目的 采用薄膜水化法制备丹参酮II_A聚乙二醇-聚己内酯（PEG-PCL）纳米胶束，并研究该胶束的细胞内分布及抗心肌缺血再灌注损伤的作用。方法 采用正交试验优选丹参酮II_A PEG-PCL纳米胶束的制备工艺条件，优选后的丹参酮II_A PEG-PCL纳米胶束进行粒径、Zeta电位和透射电镜检测表征，并进行稳定性评价，以香豆素-6作为荧光探针，评价PEG-PCL纳米胶束在细胞内的摄取及分布，再进行细胞外存留药物实验，验证PEG-PCL纳米胶束促进药物的细胞摄取性能；采用结扎冠状动脉方法构建心肌缺血再灌注损伤大鼠模型，评价丹参酮II_A PEG-PCL纳米胶束的药效作用。结果 丹参酮II_A PEG-PCL纳米胶束的优选工艺条件：丹参酮II_A与PEG-PCL投料比为1.2∶10，转速为100 r/min，水化温度为37℃，采用旋蒸方式形成薄膜，然后冷冻干燥除尽有机溶剂，在水化超声形成纳米胶束；优选工艺后的丹参酮II_A PEG-PCL纳米胶束粒径为（16.8±0.4）nm，Zeta电位为（-29.8±4.9）mV，载药量为（7.8±0.6）%，包封率为（86.4±5.2）%，稳定性良好；荧光实验表明，PEG-PCL纳米胶束可以促进药物的细胞摄取，进入细胞后，还可将药物聚集在线粒体周围，重合性良好；药效实验结果表明，丹参酮II_A PEG-PCL可以明显降低模型动物血清肌酸激酶（CK）、乳酸脱氢酶（LDH）、心肌肌钙蛋白（cTnI）水平，升高超氧化物歧化酶（SOD）水平，减少心肌梗死面积，改善心肌病理变化，这些药效结果均明显优于丹参酮II_A。结论 丹参酮II_A PEG-PCL纳米胶束可以很大程度上提高丹参酮II_A的心肌细胞摄取量，并聚集在线粒体周围，增强药物减轻心肌缺血再灌注损伤的作用。

Objective To prepare tanshinone II_A PEG-PCL micelles by membrane hydration method, and study the intracellular distribution of the micelles and the pharmacological effects of anti-myocardial ischemia-reperfusion injury. Methods Orthogonal test was used to optimize the preparation conditions of tanshinone II_A PEG-PCL micelles. The optimized tanshinone II_A PEG-PCL micelles were characterized by particle size, Zeta potential, and TEM electron microscopy. The stability of tanshinone II_A PEG-PCL micelles was evaluated. Coumarin-6 was used as a fluorescent probe to evaluate the intracellular uptake and intracellular distribution of PEG-PCL micelles, and then the extracellular drug retention test was performed to verify that PEG-PCL micelles promoted the cell uptake of the drug; The rat model of myocardial ischemia-reperfusion injury was constructed by ligation of coronary artery to evaluate the pharmacodynamic effect of tanshinone II_A PEG-PCL micelles. Results The optimal conditions for tanshinone II_A PEG-PCL micelles:the ratio of tanshinone II_A to PEG-PCL was 1.2:10, the rotation speed was 100 r/min, and the hydration temperature was 37℃. A thin film was formed by rotary evaporation, and then the organic solvent was lyophilized to form nano-micelles under hydration and ultrasound. The particle size of the optimized tanshinone II_A was (16.8±0.4) nm, the Zeta potential was-(29.8±4.9) mV, the drug loading was (7.8±0.6)%, the encapsulation efficiency was (86.4±5.2)%, and its stability was also good. Fluorescence test showed that PEG-PCL micelles can promote the cell uptake of the drug. After entering the cell, the drug can be aggregated around the mitochondria, and the coincidence was good. The results of the drug efficacy test showed that the tanshinone II_A PEG-PCL can significantly reduce the model animal serum CK, LDH and cTnI levels, elevated SOD levels, reduced myocardial infarct size, and improved myocardial pathological changes. These results were significantly better than tanshinone II_A. Conclusion Tanshinone II_A PEG-PCL micelles can greatly increase the myocardial cell uptake of tanshinone II_A, aggregate around the mitochondria, and enhance the pharmacological effects of drugs to reduce myocardial ischemia-reperfusion injury.

R283.6

湖南省卫计委项目（C201800141）