剥离-共组装法制备葫芦素插层类水滑石纳米杂化物

Synthesis of Cucurbitacin Intercalated Hydrotalcite-like Compound Nanohybrids via Delamination-coassembling Method

采用剥离-共组装法制备了电中性疏水药物葫芦素(CA)插层类水滑石(HTlc)纳米杂化物.先用胆酸钠(Ch)包覆修饰葫芦素,再与剥离的HTlc薄片共组装,形成CA-Ch-HTlc纳米杂化物.采用小角X射线散射、傅里叶变换红外吸收光谱、透射和扫描电子显微镜、Zeta电位和元素分析等技术对样品进行了表征.所制备纳米杂化物的载药量达到7.06%,表明该方法可以实现电中性疏水药物在HTlc上的有效负载.依据胆酸离子和葫芦素尺寸及纳米杂化物通道高度推测,胆酸离子在HTlc层间为双层排列,其长轴几乎垂直于HTlc层板;葫芦素分子插入(或'溶入')胆酸离子双层中.CA-Ch-HTlc纳米杂化物具有良好的药物缓释效果,其药物释放过程符合准二级动力学方程.

A nanohybrid of cucurbitacin（CA）, a charge-neutral and poorly water-soluble drug, intercalated hydrotalcite-like compounds（ HTlc） was synthesized via a delamination-coassembling method. CA molecules were initially incorporated into the micelles of sodium cholate（ Ch） , and the resulting negatively charged CA-loaded micelles and the positively charged delaminated HTlc nanosheets were then coassembled together into the CA-Ch-HTlc nanohybrid. The so-obtained nanohybrid was characterized by small angle X-ray scattering, Fourier transform infrared, transmission and scanning electron microscopy, zeta potential and elemental analyses. The results showed that the loading of CA in the nanohybrid was 7. 06%, indicating that this route could be used to achieve the effective intercalation of charge-neutral and poorly water-soluble drugs into the HTlc gallery. Based on the sizes of Ch and CA, and the gallery heights of the nanohybrid, a possible orienta-tion of Ch anions and CA molecules in the HTlc gallery was proposed. The Ch anions are arranged as a slightly tilted bilayer with their long axis approximately perpendicular to the brucite-like layer, and the CA molecules are encapsulated in the bilayer as a consequence of the hydrophobic interactions. The in vitro release of CA from the nanohybrid was examined, and the results showed that the nanohybrid had a good drug controlled release performance and its drug release process obeyed pseudo-second order kinetics model.