(羟基喜树碱@胆酸钠)-层状双金属氢氧化物纳米杂化物的组装及表征

采用“药物修饰-共组装”法制备了(羟基喜树碱@胆酸钠)-层状双金属氢氧化物纳米杂化物. 先用胆酸钠(SCL)包裹羟基喜树碱(HCPT)形成胶束, 再与微反应器制备的层状双氢氧化物(LDH)纳米片共组装形成纳米杂化物, 其载药量可达12.9%, 杂化物中HCPT以高生物活性的内酯形式存在. 采用聚乙二醇(PEG)和羧甲基纤维素(CMC)分别对所制备的(HCPT@SCL)-LDH纳米杂化物进行了表面修饰, 结果表明, 纳米杂化物的分散性得到明显改善; PEG的修饰效果优于CMC, 所获得的PEG-(HCPT@SCL)-LDH杂化物的平均粒径可小至约70 nm, 具有良好的分散性和药物缓释效果. 其药物释放过程可用准二级动力学方程描述, 颗粒内部扩散是药物释放过程的控制步骤.

Fabrication and Characterization of (Hydroxyl camptothecin@sodium cholate)-layered Double Hydroxide Nanohybrids†

(Hydroxyl camptothecin@sodium cholate)-layered double hydroxide(LDH) nanohybrids were prepared by a modified drug-coassembly method. Firstly, Hydroxyl camptothecin(HCPT) was incorporated into micelles derived from sodium cholate(SCL) which negatively charged. The negatively charged micelles intercalated HCPT@SCL-LDH nanohybrids were prepared by a co-assembly between LDH nanosheets and sodium cholate micelles with the encapsulated HCPT could keep the biological active lactone form, and the drug loading of so-obtained nanohybrid was 12.9%.(HCPT@SCL)-LDH was modified using polyethylene glycol(PEG) and carboxymethylcellulose(CMC), respectively. The results showed that the dispersity of nanohybrids was obviously improved, and PEG worked better than CMC. The PEG-(HCPT@SCL)-LDH had favorable dispersity with average size of ca. 70 nm. PEG-(HCPT@SCL)-LDH showed well controlled release property and in vitro drug release kine-tics from the nanohybrids could be fitted with the pseudo-second-order kinetic model. The diffusion of HCPT through the LDH particles played an important role in controlling the drug release.