧光强度高，可见部分神经纤维。Western blot检测示A组NF200蛋白相对表达量最高，D组NF200蛋白相对表达量明显高于B、C组（P<0.05）。.
结论: TGTP水凝胶能有效促进脊髓损伤大鼠运动功能恢复，其机制可能与调节炎症反应有关。.
Keywords: Spinal cord injury; hydrogels; inflammatory response; nerve repair; rat; tetramethylpyrazine.