地塞米松纳米胶束的制备及体外抗肿瘤作用研究

Preparation of Dexamethasone Nano-micelles and Study on Its in vitro Anti-tumor Effect

目的：制备地塞米松（Dex）纳米胶束（简称Dex胶束）,并研究其体外抗肿瘤作用。方法：以γ-聚谷氨酸（γ-PGA）为载体、二甲基亚砜为有机溶剂,采用透析法制备Dex胶束;观察并检测其形态、粒径、Zeta电位、多分散系数（PDI）、临界胶束浓度（CMC）、载药量、包封率;比较p H 5.5、7.4条件下Dex胶束和Dex的体外释药情况;比较0.05、0.1、0.2、0.5、1.0μmol/ml的Dex、γ-PGA、Dex胶束和泼尼松龙（阳性对照）对人肺腺癌A549细胞存活率的影响,比较A549细胞在4、37℃下对0.5μmol/ml的Dex胶束和Dex的摄取量。结果：所制备Dex胶束呈圆球形、形态规则,粒径为（76.25±3.74）nm,Zeta电位为5.0 m V,PDI为0.163±0.38,CMC为7.609μg/ml,载药量为（9.56±0.92）%,包封率为（89.25±1.36）%;与Dex比较,Dex胶束在p H 5.5、7.4条件下释药时间延长;在0.05-0.2μmol/ml范围内,游离Dex、γ-PGA、Dex胶束和泼尼松龙对细胞存活率的影响差异无统计学意义（P〉0.05）;在0.5、1.0μmol/ml时,Dex胶束作用下细胞存活率明显低于游离Dex或泼尼松龙作用（P〈0.05）。4℃下,细胞对Dex胶束和Dex的摄取量差异无统计学意义（P〉0.05）;37℃下,细胞对Dex胶束的摄取量明显高于游离Dex和4℃下的游离Dex、Dex胶束（P〈0.05）。结论：所制备的Dex胶束能延长Dex的释药时间,降低A549细胞的存活率和细胞的摄取效率。

OBJECTIVE： To prepare Dexamethasone （Dex） nano-micelles （called Dex micelles for short）, and to study its in vitro anti-tumor effect. METHODS： Using γ-PGA as carrier, DMSO as organic solvent, Dex micelles were prepared by dialysis method. The morphology, particle size, Zeta potential, PDI, CMC, drug-loading amount and entrapment efficiency （EE） of micelle were observed and detected. Drug release of Dex micelles and Dex were compared under pH 5.5, 7.4. The effects of free Dex, γ-PGA, Dex micelles and prednisolone （positive control） （0.05, 0.1, 0.2, 0.5, 1.0 μmol/ml） on the survival rate of human lung adenocarcinoma A549 cells were compared. The uptake amount of A549 cells to 0.5 μmol/ml Dex micelles and free Dex were compared at 4, 37 ℃. RESULTS： Prepared Dex micelles were spheroidal and completely round with particle size of （76.25 ± 3.74） nm,Zeta potential of 5.0 mV, PDI of 0.163 ± 0.38, CMC of 7.609 μg/ml, drug-loading amount of （9.56 ±0.92）% and EE of （89.25 ±1.36）%. Compared with free Dex, the duration of drug release for Dex miceUes prolonged under pH 5.5, 7.4. When the concentration ranged 0.05-0.2 μmol/ml, the effects of free Dex, γ-PGA, Dex micelles and prednisolone on cellular survival rate had no statistically significant difference （P〉0.05）. When the concentration was 0.5, 1.0 μmol/ml, survival rate ofA549 cells treated with Dex micelles was significantly lower than that treated with free Dex or prednisolone （P〈0.05）. At 4 ℃ , the uptake amount of A549 cells to Dex micelles and free Dex had no statistically significant difference （P〉0.05）. At 37 ℃, the uptake amount of A549 cells to Dex micelles was significantly higher than that of cells to free Dex, and that of A549 cells to Dex micelles and free Dex at 4 ℃. CONCLUSIONS： Prepared Dex micelles can prolong the duration of drug release of Dex, and decrease the survival rate of A549 cells and cellular uptake efficacy.