目的 制备黄芩苷-聚乙二醇-聚乳酸羟基乙酸共聚物（PEG-PLGA）载药纳米胶束，并研究其体外释药性能及在急性心肌缺血模型大鼠体内的组织分布。方法 采用正交试验优选黄芩苷PEG-PLGA纳米胶束的制备工艺，优化的黄芩苷PEG-PLGA纳米胶束再进行粒径、Zeta电位和透射电子显微镜（TEM）检测表征，采用体外释放实验、组织分布实验对该载药系统进行评价。结果 黄芩苷PEG-PLGA纳米胶束优选的制备工艺条件为黄芩苷-PEG-PLGA的质量比为1∶10，旋转蒸发仪转动速率为80 r/min，水化温度为40℃，优化的黄芩苷PEG-PLGA纳米胶束粒径为（18.5±0.5）nm，Zeta电位为（-10.9±0.7）mV，载药量为（7.9±0.3）%，包封率为（86.2±2.5）%。采用芘测定法检测PEG-PLGA纳米胶束的临界胶束质量浓度为3.8 μg/mL，TEM检测发现黄芩苷PEG-PLGA纳米胶束呈现粒径均一的圆球型；体外释放实验表明，黄芩苷PEG-PLGA纳米胶束具有明显的缓释特征；组织分布实验表明黄芩苷PEG-PLGA纳米胶束在正常大鼠脏器中分布大小顺序为肝 > 脾 > 心 > 肾 > 肺 > 脑，而在急性心肌缺血模型大鼠脏器分布大小顺序为肝 > 心 > 脾 > 肾 > 肺 > 脑，与正常大鼠比较，急性心肌缺血模型大鼠心脏中药物浓度在各时间段都呈现明显升高的趋势，在120 min时最高药物质量浓度可达（2 897±135）ng/mL，显著高于正常大鼠中心脏的最高药物浓度（2 411±89）ng/mL，该结果表明，黄芩苷PEG-PLGA纳米胶束在急性心肌缺血区域具有良好的靶向性。结论 黄芩苷PEG-PLGA纳米胶束具有良好的载药性能，体外释药缓慢，且可以将药物蓄积于缺血心肌部位，具有良好的心脏靶向性。

Objective To prepare baicalin-polyethylene glycol-poly (lactic-co-glycolic acid) copolymer (PEG-PLGA)-loaded nanomicelles, and study its in vitro drug release properties and tissue distributed in rats with acute myocardial ischemia. Methods The preparation process of baicalin PEG-PLGA nanomicelles was optimized by orthogonal test. The optimized baicalin PEG-PLGA nanomicelles were characterized by particle size, Zeta potential, and TEM electron microscopy. The in vitro release assay and tissue distribution of the acute myocardial ischemia rat model were used to evaluate this drug delivery system. Results The preferred preparation conditions for baicalin PEG-PLGA nanomicelles were a mass ratio of baicalin to PEG-PLGA at 1:10 with a rotary evaporator rotation rate of 80 r/min and a hydration temperature of 40℃. The optimized baicalin PEG-PLGA nanomicelle particle size was (18.5 ±0.5) nm, the zeta potential was (-10.9 ±0.7) mV, the drug loading was (7.9 ±0.3)%, and the encapsulation efficiency was (86.2 ±2.5)%. The critical micelle concentration of PEG-PLGA nanomicelles was 3.8 μg/mL by oxime assay. TEM showed that baicalin PEG-PLGA nanomicelles presented a spherical shape with uniform particle size, In vitro release test showed that baicalin PEG-PLGA nanomicelles had obvious sustained release characteristics; Tissue distribution test showed that the order of distribution of baicalin PEG-PLGA nanomicelles in normal rat organs was liver > spleen > heart > kidney > lung > brain, while the distribution of baicalin PEG-PLGA nanomicelles in acute myocardial ischemia model was liver > heart > spleen > kidney > brain. Compared with normal rats, the drug concentration in the heart of rats with acute myocardial ischemia showed a significant increase trend in all time periods, and the highest drug concentration at 120 min could reach (2 897 ±135) ng/mL, the highest drug concentration of the heart in the normal rats was (2 411 ±89) ng/mL, which indicated that the baicalin PEG-PLGA nanomicelles had good targeting in the acute myocardial ischemia zone. Conclusion Baicalin PEG-PLGA nanomicelles have good drug-loading properties, slow release in vitro, and can accumulate drugs in the ischemic myocardium, which has good cardiac targeting.

湖南省卫计委基金资助项目（C201800141）