生物响应酸性磷酸酶浓度的载药聚电解质的体外控释分析

Prolonged-releasing Performance of Drug Loaded Polyelectrolyte Nanocapsules Effected by Acid Phosphatease:in vitro Analysis

研制一种可响应酸性磷酸酶浓度变化的聚电解质胶囊，（PAH／PSS—B．甘油磷酸酯）胶囊，在分析胶囊的理化性质的基础上对其阿霉素药物包封和体外控释行为进行研究。通过层层组装的方法，制备囊壁含有酸性磷酸酶底物β-甘油磷酸酯的空壳胶囊和囊壁不合酸性磷酸酶底物的对照空壳胶囊；用电镜测定胶囊的大小和形态；用MTT方法分析胶囊的生物相容性。通过药物浓度梯度法进行胶囊的阿霉素药物包封并测定其包封率。将酸性磷酸酶标准品、分泌酸性磷酸酶的HepG2细胞株分别与载药阿霉素胶囊和载药阿霉素对照胶囊作用，观察阿霉素胶囊的药物控释情况和对肿瘤细胞生长的影响。空壳（PAH／PSS—β-甘油磷酸酯）胶囊粒径多在200～300nm之间，胶囊浓度≤250ug／mL时生物相容性良好，对阿霉素的包封率达68．12％；载药胶囊组和对照组分别与酸性磷酸酶标准品作用，至48h时分别释放出载药量的38％和15％，两者差异具有显著的统计学意义（P〈0．05）；载药胶囊组较载药对照组对HepG2细胞株的生长抑制作用明显增加24hHepG2细胞凋亡相差7．59％（13．73 Vs6．14），有明显统计学意义（P〈0．05）。囊壁含有酸性磷酸酶底物的载药聚电解质胶囊，可在体外响应酸性磷酸酶浓度变化，具有药物控释性状，为临床上有酸性磷酸酶升高的良、恶性疾病的药物控释治疗提供了一种新的方法，其应用前景值得进一步探讨。

The aims of the study were to prepare polyelectrolyte nanocapsules effected by acid phosphatease （ACP） and to study prolonged-releasing performance of the nanocapsules in vitro. Using the layer by layer （LbL） self-assembly technique, polyelectrolyte-β-glycerophosphoric acid nanocapsules were prepared. The morphologies of the nanocapsules were characterized by transmission electron microscopy （TEM） and biocompatibility was well examined by cell-culture method. The drug adriamycin would be loaded in nanocapsules for concentration gradient, the encapsulation efficiency could be calculated. Nanocapsules were reacted with acid phosphatease standard and HepG2 cells that express the ACE respectively. The prolonged-releasing of adriamycin was verified and tumor cells apoptosis were measured. TEM images showed that the nanocapsule sizes were between 200-300 nm. The material biocompatibility was good until the concentration of nanacapsule was up to 250 ug/mL. The drug encapsulation efficiency reached 68.12%. The release rate of polyelectrolyte （PAH/PSS-β-glycerophosphoric acid）s nanocapsules was higher than in the control nanocapsules at 48 h （38% Vs 15%） after its reaction to the ACP standard（P〈0.05）. Compared with the control, nanocapsules could significantly inhibit the growth of HepG2 cells that expressed the ACE and the efficiency of cell apoptosis was 7.59% higher at 24 h （13.73 Vs 6.14, P〈0.05）. Polyelectrolytes （PAH/PSS-β-glycerophosphoric acid） nanocapsules in vitro have response to acid phosphatease by which prolonged-releasing can be affected. This property can be used for treatment of some malignant and benign diseases with elevated acid phosphatease level.