可缓释丹参酮ⅡA的生物蛋白水凝胶调控脊髓损伤后排尿反射通路重塑的作用及机制研究

Bladder dysfunction after spinal cord injury (SCI) has been recognized as one of the severe complications for SCI patients. Repairing the injured spinal cord and reshaping the micturition reflex pathway are the fundamental means of treatment. Although various methods have been used to promote nerve regeneration, the regenerative ability of the axon is very limited after complete SCI, which is the difficult point of the present study. In this study, tanshinoneⅡA was synthesized into a bioprotein hydrogel with a multi-directional structure in the form of sustained-release microspheres. We would like to study the drug release performance and the effect of regulating axon growth of dorsal root ganglion cells (DRGs) of the sustained-release bioprotein hydrogel of tanshinone IIA in vitro. Further, the sustained-release bioprotein hydrogel of tanshinone IIA will be transplanted into the animal model of bladder dysfunction after SCI in rats. We will study the role of the sustained-release bioprotein hydrogel of tanshinone IIA in the treatment of bladder dysfunction after SCI in rats through urodynamic examination, immunofluorescence staining, neural pathway tracing and other methods. And the possible mechanism of the sustained-release bioprotein hydrogel of tanshinone IIA to repair the SCI and reshape the urinary reflex pathway will be explained. Finally, we will answer the scientific problem that whether the sustained-release bioprotein hydrogel of tanshinone IIA play the synergistic effect of drugs and materials, to promote remodeling of urinary reflex pathway after spinal cord injury, and improve bladder dysfunction following SCI.

膀胱功能障碍是脊髓损伤患者晚期死亡的首要原因，修复损伤脊髓、重塑膀胱排尿反射通路是根本的治疗手段。尽管目前已有很多方法可以促进脊髓损伤后神经再生，但在脊髓完全性损伤后，轴突的再生能力非常有限，是目前研究的难点。本研究将中药丹参的有效单体丹参酮ⅡA以缓释微球的形式复合到具有多级定向结构的生物蛋白水凝胶中，制备出可缓释丹参酮ⅡA的生物蛋白水凝胶，通过体外缓释实验和细胞实验研究其药物缓释性能及调控背根神经节细胞轴突生长的作用；进一步将可缓释丹参酮ⅡA的生物蛋白水凝胶移植到大鼠脊髓损伤后膀胱功能障碍的动物模型中，通过尿动力学检查、免疫荧光染色、神经通路示踪等方法研究其治疗大鼠脊髓损伤后膀胱功能障碍的作用和机制。通过本项目的研究，最终回答“可缓释丹参酮ⅡA的生物蛋白水凝胶是否能够发挥药物和材料的协同作用，促进脊髓损伤后排尿反射通路的重塑，改善脊髓损伤后膀胱功能障碍”这一科学问题。

膀胱功能障碍是脊髓损伤患者晚期死亡的首要原因，修复损伤脊髓、重塑膀胱排尿反射通路是根本的治疗手段。本研究将中药丹参的有效单体丹参酮ⅡA以缓释微球的形式复合到具有多级定向结构的生物蛋白水凝胶中，制备出可缓释丹参酮ⅡA的生物蛋白水凝胶，通过体外缓释实验和细胞实验研究证明该材料可以持续缓释药物，并且可以促进大鼠背根神经节细胞轴突的生长；我们进一步将可缓释丹参酮ⅡA的生物蛋白水凝胶移植到大鼠脊髓损伤后膀胱功能障碍的动物模型中，通过HE染色、小胶质细胞及其亚型的免疫荧光染色、尿动力学检查、运动诱发电位检查研究了该复合材料治疗大鼠脊髓损伤后膀胱功能障碍的作用和机制。通过本研究我们得出结论：丹参酮ⅡA复合材料可以促进大鼠脊髓损伤后膀胱功能的恢复，改善脊髓损伤大鼠的运动和感觉功能。其机制一方面可能与生物蛋白水凝胶通过微观上的定向结构诱导神经细胞轴突有序生长，填充了原发性损伤的组织缺损，避免瘢痕组织长入，促进了神经再生；另一方面，该水凝胶材料通过降解不断在损伤原位释放丹参酮ⅡA，诱导脊髓损伤后继发性损伤区域活化的小胶质细胞向M2型方向转化，减少了继发性损伤区域炎症因子的分泌，减轻了炎症反应主导的继发性损伤。最终，丹参酮IIA和定向生物蛋白水凝胶通过协同作用改善了脊髓损伤大鼠的感觉、运动和膀胱功能。