艾塞那肽聚乳酸-羟基乙酸共聚物纳米粒制备及体外评价

Preparation and in vitro evaluation of exenatide-loaded poly （lactic-co-glycolic acid） nanoparticles

摘要:

目的：探讨呼出气一氧化氮（fractional exhaled nitric oxide，FeNO）检测用于诊断咳嗽变异性哮喘（cough variant asthma，CVA）的临床价值及其影响因素。方法：连续收集2015年10月到2016年9月于我院就诊的慢性咳嗽患者607例，首先完成FeNO检测，之后通过支气管激发试验或支气管舒张试验并结合病史作为诊断CVA的标准，绘制FeNO诊断CVA的受试者工作特征曲线（receiver operating characteristic curve，ROC曲线），确定其最佳阈值；建立logisitic回归模型，通过模型分析筛选与CVA相关的因素，根据ROC曲线评价FeNO及FeNO联合其他相关因素对CVA的诊断价值。结果：607例患者中最终诊断CVA患者331例，非CVA患者276例。CVA组的FeNO水平明显高于非CVA组[（54.7±44.5） ppb vs. （19.8±11.9） ppb，P=0.000]；FeNO用于判定CVA的最佳阈值为31 ppb，约登指数最大值为0.507 6，ROC曲线下面积（area under curve，AUC）为0.794，此时检验的敏感度为61.63%，特异度为89.13%，阳性预测值为87.18%，阴性预测值为65.95%；年龄增高会引起FeNO下降，FeNO联合年龄、吸烟史诊断CVA的AUC为0.813，单用FeNO时的AUC为0.794，但两者差异无统计学意义（P=0.224）。结论：FeNO检测是诊断CVA的有效辅助手段，有助于慢性咳嗽的鉴别诊断；FeNO联合患者年龄、吸烟史诊断CVA价值不优于单用FeNO的诊断价值。

Abstract:

Objective：To prepare exenatide-loaded poly（lactic-co-glycolic acid）（PLGA） nanoparticles，and to evaluate its in vitro ef－fect and characteristics. Methods：The orthogonal experimental design was used to screen out the optimal formulation and process of exenatide-loaded PLGA nanoparticles，and dynamic light scattering and a transmission electron microscope were used for characteri－zation. In vitro simulation of gastrointestinal fluid and Caco-2 cell model were used to evaluate its stability，cellular uptake，and cellular transport. Results：The optimal formulation and process were obtained by the orthogonal design，i.e.，a volume ratio of internal water phase to oil phase of 1∶5，an ultrasonic power of 200 W，an ultrasonic time of 4 minutes，a concentration of polyvinyl alcohol of 2%，and a volume ratio of primary emulsion to external water phase of 1∶20. The nanoparticles obtained had a diameter of 116.2 nm and the transmission electron microscope showed that PLGA nanoparticles had a sphere-like shape with a regular surface. The in vit－ro study demonstrated that PLGA nanoparticles significantly prolonged the release of exenatide in gastrointestinal fluid and improved its stability（P<0.05），and 50% of exenatide was retained after 4-hour culture in simulated gastric fluid，while 80% was retained after 4-hour culture in simulated intestinal juice. The cell experiment showed that the uptake and transport of PLGA nanoparticles in the experimental group were 7 and 5 times those in the control group（P<0.05）. Conclusion：PLGA nanoparticles may be a potential effi－cient oral drug delivery system for exenatide.