纳米羟基磷灰石/壳聚糖载药微球的制备及性能

Preparation and performance of drug-loaded nano-hydroxyapatite/chitosan microspheres

以纳米羟基磷灰石和壳聚糖为基质，构建一种新型甲硝唑缓释微球，作为充填材料用于骨修复。利用乙醇为反应溶剂，聚丙烯酸为分散剂，在pH=11的条件下，制备针状纳米羟基磷灰石。采用W／O型反相乳化一交联技术制备羟基磷灰石／壳聚糖载甲硝唑复合微球。通过紫外分光光度法测定甲硝唑含量和体外累积释放度。研究结果表明：制得的羟基磷灰石／壳聚糖载药复合微球粒径主要集中在1～10μm，壳聚糖对羟基磷灰石和甲硝唑形成了很好的包覆。复合微球平均载药量为38．23％，平均包封率为54．21％，3d内对甲硝唑的释放达到82％左右。所制备的羟基磷灰石／壳聚糖载药复合微球形态圆整，粒径分布较为均匀，对甲硝唑具有较好的缓释效果。

Nano-hydroxyapatite and chitosan were selected as matrix to prepare a novel metronidazole sustained release microsphere for bone tissue recovery. Aciform nano-hydroxyapatite was synthesized in ethanol medium （pH=11） using polyacrylic acid as dispersant. Metronidazole-loaded chitosan/hydroxyapatite composite microspheres were prepared by water in oil emulsion cross-linking method. The results show that the size of as-fabricated composite microspheres is mainly distributed from 1 to 10μm, and hydroxyapatite and metronidazole are embedded very well by chitosan. The average drug loading is 38.23%, the average entrapment efficiency is 54.21%, and the cumulative release rate to metronidazole is near 82% during 3 d. The composite microspheres are spherical and distributed uniformly in diameter with a good property for the slow-release of metronidazole, which have great potential in drug delivery system.