目的 制备壳聚糖神经毒素纳米粒（CS-NT-NP），研究其鼻腔给药对大鼠血脑屏障（BBB）开放性及小鼠血清中S100β蛋白的影响。方法 采用甲酰胺提取-紫外分光光度法测定不同给药途径及不同神经毒素（NT）制剂给药后大鼠脑组织中伊文思蓝（EB）的浓度；荧光显微镜定性分析EB在脑组织中的荧光强度及分布；ELISA法测定不同NT制剂鼻腔给药后小鼠血清中S100β蛋白量的变化。结果 分别与壳聚糖（CS）组和NT水溶液组比较，CS-NT-NP能明显增加大鼠脑内EB浓度，有一定时效关系，且在120 min时达到高峰（P<0.01）；而鼻腔给药相较于ip和im给药，EB入脑量明显增加（P<0.01），且达峰时间短，荧光检测结果表现出相同的趋势，CS-NT-NP鼻腔给药后不同时间小鼠血清S100β蛋白水平显著升高。结论 CS-NT-NP鼻腔给药能显著增加BBB的开放性，进一步提高脑内NT的浓度，壳聚糖纳米粒是大分子药物入脑的良好载体。

Objective To prepare chitosan neurotoxin nanoparticles (CS-NT-NP) and study its effect on the permeability of blood brain barrier and the serum levels of S100β by intranasal administration. Methods A formamide extraction-ultraviolet spectrophotometry method was employed to determine the concentration of Evans blue (EB) in brain by different routes of administration and preparations. Qualitative analysis of fluorescence intensity and distribution of EB in brain tissue was performed by fluorescence microscopy. The serum S100β protein concentration was determined by ELISA. Results Compared with the control group and NT group, CS-NT-NP could significantly increase the content of EB in the brain with time-effect relation and reached the peak at 120 min (P<0.01); Compared with muscle injection and ip injection, intranasal administration could significantly increase the content of EB and reached peak time quickly. The results were consistent with the experimental results of qualitative analysis of fluorescence intensity and distribution of EB in brain tissue by fluorescence microscopy and S100β protein in serum. It was consistent with the experimental results of S100β protein. Conclusion CS-NT-NP by intranasal administration can significantly increase the permeability of BBB, and further increase the drug concentration in the brain, which is a good carrier of macromolecular drugs into the brain.

国家自然科学基金青年科学基金项目（81102842）